Import Android SDK Platform PI [4335822]

/google/data/ro/projects/android/fetch_artifact \
    --bid 4335822 \
    --target sdk_phone_armv7-win_sdk \
    sdk-repo-linux-sources-4335822.zip

AndroidVersion.ApiLevel has been modified to appear as 28

Change-Id: Ic8f04be005a71c2b9abeaac754d8da8d6f9a2c32

1 files changed, 8528 insertions, 0 deletions

diff --git a/android/view/ViewGroup.java b/android/view/ViewGroup.java
new file mode 100644
index 00000000..b2e5a163
--- /dev/null
+++ b/android/view/ViewGroup.java
@@ -0,0 +1,8528 @@
+/*
+ * Copyright (C) 2006 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.view;
+
+import static android.os.Build.VERSION_CODES.JELLY_BEAN_MR1;
+
+import android.animation.LayoutTransition;
+import android.annotation.CallSuper;
+import android.annotation.IdRes;
+import android.annotation.NonNull;
+import android.annotation.TestApi;
+import android.annotation.UiThread;
+import android.content.ClipData;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.content.res.Configuration;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Insets;
+import android.graphics.Matrix;
+import android.graphics.Paint;
+import android.graphics.PointF;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.graphics.Region;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Parcelable;
+import android.os.SystemClock;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.util.Pools;
+import android.util.Pools.SynchronizedPool;
+import android.util.SparseArray;
+import android.util.SparseBooleanArray;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.animation.Animation;
+import android.view.animation.AnimationUtils;
+import android.view.animation.LayoutAnimationController;
+import android.view.animation.Transformation;
+
+import com.android.internal.R;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+
+/**
+ * <p>
+ * A <code>ViewGroup</code> is a special view that can contain other views
+ * (called children.) The view group is the base class for layouts and views
+ * containers. This class also defines the
+ * {@link android.view.ViewGroup.LayoutParams} class which serves as the base
+ * class for layouts parameters.
+ * </p>
+ *
+ * <p>
+ * Also see {@link LayoutParams} for layout attributes.
+ * </p>
+ *
+ * <div class="special reference">
+ * <h3>Developer Guides</h3>
+ * <p>For more information about creating user interface layouts, read the
+ * <a href="{@docRoot}guide/topics/ui/declaring-layout.html">XML Layouts</a> developer
+ * guide.</p></div>
+ *
+ * <p>Here is a complete implementation of a custom ViewGroup that implements
+ * a simple {@link android.widget.FrameLayout} along with the ability to stack
+ * children in left and right gutters.</p>
+ *
+ * {@sample development/samples/ApiDemos/src/com/example/android/apis/view/CustomLayout.java
+ *      Complete}
+ *
+ * <p>If you are implementing XML layout attributes as shown in the example, this is the
+ * corresponding definition for them that would go in <code>res/values/attrs.xml</code>:</p>
+ *
+ * {@sample development/samples/ApiDemos/res/values/attrs.xml CustomLayout}
+ *
+ * <p>Finally the layout manager can be used in an XML layout like so:</p>
+ *
+ * {@sample development/samples/ApiDemos/res/layout/custom_layout.xml Complete}
+ *
+ * @attr ref android.R.styleable#ViewGroup_clipChildren
+ * @attr ref android.R.styleable#ViewGroup_clipToPadding
+ * @attr ref android.R.styleable#ViewGroup_layoutAnimation
+ * @attr ref android.R.styleable#ViewGroup_animationCache
+ * @attr ref android.R.styleable#ViewGroup_persistentDrawingCache
+ * @attr ref android.R.styleable#ViewGroup_alwaysDrawnWithCache
+ * @attr ref android.R.styleable#ViewGroup_addStatesFromChildren
+ * @attr ref android.R.styleable#ViewGroup_descendantFocusability
+ * @attr ref android.R.styleable#ViewGroup_animateLayoutChanges
+ * @attr ref android.R.styleable#ViewGroup_splitMotionEvents
+ * @attr ref android.R.styleable#ViewGroup_layoutMode
+ */
+@UiThread
+public abstract class ViewGroup extends View implements ViewParent, ViewManager {
+    private static final String TAG = "ViewGroup";
+
+    private static final boolean DBG = false;
+
+    /**
+     * Views which have been hidden or removed which need to be animated on
+     * their way out.
+     * This field should be made private, so it is hidden from the SDK.
+     * {@hide}
+     */
+    protected ArrayList<View> mDisappearingChildren;
+
+    /**
+     * Listener used to propagate events indicating when children are added
+     * and/or removed from a view group.
+     * This field should be made private, so it is hidden from the SDK.
+     * {@hide}
+     */
+    protected OnHierarchyChangeListener mOnHierarchyChangeListener;
+
+    // The view contained within this ViewGroup that has or contains focus.
+    private View mFocused;
+    // The view contained within this ViewGroup (excluding nested keyboard navigation clusters)
+    // that is or contains a default-focus view.
+    private View mDefaultFocus;
+    // The last child of this ViewGroup which held focus within the current cluster
+    View mFocusedInCluster;
+
+    /**
+     * A Transformation used when drawing children, to
+     * apply on the child being drawn.
+     */
+    private Transformation mChildTransformation;
+
+    /**
+     * Used to track the current invalidation region.
+     */
+    RectF mInvalidateRegion;
+
+    /**
+     * A Transformation used to calculate a correct
+     * invalidation area when the application is autoscaled.
+     */
+    Transformation mInvalidationTransformation;
+
+    // Current frontmost child that can accept drag and lies under the drag location.
+    // Used only to generate ENTER/EXIT events for pre-Nougat aps.
+    private View mCurrentDragChild;
+
+    // Metadata about the ongoing drag
+    private DragEvent mCurrentDragStartEvent;
+    private boolean mIsInterestedInDrag;
+    private HashSet<View> mChildrenInterestedInDrag;
+
+    // Used during drag dispatch
+    private PointF mLocalPoint;
+
+    // Lazily-created holder for point computations.
+    private float[] mTempPoint;
+
+    // Layout animation
+    private LayoutAnimationController mLayoutAnimationController;
+    private Animation.AnimationListener mAnimationListener;
+
+    // First touch target in the linked list of touch targets.
+    private TouchTarget mFirstTouchTarget;
+
+    // For debugging only.  You can see these in hierarchyviewer.
+    @SuppressWarnings({"FieldCanBeLocal", "UnusedDeclaration"})
+    @ViewDebug.ExportedProperty(category = "events")
+    private long mLastTouchDownTime;
+    @ViewDebug.ExportedProperty(category = "events")
+    private int mLastTouchDownIndex = -1;
+    @SuppressWarnings({"FieldCanBeLocal", "UnusedDeclaration"})
+    @ViewDebug.ExportedProperty(category = "events")
+    private float mLastTouchDownX;
+    @SuppressWarnings({"FieldCanBeLocal", "UnusedDeclaration"})
+    @ViewDebug.ExportedProperty(category = "events")
+    private float mLastTouchDownY;
+
+    // First hover target in the linked list of hover targets.
+    // The hover targets are children which have received ACTION_HOVER_ENTER.
+    // They might not have actually handled the hover event, but we will
+    // continue sending hover events to them as long as the pointer remains over
+    // their bounds and the view group does not intercept hover.
+    private HoverTarget mFirstHoverTarget;
+
+    // True if the view group itself received a hover event.
+    // It might not have actually handled the hover event.
+    private boolean mHoveredSelf;
+
+    // The child capable of showing a tooltip and currently under the pointer.
+    private View mTooltipHoverTarget;
+
+    // True if the view group is capable of showing a tooltip and the pointer is directly
+    // over the view group but not one of its child views.
+    private boolean mTooltipHoveredSelf;
+
+    /**
+     * Internal flags.
+     *
+     * This field should be made private, so it is hidden from the SDK.
+     * {@hide}
+     */
+    @ViewDebug.ExportedProperty(flagMapping = {
+            @ViewDebug.FlagToString(mask = FLAG_CLIP_CHILDREN, equals = FLAG_CLIP_CHILDREN,
+                    name = "CLIP_CHILDREN"),
+            @ViewDebug.FlagToString(mask = FLAG_CLIP_TO_PADDING, equals = FLAG_CLIP_TO_PADDING,
+                    name = "CLIP_TO_PADDING"),
+            @ViewDebug.FlagToString(mask = FLAG_PADDING_NOT_NULL, equals = FLAG_PADDING_NOT_NULL,
+                    name = "PADDING_NOT_NULL")
+    }, formatToHexString = true)
+    protected int mGroupFlags;
+
+    /**
+     * Either {@link #LAYOUT_MODE_CLIP_BOUNDS} or {@link #LAYOUT_MODE_OPTICAL_BOUNDS}.
+     */
+    private int mLayoutMode = LAYOUT_MODE_UNDEFINED;
+
+    /**
+     * NOTE: If you change the flags below make sure to reflect the changes
+     *       the DisplayList class
+     */
+
+    // When set, ViewGroup invalidates only the child's rectangle
+    // Set by default
+    static final int FLAG_CLIP_CHILDREN = 0x1;
+
+    // When set, ViewGroup excludes the padding area from the invalidate rectangle
+    // Set by default
+    private static final int FLAG_CLIP_TO_PADDING = 0x2;
+
+    // When set, dispatchDraw() will invoke invalidate(); this is set by drawChild() when
+    // a child needs to be invalidated and FLAG_OPTIMIZE_INVALIDATE is set
+    static final int FLAG_INVALIDATE_REQUIRED  = 0x4;
+
+    // When set, dispatchDraw() will run the layout animation and unset the flag
+    private static final int FLAG_RUN_ANIMATION = 0x8;
+
+    // When set, there is either no layout animation on the ViewGroup or the layout
+    // animation is over
+    // Set by default
+    static final int FLAG_ANIMATION_DONE = 0x10;
+
+    // If set, this ViewGroup has padding; if unset there is no padding and we don't need
+    // to clip it, even if FLAG_CLIP_TO_PADDING is set
+    private static final int FLAG_PADDING_NOT_NULL = 0x20;
+
+    /** @deprecated - functionality removed */
+    @Deprecated
+    private static final int FLAG_ANIMATION_CACHE = 0x40;
+
+    // When set, this ViewGroup converts calls to invalidate(Rect) to invalidate() during a
+    // layout animation; this avoid clobbering the hierarchy
+    // Automatically set when the layout animation starts, depending on the animation's
+    // characteristics
+    static final int FLAG_OPTIMIZE_INVALIDATE = 0x80;
+
+    // When set, the next call to drawChild() will clear mChildTransformation's matrix
+    static final int FLAG_CLEAR_TRANSFORMATION = 0x100;
+
+    // When set, this ViewGroup invokes mAnimationListener.onAnimationEnd() and removes
+    // the children's Bitmap caches if necessary
+    // This flag is set when the layout animation is over (after FLAG_ANIMATION_DONE is set)
+    private static final int FLAG_NOTIFY_ANIMATION_LISTENER = 0x200;
+
+    /**
+     * When set, the drawing method will call {@link #getChildDrawingOrder(int, int)}
+     * to get the index of the child to draw for that iteration.
+     *
+     * @hide
+     */
+    protected static final int FLAG_USE_CHILD_DRAWING_ORDER = 0x400;
+
+    /**
+     * When set, this ViewGroup supports static transformations on children; this causes
+     * {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} to be
+     * invoked when a child is drawn.
+     *
+     * Any subclass overriding
+     * {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} should
+     * set this flags in {@link #mGroupFlags}.
+     *
+     * {@hide}
+     */
+    protected static final int FLAG_SUPPORT_STATIC_TRANSFORMATIONS = 0x800;
+
+    // UNUSED FLAG VALUE: 0x1000;
+
+    /**
+     * When set, this ViewGroup's drawable states also include those
+     * of its children.
+     */
+    private static final int FLAG_ADD_STATES_FROM_CHILDREN = 0x2000;
+
+    /** @deprecated functionality removed */
+    @Deprecated
+    private static final int FLAG_ALWAYS_DRAWN_WITH_CACHE = 0x4000;
+
+    /** @deprecated functionality removed */
+    @Deprecated
+    private static final int FLAG_CHILDREN_DRAWN_WITH_CACHE = 0x8000;
+
+    /**
+     * When set, this group will go through its list of children to notify them of
+     * any drawable state change.
+     */
+    private static final int FLAG_NOTIFY_CHILDREN_ON_DRAWABLE_STATE_CHANGE = 0x10000;
+
+    private static final int FLAG_MASK_FOCUSABILITY = 0x60000;
+
+    /**
+     * This view will get focus before any of its descendants.
+     */
+    public static final int FOCUS_BEFORE_DESCENDANTS = 0x20000;
+
+    /**
+     * This view will get focus only if none of its descendants want it.
+     */
+    public static final int FOCUS_AFTER_DESCENDANTS = 0x40000;
+
+    /**
+     * This view will block any of its descendants from getting focus, even
+     * if they are focusable.
+     */
+    public static final int FOCUS_BLOCK_DESCENDANTS = 0x60000;
+
+    /**
+     * Used to map between enum in attrubutes and flag values.
+     */
+    private static final int[] DESCENDANT_FOCUSABILITY_FLAGS =
+            {FOCUS_BEFORE_DESCENDANTS, FOCUS_AFTER_DESCENDANTS,
+                    FOCUS_BLOCK_DESCENDANTS};
+
+    /**
+     * When set, this ViewGroup should not intercept touch events.
+     * {@hide}
+     */
+    protected static final int FLAG_DISALLOW_INTERCEPT = 0x80000;
+
+    /**
+     * When set, this ViewGroup will split MotionEvents to multiple child Views when appropriate.
+     */
+    private static final int FLAG_SPLIT_MOTION_EVENTS = 0x200000;
+
+    /**
+     * When set, this ViewGroup will not dispatch onAttachedToWindow calls
+     * to children when adding new views. This is used to prevent multiple
+     * onAttached calls when a ViewGroup adds children in its own onAttached method.
+     */
+    private static final int FLAG_PREVENT_DISPATCH_ATTACHED_TO_WINDOW = 0x400000;
+
+    /**
+     * When true, indicates that a layoutMode has been explicitly set, either with
+     * an explicit call to {@link #setLayoutMode(int)} in code or from an XML resource.
+     * This distinguishes the situation in which a layout mode was inherited from
+     * one of the ViewGroup's ancestors and cached locally.
+     */
+    private static final int FLAG_LAYOUT_MODE_WAS_EXPLICITLY_SET = 0x800000;
+
+    static final int FLAG_IS_TRANSITION_GROUP = 0x1000000;
+
+    static final int FLAG_IS_TRANSITION_GROUP_SET = 0x2000000;
+
+    /**
+     * When set, focus will not be permitted to enter this group if a touchscreen is present.
+     */
+    static final int FLAG_TOUCHSCREEN_BLOCKS_FOCUS = 0x4000000;
+
+    /**
+     * When true, indicates that a call to startActionModeForChild was made with the type parameter
+     * and should not be ignored. This helps in backwards compatibility with the existing method
+     * without a type.
+     *
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback)
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback, int)
+     */
+    private static final int FLAG_START_ACTION_MODE_FOR_CHILD_IS_TYPED = 0x8000000;
+
+    /**
+     * When true, indicates that a call to startActionModeForChild was made without the type
+     * parameter. This helps in backwards compatibility with the existing method
+     * without a type.
+     *
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback)
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback, int)
+     */
+    private static final int FLAG_START_ACTION_MODE_FOR_CHILD_IS_NOT_TYPED = 0x10000000;
+
+    /**
+     * When set, indicates that a call to showContextMenuForChild was made with explicit
+     * coordinates within the initiating child view.
+     */
+    private static final int FLAG_SHOW_CONTEXT_MENU_WITH_COORDS = 0x20000000;
+
+    /**
+     * Indicates which types of drawing caches are to be kept in memory.
+     * This field should be made private, so it is hidden from the SDK.
+     * {@hide}
+     */
+    protected int mPersistentDrawingCache;
+
+    /**
+     * Used to indicate that no drawing cache should be kept in memory.
+     */
+    public static final int PERSISTENT_NO_CACHE = 0x0;
+
+    /**
+     * Used to indicate that the animation drawing cache should be kept in memory.
+     */
+    public static final int PERSISTENT_ANIMATION_CACHE = 0x1;
+
+    /**
+     * Used to indicate that the scrolling drawing cache should be kept in memory.
+     */
+    public static final int PERSISTENT_SCROLLING_CACHE = 0x2;
+
+    /**
+     * Used to indicate that all drawing caches should be kept in memory.
+     */
+    public static final int PERSISTENT_ALL_CACHES = 0x3;
+
+    // Layout Modes
+
+    private static final int LAYOUT_MODE_UNDEFINED = -1;
+
+    /**
+     * This constant is a {@link #setLayoutMode(int) layoutMode}.
+     * Clip bounds are the raw values of {@link #getLeft() left}, {@link #getTop() top},
+     * {@link #getRight() right} and {@link #getBottom() bottom}.
+     */
+    public static final int LAYOUT_MODE_CLIP_BOUNDS = 0;
+
+    /**
+     * This constant is a {@link #setLayoutMode(int) layoutMode}.
+     * Optical bounds describe where a widget appears to be. They sit inside the clip
+     * bounds which need to cover a larger area to allow other effects,
+     * such as shadows and glows, to be drawn.
+     */
+    public static final int LAYOUT_MODE_OPTICAL_BOUNDS = 1;
+
+    /** @hide */
+    public static int LAYOUT_MODE_DEFAULT = LAYOUT_MODE_CLIP_BOUNDS;
+
+    /**
+     * We clip to padding when FLAG_CLIP_TO_PADDING and FLAG_PADDING_NOT_NULL
+     * are set at the same time.
+     */
+    protected static final int CLIP_TO_PADDING_MASK = FLAG_CLIP_TO_PADDING | FLAG_PADDING_NOT_NULL;
+
+    // Index of the child's left position in the mLocation array
+    private static final int CHILD_LEFT_INDEX = 0;
+    // Index of the child's top position in the mLocation array
+    private static final int CHILD_TOP_INDEX = 1;
+
+    // Child views of this ViewGroup
+    private View[] mChildren;
+    // Number of valid children in the mChildren array, the rest should be null or not
+    // considered as children
+    private int mChildrenCount;
+
+    // Whether layout calls are currently being suppressed, controlled by calls to
+    // suppressLayout()
+    boolean mSuppressLayout = false;
+
+    // Whether any layout calls have actually been suppressed while mSuppressLayout
+    // has been true. This tracks whether we need to issue a requestLayout() when
+    // layout is later re-enabled.
+    private boolean mLayoutCalledWhileSuppressed = false;
+
+    private static final int ARRAY_INITIAL_CAPACITY = 12;
+    private static final int ARRAY_CAPACITY_INCREMENT = 12;
+
+    private static float[] sDebugLines;
+
+    // Used to draw cached views
+    Paint mCachePaint;
+
+    // Used to animate add/remove changes in layout
+    private LayoutTransition mTransition;
+
+    // The set of views that are currently being transitioned. This list is used to track views
+    // being removed that should not actually be removed from the parent yet because they are
+    // being animated.
+    private ArrayList<View> mTransitioningViews;
+
+    // List of children changing visibility. This is used to potentially keep rendering
+    // views during a transition when they otherwise would have become gone/invisible
+    private ArrayList<View> mVisibilityChangingChildren;
+
+    // Temporary holder of presorted children, only used for
+    // input/software draw dispatch for correctly Z ordering.
+    private ArrayList<View> mPreSortedChildren;
+
+    // Indicates how many of this container's child subtrees contain transient state
+    @ViewDebug.ExportedProperty(category = "layout")
+    private int mChildCountWithTransientState = 0;
+
+    /**
+     * Currently registered axes for nested scrolling. Flag set consisting of
+     * {@link #SCROLL_AXIS_HORIZONTAL} {@link #SCROLL_AXIS_VERTICAL} or {@link #SCROLL_AXIS_NONE}
+     * for null.
+     */
+    private int mNestedScrollAxes;
+
+    // Used to manage the list of transient views, added by addTransientView()
+    private List<Integer> mTransientIndices = null;
+    private List<View> mTransientViews = null;
+
+
+    /**
+     * Empty ActionMode used as a sentinel in recursive entries to startActionModeForChild.
+     *
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback)
+     * @see #startActionModeForChild(View, android.view.ActionMode.Callback, int)
+     */
+    private static final ActionMode SENTINEL_ACTION_MODE = new ActionMode() {
+        @Override
+        public void setTitle(CharSequence title) {}
+
+        @Override
+        public void setTitle(int resId) {}
+
+        @Override
+        public void setSubtitle(CharSequence subtitle) {}
+
+        @Override
+        public void setSubtitle(int resId) {}
+
+        @Override
+        public void setCustomView(View view) {}
+
+        @Override
+        public void invalidate() {}
+
+        @Override
+        public void finish() {}
+
+        @Override
+        public Menu getMenu() {
+            return null;
+        }
+
+        @Override
+        public CharSequence getTitle() {
+            return null;
+        }
+
+        @Override
+        public CharSequence getSubtitle() {
+            return null;
+        }
+
+        @Override
+        public View getCustomView() {
+            return null;
+        }
+
+        @Override
+        public MenuInflater getMenuInflater() {
+            return null;
+        }
+    };
+
+    public ViewGroup(Context context) {
+        this(context, null);
+    }
+
+    public ViewGroup(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public ViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public ViewGroup(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+
+        initViewGroup();
+        initFromAttributes(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    private void initViewGroup() {
+        // ViewGroup doesn't draw by default
+        if (!debugDraw()) {
+            setFlags(WILL_NOT_DRAW, DRAW_MASK);
+        }
+        mGroupFlags |= FLAG_CLIP_CHILDREN;
+        mGroupFlags |= FLAG_CLIP_TO_PADDING;
+        mGroupFlags |= FLAG_ANIMATION_DONE;
+        mGroupFlags |= FLAG_ANIMATION_CACHE;
+        mGroupFlags |= FLAG_ALWAYS_DRAWN_WITH_CACHE;
+
+        if (mContext.getApplicationInfo().targetSdkVersion >= Build.VERSION_CODES.HONEYCOMB) {
+            mGroupFlags |= FLAG_SPLIT_MOTION_EVENTS;
+        }
+
+        setDescendantFocusability(FOCUS_BEFORE_DESCENDANTS);
+
+        mChildren = new View[ARRAY_INITIAL_CAPACITY];
+        mChildrenCount = 0;
+
+        mPersistentDrawingCache = PERSISTENT_SCROLLING_CACHE;
+    }
+
+    private void initFromAttributes(
+            Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ViewGroup, defStyleAttr,
+                defStyleRes);
+
+        final int N = a.getIndexCount();
+        for (int i = 0; i < N; i++) {
+            int attr = a.getIndex(i);
+            switch (attr) {
+                case R.styleable.ViewGroup_clipChildren:
+                    setClipChildren(a.getBoolean(attr, true));
+                    break;
+                case R.styleable.ViewGroup_clipToPadding:
+                    setClipToPadding(a.getBoolean(attr, true));
+                    break;
+                case R.styleable.ViewGroup_animationCache:
+                    setAnimationCacheEnabled(a.getBoolean(attr, true));
+                    break;
+                case R.styleable.ViewGroup_persistentDrawingCache:
+                    setPersistentDrawingCache(a.getInt(attr, PERSISTENT_SCROLLING_CACHE));
+                    break;
+                case R.styleable.ViewGroup_addStatesFromChildren:
+                    setAddStatesFromChildren(a.getBoolean(attr, false));
+                    break;
+                case R.styleable.ViewGroup_alwaysDrawnWithCache:
+                    setAlwaysDrawnWithCacheEnabled(a.getBoolean(attr, true));
+                    break;
+                case R.styleable.ViewGroup_layoutAnimation:
+                    int id = a.getResourceId(attr, -1);
+                    if (id > 0) {
+                        setLayoutAnimation(AnimationUtils.loadLayoutAnimation(mContext, id));
+                    }
+                    break;
+                case R.styleable.ViewGroup_descendantFocusability:
+                    setDescendantFocusability(DESCENDANT_FOCUSABILITY_FLAGS[a.getInt(attr, 0)]);
+                    break;
+                case R.styleable.ViewGroup_splitMotionEvents:
+                    setMotionEventSplittingEnabled(a.getBoolean(attr, false));
+                    break;
+                case R.styleable.ViewGroup_animateLayoutChanges:
+                    boolean animateLayoutChanges = a.getBoolean(attr, false);
+                    if (animateLayoutChanges) {
+                        setLayoutTransition(new LayoutTransition());
+                    }
+                    break;
+                case R.styleable.ViewGroup_layoutMode:
+                    setLayoutMode(a.getInt(attr, LAYOUT_MODE_UNDEFINED));
+                    break;
+                case R.styleable.ViewGroup_transitionGroup:
+                    setTransitionGroup(a.getBoolean(attr, false));
+                    break;
+                case R.styleable.ViewGroup_touchscreenBlocksFocus:
+                    setTouchscreenBlocksFocus(a.getBoolean(attr, false));
+                    break;
+            }
+        }
+
+        a.recycle();
+    }
+
+    /**
+     * Gets the descendant focusability of this view group.  The descendant
+     * focusability defines the relationship between this view group and its
+     * descendants when looking for a view to take focus in
+     * {@link #requestFocus(int, android.graphics.Rect)}.
+     *
+     * @return one of {@link #FOCUS_BEFORE_DESCENDANTS}, {@link #FOCUS_AFTER_DESCENDANTS},
+     *   {@link #FOCUS_BLOCK_DESCENDANTS}.
+     */
+    @ViewDebug.ExportedProperty(category = "focus", mapping = {
+        @ViewDebug.IntToString(from = FOCUS_BEFORE_DESCENDANTS, to = "FOCUS_BEFORE_DESCENDANTS"),
+        @ViewDebug.IntToString(from = FOCUS_AFTER_DESCENDANTS, to = "FOCUS_AFTER_DESCENDANTS"),
+        @ViewDebug.IntToString(from = FOCUS_BLOCK_DESCENDANTS, to = "FOCUS_BLOCK_DESCENDANTS")
+    })
+    public int getDescendantFocusability() {
+        return mGroupFlags & FLAG_MASK_FOCUSABILITY;
+    }
+
+    /**
+     * Set the descendant focusability of this view group. This defines the relationship
+     * between this view group and its descendants when looking for a view to
+     * take focus in {@link #requestFocus(int, android.graphics.Rect)}.
+     *
+     * @param focusability one of {@link #FOCUS_BEFORE_DESCENDANTS}, {@link #FOCUS_AFTER_DESCENDANTS},
+     *   {@link #FOCUS_BLOCK_DESCENDANTS}.
+     */
+    public void setDescendantFocusability(int focusability) {
+        switch (focusability) {
+            case FOCUS_BEFORE_DESCENDANTS:
+            case FOCUS_AFTER_DESCENDANTS:
+            case FOCUS_BLOCK_DESCENDANTS:
+                break;
+            default:
+                throw new IllegalArgumentException("must be one of FOCUS_BEFORE_DESCENDANTS, "
+                        + "FOCUS_AFTER_DESCENDANTS, FOCUS_BLOCK_DESCENDANTS");
+        }
+        mGroupFlags &= ~FLAG_MASK_FOCUSABILITY;
+        mGroupFlags |= (focusability & FLAG_MASK_FOCUSABILITY);
+    }
+
+    @Override
+    void handleFocusGainInternal(int direction, Rect previouslyFocusedRect) {
+        if (mFocused != null) {
+            mFocused.unFocus(this);
+            mFocused = null;
+            mFocusedInCluster = null;
+        }
+        super.handleFocusGainInternal(direction, previouslyFocusedRect);
+    }
+
+    @Override
+    public void requestChildFocus(View child, View focused) {
+        if (DBG) {
+            System.out.println(this + " requestChildFocus()");
+        }
+        if (getDescendantFocusability() == FOCUS_BLOCK_DESCENDANTS) {
+            return;
+        }
+
+        // Unfocus us, if necessary
+        super.unFocus(focused);
+
+        // We had a previous notion of who had focus. Clear it.
+        if (mFocused != child) {
+            if (mFocused != null) {
+                mFocused.unFocus(focused);
+            }
+
+            mFocused = child;
+        }
+        if (mParent != null) {
+            mParent.requestChildFocus(this, focused);
+        }
+    }
+
+    void setDefaultFocus(View child) {
+        // Stop at any higher view which is explicitly focused-by-default
+        if (mDefaultFocus != null && mDefaultFocus.isFocusedByDefault()) {
+            return;
+        }
+
+        mDefaultFocus = child;
+
+        if (mParent instanceof ViewGroup) {
+            ((ViewGroup) mParent).setDefaultFocus(this);
+        }
+    }
+
+    /**
+     * Clears the default-focus chain from {@param child} up to the first parent which has another
+     * default-focusable branch below it or until there is no default-focus chain.
+     *
+     * @param child
+     */
+    void clearDefaultFocus(View child) {
+        // Stop at any higher view which is explicitly focused-by-default
+        if (mDefaultFocus != child && mDefaultFocus != null
+                && mDefaultFocus.isFocusedByDefault()) {
+            return;
+        }
+
+        mDefaultFocus = null;
+
+        // Search child siblings for default focusables.
+        for (int i = 0; i < mChildrenCount; ++i) {
+            View sibling = mChildren[i];
+            if (sibling.isFocusedByDefault()) {
+                mDefaultFocus = sibling;
+                return;
+            } else if (mDefaultFocus == null && sibling.hasDefaultFocus()) {
+                mDefaultFocus = sibling;
+            }
+        }
+
+        if (mParent instanceof ViewGroup) {
+            ((ViewGroup) mParent).clearDefaultFocus(this);
+        }
+    }
+
+    @Override
+    boolean hasDefaultFocus() {
+        return mDefaultFocus != null || super.hasDefaultFocus();
+    }
+
+    /**
+     * Removes {@code child} (and associated focusedInCluster chain) from the cluster containing
+     * it.
+     * <br>
+     * This is intended to be run on {@code child}'s immediate parent. This is necessary because
+     * the chain is sometimes cleared after {@code child} has been detached.
+     */
+    void clearFocusedInCluster(View child) {
+        if (mFocusedInCluster != child) {
+            return;
+        }
+        clearFocusedInCluster();
+    }
+
+    /**
+     * Removes the focusedInCluster chain from this up to the cluster containing it.
+     */
+    void clearFocusedInCluster() {
+        View top = findKeyboardNavigationCluster();
+        ViewParent parent = this;
+        do {
+            ((ViewGroup) parent).mFocusedInCluster = null;
+            if (parent == top) {
+                break;
+            }
+            parent = parent.getParent();
+        } while (parent instanceof ViewGroup);
+    }
+
+    @Override
+    public void focusableViewAvailable(View v) {
+        if (mParent != null
+                // shortcut: don't report a new focusable view if we block our descendants from
+                // getting focus or if we're not visible
+                && (getDescendantFocusability() != FOCUS_BLOCK_DESCENDANTS)
+                && ((mViewFlags & VISIBILITY_MASK) == VISIBLE)
+                && (isFocusableInTouchMode() || !shouldBlockFocusForTouchscreen())
+                // shortcut: don't report a new focusable view if we already are focused
+                // (and we don't prefer our descendants)
+                //
+                // note: knowing that mFocused is non-null is not a good enough reason
+                // to break the traversal since in that case we'd actually have to find
+                // the focused view and make sure it wasn't FOCUS_AFTER_DESCENDANTS and
+                // an ancestor of v; this will get checked for at ViewAncestor
+                && !(isFocused() && getDescendantFocusability() != FOCUS_AFTER_DESCENDANTS)) {
+            mParent.focusableViewAvailable(v);
+        }
+    }
+
+    @Override
+    public boolean showContextMenuForChild(View originalView) {
+        if (isShowingContextMenuWithCoords()) {
+            // We're being called for compatibility. Return false and let the version
+            // with coordinates recurse up.
+            return false;
+        }
+        return mParent != null && mParent.showContextMenuForChild(originalView);
+    }
+
+    /**
+     * @hide used internally for compatibility with existing app code only
+     */
+    public final boolean isShowingContextMenuWithCoords() {
+        return (mGroupFlags & FLAG_SHOW_CONTEXT_MENU_WITH_COORDS) != 0;
+    }
+
+    @Override
+    public boolean showContextMenuForChild(View originalView, float x, float y) {
+        try {
+            mGroupFlags |= FLAG_SHOW_CONTEXT_MENU_WITH_COORDS;
+            if (showContextMenuForChild(originalView)) {
+                return true;
+            }
+        } finally {
+            mGroupFlags &= ~FLAG_SHOW_CONTEXT_MENU_WITH_COORDS;
+        }
+        return mParent != null && mParent.showContextMenuForChild(originalView, x, y);
+    }
+
+    @Override
+    public ActionMode startActionModeForChild(View originalView, ActionMode.Callback callback) {
+        if ((mGroupFlags & FLAG_START_ACTION_MODE_FOR_CHILD_IS_TYPED) == 0) {
+            // This is the original call.
+            try {
+                mGroupFlags |= FLAG_START_ACTION_MODE_FOR_CHILD_IS_NOT_TYPED;
+                return startActionModeForChild(originalView, callback, ActionMode.TYPE_PRIMARY);
+            } finally {
+                mGroupFlags &= ~FLAG_START_ACTION_MODE_FOR_CHILD_IS_NOT_TYPED;
+            }
+        } else {
+            // We are being called from the new method with type.
+            return SENTINEL_ACTION_MODE;
+        }
+    }
+
+    @Override
+    public ActionMode startActionModeForChild(
+            View originalView, ActionMode.Callback callback, int type) {
+        if ((mGroupFlags & FLAG_START_ACTION_MODE_FOR_CHILD_IS_NOT_TYPED) == 0
+                && type == ActionMode.TYPE_PRIMARY) {
+            ActionMode mode;
+            try {
+                mGroupFlags |= FLAG_START_ACTION_MODE_FOR_CHILD_IS_TYPED;
+                mode = startActionModeForChild(originalView, callback);
+            } finally {
+                mGroupFlags &= ~FLAG_START_ACTION_MODE_FOR_CHILD_IS_TYPED;
+            }
+            if (mode != SENTINEL_ACTION_MODE) {
+                return mode;
+            }
+        }
+        if (mParent != null) {
+            try {
+                return mParent.startActionModeForChild(originalView, callback, type);
+            } catch (AbstractMethodError ame) {
+                // Custom view parents might not implement this method.
+                return mParent.startActionModeForChild(originalView, callback);
+            }
+        }
+        return null;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean dispatchActivityResult(
+            String who, int requestCode, int resultCode, Intent data) {
+        if (super.dispatchActivityResult(who, requestCode, resultCode, data)) {
+            return true;
+        }
+        int childCount = getChildCount();
+        for (int i = 0; i < childCount; i++) {
+            View child = getChildAt(i);
+            if (child.dispatchActivityResult(who, requestCode, resultCode, data)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Find the nearest view in the specified direction that wants to take
+     * focus.
+     *
+     * @param focused The view that currently has focus
+     * @param direction One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and
+     *        FOCUS_RIGHT, or 0 for not applicable.
+     */
+    @Override
+    public View focusSearch(View focused, int direction) {
+        if (isRootNamespace()) {
+            // root namespace means we should consider ourselves the top of the
+            // tree for focus searching; otherwise we could be focus searching
+            // into other tabs.  see LocalActivityManager and TabHost for more info.
+            return FocusFinder.getInstance().findNextFocus(this, focused, direction);
+        } else if (mParent != null) {
+            return mParent.focusSearch(focused, direction);
+        }
+        return null;
+    }
+
+    @Override
+    public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
+        return false;
+    }
+
+    @Override
+    public boolean requestSendAccessibilityEvent(View child, AccessibilityEvent event) {
+        ViewParent parent = mParent;
+        if (parent == null) {
+            return false;
+        }
+        final boolean propagate = onRequestSendAccessibilityEvent(child, event);
+        if (!propagate) {
+            return false;
+        }
+        return parent.requestSendAccessibilityEvent(this, event);
+    }
+
+    /**
+     * Called when a child has requested sending an {@link AccessibilityEvent} and
+     * gives an opportunity to its parent to augment the event.
+     * <p>
+     * If an {@link android.view.View.AccessibilityDelegate} has been specified via calling
+     * {@link android.view.View#setAccessibilityDelegate(android.view.View.AccessibilityDelegate)} its
+     * {@link android.view.View.AccessibilityDelegate#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)}
+     * is responsible for handling this call.
+     * </p>
+     *
+     * @param child The child which requests sending the event.
+     * @param event The event to be sent.
+     * @return True if the event should be sent.
+     *
+     * @see #requestSendAccessibilityEvent(View, AccessibilityEvent)
+     */
+    public boolean onRequestSendAccessibilityEvent(View child, AccessibilityEvent event) {
+        if (mAccessibilityDelegate != null) {
+            return mAccessibilityDelegate.onRequestSendAccessibilityEvent(this, child, event);
+        } else {
+            return onRequestSendAccessibilityEventInternal(child, event);
+        }
+    }
+
+    /**
+     * @see #onRequestSendAccessibilityEvent(View, AccessibilityEvent)
+     *
+     * Note: Called from the default {@link View.AccessibilityDelegate}.
+     *
+     * @hide
+     */
+    public boolean onRequestSendAccessibilityEventInternal(View child, AccessibilityEvent event) {
+        return true;
+    }
+
+    /**
+     * Called when a child view has changed whether or not it is tracking transient state.
+     */
+    @Override
+    public void childHasTransientStateChanged(View child, boolean childHasTransientState) {
+        final boolean oldHasTransientState = hasTransientState();
+        if (childHasTransientState) {
+            mChildCountWithTransientState++;
+        } else {
+            mChildCountWithTransientState--;
+        }
+
+        final boolean newHasTransientState = hasTransientState();
+        if (mParent != null && oldHasTransientState != newHasTransientState) {
+            try {
+                mParent.childHasTransientStateChanged(this, newHasTransientState);
+            } catch (AbstractMethodError e) {
+                Log.e(TAG, mParent.getClass().getSimpleName() +
+                        " does not fully implement ViewParent", e);
+            }
+        }
+    }
+
+    @Override
+    public boolean hasTransientState() {
+        return mChildCountWithTransientState > 0 || super.hasTransientState();
+    }
+
+    @Override
+    public boolean dispatchUnhandledMove(View focused, int direction) {
+        return mFocused != null &&
+                mFocused.dispatchUnhandledMove(focused, direction);
+    }
+
+    @Override
+    public void clearChildFocus(View child) {
+        if (DBG) {
+            System.out.println(this + " clearChildFocus()");
+        }
+
+        mFocused = null;
+        if (mParent != null) {
+            mParent.clearChildFocus(this);
+        }
+    }
+
+    @Override
+    public void clearFocus() {
+        if (DBG) {
+            System.out.println(this + " clearFocus()");
+        }
+        if (mFocused == null) {
+            super.clearFocus();
+        } else {
+            View focused = mFocused;
+            mFocused = null;
+            focused.clearFocus();
+        }
+    }
+
+    @Override
+    void unFocus(View focused) {
+        if (DBG) {
+            System.out.println(this + " unFocus()");
+        }
+        if (mFocused == null) {
+            super.unFocus(focused);
+        } else {
+            mFocused.unFocus(focused);
+            mFocused = null;
+        }
+    }
+
+    /**
+     * Returns the focused child of this view, if any. The child may have focus
+     * or contain focus.
+     *
+     * @return the focused child or null.
+     */
+    public View getFocusedChild() {
+        return mFocused;
+    }
+
+    View getDeepestFocusedChild() {
+        View v = this;
+        while (v != null) {
+            if (v.isFocused()) {
+                return v;
+            }
+            v = v instanceof ViewGroup ? ((ViewGroup) v).getFocusedChild() : null;
+        }
+        return null;
+    }
+
+    /**
+     * Returns true if this view has or contains focus
+     *
+     * @return true if this view has or contains focus
+     */
+    @Override
+    public boolean hasFocus() {
+        return (mPrivateFlags & PFLAG_FOCUSED) != 0 || mFocused != null;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see android.view.View#findFocus()
+     */
+    @Override
+    public View findFocus() {
+        if (DBG) {
+            System.out.println("Find focus in " + this + ": flags="
+                    + isFocused() + ", child=" + mFocused);
+        }
+
+        if (isFocused()) {
+            return this;
+        }
+
+        if (mFocused != null) {
+            return mFocused.findFocus();
+        }
+        return null;
+    }
+
+    @Override
+    boolean hasFocusable(boolean allowAutoFocus, boolean dispatchExplicit) {
+        // This should probably be super.hasFocusable, but that would change
+        // behavior. Historically, we have not checked the ancestor views for
+        // shouldBlockFocusForTouchscreen() in ViewGroup.hasFocusable.
+
+        // Invisible and gone views are never focusable.
+        if ((mViewFlags & VISIBILITY_MASK) != VISIBLE) {
+            return false;
+        }
+
+        // Only use effective focusable value when allowed.
+        if ((allowAutoFocus || getFocusable() != FOCUSABLE_AUTO) && isFocusable()) {
+            return true;
+        }
+
+        // Determine whether we have a focused descendant.
+        final int descendantFocusability = getDescendantFocusability();
+        if (descendantFocusability != FOCUS_BLOCK_DESCENDANTS) {
+            return hasFocusableChild(dispatchExplicit);
+        }
+
+        return false;
+    }
+
+    boolean hasFocusableChild(boolean dispatchExplicit) {
+        // Determine whether we have a focusable descendant.
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+
+            // In case the subclass has overridden has[Explicit]Focusable, dispatch
+            // to the expected one for each child even though we share logic here.
+            if ((dispatchExplicit && child.hasExplicitFocusable())
+                    || (!dispatchExplicit && child.hasFocusable())) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public void addFocusables(ArrayList<View> views, int direction, int focusableMode) {
+        final int focusableCount = views.size();
+
+        final int descendantFocusability = getDescendantFocusability();
+        final boolean blockFocusForTouchscreen = shouldBlockFocusForTouchscreen();
+        final boolean focusSelf = (isFocusableInTouchMode() || !blockFocusForTouchscreen);
+
+        if (descendantFocusability == FOCUS_BLOCK_DESCENDANTS) {
+            if (focusSelf) {
+                super.addFocusables(views, direction, focusableMode);
+            }
+            return;
+        }
+
+        if (blockFocusForTouchscreen) {
+            focusableMode |= FOCUSABLES_TOUCH_MODE;
+        }
+
+        if ((descendantFocusability == FOCUS_BEFORE_DESCENDANTS) && focusSelf) {
+            super.addFocusables(views, direction, focusableMode);
+        }
+
+        int count = 0;
+        final View[] children = new View[mChildrenCount];
+        for (int i = 0; i < mChildrenCount; ++i) {
+            View child = mChildren[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                children[count++] = child;
+            }
+        }
+        FocusFinder.sort(children, 0, count, this, isLayoutRtl());
+        for (int i = 0; i < count; ++i) {
+            children[i].addFocusables(views, direction, focusableMode);
+        }
+
+        // When set to FOCUS_AFTER_DESCENDANTS, we only add ourselves if
+        // there aren't any focusable descendants.  this is
+        // to avoid the focus search finding layouts when a more precise search
+        // among the focusable children would be more interesting.
+        if ((descendantFocusability == FOCUS_AFTER_DESCENDANTS) && focusSelf
+                && focusableCount == views.size()) {
+            super.addFocusables(views, direction, focusableMode);
+        }
+    }
+
+    @Override
+    public void addKeyboardNavigationClusters(Collection<View> views, int direction) {
+        final int focusableCount = views.size();
+
+        if (isKeyboardNavigationCluster()) {
+            // Cluster-navigation can enter a touchscreenBlocksFocus cluster, so temporarily
+            // disable touchscreenBlocksFocus to evaluate whether it contains focusables.
+            final boolean blockedFocus = getTouchscreenBlocksFocus();
+            try {
+                setTouchscreenBlocksFocusNoRefocus(false);
+                super.addKeyboardNavigationClusters(views, direction);
+            } finally {
+                setTouchscreenBlocksFocusNoRefocus(blockedFocus);
+            }
+        } else {
+            super.addKeyboardNavigationClusters(views, direction);
+        }
+
+        if (focusableCount != views.size()) {
+            // No need to look for groups inside a group.
+            return;
+        }
+
+        if (getDescendantFocusability() == FOCUS_BLOCK_DESCENDANTS) {
+            return;
+        }
+
+        int count = 0;
+        final View[] visibleChildren = new View[mChildrenCount];
+        for (int i = 0; i < mChildrenCount; ++i) {
+            final View child = mChildren[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                visibleChildren[count++] = child;
+            }
+        }
+        FocusFinder.sort(visibleChildren, 0, count, this, isLayoutRtl());
+        for (int i = 0; i < count; ++i) {
+            visibleChildren[i].addKeyboardNavigationClusters(views, direction);
+        }
+    }
+
+    /**
+     * Set whether this ViewGroup should ignore focus requests for itself and its children.
+     * If this option is enabled and the ViewGroup or a descendant currently has focus, focus
+     * will proceed forward.
+     *
+     * @param touchscreenBlocksFocus true to enable blocking focus in the presence of a touchscreen
+     */
+    public void setTouchscreenBlocksFocus(boolean touchscreenBlocksFocus) {
+        if (touchscreenBlocksFocus) {
+            mGroupFlags |= FLAG_TOUCHSCREEN_BLOCKS_FOCUS;
+            if (hasFocus() && !isKeyboardNavigationCluster()) {
+                final View focusedChild = getDeepestFocusedChild();
+                if (!focusedChild.isFocusableInTouchMode()) {
+                    final View newFocus = focusSearch(FOCUS_FORWARD);
+                    if (newFocus != null) {
+                        newFocus.requestFocus();
+                    }
+                }
+            }
+        } else {
+            mGroupFlags &= ~FLAG_TOUCHSCREEN_BLOCKS_FOCUS;
+        }
+    }
+
+    private void setTouchscreenBlocksFocusNoRefocus(boolean touchscreenBlocksFocus) {
+        if (touchscreenBlocksFocus) {
+            mGroupFlags |= FLAG_TOUCHSCREEN_BLOCKS_FOCUS;
+        } else {
+            mGroupFlags &= ~FLAG_TOUCHSCREEN_BLOCKS_FOCUS;
+        }
+    }
+
+    /**
+     * Check whether this ViewGroup should ignore focus requests for itself and its children.
+     */
+    @ViewDebug.ExportedProperty(category = "focus")
+    public boolean getTouchscreenBlocksFocus() {
+        return (mGroupFlags & FLAG_TOUCHSCREEN_BLOCKS_FOCUS) != 0;
+    }
+
+    boolean shouldBlockFocusForTouchscreen() {
+        // There is a special case for keyboard-navigation clusters. We allow cluster navigation
+        // to jump into blockFocusForTouchscreen ViewGroups which are clusters. Once in the
+        // cluster, focus is free to move around within it.
+        return getTouchscreenBlocksFocus() &&
+                mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_TOUCHSCREEN)
+                && !(isKeyboardNavigationCluster()
+                        && (hasFocus() || (findKeyboardNavigationCluster() != this)));
+    }
+
+    @Override
+    public void findViewsWithText(ArrayList<View> outViews, CharSequence text, int flags) {
+        super.findViewsWithText(outViews, text, flags);
+        final int childrenCount = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < childrenCount; i++) {
+            View child = children[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE
+                    && (child.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
+                child.findViewsWithText(outViews, text, flags);
+            }
+        }
+    }
+
+    /** @hide */
+    @Override
+    public View findViewByAccessibilityIdTraversal(int accessibilityId) {
+        View foundView = super.findViewByAccessibilityIdTraversal(accessibilityId);
+        if (foundView != null) {
+            return foundView;
+        }
+
+        if (getAccessibilityNodeProvider() != null) {
+            return null;
+        }
+
+        final int childrenCount = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < childrenCount; i++) {
+            View child = children[i];
+            foundView = child.findViewByAccessibilityIdTraversal(accessibilityId);
+            if (foundView != null) {
+                return foundView;
+            }
+        }
+
+        return null;
+    }
+
+    /** @hide */
+    @Override
+    public View findViewByAutofillIdTraversal(int autofillId) {
+        View foundView = super.findViewByAutofillIdTraversal(autofillId);
+        if (foundView != null) {
+            return foundView;
+        }
+
+        final int childrenCount = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < childrenCount; i++) {
+            View child = children[i];
+            foundView = child.findViewByAutofillIdTraversal(autofillId);
+            if (foundView != null) {
+                return foundView;
+            }
+        }
+
+        return null;
+    }
+
+    @Override
+    public void dispatchWindowFocusChanged(boolean hasFocus) {
+        super.dispatchWindowFocusChanged(hasFocus);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchWindowFocusChanged(hasFocus);
+        }
+    }
+
+    @Override
+    public void addTouchables(ArrayList<View> views) {
+        super.addTouchables(views);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                child.addTouchables(views);
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void makeOptionalFitsSystemWindows() {
+        super.makeOptionalFitsSystemWindows();
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].makeOptionalFitsSystemWindows();
+        }
+    }
+
+    @Override
+    public void dispatchDisplayHint(int hint) {
+        super.dispatchDisplayHint(hint);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchDisplayHint(hint);
+        }
+    }
+
+    /**
+     * Called when a view's visibility has changed. Notify the parent to take any appropriate
+     * action.
+     *
+     * @param child The view whose visibility has changed
+     * @param oldVisibility The previous visibility value (GONE, INVISIBLE, or VISIBLE).
+     * @param newVisibility The new visibility value (GONE, INVISIBLE, or VISIBLE).
+     * @hide
+     */
+    protected void onChildVisibilityChanged(View child, int oldVisibility, int newVisibility) {
+        if (mTransition != null) {
+            if (newVisibility == VISIBLE) {
+                mTransition.showChild(this, child, oldVisibility);
+            } else {
+                mTransition.hideChild(this, child, newVisibility);
+                if (mTransitioningViews != null && mTransitioningViews.contains(child)) {
+                    // Only track this on disappearing views - appearing views are already visible
+                    // and don't need special handling during drawChild()
+                    if (mVisibilityChangingChildren == null) {
+                        mVisibilityChangingChildren = new ArrayList<View>();
+                    }
+                    mVisibilityChangingChildren.add(child);
+                    addDisappearingView(child);
+                }
+            }
+        }
+
+        // in all cases, for drags
+        if (newVisibility == VISIBLE && mCurrentDragStartEvent != null) {
+            if (!mChildrenInterestedInDrag.contains(child)) {
+                notifyChildOfDragStart(child);
+            }
+        }
+    }
+
+    @Override
+    protected void dispatchVisibilityChanged(View changedView, int visibility) {
+        super.dispatchVisibilityChanged(changedView, visibility);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchVisibilityChanged(changedView, visibility);
+        }
+    }
+
+    @Override
+    public void dispatchWindowVisibilityChanged(int visibility) {
+        super.dispatchWindowVisibilityChanged(visibility);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchWindowVisibilityChanged(visibility);
+        }
+    }
+
+    @Override
+    boolean dispatchVisibilityAggregated(boolean isVisible) {
+        isVisible = super.dispatchVisibilityAggregated(isVisible);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            // Only dispatch to visible children. Not visible children and their subtrees already
+            // know that they aren't visible and that's not going to change as a result of
+            // whatever triggered this dispatch.
+            if (children[i].getVisibility() == VISIBLE) {
+                children[i].dispatchVisibilityAggregated(isVisible);
+            }
+        }
+        return isVisible;
+    }
+
+    @Override
+    public void dispatchConfigurationChanged(Configuration newConfig) {
+        super.dispatchConfigurationChanged(newConfig);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchConfigurationChanged(newConfig);
+        }
+    }
+
+    @Override
+    public void recomputeViewAttributes(View child) {
+        if (mAttachInfo != null && !mAttachInfo.mRecomputeGlobalAttributes) {
+            ViewParent parent = mParent;
+            if (parent != null) parent.recomputeViewAttributes(this);
+        }
+    }
+
+    @Override
+    void dispatchCollectViewAttributes(AttachInfo attachInfo, int visibility) {
+        if ((visibility & VISIBILITY_MASK) == VISIBLE) {
+            super.dispatchCollectViewAttributes(attachInfo, visibility);
+            final int count = mChildrenCount;
+            final View[] children = mChildren;
+            for (int i = 0; i < count; i++) {
+                final View child = children[i];
+                child.dispatchCollectViewAttributes(attachInfo,
+                        visibility | (child.mViewFlags&VISIBILITY_MASK));
+            }
+        }
+    }
+
+    @Override
+    public void bringChildToFront(View child) {
+        final int index = indexOfChild(child);
+        if (index >= 0) {
+            removeFromArray(index);
+            addInArray(child, mChildrenCount);
+            child.mParent = this;
+            requestLayout();
+            invalidate();
+        }
+    }
+
+    private PointF getLocalPoint() {
+        if (mLocalPoint == null) mLocalPoint = new PointF();
+        return mLocalPoint;
+    }
+
+    @Override
+    boolean dispatchDragEnterExitInPreN(DragEvent event) {
+        if (event.mAction == DragEvent.ACTION_DRAG_EXITED && mCurrentDragChild != null) {
+            // The drag exited a sub-tree of views; notify of the exit all descendants that are in
+            // entered state.
+            // We don't need this recursive delivery for ENTERED events because they get generated
+            // from the recursive delivery of LOCATION/DROP events, and hence, don't need their own
+            // recursion.
+            mCurrentDragChild.dispatchDragEnterExitInPreN(event);
+            mCurrentDragChild = null;
+        }
+        return mIsInterestedInDrag && super.dispatchDragEnterExitInPreN(event);
+    }
+
+    // TODO: Write real docs
+    @Override
+    public boolean dispatchDragEvent(DragEvent event) {
+        boolean retval = false;
+        final float tx = event.mX;
+        final float ty = event.mY;
+        final ClipData td = event.mClipData;
+
+        // Dispatch down the view hierarchy
+        final PointF localPoint = getLocalPoint();
+
+        switch (event.mAction) {
+        case DragEvent.ACTION_DRAG_STARTED: {
+            // Clear the state to recalculate which views we drag over.
+            mCurrentDragChild = null;
+
+            // Set up our tracking of drag-started notifications
+            mCurrentDragStartEvent = DragEvent.obtain(event);
+            if (mChildrenInterestedInDrag == null) {
+                mChildrenInterestedInDrag = new HashSet<View>();
+            } else {
+                mChildrenInterestedInDrag.clear();
+            }
+
+            // Now dispatch down to our children, caching the responses
+            final int count = mChildrenCount;
+            final View[] children = mChildren;
+            for (int i = 0; i < count; i++) {
+                final View child = children[i];
+                child.mPrivateFlags2 &= ~View.DRAG_MASK;
+                if (child.getVisibility() == VISIBLE) {
+                    if (notifyChildOfDragStart(children[i])) {
+                        retval = true;
+                    }
+                }
+            }
+
+            // Notify itself of the drag start.
+            mIsInterestedInDrag = super.dispatchDragEvent(event);
+            if (mIsInterestedInDrag) {
+                retval = true;
+            }
+
+            if (!retval) {
+                // Neither us nor any of our children are interested in this drag, so stop tracking
+                // the current drag event.
+                mCurrentDragStartEvent.recycle();
+                mCurrentDragStartEvent = null;
+            }
+        } break;
+
+        case DragEvent.ACTION_DRAG_ENDED: {
+            // Release the bookkeeping now that the drag lifecycle has ended
+            final HashSet<View> childrenInterestedInDrag = mChildrenInterestedInDrag;
+            if (childrenInterestedInDrag != null) {
+                for (View child : childrenInterestedInDrag) {
+                    // If a child was interested in the ongoing drag, it's told that it's over
+                    if (child.dispatchDragEvent(event)) {
+                        retval = true;
+                    }
+                }
+                childrenInterestedInDrag.clear();
+            }
+            if (mCurrentDragStartEvent != null) {
+                mCurrentDragStartEvent.recycle();
+                mCurrentDragStartEvent = null;
+            }
+
+            if (mIsInterestedInDrag) {
+                if (super.dispatchDragEvent(event)) {
+                    retval = true;
+                }
+                mIsInterestedInDrag = false;
+            }
+        } break;
+
+        case DragEvent.ACTION_DRAG_LOCATION:
+        case DragEvent.ACTION_DROP: {
+            // Find the [possibly new] drag target
+            View target = findFrontmostDroppableChildAt(event.mX, event.mY, localPoint);
+
+            if (target != mCurrentDragChild) {
+                if (sCascadedDragDrop) {
+                    // For pre-Nougat apps, make sure that the whole hierarchy of views that contain
+                    // the drag location is kept in the state between ENTERED and EXITED events.
+                    // (Starting with N, only the innermost view will be in that state).
+
+                    final int action = event.mAction;
+                    // Position should not be available for ACTION_DRAG_ENTERED and
+                    // ACTION_DRAG_EXITED.
+                    event.mX = 0;
+                    event.mY = 0;
+                    event.mClipData = null;
+
+                    if (mCurrentDragChild != null) {
+                        event.mAction = DragEvent.ACTION_DRAG_EXITED;
+                        mCurrentDragChild.dispatchDragEnterExitInPreN(event);
+                    }
+
+                    if (target != null) {
+                        event.mAction = DragEvent.ACTION_DRAG_ENTERED;
+                        target.dispatchDragEnterExitInPreN(event);
+                    }
+
+                    event.mAction = action;
+                    event.mX = tx;
+                    event.mY = ty;
+                    event.mClipData = td;
+                }
+                mCurrentDragChild = target;
+            }
+
+            if (target == null && mIsInterestedInDrag) {
+                target = this;
+            }
+
+            // Dispatch the actual drag notice, localized into the target coordinates.
+            if (target != null) {
+                if (target != this) {
+                    event.mX = localPoint.x;
+                    event.mY = localPoint.y;
+
+                    retval = target.dispatchDragEvent(event);
+
+                    event.mX = tx;
+                    event.mY = ty;
+
+                    if (mIsInterestedInDrag) {
+                        final boolean eventWasConsumed;
+                        if (sCascadedDragDrop) {
+                            eventWasConsumed = retval;
+                        } else {
+                            eventWasConsumed = event.mEventHandlerWasCalled;
+                        }
+
+                        if (!eventWasConsumed) {
+                            retval = super.dispatchDragEvent(event);
+                        }
+                    }
+                } else {
+                    retval = super.dispatchDragEvent(event);
+                }
+            }
+        } break;
+        }
+
+        return retval;
+    }
+
+    // Find the frontmost child view that lies under the given point, and calculate
+    // the position within its own local coordinate system.
+    View findFrontmostDroppableChildAt(float x, float y, PointF outLocalPoint) {
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = count - 1; i >= 0; i--) {
+            final View child = children[i];
+            if (!child.canAcceptDrag()) {
+                continue;
+            }
+
+            if (isTransformedTouchPointInView(x, y, child, outLocalPoint)) {
+                return child;
+            }
+        }
+        return null;
+    }
+
+    boolean notifyChildOfDragStart(View child) {
+        // The caller guarantees that the child is not in mChildrenInterestedInDrag yet.
+
+        if (ViewDebug.DEBUG_DRAG) {
+            Log.d(View.VIEW_LOG_TAG, "Sending drag-started to view: " + child);
+        }
+
+        final float tx = mCurrentDragStartEvent.mX;
+        final float ty = mCurrentDragStartEvent.mY;
+
+        final float[] point = getTempPoint();
+        point[0] = tx;
+        point[1] = ty;
+        transformPointToViewLocal(point, child);
+
+        mCurrentDragStartEvent.mX = point[0];
+        mCurrentDragStartEvent.mY = point[1];
+        final boolean canAccept = child.dispatchDragEvent(mCurrentDragStartEvent);
+        mCurrentDragStartEvent.mX = tx;
+        mCurrentDragStartEvent.mY = ty;
+        mCurrentDragStartEvent.mEventHandlerWasCalled = false;
+        if (canAccept) {
+            mChildrenInterestedInDrag.add(child);
+            if (!child.canAcceptDrag()) {
+                child.mPrivateFlags2 |= View.PFLAG2_DRAG_CAN_ACCEPT;
+                child.refreshDrawableState();
+            }
+        }
+        return canAccept;
+    }
+
+    @Override
+    public void dispatchWindowSystemUiVisiblityChanged(int visible) {
+        super.dispatchWindowSystemUiVisiblityChanged(visible);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i=0; i <count; i++) {
+            final View child = children[i];
+            child.dispatchWindowSystemUiVisiblityChanged(visible);
+        }
+    }
+
+    @Override
+    public void dispatchSystemUiVisibilityChanged(int visible) {
+        super.dispatchSystemUiVisibilityChanged(visible);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i=0; i <count; i++) {
+            final View child = children[i];
+            child.dispatchSystemUiVisibilityChanged(visible);
+        }
+    }
+
+    @Override
+    boolean updateLocalSystemUiVisibility(int localValue, int localChanges) {
+        boolean changed = super.updateLocalSystemUiVisibility(localValue, localChanges);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i=0; i <count; i++) {
+            final View child = children[i];
+            changed |= child.updateLocalSystemUiVisibility(localValue, localChanges);
+        }
+        return changed;
+    }
+
+    @Override
+    public boolean dispatchKeyEventPreIme(KeyEvent event) {
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            return super.dispatchKeyEventPreIme(event);
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            return mFocused.dispatchKeyEventPreIme(event);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean dispatchKeyEvent(KeyEvent event) {
+        if (mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onKeyEvent(event, 1);
+        }
+
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            if (super.dispatchKeyEvent(event)) {
+                return true;
+            }
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            if (mFocused.dispatchKeyEvent(event)) {
+                return true;
+            }
+        }
+
+        if (mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onUnhandledEvent(event, 1);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean dispatchKeyShortcutEvent(KeyEvent event) {
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            return super.dispatchKeyShortcutEvent(event);
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            return mFocused.dispatchKeyShortcutEvent(event);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean dispatchTrackballEvent(MotionEvent event) {
+        if (mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onTrackballEvent(event, 1);
+        }
+
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            if (super.dispatchTrackballEvent(event)) {
+                return true;
+            }
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            if (mFocused.dispatchTrackballEvent(event)) {
+                return true;
+            }
+        }
+
+        if (mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onUnhandledEvent(event, 1);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean dispatchCapturedPointerEvent(MotionEvent event) {
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            if (super.dispatchCapturedPointerEvent(event)) {
+                return true;
+            }
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            if (mFocused.dispatchCapturedPointerEvent(event)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public void dispatchPointerCaptureChanged(boolean hasCapture) {
+        exitHoverTargets();
+
+        super.dispatchPointerCaptureChanged(hasCapture);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchPointerCaptureChanged(hasCapture);
+        }
+    }
+
+    @Override
+    public PointerIcon onResolvePointerIcon(MotionEvent event, int pointerIndex) {
+        final float x = event.getX(pointerIndex);
+        final float y = event.getY(pointerIndex);
+        if (isOnScrollbarThumb(x, y) || isDraggingScrollBar()) {
+            return PointerIcon.getSystemIcon(mContext, PointerIcon.TYPE_ARROW);
+        }
+        // Check what the child under the pointer says about the pointer.
+        final int childrenCount = mChildrenCount;
+        if (childrenCount != 0) {
+            final ArrayList<View> preorderedList = buildOrderedChildList();
+            final boolean customOrder = preorderedList == null
+                    && isChildrenDrawingOrderEnabled();
+            final View[] children = mChildren;
+            for (int i = childrenCount - 1; i >= 0; i--) {
+                final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+                final View child = getAndVerifyPreorderedView(preorderedList, children, childIndex);
+                if (!canViewReceivePointerEvents(child)
+                        || !isTransformedTouchPointInView(x, y, child, null)) {
+                    continue;
+                }
+                final PointerIcon pointerIcon =
+                        dispatchResolvePointerIcon(event, pointerIndex, child);
+                if (pointerIcon != null) {
+                    if (preorderedList != null) preorderedList.clear();
+                    return pointerIcon;
+                }
+            }
+            if (preorderedList != null) preorderedList.clear();
+        }
+
+        // The pointer is not a child or the child has no preferences, returning the default
+        // implementation.
+        return super.onResolvePointerIcon(event, pointerIndex);
+    }
+
+    private PointerIcon dispatchResolvePointerIcon(MotionEvent event, int pointerIndex,
+            View child) {
+        final PointerIcon pointerIcon;
+        if (!child.hasIdentityMatrix()) {
+            MotionEvent transformedEvent = getTransformedMotionEvent(event, child);
+            pointerIcon = child.onResolvePointerIcon(transformedEvent, pointerIndex);
+            transformedEvent.recycle();
+        } else {
+            final float offsetX = mScrollX - child.mLeft;
+            final float offsetY = mScrollY - child.mTop;
+            event.offsetLocation(offsetX, offsetY);
+            pointerIcon = child.onResolvePointerIcon(event, pointerIndex);
+            event.offsetLocation(-offsetX, -offsetY);
+        }
+        return pointerIcon;
+    }
+
+    private int getAndVerifyPreorderedIndex(int childrenCount, int i, boolean customOrder) {
+        final int childIndex;
+        if (customOrder) {
+            final int childIndex1 = getChildDrawingOrder(childrenCount, i);
+            if (childIndex1 >= childrenCount) {
+                throw new IndexOutOfBoundsException("getChildDrawingOrder() "
+                        + "returned invalid index " + childIndex1
+                        + " (child count is " + childrenCount + ")");
+            }
+            childIndex = childIndex1;
+        } else {
+            childIndex = i;
+        }
+        return childIndex;
+    }
+
+    @SuppressWarnings({"ConstantConditions"})
+    @Override
+    protected boolean dispatchHoverEvent(MotionEvent event) {
+        final int action = event.getAction();
+
+        // First check whether the view group wants to intercept the hover event.
+        final boolean interceptHover = onInterceptHoverEvent(event);
+        event.setAction(action); // restore action in case it was changed
+
+        MotionEvent eventNoHistory = event;
+        boolean handled = false;
+
+        // Send events to the hovered children and build a new list of hover targets until
+        // one is found that handles the event.
+        HoverTarget firstOldHoverTarget = mFirstHoverTarget;
+        mFirstHoverTarget = null;
+        if (!interceptHover && action != MotionEvent.ACTION_HOVER_EXIT) {
+            final float x = event.getX();
+            final float y = event.getY();
+            final int childrenCount = mChildrenCount;
+            if (childrenCount != 0) {
+                final ArrayList<View> preorderedList = buildOrderedChildList();
+                final boolean customOrder = preorderedList == null
+                        && isChildrenDrawingOrderEnabled();
+                final View[] children = mChildren;
+                HoverTarget lastHoverTarget = null;
+                for (int i = childrenCount - 1; i >= 0; i--) {
+                    final int childIndex = getAndVerifyPreorderedIndex(
+                            childrenCount, i, customOrder);
+                    final View child = getAndVerifyPreorderedView(
+                            preorderedList, children, childIndex);
+                    if (!canViewReceivePointerEvents(child)
+                            || !isTransformedTouchPointInView(x, y, child, null)) {
+                        continue;
+                    }
+
+                    // Obtain a hover target for this child.  Dequeue it from the
+                    // old hover target list if the child was previously hovered.
+                    HoverTarget hoverTarget = firstOldHoverTarget;
+                    final boolean wasHovered;
+                    for (HoverTarget predecessor = null; ;) {
+                        if (hoverTarget == null) {
+                            hoverTarget = HoverTarget.obtain(child);
+                            wasHovered = false;
+                            break;
+                        }
+
+                        if (hoverTarget.child == child) {
+                            if (predecessor != null) {
+                                predecessor.next = hoverTarget.next;
+                            } else {
+                                firstOldHoverTarget = hoverTarget.next;
+                            }
+                            hoverTarget.next = null;
+                            wasHovered = true;
+                            break;
+                        }
+
+                        predecessor = hoverTarget;
+                        hoverTarget = hoverTarget.next;
+                    }
+
+                    // Enqueue the hover target onto the new hover target list.
+                    if (lastHoverTarget != null) {
+                        lastHoverTarget.next = hoverTarget;
+                    } else {
+                        mFirstHoverTarget = hoverTarget;
+                    }
+                    lastHoverTarget = hoverTarget;
+
+                    // Dispatch the event to the child.
+                    if (action == MotionEvent.ACTION_HOVER_ENTER) {
+                        if (!wasHovered) {
+                            // Send the enter as is.
+                            handled |= dispatchTransformedGenericPointerEvent(
+                                    event, child); // enter
+                        }
+                    } else if (action == MotionEvent.ACTION_HOVER_MOVE) {
+                        if (!wasHovered) {
+                            // Synthesize an enter from a move.
+                            eventNoHistory = obtainMotionEventNoHistoryOrSelf(eventNoHistory);
+                            eventNoHistory.setAction(MotionEvent.ACTION_HOVER_ENTER);
+                            handled |= dispatchTransformedGenericPointerEvent(
+                                    eventNoHistory, child); // enter
+                            eventNoHistory.setAction(action);
+
+                            handled |= dispatchTransformedGenericPointerEvent(
+                                    eventNoHistory, child); // move
+                        } else {
+                            // Send the move as is.
+                            handled |= dispatchTransformedGenericPointerEvent(event, child);
+                        }
+                    }
+                    if (handled) {
+                        break;
+                    }
+                }
+                if (preorderedList != null) preorderedList.clear();
+            }
+        }
+
+        // Send exit events to all previously hovered children that are no longer hovered.
+        while (firstOldHoverTarget != null) {
+            final View child = firstOldHoverTarget.child;
+
+            // Exit the old hovered child.
+            if (action == MotionEvent.ACTION_HOVER_EXIT) {
+                // Send the exit as is.
+                handled |= dispatchTransformedGenericPointerEvent(
+                        event, child); // exit
+            } else {
+                // Synthesize an exit from a move or enter.
+                // Ignore the result because hover focus has moved to a different view.
+                if (action == MotionEvent.ACTION_HOVER_MOVE) {
+                    final boolean hoverExitPending = event.isHoverExitPending();
+                    event.setHoverExitPending(true);
+                    dispatchTransformedGenericPointerEvent(
+                            event, child); // move
+                    event.setHoverExitPending(hoverExitPending);
+                }
+                eventNoHistory = obtainMotionEventNoHistoryOrSelf(eventNoHistory);
+                eventNoHistory.setAction(MotionEvent.ACTION_HOVER_EXIT);
+                dispatchTransformedGenericPointerEvent(
+                        eventNoHistory, child); // exit
+                eventNoHistory.setAction(action);
+            }
+
+            final HoverTarget nextOldHoverTarget = firstOldHoverTarget.next;
+            firstOldHoverTarget.recycle();
+            firstOldHoverTarget = nextOldHoverTarget;
+        }
+
+        // Send events to the view group itself if no children have handled it and the view group
+        // itself is not currently being hover-exited.
+        boolean newHoveredSelf = !handled &&
+                (action != MotionEvent.ACTION_HOVER_EXIT) && !event.isHoverExitPending();
+        if (newHoveredSelf == mHoveredSelf) {
+            if (newHoveredSelf) {
+                // Send event to the view group as before.
+                handled |= super.dispatchHoverEvent(event);
+            }
+        } else {
+            if (mHoveredSelf) {
+                // Exit the view group.
+                if (action == MotionEvent.ACTION_HOVER_EXIT) {
+                    // Send the exit as is.
+                    handled |= super.dispatchHoverEvent(event); // exit
+                } else {
+                    // Synthesize an exit from a move or enter.
+                    // Ignore the result because hover focus is moving to a different view.
+                    if (action == MotionEvent.ACTION_HOVER_MOVE) {
+                        super.dispatchHoverEvent(event); // move
+                    }
+                    eventNoHistory = obtainMotionEventNoHistoryOrSelf(eventNoHistory);
+                    eventNoHistory.setAction(MotionEvent.ACTION_HOVER_EXIT);
+                    super.dispatchHoverEvent(eventNoHistory); // exit
+                    eventNoHistory.setAction(action);
+                }
+                mHoveredSelf = false;
+            }
+
+            if (newHoveredSelf) {
+                // Enter the view group.
+                if (action == MotionEvent.ACTION_HOVER_ENTER) {
+                    // Send the enter as is.
+                    handled |= super.dispatchHoverEvent(event); // enter
+                    mHoveredSelf = true;
+                } else if (action == MotionEvent.ACTION_HOVER_MOVE) {
+                    // Synthesize an enter from a move.
+                    eventNoHistory = obtainMotionEventNoHistoryOrSelf(eventNoHistory);
+                    eventNoHistory.setAction(MotionEvent.ACTION_HOVER_ENTER);
+                    handled |= super.dispatchHoverEvent(eventNoHistory); // enter
+                    eventNoHistory.setAction(action);
+
+                    handled |= super.dispatchHoverEvent(eventNoHistory); // move
+                    mHoveredSelf = true;
+                }
+            }
+        }
+
+        // Recycle the copy of the event that we made.
+        if (eventNoHistory != event) {
+            eventNoHistory.recycle();
+        }
+
+        // Done.
+        return handled;
+    }
+
+    private void exitHoverTargets() {
+        if (mHoveredSelf || mFirstHoverTarget != null) {
+            final long now = SystemClock.uptimeMillis();
+            MotionEvent event = MotionEvent.obtain(now, now,
+                    MotionEvent.ACTION_HOVER_EXIT, 0.0f, 0.0f, 0);
+            event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+            dispatchHoverEvent(event);
+            event.recycle();
+        }
+    }
+
+    private void cancelHoverTarget(View view) {
+        HoverTarget predecessor = null;
+        HoverTarget target = mFirstHoverTarget;
+        while (target != null) {
+            final HoverTarget next = target.next;
+            if (target.child == view) {
+                if (predecessor == null) {
+                    mFirstHoverTarget = next;
+                } else {
+                    predecessor.next = next;
+                }
+                target.recycle();
+
+                final long now = SystemClock.uptimeMillis();
+                MotionEvent event = MotionEvent.obtain(now, now,
+                        MotionEvent.ACTION_HOVER_EXIT, 0.0f, 0.0f, 0);
+                event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+                view.dispatchHoverEvent(event);
+                event.recycle();
+                return;
+            }
+            predecessor = target;
+            target = next;
+        }
+    }
+
+    @Override
+    boolean dispatchTooltipHoverEvent(MotionEvent event) {
+        final int action = event.getAction();
+        switch (action) {
+            case MotionEvent.ACTION_HOVER_ENTER:
+                break;
+
+            case MotionEvent.ACTION_HOVER_MOVE:
+                View newTarget = null;
+
+                // Check what the child under the pointer says about the tooltip.
+                final int childrenCount = mChildrenCount;
+                if (childrenCount != 0) {
+                    final float x = event.getX();
+                    final float y = event.getY();
+
+                    final ArrayList<View> preorderedList = buildOrderedChildList();
+                    final boolean customOrder = preorderedList == null
+                            && isChildrenDrawingOrderEnabled();
+                    final View[] children = mChildren;
+                    for (int i = childrenCount - 1; i >= 0; i--) {
+                        final int childIndex =
+                                getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+                        final View child =
+                                getAndVerifyPreorderedView(preorderedList, children, childIndex);
+                        if (!canViewReceivePointerEvents(child)
+                                || !isTransformedTouchPointInView(x, y, child, null)) {
+                            continue;
+                        }
+                        if (dispatchTooltipHoverEvent(event, child)) {
+                            newTarget = child;
+                            break;
+                        }
+                    }
+                    if (preorderedList != null) preorderedList.clear();
+                }
+
+                if (mTooltipHoverTarget != newTarget) {
+                    if (mTooltipHoverTarget != null) {
+                        event.setAction(MotionEvent.ACTION_HOVER_EXIT);
+                        mTooltipHoverTarget.dispatchTooltipHoverEvent(event);
+                        event.setAction(action);
+                    }
+                    mTooltipHoverTarget = newTarget;
+                }
+
+                if (mTooltipHoverTarget != null) {
+                    if (mTooltipHoveredSelf) {
+                        mTooltipHoveredSelf = false;
+                        event.setAction(MotionEvent.ACTION_HOVER_EXIT);
+                        super.dispatchTooltipHoverEvent(event);
+                        event.setAction(action);
+                    }
+                    return true;
+                }
+
+                mTooltipHoveredSelf = super.dispatchTooltipHoverEvent(event);
+                return mTooltipHoveredSelf;
+
+            case MotionEvent.ACTION_HOVER_EXIT:
+                if (mTooltipHoverTarget != null) {
+                    mTooltipHoverTarget.dispatchTooltipHoverEvent(event);
+                    mTooltipHoverTarget = null;
+                } else if (mTooltipHoveredSelf) {
+                    super.dispatchTooltipHoverEvent(event);
+                    mTooltipHoveredSelf = false;
+                }
+                break;
+        }
+        return false;
+    }
+
+    private boolean dispatchTooltipHoverEvent(MotionEvent event, View child) {
+        final boolean result;
+        if (!child.hasIdentityMatrix()) {
+            MotionEvent transformedEvent = getTransformedMotionEvent(event, child);
+            result = child.dispatchTooltipHoverEvent(transformedEvent);
+            transformedEvent.recycle();
+        } else {
+            final float offsetX = mScrollX - child.mLeft;
+            final float offsetY = mScrollY - child.mTop;
+            event.offsetLocation(offsetX, offsetY);
+            result = child.dispatchTooltipHoverEvent(event);
+            event.offsetLocation(-offsetX, -offsetY);
+        }
+        return result;
+    }
+
+    private void exitTooltipHoverTargets() {
+        if (mTooltipHoveredSelf || mTooltipHoverTarget != null) {
+            final long now = SystemClock.uptimeMillis();
+            MotionEvent event = MotionEvent.obtain(now, now,
+                    MotionEvent.ACTION_HOVER_EXIT, 0.0f, 0.0f, 0);
+            event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+            dispatchTooltipHoverEvent(event);
+            event.recycle();
+        }
+    }
+
+    /** @hide */
+    @Override
+    protected boolean hasHoveredChild() {
+        return mFirstHoverTarget != null;
+    }
+
+    @Override
+    public void addChildrenForAccessibility(ArrayList<View> outChildren) {
+        if (getAccessibilityNodeProvider() != null) {
+            return;
+        }
+        ChildListForAccessibility children = ChildListForAccessibility.obtain(this, true);
+        try {
+            final int childrenCount = children.getChildCount();
+            for (int i = 0; i < childrenCount; i++) {
+                View child = children.getChildAt(i);
+                if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                    if (child.includeForAccessibility()) {
+                        outChildren.add(child);
+                    } else {
+                        child.addChildrenForAccessibility(outChildren);
+                    }
+                }
+            }
+        } finally {
+            children.recycle();
+        }
+    }
+
+    /**
+     * Implement this method to intercept hover events before they are handled
+     * by child views.
+     * <p>
+     * This method is called before dispatching a hover event to a child of
+     * the view group or to the view group's own {@link #onHoverEvent} to allow
+     * the view group a chance to intercept the hover event.
+     * This method can also be used to watch all pointer motions that occur within
+     * the bounds of the view group even when the pointer is hovering over
+     * a child of the view group rather than over the view group itself.
+     * </p><p>
+     * The view group can prevent its children from receiving hover events by
+     * implementing this method and returning <code>true</code> to indicate
+     * that it would like to intercept hover events.  The view group must
+     * continuously return <code>true</code> from {@link #onInterceptHoverEvent}
+     * for as long as it wishes to continue intercepting hover events from
+     * its children.
+     * </p><p>
+     * Interception preserves the invariant that at most one view can be
+     * hovered at a time by transferring hover focus from the currently hovered
+     * child to the view group or vice-versa as needed.
+     * </p><p>
+     * If this method returns <code>true</code> and a child is already hovered, then the
+     * child view will first receive a hover exit event and then the view group
+     * itself will receive a hover enter event in {@link #onHoverEvent}.
+     * Likewise, if this method had previously returned <code>true</code> to intercept hover
+     * events and instead returns <code>false</code> while the pointer is hovering
+     * within the bounds of one of a child, then the view group will first receive a
+     * hover exit event in {@link #onHoverEvent} and then the hovered child will
+     * receive a hover enter event.
+     * </p><p>
+     * The default implementation handles mouse hover on the scroll bars.
+     * </p>
+     *
+     * @param event The motion event that describes the hover.
+     * @return True if the view group would like to intercept the hover event
+     * and prevent its children from receiving it.
+     */
+    public boolean onInterceptHoverEvent(MotionEvent event) {
+        if (event.isFromSource(InputDevice.SOURCE_MOUSE)) {
+            final int action = event.getAction();
+            final float x = event.getX();
+            final float y = event.getY();
+            if ((action == MotionEvent.ACTION_HOVER_MOVE
+                    || action == MotionEvent.ACTION_HOVER_ENTER) && isOnScrollbar(x, y)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static MotionEvent obtainMotionEventNoHistoryOrSelf(MotionEvent event) {
+        if (event.getHistorySize() == 0) {
+            return event;
+        }
+        return MotionEvent.obtainNoHistory(event);
+    }
+
+    @Override
+    protected boolean dispatchGenericPointerEvent(MotionEvent event) {
+        // Send the event to the child under the pointer.
+        final int childrenCount = mChildrenCount;
+        if (childrenCount != 0) {
+            final float x = event.getX();
+            final float y = event.getY();
+
+            final ArrayList<View> preorderedList = buildOrderedChildList();
+            final boolean customOrder = preorderedList == null
+                    && isChildrenDrawingOrderEnabled();
+            final View[] children = mChildren;
+            for (int i = childrenCount - 1; i >= 0; i--) {
+                final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+                final View child = getAndVerifyPreorderedView(preorderedList, children, childIndex);
+                if (!canViewReceivePointerEvents(child)
+                        || !isTransformedTouchPointInView(x, y, child, null)) {
+                    continue;
+                }
+
+                if (dispatchTransformedGenericPointerEvent(event, child)) {
+                    if (preorderedList != null) preorderedList.clear();
+                    return true;
+                }
+            }
+            if (preorderedList != null) preorderedList.clear();
+        }
+
+        // No child handled the event.  Send it to this view group.
+        return super.dispatchGenericPointerEvent(event);
+    }
+
+    @Override
+    protected boolean dispatchGenericFocusedEvent(MotionEvent event) {
+        // Send the event to the focused child or to this view group if it has focus.
+        if ((mPrivateFlags & (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS))
+                == (PFLAG_FOCUSED | PFLAG_HAS_BOUNDS)) {
+            return super.dispatchGenericFocusedEvent(event);
+        } else if (mFocused != null && (mFocused.mPrivateFlags & PFLAG_HAS_BOUNDS)
+                == PFLAG_HAS_BOUNDS) {
+            return mFocused.dispatchGenericMotionEvent(event);
+        }
+        return false;
+    }
+
+    /**
+     * Dispatches a generic pointer event to a child, taking into account
+     * transformations that apply to the child.
+     *
+     * @param event The event to send.
+     * @param child The view to send the event to.
+     * @return {@code true} if the child handled the event.
+     */
+    private boolean dispatchTransformedGenericPointerEvent(MotionEvent event, View child) {
+        boolean handled;
+        if (!child.hasIdentityMatrix()) {
+            MotionEvent transformedEvent = getTransformedMotionEvent(event, child);
+            handled = child.dispatchGenericMotionEvent(transformedEvent);
+            transformedEvent.recycle();
+        } else {
+            final float offsetX = mScrollX - child.mLeft;
+            final float offsetY = mScrollY - child.mTop;
+            event.offsetLocation(offsetX, offsetY);
+            handled = child.dispatchGenericMotionEvent(event);
+            event.offsetLocation(-offsetX, -offsetY);
+        }
+        return handled;
+    }
+
+    /**
+     * Returns a MotionEvent that's been transformed into the child's local coordinates.
+     *
+     * It's the responsibility of the caller to recycle it once they're finished with it.
+     * @param event The event to transform.
+     * @param child The view whose coordinate space is to be used.
+     * @return A copy of the the given MotionEvent, transformed into the given View's coordinate
+     *         space.
+     */
+    private MotionEvent getTransformedMotionEvent(MotionEvent event, View child) {
+        final float offsetX = mScrollX - child.mLeft;
+        final float offsetY = mScrollY - child.mTop;
+        final MotionEvent transformedEvent = MotionEvent.obtain(event);
+        transformedEvent.offsetLocation(offsetX, offsetY);
+        if (!child.hasIdentityMatrix()) {
+            transformedEvent.transform(child.getInverseMatrix());
+        }
+        return transformedEvent;
+    }
+
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent ev) {
+        if (mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onTouchEvent(ev, 1);
+        }
+
+        // If the event targets the accessibility focused view and this is it, start
+        // normal event dispatch. Maybe a descendant is what will handle the click.
+        if (ev.isTargetAccessibilityFocus() && isAccessibilityFocusedViewOrHost()) {
+            ev.setTargetAccessibilityFocus(false);
+        }
+
+        boolean handled = false;
+        if (onFilterTouchEventForSecurity(ev)) {
+            final int action = ev.getAction();
+            final int actionMasked = action & MotionEvent.ACTION_MASK;
+
+            // Handle an initial down.
+            if (actionMasked == MotionEvent.ACTION_DOWN) {
+                // Throw away all previous state when starting a new touch gesture.
+                // The framework may have dropped the up or cancel event for the previous gesture
+                // due to an app switch, ANR, or some other state change.
+                cancelAndClearTouchTargets(ev);
+                resetTouchState();
+            }
+
+            // Check for interception.
+            final boolean intercepted;
+            if (actionMasked == MotionEvent.ACTION_DOWN
+                    || mFirstTouchTarget != null) {
+                final boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0;
+                if (!disallowIntercept) {
+                    intercepted = onInterceptTouchEvent(ev);
+                    ev.setAction(action); // restore action in case it was changed
+                } else {
+                    intercepted = false;
+                }
+            } else {
+                // There are no touch targets and this action is not an initial down
+                // so this view group continues to intercept touches.
+                intercepted = true;
+            }
+
+            // If intercepted, start normal event dispatch. Also if there is already
+            // a view that is handling the gesture, do normal event dispatch.
+            if (intercepted || mFirstTouchTarget != null) {
+                ev.setTargetAccessibilityFocus(false);
+            }
+
+            // Check for cancelation.
+            final boolean canceled = resetCancelNextUpFlag(this)
+                    || actionMasked == MotionEvent.ACTION_CANCEL;
+
+            // Update list of touch targets for pointer down, if needed.
+            final boolean split = (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) != 0;
+            TouchTarget newTouchTarget = null;
+            boolean alreadyDispatchedToNewTouchTarget = false;
+            if (!canceled && !intercepted) {
+
+                // If the event is targeting accessiiblity focus we give it to the
+                // view that has accessibility focus and if it does not handle it
+                // we clear the flag and dispatch the event to all children as usual.
+                // We are looking up the accessibility focused host to avoid keeping
+                // state since these events are very rare.
+                View childWithAccessibilityFocus = ev.isTargetAccessibilityFocus()
+                        ? findChildWithAccessibilityFocus() : null;
+
+                if (actionMasked == MotionEvent.ACTION_DOWN
+                        || (split && actionMasked == MotionEvent.ACTION_POINTER_DOWN)
+                        || actionMasked == MotionEvent.ACTION_HOVER_MOVE) {
+                    final int actionIndex = ev.getActionIndex(); // always 0 for down
+                    final int idBitsToAssign = split ? 1 << ev.getPointerId(actionIndex)
+                            : TouchTarget.ALL_POINTER_IDS;
+
+                    // Clean up earlier touch targets for this pointer id in case they
+                    // have become out of sync.
+                    removePointersFromTouchTargets(idBitsToAssign);
+
+                    final int childrenCount = mChildrenCount;
+                    if (newTouchTarget == null && childrenCount != 0) {
+                        final float x = ev.getX(actionIndex);
+                        final float y = ev.getY(actionIndex);
+                        // Find a child that can receive the event.
+                        // Scan children from front to back.
+                        final ArrayList<View> preorderedList = buildTouchDispatchChildList();
+                        final boolean customOrder = preorderedList == null
+                                && isChildrenDrawingOrderEnabled();
+                        final View[] children = mChildren;
+                        for (int i = childrenCount - 1; i >= 0; i--) {
+                            final int childIndex = getAndVerifyPreorderedIndex(
+                                    childrenCount, i, customOrder);
+                            final View child = getAndVerifyPreorderedView(
+                                    preorderedList, children, childIndex);
+
+                            // If there is a view that has accessibility focus we want it
+                            // to get the event first and if not handled we will perform a
+                            // normal dispatch. We may do a double iteration but this is
+                            // safer given the timeframe.
+                            if (childWithAccessibilityFocus != null) {
+                                if (childWithAccessibilityFocus != child) {
+                                    continue;
+                                }
+                                childWithAccessibilityFocus = null;
+                                i = childrenCount - 1;
+                            }
+
+                            if (!canViewReceivePointerEvents(child)
+                                    || !isTransformedTouchPointInView(x, y, child, null)) {
+                                ev.setTargetAccessibilityFocus(false);
+                                continue;
+                            }
+
+                            newTouchTarget = getTouchTarget(child);
+                            if (newTouchTarget != null) {
+                                // Child is already receiving touch within its bounds.
+                                // Give it the new pointer in addition to the ones it is handling.
+                                newTouchTarget.pointerIdBits |= idBitsToAssign;
+                                break;
+                            }
+
+                            resetCancelNextUpFlag(child);
+                            if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) {
+                                // Child wants to receive touch within its bounds.
+                                mLastTouchDownTime = ev.getDownTime();
+                                if (preorderedList != null) {
+                                    // childIndex points into presorted list, find original index
+                                    for (int j = 0; j < childrenCount; j++) {
+                                        if (children[childIndex] == mChildren[j]) {
+                                            mLastTouchDownIndex = j;
+                                            break;
+                                        }
+                                    }
+                                } else {
+                                    mLastTouchDownIndex = childIndex;
+                                }
+                                mLastTouchDownX = ev.getX();
+                                mLastTouchDownY = ev.getY();
+                                newTouchTarget = addTouchTarget(child, idBitsToAssign);
+                                alreadyDispatchedToNewTouchTarget = true;
+                                break;
+                            }
+
+                            // The accessibility focus didn't handle the event, so clear
+                            // the flag and do a normal dispatch to all children.
+                            ev.setTargetAccessibilityFocus(false);
+                        }
+                        if (preorderedList != null) preorderedList.clear();
+                    }
+
+                    if (newTouchTarget == null && mFirstTouchTarget != null) {
+                        // Did not find a child to receive the event.
+                        // Assign the pointer to the least recently added target.
+                        newTouchTarget = mFirstTouchTarget;
+                        while (newTouchTarget.next != null) {
+                            newTouchTarget = newTouchTarget.next;
+                        }
+                        newTouchTarget.pointerIdBits |= idBitsToAssign;
+                    }
+                }
+            }
+
+            // Dispatch to touch targets.
+            if (mFirstTouchTarget == null) {
+                // No touch targets so treat this as an ordinary view.
+                handled = dispatchTransformedTouchEvent(ev, canceled, null,
+                        TouchTarget.ALL_POINTER_IDS);
+            } else {
+                // Dispatch to touch targets, excluding the new touch target if we already
+                // dispatched to it.  Cancel touch targets if necessary.
+                TouchTarget predecessor = null;
+                TouchTarget target = mFirstTouchTarget;
+                while (target != null) {
+                    final TouchTarget next = target.next;
+                    if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) {
+                        handled = true;
+                    } else {
+                        final boolean cancelChild = resetCancelNextUpFlag(target.child)
+                                || intercepted;
+                        if (dispatchTransformedTouchEvent(ev, cancelChild,
+                                target.child, target.pointerIdBits)) {
+                            handled = true;
+                        }
+                        if (cancelChild) {
+                            if (predecessor == null) {
+                                mFirstTouchTarget = next;
+                            } else {
+                                predecessor.next = next;
+                            }
+                            target.recycle();
+                            target = next;
+                            continue;
+                        }
+                    }
+                    predecessor = target;
+                    target = next;
+                }
+            }
+
+            // Update list of touch targets for pointer up or cancel, if needed.
+            if (canceled
+                    || actionMasked == MotionEvent.ACTION_UP
+                    || actionMasked == MotionEvent.ACTION_HOVER_MOVE) {
+                resetTouchState();
+            } else if (split && actionMasked == MotionEvent.ACTION_POINTER_UP) {
+                final int actionIndex = ev.getActionIndex();
+                final int idBitsToRemove = 1 << ev.getPointerId(actionIndex);
+                removePointersFromTouchTargets(idBitsToRemove);
+            }
+        }
+
+        if (!handled && mInputEventConsistencyVerifier != null) {
+            mInputEventConsistencyVerifier.onUnhandledEvent(ev, 1);
+        }
+        return handled;
+    }
+
+    /**
+     * Provide custom ordering of views in which the touch will be dispatched.
+     *
+     * This is called within a tight loop, so you are not allowed to allocate objects, including
+     * the return array. Instead, you should return a pre-allocated list that will be cleared
+     * after the dispatch is finished.
+     * @hide
+     */
+    public ArrayList<View> buildTouchDispatchChildList() {
+        return buildOrderedChildList();
+    }
+
+    /**
+     * Finds the child which has accessibility focus.
+     *
+     * @return The child that has focus.
+     */
+    private View findChildWithAccessibilityFocus() {
+        ViewRootImpl viewRoot = getViewRootImpl();
+        if (viewRoot == null) {
+            return null;
+        }
+
+        View current = viewRoot.getAccessibilityFocusedHost();
+        if (current == null) {
+            return null;
+        }
+
+        ViewParent parent = current.getParent();
+        while (parent instanceof View) {
+            if (parent == this) {
+                return current;
+            }
+            current = (View) parent;
+            parent = current.getParent();
+        }
+
+        return null;
+    }
+
+    /**
+     * Resets all touch state in preparation for a new cycle.
+     */
+    private void resetTouchState() {
+        clearTouchTargets();
+        resetCancelNextUpFlag(this);
+        mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
+        mNestedScrollAxes = SCROLL_AXIS_NONE;
+    }
+
+    /**
+     * Resets the cancel next up flag.
+     * Returns true if the flag was previously set.
+     */
+    private static boolean resetCancelNextUpFlag(@NonNull View view) {
+        if ((view.mPrivateFlags & PFLAG_CANCEL_NEXT_UP_EVENT) != 0) {
+            view.mPrivateFlags &= ~PFLAG_CANCEL_NEXT_UP_EVENT;
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Clears all touch targets.
+     */
+    private void clearTouchTargets() {
+        TouchTarget target = mFirstTouchTarget;
+        if (target != null) {
+            do {
+                TouchTarget next = target.next;
+                target.recycle();
+                target = next;
+            } while (target != null);
+            mFirstTouchTarget = null;
+        }
+    }
+
+    /**
+     * Cancels and clears all touch targets.
+     */
+    private void cancelAndClearTouchTargets(MotionEvent event) {
+        if (mFirstTouchTarget != null) {
+            boolean syntheticEvent = false;
+            if (event == null) {
+                final long now = SystemClock.uptimeMillis();
+                event = MotionEvent.obtain(now, now,
+                        MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
+                event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+                syntheticEvent = true;
+            }
+
+            for (TouchTarget target = mFirstTouchTarget; target != null; target = target.next) {
+                resetCancelNextUpFlag(target.child);
+                dispatchTransformedTouchEvent(event, true, target.child, target.pointerIdBits);
+            }
+            clearTouchTargets();
+
+            if (syntheticEvent) {
+                event.recycle();
+            }
+        }
+    }
+
+    /**
+     * Gets the touch target for specified child view.
+     * Returns null if not found.
+     */
+    private TouchTarget getTouchTarget(@NonNull View child) {
+        for (TouchTarget target = mFirstTouchTarget; target != null; target = target.next) {
+            if (target.child == child) {
+                return target;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Adds a touch target for specified child to the beginning of the list.
+     * Assumes the target child is not already present.
+     */
+    private TouchTarget addTouchTarget(@NonNull View child, int pointerIdBits) {
+        final TouchTarget target = TouchTarget.obtain(child, pointerIdBits);
+        target.next = mFirstTouchTarget;
+        mFirstTouchTarget = target;
+        return target;
+    }
+
+    /**
+     * Removes the pointer ids from consideration.
+     */
+    private void removePointersFromTouchTargets(int pointerIdBits) {
+        TouchTarget predecessor = null;
+        TouchTarget target = mFirstTouchTarget;
+        while (target != null) {
+            final TouchTarget next = target.next;
+            if ((target.pointerIdBits & pointerIdBits) != 0) {
+                target.pointerIdBits &= ~pointerIdBits;
+                if (target.pointerIdBits == 0) {
+                    if (predecessor == null) {
+                        mFirstTouchTarget = next;
+                    } else {
+                        predecessor.next = next;
+                    }
+                    target.recycle();
+                    target = next;
+                    continue;
+                }
+            }
+            predecessor = target;
+            target = next;
+        }
+    }
+
+    private void cancelTouchTarget(View view) {
+        TouchTarget predecessor = null;
+        TouchTarget target = mFirstTouchTarget;
+        while (target != null) {
+            final TouchTarget next = target.next;
+            if (target.child == view) {
+                if (predecessor == null) {
+                    mFirstTouchTarget = next;
+                } else {
+                    predecessor.next = next;
+                }
+                target.recycle();
+
+                final long now = SystemClock.uptimeMillis();
+                MotionEvent event = MotionEvent.obtain(now, now,
+                        MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
+                event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+                view.dispatchTouchEvent(event);
+                event.recycle();
+                return;
+            }
+            predecessor = target;
+            target = next;
+        }
+    }
+
+    /**
+     * Returns true if a child view can receive pointer events.
+     * @hide
+     */
+    private static boolean canViewReceivePointerEvents(@NonNull View child) {
+        return (child.mViewFlags & VISIBILITY_MASK) == VISIBLE
+                || child.getAnimation() != null;
+    }
+
+    private float[] getTempPoint() {
+        if (mTempPoint == null) {
+            mTempPoint = new float[2];
+        }
+        return mTempPoint;
+    }
+
+    /**
+     * Returns true if a child view contains the specified point when transformed
+     * into its coordinate space.
+     * Child must not be null.
+     * @hide
+     */
+    protected boolean isTransformedTouchPointInView(float x, float y, View child,
+            PointF outLocalPoint) {
+        final float[] point = getTempPoint();
+        point[0] = x;
+        point[1] = y;
+        transformPointToViewLocal(point, child);
+        final boolean isInView = child.pointInView(point[0], point[1]);
+        if (isInView && outLocalPoint != null) {
+            outLocalPoint.set(point[0], point[1]);
+        }
+        return isInView;
+    }
+
+    /**
+     * @hide
+     */
+    public void transformPointToViewLocal(float[] point, View child) {
+        point[0] += mScrollX - child.mLeft;
+        point[1] += mScrollY - child.mTop;
+
+        if (!child.hasIdentityMatrix()) {
+            child.getInverseMatrix().mapPoints(point);
+        }
+    }
+
+    /**
+     * Transforms a motion event into the coordinate space of a particular child view,
+     * filters out irrelevant pointer ids, and overrides its action if necessary.
+     * If child is null, assumes the MotionEvent will be sent to this ViewGroup instead.
+     */
+    private boolean dispatchTransformedTouchEvent(MotionEvent event, boolean cancel,
+            View child, int desiredPointerIdBits) {
+        final boolean handled;
+
+        // Canceling motions is a special case.  We don't need to perform any transformations
+        // or filtering.  The important part is the action, not the contents.
+        final int oldAction = event.getAction();
+        if (cancel || oldAction == MotionEvent.ACTION_CANCEL) {
+            event.setAction(MotionEvent.ACTION_CANCEL);
+            if (child == null) {
+                handled = super.dispatchTouchEvent(event);
+            } else {
+                handled = child.dispatchTouchEvent(event);
+            }
+            event.setAction(oldAction);
+            return handled;
+        }
+
+        // Calculate the number of pointers to deliver.
+        final int oldPointerIdBits = event.getPointerIdBits();
+        final int newPointerIdBits = oldPointerIdBits & desiredPointerIdBits;
+
+        // If for some reason we ended up in an inconsistent state where it looks like we
+        // might produce a motion event with no pointers in it, then drop the event.
+        if (newPointerIdBits == 0) {
+            return false;
+        }
+
+        // If the number of pointers is the same and we don't need to perform any fancy
+        // irreversible transformations, then we can reuse the motion event for this
+        // dispatch as long as we are careful to revert any changes we make.
+        // Otherwise we need to make a copy.
+        final MotionEvent transformedEvent;
+        if (newPointerIdBits == oldPointerIdBits) {
+            if (child == null || child.hasIdentityMatrix()) {
+                if (child == null) {
+                    handled = super.dispatchTouchEvent(event);
+                } else {
+                    final float offsetX = mScrollX - child.mLeft;
+                    final float offsetY = mScrollY - child.mTop;
+                    event.offsetLocation(offsetX, offsetY);
+
+                    handled = child.dispatchTouchEvent(event);
+
+                    event.offsetLocation(-offsetX, -offsetY);
+                }
+                return handled;
+            }
+            transformedEvent = MotionEvent.obtain(event);
+        } else {
+            transformedEvent = event.split(newPointerIdBits);
+        }
+
+        // Perform any necessary transformations and dispatch.
+        if (child == null) {
+            handled = super.dispatchTouchEvent(transformedEvent);
+        } else {
+            final float offsetX = mScrollX - child.mLeft;
+            final float offsetY = mScrollY - child.mTop;
+            transformedEvent.offsetLocation(offsetX, offsetY);
+            if (! child.hasIdentityMatrix()) {
+                transformedEvent.transform(child.getInverseMatrix());
+            }
+
+            handled = child.dispatchTouchEvent(transformedEvent);
+        }
+
+        // Done.
+        transformedEvent.recycle();
+        return handled;
+    }
+
+    /**
+     * Enable or disable the splitting of MotionEvents to multiple children during touch event
+     * dispatch. This behavior is enabled by default for applications that target an
+     * SDK version of {@link Build.VERSION_CODES#HONEYCOMB} or newer.
+     *
+     * <p>When this option is enabled MotionEvents may be split and dispatched to different child
+     * views depending on where each pointer initially went down. This allows for user interactions
+     * such as scrolling two panes of content independently, chording of buttons, and performing
+     * independent gestures on different pieces of content.
+     *
+     * @param split <code>true</code> to allow MotionEvents to be split and dispatched to multiple
+     *              child views. <code>false</code> to only allow one child view to be the target of
+     *              any MotionEvent received by this ViewGroup.
+     * @attr ref android.R.styleable#ViewGroup_splitMotionEvents
+     */
+    public void setMotionEventSplittingEnabled(boolean split) {
+        // TODO Applications really shouldn't change this setting mid-touch event,
+        // but perhaps this should handle that case and send ACTION_CANCELs to any child views
+        // with gestures in progress when this is changed.
+        if (split) {
+            mGroupFlags |= FLAG_SPLIT_MOTION_EVENTS;
+        } else {
+            mGroupFlags &= ~FLAG_SPLIT_MOTION_EVENTS;
+        }
+    }
+
+    /**
+     * Returns true if MotionEvents dispatched to this ViewGroup can be split to multiple children.
+     * @return true if MotionEvents dispatched to this ViewGroup can be split to multiple children.
+     */
+    public boolean isMotionEventSplittingEnabled() {
+        return (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) == FLAG_SPLIT_MOTION_EVENTS;
+    }
+
+    /**
+     * Returns true if this ViewGroup should be considered as a single entity for removal
+     * when executing an Activity transition. If this is false, child elements will move
+     * individually during the transition.
+     *
+     * @return True if the ViewGroup should be acted on together during an Activity transition.
+     * The default value is true when there is a non-null background or if
+     * {@link #getTransitionName()} is not null or if a
+     * non-null {@link android.view.ViewOutlineProvider} other than
+     * {@link android.view.ViewOutlineProvider#BACKGROUND} was given to
+     * {@link #setOutlineProvider(ViewOutlineProvider)} and false otherwise.
+     */
+    public boolean isTransitionGroup() {
+        if ((mGroupFlags & FLAG_IS_TRANSITION_GROUP_SET) != 0) {
+            return ((mGroupFlags & FLAG_IS_TRANSITION_GROUP) != 0);
+        } else {
+            final ViewOutlineProvider outlineProvider = getOutlineProvider();
+            return getBackground() != null || getTransitionName() != null ||
+                    (outlineProvider != null && outlineProvider != ViewOutlineProvider.BACKGROUND);
+        }
+    }
+
+    /**
+     * Changes whether or not this ViewGroup should be treated as a single entity during
+     * Activity Transitions.
+     * @param isTransitionGroup Whether or not the ViewGroup should be treated as a unit
+     *                          in Activity transitions. If false, the ViewGroup won't transition,
+     *                          only its children. If true, the entire ViewGroup will transition
+     *                          together.
+     * @see android.app.ActivityOptions#makeSceneTransitionAnimation(android.app.Activity,
+     * android.util.Pair[])
+     */
+    public void setTransitionGroup(boolean isTransitionGroup) {
+        mGroupFlags |= FLAG_IS_TRANSITION_GROUP_SET;
+        if (isTransitionGroup) {
+            mGroupFlags |= FLAG_IS_TRANSITION_GROUP;
+        } else {
+            mGroupFlags &= ~FLAG_IS_TRANSITION_GROUP;
+        }
+    }
+
+    @Override
+    public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
+
+        if (disallowIntercept == ((mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0)) {
+            // We're already in this state, assume our ancestors are too
+            return;
+        }
+
+        if (disallowIntercept) {
+            mGroupFlags |= FLAG_DISALLOW_INTERCEPT;
+        } else {
+            mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
+        }
+
+        // Pass it up to our parent
+        if (mParent != null) {
+            mParent.requestDisallowInterceptTouchEvent(disallowIntercept);
+        }
+    }
+
+    /**
+     * Implement this method to intercept all touch screen motion events.  This
+     * allows you to watch events as they are dispatched to your children, and
+     * take ownership of the current gesture at any point.
+     *
+     * <p>Using this function takes some care, as it has a fairly complicated
+     * interaction with {@link View#onTouchEvent(MotionEvent)
+     * View.onTouchEvent(MotionEvent)}, and using it requires implementing
+     * that method as well as this one in the correct way.  Events will be
+     * received in the following order:
+     *
+     * <ol>
+     * <li> You will receive the down event here.
+     * <li> The down event will be handled either by a child of this view
+     * group, or given to your own onTouchEvent() method to handle; this means
+     * you should implement onTouchEvent() to return true, so you will
+     * continue to see the rest of the gesture (instead of looking for
+     * a parent view to handle it).  Also, by returning true from
+     * onTouchEvent(), you will not receive any following
+     * events in onInterceptTouchEvent() and all touch processing must
+     * happen in onTouchEvent() like normal.
+     * <li> For as long as you return false from this function, each following
+     * event (up to and including the final up) will be delivered first here
+     * and then to the target's onTouchEvent().
+     * <li> If you return true from here, you will not receive any
+     * following events: the target view will receive the same event but
+     * with the action {@link MotionEvent#ACTION_CANCEL}, and all further
+     * events will be delivered to your onTouchEvent() method and no longer
+     * appear here.
+     * </ol>
+     *
+     * @param ev The motion event being dispatched down the hierarchy.
+     * @return Return true to steal motion events from the children and have
+     * them dispatched to this ViewGroup through onTouchEvent().
+     * The current target will receive an ACTION_CANCEL event, and no further
+     * messages will be delivered here.
+     */
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        if (ev.isFromSource(InputDevice.SOURCE_MOUSE)
+                && ev.getAction() == MotionEvent.ACTION_DOWN
+                && ev.isButtonPressed(MotionEvent.BUTTON_PRIMARY)
+                && isOnScrollbarThumb(ev.getX(), ev.getY())) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * Looks for a view to give focus to respecting the setting specified by
+     * {@link #getDescendantFocusability()}.
+     *
+     * Uses {@link #onRequestFocusInDescendants(int, android.graphics.Rect)} to
+     * find focus within the children of this group when appropriate.
+     *
+     * @see #FOCUS_BEFORE_DESCENDANTS
+     * @see #FOCUS_AFTER_DESCENDANTS
+     * @see #FOCUS_BLOCK_DESCENDANTS
+     * @see #onRequestFocusInDescendants(int, android.graphics.Rect)
+     */
+    @Override
+    public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
+        if (DBG) {
+            System.out.println(this + " ViewGroup.requestFocus direction="
+                    + direction);
+        }
+        int descendantFocusability = getDescendantFocusability();
+
+        switch (descendantFocusability) {
+            case FOCUS_BLOCK_DESCENDANTS:
+                return super.requestFocus(direction, previouslyFocusedRect);
+            case FOCUS_BEFORE_DESCENDANTS: {
+                final boolean took = super.requestFocus(direction, previouslyFocusedRect);
+                return took ? took : onRequestFocusInDescendants(direction, previouslyFocusedRect);
+            }
+            case FOCUS_AFTER_DESCENDANTS: {
+                final boolean took = onRequestFocusInDescendants(direction, previouslyFocusedRect);
+                return took ? took : super.requestFocus(direction, previouslyFocusedRect);
+            }
+            default:
+                throw new IllegalStateException("descendant focusability must be "
+                        + "one of FOCUS_BEFORE_DESCENDANTS, FOCUS_AFTER_DESCENDANTS, FOCUS_BLOCK_DESCENDANTS "
+                        + "but is " + descendantFocusability);
+        }
+    }
+
+    /**
+     * Look for a descendant to call {@link View#requestFocus} on.
+     * Called by {@link ViewGroup#requestFocus(int, android.graphics.Rect)}
+     * when it wants to request focus within its children.  Override this to
+     * customize how your {@link ViewGroup} requests focus within its children.
+     * @param direction One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT
+     * @param previouslyFocusedRect The rectangle (in this View's coordinate system)
+     *        to give a finer grained hint about where focus is coming from.  May be null
+     *        if there is no hint.
+     * @return Whether focus was taken.
+     */
+    @SuppressWarnings({"ConstantConditions"})
+    protected boolean onRequestFocusInDescendants(int direction,
+            Rect previouslyFocusedRect) {
+        int index;
+        int increment;
+        int end;
+        int count = mChildrenCount;
+        if ((direction & FOCUS_FORWARD) != 0) {
+            index = 0;
+            increment = 1;
+            end = count;
+        } else {
+            index = count - 1;
+            increment = -1;
+            end = -1;
+        }
+        final View[] children = mChildren;
+        for (int i = index; i != end; i += increment) {
+            View child = children[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                if (child.requestFocus(direction, previouslyFocusedRect)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public boolean restoreDefaultFocus() {
+        if (mDefaultFocus != null
+                && getDescendantFocusability() != FOCUS_BLOCK_DESCENDANTS
+                && (mDefaultFocus.mViewFlags & VISIBILITY_MASK) == VISIBLE
+                && mDefaultFocus.restoreDefaultFocus()) {
+            return true;
+        }
+        return super.restoreDefaultFocus();
+    }
+
+    /**
+     * @hide
+     */
+    @TestApi
+    @Override
+    public boolean restoreFocusInCluster(@FocusRealDirection int direction) {
+        // Allow cluster-navigation to enter touchscreenBlocksFocus ViewGroups.
+        if (isKeyboardNavigationCluster()) {
+            final boolean blockedFocus = getTouchscreenBlocksFocus();
+            try {
+                setTouchscreenBlocksFocusNoRefocus(false);
+                return restoreFocusInClusterInternal(direction);
+            } finally {
+                setTouchscreenBlocksFocusNoRefocus(blockedFocus);
+            }
+        } else {
+            return restoreFocusInClusterInternal(direction);
+        }
+    }
+
+    private boolean restoreFocusInClusterInternal(@FocusRealDirection int direction) {
+        if (mFocusedInCluster != null && getDescendantFocusability() != FOCUS_BLOCK_DESCENDANTS
+                && (mFocusedInCluster.mViewFlags & VISIBILITY_MASK) == VISIBLE
+                && mFocusedInCluster.restoreFocusInCluster(direction)) {
+            return true;
+        }
+        return super.restoreFocusInCluster(direction);
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean restoreFocusNotInCluster() {
+        if (mFocusedInCluster != null) {
+            // since clusters don't nest; we can assume that a non-null mFocusedInCluster
+            // will refer to a view not-in a cluster.
+            return restoreFocusInCluster(View.FOCUS_DOWN);
+        }
+        if (isKeyboardNavigationCluster() || (mViewFlags & VISIBILITY_MASK) != VISIBLE) {
+            return false;
+        }
+        int descendentFocusability = getDescendantFocusability();
+        if (descendentFocusability == FOCUS_BLOCK_DESCENDANTS) {
+            return super.requestFocus(FOCUS_DOWN, null);
+        }
+        if (descendentFocusability == FOCUS_BEFORE_DESCENDANTS
+                && super.requestFocus(FOCUS_DOWN, null)) {
+            return true;
+        }
+        for (int i = 0; i < mChildrenCount; ++i) {
+            View child = mChildren[i];
+            if (!child.isKeyboardNavigationCluster()
+                    && child.restoreFocusNotInCluster()) {
+                return true;
+            }
+        }
+        if (descendentFocusability == FOCUS_AFTER_DESCENDANTS && !hasFocusableChild(false)) {
+            return super.requestFocus(FOCUS_DOWN, null);
+        }
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @hide
+     */
+    @Override
+    public void dispatchStartTemporaryDetach() {
+        super.dispatchStartTemporaryDetach();
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchStartTemporaryDetach();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @hide
+     */
+    @Override
+    public void dispatchFinishTemporaryDetach() {
+        super.dispatchFinishTemporaryDetach();
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchFinishTemporaryDetach();
+        }
+    }
+
+    @Override
+    void dispatchAttachedToWindow(AttachInfo info, int visibility) {
+        mGroupFlags |= FLAG_PREVENT_DISPATCH_ATTACHED_TO_WINDOW;
+        super.dispatchAttachedToWindow(info, visibility);
+        mGroupFlags &= ~FLAG_PREVENT_DISPATCH_ATTACHED_TO_WINDOW;
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+            child.dispatchAttachedToWindow(info,
+                    combineVisibility(visibility, child.getVisibility()));
+        }
+        final int transientCount = mTransientIndices == null ? 0 : mTransientIndices.size();
+        for (int i = 0; i < transientCount; ++i) {
+            View view = mTransientViews.get(i);
+            view.dispatchAttachedToWindow(info,
+                    combineVisibility(visibility, view.getVisibility()));
+        }
+    }
+
+    @Override
+    void dispatchScreenStateChanged(int screenState) {
+        super.dispatchScreenStateChanged(screenState);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchScreenStateChanged(screenState);
+        }
+    }
+
+    @Override
+    void dispatchMovedToDisplay(Display display, Configuration config) {
+        super.dispatchMovedToDisplay(display, config);
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchMovedToDisplay(display, config);
+        }
+    }
+
+    /** @hide */
+    @Override
+    public boolean dispatchPopulateAccessibilityEventInternal(AccessibilityEvent event) {
+        boolean handled = false;
+        if (includeForAccessibility()) {
+            handled = super.dispatchPopulateAccessibilityEventInternal(event);
+            if (handled) {
+                return handled;
+            }
+        }
+        // Let our children have a shot in populating the event.
+        ChildListForAccessibility children = ChildListForAccessibility.obtain(this, true);
+        try {
+            final int childCount = children.getChildCount();
+            for (int i = 0; i < childCount; i++) {
+                View child = children.getChildAt(i);
+                if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                    handled = child.dispatchPopulateAccessibilityEvent(event);
+                    if (handled) {
+                        return handled;
+                    }
+                }
+            }
+        } finally {
+            children.recycle();
+        }
+        return false;
+    }
+
+    /**
+     * Dispatch creation of {@link ViewStructure} down the hierarchy.  This implementation
+     * adds in all child views of the view group, in addition to calling the default View
+     * implementation.
+     */
+    @Override
+    public void dispatchProvideStructure(ViewStructure structure) {
+        super.dispatchProvideStructure(structure);
+        if (isAssistBlocked() || structure.getChildCount() != 0) {
+            return;
+        }
+        final int childrenCount = mChildrenCount;
+        if (childrenCount <= 0) {
+            return;
+        }
+
+        if (!isLaidOut()) {
+            Log.v(VIEW_LOG_TAG, "dispatchProvideStructure(): not laid out, ignoring "
+                    + childrenCount + " children of " + getAccessibilityViewId());
+            return;
+        }
+
+        structure.setChildCount(childrenCount);
+        ArrayList<View> preorderedList = buildOrderedChildList();
+        boolean customOrder = preorderedList == null
+                && isChildrenDrawingOrderEnabled();
+        for (int i = 0; i < childrenCount; i++) {
+            int childIndex;
+            try {
+                childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+            } catch (IndexOutOfBoundsException e) {
+                childIndex = i;
+                if (mContext.getApplicationInfo().targetSdkVersion < Build.VERSION_CODES.M) {
+                    Log.w(TAG, "Bad getChildDrawingOrder while collecting assist @ "
+                            + i + " of " + childrenCount, e);
+                    // At least one app is failing when we call getChildDrawingOrder
+                    // at this point, so deal semi-gracefully with it by falling back
+                    // on the basic order.
+                    customOrder = false;
+                    if (i > 0) {
+                        // If we failed at the first index, there really isn't
+                        // anything to do -- we will just proceed with the simple
+                        // sequence order.
+                        // Otherwise, we failed in the middle, so need to come up
+                        // with an order for the remaining indices and use that.
+                        // Failed at the first one, easy peasy.
+                        int[] permutation = new int[childrenCount];
+                        SparseBooleanArray usedIndices = new SparseBooleanArray();
+                        // Go back and collected the indices we have done so far.
+                        for (int j = 0; j < i; j++) {
+                            permutation[j] = getChildDrawingOrder(childrenCount, j);
+                            usedIndices.put(permutation[j], true);
+                        }
+                        // Fill in the remaining indices with indices that have not
+                        // yet been used.
+                        int nextIndex = 0;
+                        for (int j = i; j < childrenCount; j++) {
+                            while (usedIndices.get(nextIndex, false)) {
+                                nextIndex++;
+                            }
+                            permutation[j] = nextIndex;
+                            nextIndex++;
+                        }
+                        // Build the final view list.
+                        preorderedList = new ArrayList<>(childrenCount);
+                        for (int j = 0; j < childrenCount; j++) {
+                            final int index = permutation[j];
+                            final View child = mChildren[index];
+                            preorderedList.add(child);
+                        }
+                    }
+                } else {
+                    throw e;
+                }
+            }
+            final View child = getAndVerifyPreorderedView(preorderedList, mChildren,
+                    childIndex);
+            final ViewStructure cstructure = structure.newChild(i);
+            child.dispatchProvideStructure(cstructure);
+        }
+        if (preorderedList != null) {
+            preorderedList.clear();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>This implementation adds in all child views of the view group, in addition to calling the
+     * default {@link View} implementation.
+     */
+    @Override
+    public void dispatchProvideAutofillStructure(ViewStructure structure,
+            @AutofillFlags int flags) {
+        super.dispatchProvideAutofillStructure(structure, flags);
+        if (structure.getChildCount() != 0) {
+            return;
+        }
+
+        if (!isLaidOut()) {
+            Log.v(VIEW_LOG_TAG, "dispatchProvideAutofillStructure(): not laid out, ignoring "
+                    + mChildrenCount + " children of " + getAutofillId());
+            return;
+        }
+
+        final ChildListForAutoFill children = getChildrenForAutofill(flags);
+        final int childrenCount = children.size();
+        structure.setChildCount(childrenCount);
+        for (int i = 0; i < childrenCount; i++) {
+            final View child = children.get(i);
+            final ViewStructure cstructure = structure.newChild(i);
+            child.dispatchProvideAutofillStructure(cstructure, flags);
+        }
+        children.recycle();
+    }
+
+    /**
+     * Gets the children for autofill. Children for autofill are the first
+     * level descendants that are important for autofill. The returned
+     * child list object is pooled and the caller must recycle it once done.
+     * @hide */
+    private @NonNull ChildListForAutoFill getChildrenForAutofill(@AutofillFlags int flags) {
+        final ChildListForAutoFill children = ChildListForAutoFill.obtain();
+        populateChildrenForAutofill(children, flags);
+        return children;
+    }
+
+    /** @hide */
+    private void populateChildrenForAutofill(ArrayList<View> list, @AutofillFlags int flags) {
+        final int childrenCount = mChildrenCount;
+        if (childrenCount <= 0) {
+            return;
+        }
+        final ArrayList<View> preorderedList = buildOrderedChildList();
+        final boolean customOrder = preorderedList == null
+                && isChildrenDrawingOrderEnabled();
+        for (int i = 0; i < childrenCount; i++) {
+            final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+            final View child = (preorderedList == null)
+                    ? mChildren[childIndex] : preorderedList.get(childIndex);
+            if ((flags & AUTOFILL_FLAG_INCLUDE_NOT_IMPORTANT_VIEWS) != 0
+                    || child.isImportantForAutofill()) {
+                list.add(child);
+            } else if (child instanceof ViewGroup) {
+                ((ViewGroup) child).populateChildrenForAutofill(list, flags);
+            }
+        }
+    }
+
+    private static View getAndVerifyPreorderedView(ArrayList<View> preorderedList, View[] children,
+            int childIndex) {
+        final View child;
+        if (preorderedList != null) {
+            child = preorderedList.get(childIndex);
+            if (child == null) {
+                throw new RuntimeException("Invalid preorderedList contained null child at index "
+                        + childIndex);
+            }
+        } else {
+            child = children[childIndex];
+        }
+        return child;
+    }
+
+    /** @hide */
+    @Override
+    public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfoInternal(info);
+        if (getAccessibilityNodeProvider() != null) {
+            return;
+        }
+        if (mAttachInfo != null) {
+            final ArrayList<View> childrenForAccessibility = mAttachInfo.mTempArrayList;
+            childrenForAccessibility.clear();
+            addChildrenForAccessibility(childrenForAccessibility);
+            final int childrenForAccessibilityCount = childrenForAccessibility.size();
+            for (int i = 0; i < childrenForAccessibilityCount; i++) {
+                final View child = childrenForAccessibility.get(i);
+                info.addChildUnchecked(child);
+            }
+            childrenForAccessibility.clear();
+        }
+    }
+
+    @Override
+    public CharSequence getAccessibilityClassName() {
+        return ViewGroup.class.getName();
+    }
+
+    @Override
+    public void notifySubtreeAccessibilityStateChanged(View child, View source, int changeType) {
+        // If this is a live region, we should send a subtree change event
+        // from this view. Otherwise, we can let it propagate up.
+        if (getAccessibilityLiveRegion() != ACCESSIBILITY_LIVE_REGION_NONE) {
+            notifyViewAccessibilityStateChangedIfNeeded(
+                    AccessibilityEvent.CONTENT_CHANGE_TYPE_SUBTREE);
+        } else if (mParent != null) {
+            try {
+                mParent.notifySubtreeAccessibilityStateChanged(this, source, changeType);
+            } catch (AbstractMethodError e) {
+                Log.e(VIEW_LOG_TAG, mParent.getClass().getSimpleName() +
+                        " does not fully implement ViewParent", e);
+            }
+        }
+    }
+
+    /** @hide */
+    @Override
+    public void notifySubtreeAccessibilityStateChangedIfNeeded() {
+        if (!AccessibilityManager.getInstance(mContext).isEnabled() || mAttachInfo == null) {
+            return;
+        }
+        // If something important for a11y is happening in this subtree, make sure it's dispatched
+        // from a view that is important for a11y so it doesn't get lost.
+        if ((getImportantForAccessibility() != IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS)
+                && !isImportantForAccessibility() && (getChildCount() > 0)) {
+            ViewParent a11yParent = getParentForAccessibility();
+            if (a11yParent instanceof View) {
+                ((View) a11yParent).notifySubtreeAccessibilityStateChangedIfNeeded();
+                return;
+            }
+        }
+        super.notifySubtreeAccessibilityStateChangedIfNeeded();
+    }
+
+    @Override
+    void resetSubtreeAccessibilityStateChanged() {
+        super.resetSubtreeAccessibilityStateChanged();
+        View[] children = mChildren;
+        final int childCount = mChildrenCount;
+        for (int i = 0; i < childCount; i++) {
+            children[i].resetSubtreeAccessibilityStateChanged();
+        }
+    }
+
+    /**
+     * Counts the number of children of this View that will be sent to an accessibility service.
+     *
+     * @return The number of children an {@code AccessibilityNodeInfo} rooted at this View
+     * would have.
+     */
+    int getNumChildrenForAccessibility() {
+        int numChildrenForAccessibility = 0;
+        for (int i = 0; i < getChildCount(); i++) {
+            View child = getChildAt(i);
+            if (child.includeForAccessibility()) {
+                numChildrenForAccessibility++;
+            } else if (child instanceof ViewGroup) {
+                numChildrenForAccessibility += ((ViewGroup) child)
+                        .getNumChildrenForAccessibility();
+            }
+        }
+        return numChildrenForAccessibility;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>Subclasses should always call <code>super.onNestedPrePerformAccessibilityAction</code></p>
+     *
+     * @param target The target view dispatching this action
+     * @param action Action being performed; see
+     *               {@link android.view.accessibility.AccessibilityNodeInfo}
+     * @param args Optional action arguments
+     * @return false by default. Subclasses should return true if they handle the event.
+     */
+    @Override
+    public boolean onNestedPrePerformAccessibilityAction(View target, int action, Bundle args) {
+        return false;
+    }
+
+    @Override
+    void dispatchDetachedFromWindow() {
+        // If we still have a touch target, we are still in the process of
+        // dispatching motion events to a child; we need to get rid of that
+        // child to avoid dispatching events to it after the window is torn
+        // down. To make sure we keep the child in a consistent state, we
+        // first send it an ACTION_CANCEL motion event.
+        cancelAndClearTouchTargets(null);
+
+        // Similarly, set ACTION_EXIT to all hover targets and clear them.
+        exitHoverTargets();
+        exitTooltipHoverTargets();
+
+        // In case view is detached while transition is running
+        mLayoutCalledWhileSuppressed = false;
+
+        // Tear down our drag tracking
+        mChildrenInterestedInDrag = null;
+        mIsInterestedInDrag = false;
+        if (mCurrentDragStartEvent != null) {
+            mCurrentDragStartEvent.recycle();
+            mCurrentDragStartEvent = null;
+        }
+
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchDetachedFromWindow();
+        }
+        clearDisappearingChildren();
+        final int transientCount = mTransientViews == null ? 0 : mTransientIndices.size();
+        for (int i = 0; i < transientCount; ++i) {
+            View view = mTransientViews.get(i);
+            view.dispatchDetachedFromWindow();
+        }
+        super.dispatchDetachedFromWindow();
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    protected void internalSetPadding(int left, int top, int right, int bottom) {
+        super.internalSetPadding(left, top, right, bottom);
+
+        if ((mPaddingLeft | mPaddingTop | mPaddingRight | mPaddingBottom) != 0) {
+            mGroupFlags |= FLAG_PADDING_NOT_NULL;
+        } else {
+            mGroupFlags &= ~FLAG_PADDING_NOT_NULL;
+        }
+    }
+
+    @Override
+    protected void dispatchSaveInstanceState(SparseArray<Parcelable> container) {
+        super.dispatchSaveInstanceState(container);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            View c = children[i];
+            if ((c.mViewFlags & PARENT_SAVE_DISABLED_MASK) != PARENT_SAVE_DISABLED) {
+                c.dispatchSaveInstanceState(container);
+            }
+        }
+    }
+
+    /**
+     * Perform dispatching of a {@link #saveHierarchyState(android.util.SparseArray)}  freeze()}
+     * to only this view, not to its children.  For use when overriding
+     * {@link #dispatchSaveInstanceState(android.util.SparseArray)}  dispatchFreeze()} to allow
+     * subclasses to freeze their own state but not the state of their children.
+     *
+     * @param container the container
+     */
+    protected void dispatchFreezeSelfOnly(SparseArray<Parcelable> container) {
+        super.dispatchSaveInstanceState(container);
+    }
+
+    @Override
+    protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) {
+        super.dispatchRestoreInstanceState(container);
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            View c = children[i];
+            if ((c.mViewFlags & PARENT_SAVE_DISABLED_MASK) != PARENT_SAVE_DISABLED) {
+                c.dispatchRestoreInstanceState(container);
+            }
+        }
+    }
+
+    /**
+     * Perform dispatching of a {@link #restoreHierarchyState(android.util.SparseArray)}
+     * to only this view, not to its children.  For use when overriding
+     * {@link #dispatchRestoreInstanceState(android.util.SparseArray)} to allow
+     * subclasses to thaw their own state but not the state of their children.
+     *
+     * @param container the container
+     */
+    protected void dispatchThawSelfOnly(SparseArray<Parcelable> container) {
+        super.dispatchRestoreInstanceState(container);
+    }
+
+    /**
+     * Enables or disables the drawing cache for each child of this view group.
+     *
+     * @param enabled true to enable the cache, false to dispose of it
+     */
+    protected void setChildrenDrawingCacheEnabled(boolean enabled) {
+        if (enabled || (mPersistentDrawingCache & PERSISTENT_ALL_CACHES) != PERSISTENT_ALL_CACHES) {
+            final View[] children = mChildren;
+            final int count = mChildrenCount;
+            for (int i = 0; i < count; i++) {
+                children[i].setDrawingCacheEnabled(enabled);
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public Bitmap createSnapshot(Bitmap.Config quality, int backgroundColor, boolean skipChildren) {
+        int count = mChildrenCount;
+        int[] visibilities = null;
+
+        if (skipChildren) {
+            visibilities = new int[count];
+            for (int i = 0; i < count; i++) {
+                View child = getChildAt(i);
+                visibilities[i] = child.getVisibility();
+                if (visibilities[i] == View.VISIBLE) {
+                    child.mViewFlags = (child.mViewFlags & ~View.VISIBILITY_MASK)
+                            | (View.INVISIBLE & View.VISIBILITY_MASK);
+                }
+            }
+        }
+
+        Bitmap b = super.createSnapshot(quality, backgroundColor, skipChildren);
+
+        if (skipChildren) {
+            for (int i = 0; i < count; i++) {
+                View child = getChildAt(i);
+                child.mViewFlags = (child.mViewFlags & ~View.VISIBILITY_MASK)
+                        | (visibilities[i] & View.VISIBILITY_MASK);
+            }
+        }
+
+        return b;
+    }
+
+    /** Return true if this ViewGroup is laying out using optical bounds. */
+    boolean isLayoutModeOptical() {
+        return mLayoutMode == LAYOUT_MODE_OPTICAL_BOUNDS;
+    }
+
+    @Override
+    Insets computeOpticalInsets() {
+        if (isLayoutModeOptical()) {
+            int left = 0;
+            int top = 0;
+            int right = 0;
+            int bottom = 0;
+            for (int i = 0; i < mChildrenCount; i++) {
+                View child = getChildAt(i);
+                if (child.getVisibility() == VISIBLE) {
+                    Insets insets = child.getOpticalInsets();
+                    left =   Math.max(left,   insets.left);
+                    top =    Math.max(top,    insets.top);
+                    right =  Math.max(right,  insets.right);
+                    bottom = Math.max(bottom, insets.bottom);
+                }
+            }
+            return Insets.of(left, top, right, bottom);
+        } else {
+            return Insets.NONE;
+        }
+    }
+
+    private static void fillRect(Canvas canvas, Paint paint, int x1, int y1, int x2, int y2) {
+        if (x1 != x2 && y1 != y2) {
+            if (x1 > x2) {
+                int tmp = x1; x1 = x2; x2 = tmp;
+            }
+            if (y1 > y2) {
+                int tmp = y1; y1 = y2; y2 = tmp;
+            }
+            canvas.drawRect(x1, y1, x2, y2, paint);
+        }
+    }
+
+    private static int sign(int x) {
+        return (x >= 0) ? 1 : -1;
+    }
+
+    private static void drawCorner(Canvas c, Paint paint, int x1, int y1, int dx, int dy, int lw) {
+        fillRect(c, paint, x1, y1, x1 + dx, y1 + lw * sign(dy));
+        fillRect(c, paint, x1, y1, x1 + lw * sign(dx), y1 + dy);
+    }
+
+    private static void drawRectCorners(Canvas canvas, int x1, int y1, int x2, int y2, Paint paint,
+            int lineLength, int lineWidth) {
+        drawCorner(canvas, paint, x1, y1, lineLength, lineLength, lineWidth);
+        drawCorner(canvas, paint, x1, y2, lineLength, -lineLength, lineWidth);
+        drawCorner(canvas, paint, x2, y1, -lineLength, lineLength, lineWidth);
+        drawCorner(canvas, paint, x2, y2, -lineLength, -lineLength, lineWidth);
+    }
+
+    private static void fillDifference(Canvas canvas,
+            int x2, int y2, int x3, int y3,
+            int dx1, int dy1, int dx2, int dy2, Paint paint) {
+        int x1 = x2 - dx1;
+        int y1 = y2 - dy1;
+
+        int x4 = x3 + dx2;
+        int y4 = y3 + dy2;
+
+        fillRect(canvas, paint, x1, y1, x4, y2);
+        fillRect(canvas, paint, x1, y2, x2, y3);
+        fillRect(canvas, paint, x3, y2, x4, y3);
+        fillRect(canvas, paint, x1, y3, x4, y4);
+    }
+
+    /**
+     * Layout debugging code which draws rectangles around layout params.
+     *
+     * <p>This function is called automatically when the developer setting is enabled.<p/>
+     *
+     * <p>It is strongly advised to only call this function from debug builds as there is
+     * a risk of leaking unwanted layout information.<p/>
+     *
+     * @param canvas the canvas on which to draw
+     * @param paint the paint used to draw through
+     */
+    protected void onDebugDrawMargins(Canvas canvas, Paint paint) {
+        for (int i = 0; i < getChildCount(); i++) {
+            View c = getChildAt(i);
+            c.getLayoutParams().onDebugDraw(c, canvas, paint);
+        }
+    }
+
+    /**
+     * Layout debugging code which draws rectangles around:
+     * <ul>
+     *     <li>optical bounds<li/>
+     *     <li>margins<li/>
+     *     <li>clip bounds<li/>
+     * <ul/>
+     *
+     * <p>This function is called automatically when the developer setting is enabled.<p/>
+     *
+     * <p>It is strongly advised to only call this function from debug builds as there is
+     * a risk of leaking unwanted layout information.<p/>
+     *
+     * @param canvas the canvas on which to draw
+     */
+    protected void onDebugDraw(Canvas canvas) {
+        Paint paint = getDebugPaint();
+
+        // Draw optical bounds
+        {
+            paint.setColor(Color.RED);
+            paint.setStyle(Paint.Style.STROKE);
+
+            for (int i = 0; i < getChildCount(); i++) {
+                View c = getChildAt(i);
+                if (c.getVisibility() != View.GONE) {
+                    Insets insets = c.getOpticalInsets();
+
+                    drawRect(canvas, paint,
+                            c.getLeft() + insets.left,
+                            c.getTop() + insets.top,
+                            c.getRight() - insets.right - 1,
+                            c.getBottom() - insets.bottom - 1);
+                }
+            }
+        }
+
+        // Draw margins
+        {
+            paint.setColor(Color.argb(63, 255, 0, 255));
+            paint.setStyle(Paint.Style.FILL);
+
+            onDebugDrawMargins(canvas, paint);
+        }
+
+        // Draw clip bounds
+        {
+            paint.setColor(DEBUG_CORNERS_COLOR);
+            paint.setStyle(Paint.Style.FILL);
+
+            int lineLength = dipsToPixels(DEBUG_CORNERS_SIZE_DIP);
+            int lineWidth = dipsToPixels(1);
+            for (int i = 0; i < getChildCount(); i++) {
+                View c = getChildAt(i);
+                if (c.getVisibility() != View.GONE) {
+                    drawRectCorners(canvas, c.getLeft(), c.getTop(), c.getRight(), c.getBottom(),
+                            paint, lineLength, lineWidth);
+                }
+            }
+        }
+    }
+
+    @Override
+    protected void dispatchDraw(Canvas canvas) {
+        boolean usingRenderNodeProperties = canvas.isRecordingFor(mRenderNode);
+        final int childrenCount = mChildrenCount;
+        final View[] children = mChildren;
+        int flags = mGroupFlags;
+
+        if ((flags & FLAG_RUN_ANIMATION) != 0 && canAnimate()) {
+            final boolean buildCache = !isHardwareAccelerated();
+            for (int i = 0; i < childrenCount; i++) {
+                final View child = children[i];
+                if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE) {
+                    final LayoutParams params = child.getLayoutParams();
+                    attachLayoutAnimationParameters(child, params, i, childrenCount);
+                    bindLayoutAnimation(child);
+                }
+            }
+
+            final LayoutAnimationController controller = mLayoutAnimationController;
+            if (controller.willOverlap()) {
+                mGroupFlags |= FLAG_OPTIMIZE_INVALIDATE;
+            }
+
+            controller.start();
+
+            mGroupFlags &= ~FLAG_RUN_ANIMATION;
+            mGroupFlags &= ~FLAG_ANIMATION_DONE;
+
+            if (mAnimationListener != null) {
+                mAnimationListener.onAnimationStart(controller.getAnimation());
+            }
+        }
+
+        int clipSaveCount = 0;
+        final boolean clipToPadding = (flags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK;
+        if (clipToPadding) {
+            clipSaveCount = canvas.save(Canvas.CLIP_SAVE_FLAG);
+            canvas.clipRect(mScrollX + mPaddingLeft, mScrollY + mPaddingTop,
+                    mScrollX + mRight - mLeft - mPaddingRight,
+                    mScrollY + mBottom - mTop - mPaddingBottom);
+        }
+
+        // We will draw our child's animation, let's reset the flag
+        mPrivateFlags &= ~PFLAG_DRAW_ANIMATION;
+        mGroupFlags &= ~FLAG_INVALIDATE_REQUIRED;
+
+        boolean more = false;
+        final long drawingTime = getDrawingTime();
+
+        if (usingRenderNodeProperties) canvas.insertReorderBarrier();
+        final int transientCount = mTransientIndices == null ? 0 : mTransientIndices.size();
+        int transientIndex = transientCount != 0 ? 0 : -1;
+        // Only use the preordered list if not HW accelerated, since the HW pipeline will do the
+        // draw reordering internally
+        final ArrayList<View> preorderedList = usingRenderNodeProperties
+                ? null : buildOrderedChildList();
+        final boolean customOrder = preorderedList == null
+                && isChildrenDrawingOrderEnabled();
+        for (int i = 0; i < childrenCount; i++) {
+            while (transientIndex >= 0 && mTransientIndices.get(transientIndex) == i) {
+                final View transientChild = mTransientViews.get(transientIndex);
+                if ((transientChild.mViewFlags & VISIBILITY_MASK) == VISIBLE ||
+                        transientChild.getAnimation() != null) {
+                    more |= drawChild(canvas, transientChild, drawingTime);
+                }
+                transientIndex++;
+                if (transientIndex >= transientCount) {
+                    transientIndex = -1;
+                }
+            }
+
+            final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+            final View child = getAndVerifyPreorderedView(preorderedList, children, childIndex);
+            if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE || child.getAnimation() != null) {
+                more |= drawChild(canvas, child, drawingTime);
+            }
+        }
+        while (transientIndex >= 0) {
+            // there may be additional transient views after the normal views
+            final View transientChild = mTransientViews.get(transientIndex);
+            if ((transientChild.mViewFlags & VISIBILITY_MASK) == VISIBLE ||
+                    transientChild.getAnimation() != null) {
+                more |= drawChild(canvas, transientChild, drawingTime);
+            }
+            transientIndex++;
+            if (transientIndex >= transientCount) {
+                break;
+            }
+        }
+        if (preorderedList != null) preorderedList.clear();
+
+        // Draw any disappearing views that have animations
+        if (mDisappearingChildren != null) {
+            final ArrayList<View> disappearingChildren = mDisappearingChildren;
+            final int disappearingCount = disappearingChildren.size() - 1;
+            // Go backwards -- we may delete as animations finish
+            for (int i = disappearingCount; i >= 0; i--) {
+                final View child = disappearingChildren.get(i);
+                more |= drawChild(canvas, child, drawingTime);
+            }
+        }
+        if (usingRenderNodeProperties) canvas.insertInorderBarrier();
+
+        if (debugDraw()) {
+            onDebugDraw(canvas);
+        }
+
+        if (clipToPadding) {
+            canvas.restoreToCount(clipSaveCount);
+        }
+
+        // mGroupFlags might have been updated by drawChild()
+        flags = mGroupFlags;
+
+        if ((flags & FLAG_INVALIDATE_REQUIRED) == FLAG_INVALIDATE_REQUIRED) {
+            invalidate(true);
+        }
+
+        if ((flags & FLAG_ANIMATION_DONE) == 0 && (flags & FLAG_NOTIFY_ANIMATION_LISTENER) == 0 &&
+                mLayoutAnimationController.isDone() && !more) {
+            // We want to erase the drawing cache and notify the listener after the
+            // next frame is drawn because one extra invalidate() is caused by
+            // drawChild() after the animation is over
+            mGroupFlags |= FLAG_NOTIFY_ANIMATION_LISTENER;
+            final Runnable end = new Runnable() {
+               @Override
+               public void run() {
+                   notifyAnimationListener();
+               }
+            };
+            post(end);
+        }
+    }
+
+    /**
+     * Returns the ViewGroupOverlay for this view group, creating it if it does
+     * not yet exist. In addition to {@link ViewOverlay}'s support for drawables,
+     * {@link ViewGroupOverlay} allows views to be added to the overlay. These
+     * views, like overlay drawables, are visual-only; they do not receive input
+     * events and should not be used as anything other than a temporary
+     * representation of a view in a parent container, such as might be used
+     * by an animation effect.
+     *
+     * <p>Note: Overlays do not currently work correctly with {@link
+     * SurfaceView} or {@link TextureView}; contents in overlays for these
+     * types of views may not display correctly.</p>
+     *
+     * @return The ViewGroupOverlay object for this view.
+     * @see ViewGroupOverlay
+     */
+    @Override
+    public ViewGroupOverlay getOverlay() {
+        if (mOverlay == null) {
+            mOverlay = new ViewGroupOverlay(mContext, this);
+        }
+        return (ViewGroupOverlay) mOverlay;
+    }
+
+    /**
+     * Returns the index of the child to draw for this iteration. Override this
+     * if you want to change the drawing order of children. By default, it
+     * returns i.
+     * <p>
+     * NOTE: In order for this method to be called, you must enable child ordering
+     * first by calling {@link #setChildrenDrawingOrderEnabled(boolean)}.
+     *
+     * @param i The current iteration.
+     * @return The index of the child to draw this iteration.
+     *
+     * @see #setChildrenDrawingOrderEnabled(boolean)
+     * @see #isChildrenDrawingOrderEnabled()
+     */
+    protected int getChildDrawingOrder(int childCount, int i) {
+        return i;
+    }
+
+    private boolean hasChildWithZ() {
+        for (int i = 0; i < mChildrenCount; i++) {
+            if (mChildren[i].getZ() != 0) return true;
+        }
+        return false;
+    }
+
+    /**
+     * Populates (and returns) mPreSortedChildren with a pre-ordered list of the View's children,
+     * sorted first by Z, then by child drawing order (if applicable). This list must be cleared
+     * after use to avoid leaking child Views.
+     *
+     * Uses a stable, insertion sort which is commonly O(n) for ViewGroups with very few elevated
+     * children.
+     */
+    ArrayList<View> buildOrderedChildList() {
+        final int childrenCount = mChildrenCount;
+        if (childrenCount <= 1 || !hasChildWithZ()) return null;
+
+        if (mPreSortedChildren == null) {
+            mPreSortedChildren = new ArrayList<>(childrenCount);
+        } else {
+            // callers should clear, so clear shouldn't be necessary, but for safety...
+            mPreSortedChildren.clear();
+            mPreSortedChildren.ensureCapacity(childrenCount);
+        }
+
+        final boolean customOrder = isChildrenDrawingOrderEnabled();
+        for (int i = 0; i < childrenCount; i++) {
+            // add next child (in child order) to end of list
+            final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+            final View nextChild = mChildren[childIndex];
+            final float currentZ = nextChild.getZ();
+
+            // insert ahead of any Views with greater Z
+            int insertIndex = i;
+            while (insertIndex > 0 && mPreSortedChildren.get(insertIndex - 1).getZ() > currentZ) {
+                insertIndex--;
+            }
+            mPreSortedChildren.add(insertIndex, nextChild);
+        }
+        return mPreSortedChildren;
+    }
+
+    private void notifyAnimationListener() {
+        mGroupFlags &= ~FLAG_NOTIFY_ANIMATION_LISTENER;
+        mGroupFlags |= FLAG_ANIMATION_DONE;
+
+        if (mAnimationListener != null) {
+           final Runnable end = new Runnable() {
+               @Override
+               public void run() {
+                   mAnimationListener.onAnimationEnd(mLayoutAnimationController.getAnimation());
+               }
+           };
+           post(end);
+        }
+
+        invalidate(true);
+    }
+
+    /**
+     * This method is used to cause children of this ViewGroup to restore or recreate their
+     * display lists. It is called by getDisplayList() when the parent ViewGroup does not need
+     * to recreate its own display list, which would happen if it went through the normal
+     * draw/dispatchDraw mechanisms.
+     *
+     * @hide
+     */
+    @Override
+    protected void dispatchGetDisplayList() {
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+            if (((child.mViewFlags & VISIBILITY_MASK) == VISIBLE || child.getAnimation() != null)) {
+                recreateChildDisplayList(child);
+            }
+        }
+        if (mOverlay != null) {
+            View overlayView = mOverlay.getOverlayView();
+            recreateChildDisplayList(overlayView);
+        }
+        if (mDisappearingChildren != null) {
+            final ArrayList<View> disappearingChildren = mDisappearingChildren;
+            final int disappearingCount = disappearingChildren.size();
+            for (int i = 0; i < disappearingCount; ++i) {
+                final View child = disappearingChildren.get(i);
+                recreateChildDisplayList(child);
+            }
+        }
+    }
+
+    private void recreateChildDisplayList(View child) {
+        child.mRecreateDisplayList = (child.mPrivateFlags & PFLAG_INVALIDATED) != 0;
+        child.mPrivateFlags &= ~PFLAG_INVALIDATED;
+        child.updateDisplayListIfDirty();
+        child.mRecreateDisplayList = false;
+    }
+
+    /**
+     * Draw one child of this View Group. This method is responsible for getting
+     * the canvas in the right state. This includes clipping, translating so
+     * that the child's scrolled origin is at 0, 0, and applying any animation
+     * transformations.
+     *
+     * @param canvas The canvas on which to draw the child
+     * @param child Who to draw
+     * @param drawingTime The time at which draw is occurring
+     * @return True if an invalidate() was issued
+     */
+    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
+        return child.draw(canvas, this, drawingTime);
+    }
+
+    @Override
+    void getScrollIndicatorBounds(@NonNull Rect out) {
+        super.getScrollIndicatorBounds(out);
+
+        // If we have padding and we're supposed to clip children to that
+        // padding, offset the scroll indicators to match our clip bounds.
+        final boolean clipToPadding = (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK;
+        if (clipToPadding) {
+            out.left += mPaddingLeft;
+            out.right -= mPaddingRight;
+            out.top += mPaddingTop;
+            out.bottom -= mPaddingBottom;
+        }
+    }
+
+    /**
+     * Returns whether this group's children are clipped to their bounds before drawing.
+     * The default value is true.
+     * @see #setClipChildren(boolean)
+     *
+     * @return True if the group's children will be clipped to their bounds,
+     * false otherwise.
+     */
+    @ViewDebug.ExportedProperty(category = "drawing")
+    public boolean getClipChildren() {
+        return ((mGroupFlags & FLAG_CLIP_CHILDREN) != 0);
+    }
+
+    /**
+     * By default, children are clipped to their bounds before drawing. This
+     * allows view groups to override this behavior for animations, etc.
+     *
+     * @param clipChildren true to clip children to their bounds,
+     *        false otherwise
+     * @attr ref android.R.styleable#ViewGroup_clipChildren
+     */
+    public void setClipChildren(boolean clipChildren) {
+        boolean previousValue = (mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN;
+        if (clipChildren != previousValue) {
+            setBooleanFlag(FLAG_CLIP_CHILDREN, clipChildren);
+            for (int i = 0; i < mChildrenCount; ++i) {
+                View child = getChildAt(i);
+                if (child.mRenderNode != null) {
+                    child.mRenderNode.setClipToBounds(clipChildren);
+                }
+            }
+            invalidate(true);
+        }
+    }
+
+    /**
+     * Sets whether this ViewGroup will clip its children to its padding and resize (but not
+     * clip) any EdgeEffect to the padded region, if padding is present.
+     * <p>
+     * By default, children are clipped to the padding of their parent
+     * ViewGroup. This clipping behavior is only enabled if padding is non-zero.
+     *
+     * @param clipToPadding true to clip children to the padding of the group, and resize (but
+     *        not clip) any EdgeEffect to the padded region. False otherwise.
+     * @attr ref android.R.styleable#ViewGroup_clipToPadding
+     */
+    public void setClipToPadding(boolean clipToPadding) {
+        if (hasBooleanFlag(FLAG_CLIP_TO_PADDING) != clipToPadding) {
+            setBooleanFlag(FLAG_CLIP_TO_PADDING, clipToPadding);
+            invalidate(true);
+        }
+    }
+
+    /**
+     * Returns whether this ViewGroup will clip its children to its padding, and resize (but
+     * not clip) any EdgeEffect to the padded region, if padding is present.
+     * <p>
+     * By default, children are clipped to the padding of their parent
+     * Viewgroup. This clipping behavior is only enabled if padding is non-zero.
+     *
+     * @return true if this ViewGroup clips children to its padding and resizes (but doesn't
+     *         clip) any EdgeEffect to the padded region, false otherwise.
+     *
+     * @attr ref android.R.styleable#ViewGroup_clipToPadding
+     */
+    @ViewDebug.ExportedProperty(category = "drawing")
+    public boolean getClipToPadding() {
+        return hasBooleanFlag(FLAG_CLIP_TO_PADDING);
+    }
+
+    @Override
+    public void dispatchSetSelected(boolean selected) {
+        final View[] children = mChildren;
+        final int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            children[i].setSelected(selected);
+        }
+    }
+
+    @Override
+    public void dispatchSetActivated(boolean activated) {
+        final View[] children = mChildren;
+        final int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            children[i].setActivated(activated);
+        }
+    }
+
+    @Override
+    protected void dispatchSetPressed(boolean pressed) {
+        final View[] children = mChildren;
+        final int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+            // Children that are clickable on their own should not
+            // show a pressed state when their parent view does.
+            // Clearing a pressed state always propagates.
+            if (!pressed || (!child.isClickable() && !child.isLongClickable())) {
+                child.setPressed(pressed);
+            }
+        }
+    }
+
+    /**
+     * Dispatches drawable hotspot changes to child views that meet at least
+     * one of the following criteria:
+     * <ul>
+     *     <li>Returns {@code false} from both {@link View#isClickable()} and
+     *     {@link View#isLongClickable()}</li>
+     *     <li>Requests duplication of parent state via
+     *     {@link View#setDuplicateParentStateEnabled(boolean)}</li>
+     * </ul>
+     *
+     * @param x hotspot x coordinate
+     * @param y hotspot y coordinate
+     * @see #drawableHotspotChanged(float, float)
+     */
+    @Override
+    public void dispatchDrawableHotspotChanged(float x, float y) {
+        final int count = mChildrenCount;
+        if (count == 0) {
+            return;
+        }
+
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            final View child = children[i];
+            // Children that are clickable on their own should not
+            // receive hotspots when their parent view does.
+            final boolean nonActionable = !child.isClickable() && !child.isLongClickable();
+            final boolean duplicatesState = (child.mViewFlags & DUPLICATE_PARENT_STATE) != 0;
+            if (nonActionable || duplicatesState) {
+                final float[] point = getTempPoint();
+                point[0] = x;
+                point[1] = y;
+                transformPointToViewLocal(point, child);
+                child.drawableHotspotChanged(point[0], point[1]);
+            }
+        }
+    }
+
+    @Override
+    void dispatchCancelPendingInputEvents() {
+        super.dispatchCancelPendingInputEvents();
+
+        final View[] children = mChildren;
+        final int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            children[i].dispatchCancelPendingInputEvents();
+        }
+    }
+
+    /**
+     * When this property is set to true, this ViewGroup supports static transformations on
+     * children; this causes
+     * {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} to be
+     * invoked when a child is drawn.
+     *
+     * Any subclass overriding
+     * {@link #getChildStaticTransformation(View, android.view.animation.Transformation)} should
+     * set this property to true.
+     *
+     * @param enabled True to enable static transformations on children, false otherwise.
+     *
+     * @see #getChildStaticTransformation(View, android.view.animation.Transformation)
+     */
+    protected void setStaticTransformationsEnabled(boolean enabled) {
+        setBooleanFlag(FLAG_SUPPORT_STATIC_TRANSFORMATIONS, enabled);
+    }
+
+    /**
+     * Sets  <code>t</code> to be the static transformation of the child, if set, returning a
+     * boolean to indicate whether a static transform was set. The default implementation
+     * simply returns <code>false</code>; subclasses may override this method for different
+     * behavior. {@link #setStaticTransformationsEnabled(boolean)} must be set to true
+     * for this method to be called.
+     *
+     * @param child The child view whose static transform is being requested
+     * @param t The Transformation which will hold the result
+     * @return true if the transformation was set, false otherwise
+     * @see #setStaticTransformationsEnabled(boolean)
+     */
+    protected boolean getChildStaticTransformation(View child, Transformation t) {
+        return false;
+    }
+
+    Transformation getChildTransformation() {
+        if (mChildTransformation == null) {
+            mChildTransformation = new Transformation();
+        }
+        return mChildTransformation;
+    }
+
+    /**
+     * {@hide}
+     */
+    @Override
+    protected <T extends View> T findViewTraversal(@IdRes int id) {
+        if (id == mID) {
+            return (T) this;
+        }
+
+        final View[] where = mChildren;
+        final int len = mChildrenCount;
+
+        for (int i = 0; i < len; i++) {
+            View v = where[i];
+
+            if ((v.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
+                v = v.findViewById(id);
+
+                if (v != null) {
+                    return (T) v;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * {@hide}
+     */
+    @Override
+    protected <T extends View> T findViewWithTagTraversal(Object tag) {
+        if (tag != null && tag.equals(mTag)) {
+            return (T) this;
+        }
+
+        final View[] where = mChildren;
+        final int len = mChildrenCount;
+
+        for (int i = 0; i < len; i++) {
+            View v = where[i];
+
+            if ((v.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
+                v = v.findViewWithTag(tag);
+
+                if (v != null) {
+                    return (T) v;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * {@hide}
+     */
+    @Override
+    protected <T extends View> T findViewByPredicateTraversal(Predicate<View> predicate,
+            View childToSkip) {
+        if (predicate.test(this)) {
+            return (T) this;
+        }
+
+        final View[] where = mChildren;
+        final int len = mChildrenCount;
+
+        for (int i = 0; i < len; i++) {
+            View v = where[i];
+
+            if (v != childToSkip && (v.mPrivateFlags & PFLAG_IS_ROOT_NAMESPACE) == 0) {
+                v = v.findViewByPredicate(predicate);
+
+                if (v != null) {
+                    return (T) v;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * This method adds a view to this container at the specified index purely for the
+     * purposes of allowing that view to draw even though it is not a normal child of
+     * the container. That is, the view does not participate in layout, focus, accessibility,
+     * input, or other normal view operations; it is purely an item to be drawn during the normal
+     * rendering operation of this container. The index that it is added at is the order
+     * in which it will be drawn, with respect to the other views in the container.
+     * For example, a transient view added at index 0 will be drawn before all other views
+     * in the container because it will be drawn first (including before any real view
+     * at index 0). There can be more than one transient view at any particular index;
+     * these views will be drawn in the order in which they were added to the list of
+     * transient views. The index of transient views can also be greater than the number
+     * of normal views in the container; that just means that they will be drawn after all
+     * other views are drawn.
+     *
+     * <p>Note that since transient views do not participate in layout, they must be sized
+     * manually or, more typically, they should just use the size that they had before they
+     * were removed from their container.</p>
+     *
+     * <p>Transient views are useful for handling animations of views that have been removed
+     * from the container, but which should be animated out after the removal. Adding these
+     * views as transient views allows them to participate in drawing without side-effecting
+     * the layout of the container.</p>
+     *
+     * <p>Transient views must always be explicitly {@link #removeTransientView(View) removed}
+     * from the container when they are no longer needed. For example, a transient view
+     * which is added in order to fade it out in its old location should be removed
+     * once the animation is complete.</p>
+     *
+     * @param view The view to be added
+     * @param index The index at which this view should be drawn, must be >= 0.
+     * This value is relative to the {@link #getChildAt(int) index} values in the normal
+     * child list of this container, where any transient view at a particular index will
+     * be drawn before any normal child at that same index.
+     *
+     * @hide
+     */
+    public void addTransientView(View view, int index) {
+        if (index < 0) {
+            return;
+        }
+        if (mTransientIndices == null) {
+            mTransientIndices = new ArrayList<Integer>();
+            mTransientViews = new ArrayList<View>();
+        }
+        final int oldSize = mTransientIndices.size();
+        if (oldSize > 0) {
+            int insertionIndex;
+            for (insertionIndex = 0; insertionIndex < oldSize; ++insertionIndex) {
+                if (index < mTransientIndices.get(insertionIndex)) {
+                    break;
+                }
+            }
+            mTransientIndices.add(insertionIndex, index);
+            mTransientViews.add(insertionIndex, view);
+        } else {
+            mTransientIndices.add(index);
+            mTransientViews.add(view);
+        }
+        view.mParent = this;
+        view.dispatchAttachedToWindow(mAttachInfo, (mViewFlags&VISIBILITY_MASK));
+        invalidate(true);
+    }
+
+    /**
+     * Removes a view from the list of transient views in this container. If there is no
+     * such transient view, this method does nothing.
+     *
+     * @param view The transient view to be removed
+     *
+     * @hide
+     */
+    public void removeTransientView(View view) {
+        if (mTransientViews == null) {
+            return;
+        }
+        final int size = mTransientViews.size();
+        for (int i = 0; i < size; ++i) {
+            if (view == mTransientViews.get(i)) {
+                mTransientViews.remove(i);
+                mTransientIndices.remove(i);
+                view.mParent = null;
+                view.dispatchDetachedFromWindow();
+                invalidate(true);
+                return;
+            }
+        }
+    }
+
+    /**
+     * Returns the number of transient views in this container. Specific transient
+     * views and the index at which they were added can be retrieved via
+     * {@link #getTransientView(int)} and {@link #getTransientViewIndex(int)}.
+     *
+     * @see #addTransientView(View, int)
+     * @return The number of transient views in this container
+     *
+     * @hide
+     */
+    public int getTransientViewCount() {
+        return mTransientIndices == null ? 0 : mTransientIndices.size();
+    }
+
+    /**
+     * Given a valid position within the list of transient views, returns the index of
+     * the transient view at that position.
+     *
+     * @param position The position of the index being queried. Must be at least 0
+     * and less than the value returned by {@link #getTransientViewCount()}.
+     * @return The index of the transient view stored in the given position if the
+     * position is valid, otherwise -1
+     *
+     * @hide
+     */
+    public int getTransientViewIndex(int position) {
+        if (position < 0 || mTransientIndices == null || position >= mTransientIndices.size()) {
+            return -1;
+        }
+        return mTransientIndices.get(position);
+    }
+
+    /**
+     * Given a valid position within the list of transient views, returns the
+     * transient view at that position.
+     *
+     * @param position The position of the view being queried. Must be at least 0
+     * and less than the value returned by {@link #getTransientViewCount()}.
+     * @return The transient view stored in the given position if the
+     * position is valid, otherwise null
+     *
+     * @hide
+     */
+    public View getTransientView(int position) {
+        if (mTransientViews == null || position >= mTransientViews.size()) {
+            return null;
+        }
+        return mTransientViews.get(position);
+    }
+
+    /**
+     * <p>Adds a child view. If no layout parameters are already set on the child, the
+     * default parameters for this ViewGroup are set on the child.</p>
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param child the child view to add
+     *
+     * @see #generateDefaultLayoutParams()
+     */
+    public void addView(View child) {
+        addView(child, -1);
+    }
+
+    /**
+     * Adds a child view. If no layout parameters are already set on the child, the
+     * default parameters for this ViewGroup are set on the child.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param child the child view to add
+     * @param index the position at which to add the child
+     *
+     * @see #generateDefaultLayoutParams()
+     */
+    public void addView(View child, int index) {
+        if (child == null) {
+            throw new IllegalArgumentException("Cannot add a null child view to a ViewGroup");
+        }
+        LayoutParams params = child.getLayoutParams();
+        if (params == null) {
+            params = generateDefaultLayoutParams();
+            if (params == null) {
+                throw new IllegalArgumentException("generateDefaultLayoutParams() cannot return null");
+            }
+        }
+        addView(child, index, params);
+    }
+
+    /**
+     * Adds a child view with this ViewGroup's default layout parameters and the
+     * specified width and height.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param child the child view to add
+     */
+    public void addView(View child, int width, int height) {
+        final LayoutParams params = generateDefaultLayoutParams();
+        params.width = width;
+        params.height = height;
+        addView(child, -1, params);
+    }
+
+    /**
+     * Adds a child view with the specified layout parameters.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param child the child view to add
+     * @param params the layout parameters to set on the child
+     */
+    @Override
+    public void addView(View child, LayoutParams params) {
+        addView(child, -1, params);
+    }
+
+    /**
+     * Adds a child view with the specified layout parameters.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param child the child view to add
+     * @param index the position at which to add the child or -1 to add last
+     * @param params the layout parameters to set on the child
+     */
+    public void addView(View child, int index, LayoutParams params) {
+        if (DBG) {
+            System.out.println(this + " addView");
+        }
+
+        if (child == null) {
+            throw new IllegalArgumentException("Cannot add a null child view to a ViewGroup");
+        }
+
+        // addViewInner() will call child.requestLayout() when setting the new LayoutParams
+        // therefore, we call requestLayout() on ourselves before, so that the child's request
+        // will be blocked at our level
+        requestLayout();
+        invalidate(true);
+        addViewInner(child, index, params, false);
+    }
+
+    @Override
+    public void updateViewLayout(View view, ViewGroup.LayoutParams params) {
+        if (!checkLayoutParams(params)) {
+            throw new IllegalArgumentException("Invalid LayoutParams supplied to " + this);
+        }
+        if (view.mParent != this) {
+            throw new IllegalArgumentException("Given view not a child of " + this);
+        }
+        view.setLayoutParams(params);
+    }
+
+    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
+        return  p != null;
+    }
+
+    /**
+     * Interface definition for a callback to be invoked when the hierarchy
+     * within this view changed. The hierarchy changes whenever a child is added
+     * to or removed from this view.
+     */
+    public interface OnHierarchyChangeListener {
+        /**
+         * Called when a new child is added to a parent view.
+         *
+         * @param parent the view in which a child was added
+         * @param child the new child view added in the hierarchy
+         */
+        void onChildViewAdded(View parent, View child);
+
+        /**
+         * Called when a child is removed from a parent view.
+         *
+         * @param parent the view from which the child was removed
+         * @param child the child removed from the hierarchy
+         */
+        void onChildViewRemoved(View parent, View child);
+    }
+
+    /**
+     * Register a callback to be invoked when a child is added to or removed
+     * from this view.
+     *
+     * @param listener the callback to invoke on hierarchy change
+     */
+    public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
+        mOnHierarchyChangeListener = listener;
+    }
+
+    void dispatchViewAdded(View child) {
+        onViewAdded(child);
+        if (mOnHierarchyChangeListener != null) {
+            mOnHierarchyChangeListener.onChildViewAdded(this, child);
+        }
+    }
+
+    /**
+     * Called when a new child is added to this ViewGroup. Overrides should always
+     * call super.onViewAdded.
+     *
+     * @param child the added child view
+     */
+    public void onViewAdded(View child) {
+    }
+
+    void dispatchViewRemoved(View child) {
+        onViewRemoved(child);
+        if (mOnHierarchyChangeListener != null) {
+            mOnHierarchyChangeListener.onChildViewRemoved(this, child);
+        }
+    }
+
+    /**
+     * Called when a child view is removed from this ViewGroup. Overrides should always
+     * call super.onViewRemoved.
+     *
+     * @param child the removed child view
+     */
+    public void onViewRemoved(View child) {
+    }
+
+    private void clearCachedLayoutMode() {
+        if (!hasBooleanFlag(FLAG_LAYOUT_MODE_WAS_EXPLICITLY_SET)) {
+           mLayoutMode = LAYOUT_MODE_UNDEFINED;
+        }
+    }
+
+    @Override
+    protected void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        clearCachedLayoutMode();
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        clearCachedLayoutMode();
+    }
+
+    /** @hide */
+    @Override
+    protected void destroyHardwareResources() {
+        super.destroyHardwareResources();
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            getChildAt(i).destroyHardwareResources();
+        }
+    }
+
+    /**
+     * Adds a view during layout. This is useful if in your onLayout() method,
+     * you need to add more views (as does the list view for example).
+     *
+     * If index is negative, it means put it at the end of the list.
+     *
+     * @param child the view to add to the group
+     * @param index the index at which the child must be added or -1 to add last
+     * @param params the layout parameters to associate with the child
+     * @return true if the child was added, false otherwise
+     */
+    protected boolean addViewInLayout(View child, int index, LayoutParams params) {
+        return addViewInLayout(child, index, params, false);
+    }
+
+    /**
+     * Adds a view during layout. This is useful if in your onLayout() method,
+     * you need to add more views (as does the list view for example).
+     *
+     * If index is negative, it means put it at the end of the list.
+     *
+     * @param child the view to add to the group
+     * @param index the index at which the child must be added or -1 to add last
+     * @param params the layout parameters to associate with the child
+     * @param preventRequestLayout if true, calling this method will not trigger a
+     *        layout request on child
+     * @return true if the child was added, false otherwise
+     */
+    protected boolean addViewInLayout(View child, int index, LayoutParams params,
+            boolean preventRequestLayout) {
+        if (child == null) {
+            throw new IllegalArgumentException("Cannot add a null child view to a ViewGroup");
+        }
+        child.mParent = null;
+        addViewInner(child, index, params, preventRequestLayout);
+        child.mPrivateFlags = (child.mPrivateFlags & ~PFLAG_DIRTY_MASK) | PFLAG_DRAWN;
+        return true;
+    }
+
+    /**
+     * Prevents the specified child to be laid out during the next layout pass.
+     *
+     * @param child the child on which to perform the cleanup
+     */
+    protected void cleanupLayoutState(View child) {
+        child.mPrivateFlags &= ~View.PFLAG_FORCE_LAYOUT;
+    }
+
+    private void addViewInner(View child, int index, LayoutParams params,
+            boolean preventRequestLayout) {
+
+        if (mTransition != null) {
+            // Don't prevent other add transitions from completing, but cancel remove
+            // transitions to let them complete the process before we add to the container
+            mTransition.cancel(LayoutTransition.DISAPPEARING);
+        }
+
+        if (child.getParent() != null) {
+            throw new IllegalStateException("The specified child already has a parent. " +
+                    "You must call removeView() on the child's parent first.");
+        }
+
+        if (mTransition != null) {
+            mTransition.addChild(this, child);
+        }
+
+        if (!checkLayoutParams(params)) {
+            params = generateLayoutParams(params);
+        }
+
+        if (preventRequestLayout) {
+            child.mLayoutParams = params;
+        } else {
+            child.setLayoutParams(params);
+        }
+
+        if (index < 0) {
+            index = mChildrenCount;
+        }
+
+        addInArray(child, index);
+
+        // tell our children
+        if (preventRequestLayout) {
+            child.assignParent(this);
+        } else {
+            child.mParent = this;
+        }
+
+        final boolean childHasFocus = child.hasFocus();
+        if (childHasFocus) {
+            requestChildFocus(child, child.findFocus());
+        }
+
+        AttachInfo ai = mAttachInfo;
+        if (ai != null && (mGroupFlags & FLAG_PREVENT_DISPATCH_ATTACHED_TO_WINDOW) == 0) {
+            boolean lastKeepOn = ai.mKeepScreenOn;
+            ai.mKeepScreenOn = false;
+            child.dispatchAttachedToWindow(mAttachInfo, (mViewFlags&VISIBILITY_MASK));
+            if (ai.mKeepScreenOn) {
+                needGlobalAttributesUpdate(true);
+            }
+            ai.mKeepScreenOn = lastKeepOn;
+        }
+
+        if (child.isLayoutDirectionInherited()) {
+            child.resetRtlProperties();
+        }
+
+        dispatchViewAdded(child);
+
+        if ((child.mViewFlags & DUPLICATE_PARENT_STATE) == DUPLICATE_PARENT_STATE) {
+            mGroupFlags |= FLAG_NOTIFY_CHILDREN_ON_DRAWABLE_STATE_CHANGE;
+        }
+
+        if (child.hasTransientState()) {
+            childHasTransientStateChanged(child, true);
+        }
+
+        if (child.getVisibility() != View.GONE) {
+            notifySubtreeAccessibilityStateChangedIfNeeded();
+        }
+
+        if (mTransientIndices != null) {
+            final int transientCount = mTransientIndices.size();
+            for (int i = 0; i < transientCount; ++i) {
+                final int oldIndex = mTransientIndices.get(i);
+                if (index <= oldIndex) {
+                    mTransientIndices.set(i, oldIndex + 1);
+                }
+            }
+        }
+
+        if (mCurrentDragStartEvent != null && child.getVisibility() == VISIBLE) {
+            notifyChildOfDragStart(child);
+        }
+
+        if (child.hasDefaultFocus()) {
+            // When adding a child that contains default focus, either during inflation or while
+            // manually assembling the hierarchy, update the ancestor default-focus chain.
+            setDefaultFocus(child);
+        }
+    }
+
+    private void addInArray(View child, int index) {
+        View[] children = mChildren;
+        final int count = mChildrenCount;
+        final int size = children.length;
+        if (index == count) {
+            if (size == count) {
+                mChildren = new View[size + ARRAY_CAPACITY_INCREMENT];
+                System.arraycopy(children, 0, mChildren, 0, size);
+                children = mChildren;
+            }
+            children[mChildrenCount++] = child;
+        } else if (index < count) {
+            if (size == count) {
+                mChildren = new View[size + ARRAY_CAPACITY_INCREMENT];
+                System.arraycopy(children, 0, mChildren, 0, index);
+                System.arraycopy(children, index, mChildren, index + 1, count - index);
+                children = mChildren;
+            } else {
+                System.arraycopy(children, index, children, index + 1, count - index);
+            }
+            children[index] = child;
+            mChildrenCount++;
+            if (mLastTouchDownIndex >= index) {
+                mLastTouchDownIndex++;
+            }
+        } else {
+            throw new IndexOutOfBoundsException("index=" + index + " count=" + count);
+        }
+    }
+
+    // This method also sets the child's mParent to null
+    private void removeFromArray(int index) {
+        final View[] children = mChildren;
+        if (!(mTransitioningViews != null && mTransitioningViews.contains(children[index]))) {
+            children[index].mParent = null;
+        }
+        final int count = mChildrenCount;
+        if (index == count - 1) {
+            children[--mChildrenCount] = null;
+        } else if (index >= 0 && index < count) {
+            System.arraycopy(children, index + 1, children, index, count - index - 1);
+            children[--mChildrenCount] = null;
+        } else {
+            throw new IndexOutOfBoundsException();
+        }
+        if (mLastTouchDownIndex == index) {
+            mLastTouchDownTime = 0;
+            mLastTouchDownIndex = -1;
+        } else if (mLastTouchDownIndex > index) {
+            mLastTouchDownIndex--;
+        }
+    }
+
+    // This method also sets the children's mParent to null
+    private void removeFromArray(int start, int count) {
+        final View[] children = mChildren;
+        final int childrenCount = mChildrenCount;
+
+        start = Math.max(0, start);
+        final int end = Math.min(childrenCount, start + count);
+
+        if (start == end) {
+            return;
+        }
+
+        if (end == childrenCount) {
+            for (int i = start; i < end; i++) {
+                children[i].mParent = null;
+                children[i] = null;
+            }
+        } else {
+            for (int i = start; i < end; i++) {
+                children[i].mParent = null;
+            }
+
+            // Since we're looping above, we might as well do the copy, but is arraycopy()
+            // faster than the extra 2 bounds checks we would do in the loop?
+            System.arraycopy(children, end, children, start, childrenCount - end);
+
+            for (int i = childrenCount - (end - start); i < childrenCount; i++) {
+                children[i] = null;
+            }
+        }
+
+        mChildrenCount -= (end - start);
+    }
+
+    private void bindLayoutAnimation(View child) {
+        Animation a = mLayoutAnimationController.getAnimationForView(child);
+        child.setAnimation(a);
+    }
+
+    /**
+     * Subclasses should override this method to set layout animation
+     * parameters on the supplied child.
+     *
+     * @param child the child to associate with animation parameters
+     * @param params the child's layout parameters which hold the animation
+     *        parameters
+     * @param index the index of the child in the view group
+     * @param count the number of children in the view group
+     */
+    protected void attachLayoutAnimationParameters(View child,
+            LayoutParams params, int index, int count) {
+        LayoutAnimationController.AnimationParameters animationParams =
+                    params.layoutAnimationParameters;
+        if (animationParams == null) {
+            animationParams = new LayoutAnimationController.AnimationParameters();
+            params.layoutAnimationParameters = animationParams;
+        }
+
+        animationParams.count = count;
+        animationParams.index = index;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     */
+    @Override
+    public void removeView(View view) {
+        if (removeViewInternal(view)) {
+            requestLayout();
+            invalidate(true);
+        }
+    }
+
+    /**
+     * Removes a view during layout. This is useful if in your onLayout() method,
+     * you need to remove more views.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param view the view to remove from the group
+     */
+    public void removeViewInLayout(View view) {
+        removeViewInternal(view);
+    }
+
+    /**
+     * Removes a range of views during layout. This is useful if in your onLayout() method,
+     * you need to remove more views.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param start the index of the first view to remove from the group
+     * @param count the number of views to remove from the group
+     */
+    public void removeViewsInLayout(int start, int count) {
+        removeViewsInternal(start, count);
+    }
+
+    /**
+     * Removes the view at the specified position in the group.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param index the position in the group of the view to remove
+     */
+    public void removeViewAt(int index) {
+        removeViewInternal(index, getChildAt(index));
+        requestLayout();
+        invalidate(true);
+    }
+
+    /**
+     * Removes the specified range of views from the group.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     *
+     * @param start the first position in the group of the range of views to remove
+     * @param count the number of views to remove
+     */
+    public void removeViews(int start, int count) {
+        removeViewsInternal(start, count);
+        requestLayout();
+        invalidate(true);
+    }
+
+    private boolean removeViewInternal(View view) {
+        final int index = indexOfChild(view);
+        if (index >= 0) {
+            removeViewInternal(index, view);
+            return true;
+        }
+        return false;
+    }
+
+    private void removeViewInternal(int index, View view) {
+        if (mTransition != null) {
+            mTransition.removeChild(this, view);
+        }
+
+        boolean clearChildFocus = false;
+        if (view == mFocused) {
+            view.unFocus(null);
+            clearChildFocus = true;
+        }
+        if (view == mFocusedInCluster) {
+            clearFocusedInCluster(view);
+        }
+
+        view.clearAccessibilityFocus();
+
+        cancelTouchTarget(view);
+        cancelHoverTarget(view);
+
+        if (view.getAnimation() != null ||
+                (mTransitioningViews != null && mTransitioningViews.contains(view))) {
+            addDisappearingView(view);
+        } else if (view.mAttachInfo != null) {
+           view.dispatchDetachedFromWindow();
+        }
+
+        if (view.hasTransientState()) {
+            childHasTransientStateChanged(view, false);
+        }
+
+        needGlobalAttributesUpdate(false);
+
+        removeFromArray(index);
+
+        if (view == mDefaultFocus) {
+            clearDefaultFocus(view);
+        }
+        if (clearChildFocus) {
+            clearChildFocus(view);
+            if (!rootViewRequestFocus()) {
+                notifyGlobalFocusCleared(this);
+            }
+        }
+
+        dispatchViewRemoved(view);
+
+        if (view.getVisibility() != View.GONE) {
+            notifySubtreeAccessibilityStateChangedIfNeeded();
+        }
+
+        int transientCount = mTransientIndices == null ? 0 : mTransientIndices.size();
+        for (int i = 0; i < transientCount; ++i) {
+            final int oldIndex = mTransientIndices.get(i);
+            if (index < oldIndex) {
+                mTransientIndices.set(i, oldIndex - 1);
+            }
+        }
+
+        if (mCurrentDragStartEvent != null) {
+            mChildrenInterestedInDrag.remove(view);
+        }
+    }
+
+    /**
+     * Sets the LayoutTransition object for this ViewGroup. If the LayoutTransition object is
+     * not null, changes in layout which occur because of children being added to or removed from
+     * the ViewGroup will be animated according to the animations defined in that LayoutTransition
+     * object. By default, the transition object is null (so layout changes are not animated).
+     *
+     * <p>Replacing a non-null transition will cause that previous transition to be
+     * canceled, if it is currently running, to restore this container to
+     * its correct post-transition state.</p>
+     *
+     * @param transition The LayoutTransition object that will animated changes in layout. A value
+     * of <code>null</code> means no transition will run on layout changes.
+     * @attr ref android.R.styleable#ViewGroup_animateLayoutChanges
+     */
+    public void setLayoutTransition(LayoutTransition transition) {
+        if (mTransition != null) {
+            LayoutTransition previousTransition = mTransition;
+            previousTransition.cancel();
+            previousTransition.removeTransitionListener(mLayoutTransitionListener);
+        }
+        mTransition = transition;
+        if (mTransition != null) {
+            mTransition.addTransitionListener(mLayoutTransitionListener);
+        }
+    }
+
+    /**
+     * Gets the LayoutTransition object for this ViewGroup. If the LayoutTransition object is
+     * not null, changes in layout which occur because of children being added to or removed from
+     * the ViewGroup will be animated according to the animations defined in that LayoutTransition
+     * object. By default, the transition object is null (so layout changes are not animated).
+     *
+     * @return LayoutTranstion The LayoutTransition object that will animated changes in layout.
+     * A value of <code>null</code> means no transition will run on layout changes.
+     */
+    public LayoutTransition getLayoutTransition() {
+        return mTransition;
+    }
+
+    private void removeViewsInternal(int start, int count) {
+        final int end = start + count;
+
+        if (start < 0 || count < 0 || end > mChildrenCount) {
+            throw new IndexOutOfBoundsException();
+        }
+
+        final View focused = mFocused;
+        final boolean detach = mAttachInfo != null;
+        boolean clearChildFocus = false;
+        View clearDefaultFocus = null;
+
+        final View[] children = mChildren;
+
+        for (int i = start; i < end; i++) {
+            final View view = children[i];
+
+            if (mTransition != null) {
+                mTransition.removeChild(this, view);
+            }
+
+            if (view == focused) {
+                view.unFocus(null);
+                clearChildFocus = true;
+            }
+            if (view == mDefaultFocus) {
+                clearDefaultFocus = view;
+            }
+            if (view == mFocusedInCluster) {
+                clearFocusedInCluster(view);
+            }
+
+            view.clearAccessibilityFocus();
+
+            cancelTouchTarget(view);
+            cancelHoverTarget(view);
+
+            if (view.getAnimation() != null ||
+                (mTransitioningViews != null && mTransitioningViews.contains(view))) {
+                addDisappearingView(view);
+            } else if (detach) {
+               view.dispatchDetachedFromWindow();
+            }
+
+            if (view.hasTransientState()) {
+                childHasTransientStateChanged(view, false);
+            }
+
+            needGlobalAttributesUpdate(false);
+
+            dispatchViewRemoved(view);
+        }
+
+        removeFromArray(start, count);
+
+        if (clearDefaultFocus != null) {
+            clearDefaultFocus(clearDefaultFocus);
+        }
+        if (clearChildFocus) {
+            clearChildFocus(focused);
+            if (!rootViewRequestFocus()) {
+                notifyGlobalFocusCleared(focused);
+            }
+        }
+    }
+
+    /**
+     * Call this method to remove all child views from the
+     * ViewGroup.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     */
+    public void removeAllViews() {
+        removeAllViewsInLayout();
+        requestLayout();
+        invalidate(true);
+    }
+
+    /**
+     * Called by a ViewGroup subclass to remove child views from itself,
+     * when it must first know its size on screen before it can calculate how many
+     * child views it will render. An example is a Gallery or a ListView, which
+     * may "have" 50 children, but actually only render the number of children
+     * that can currently fit inside the object on screen. Do not call
+     * this method unless you are extending ViewGroup and understand the
+     * view measuring and layout pipeline.
+     *
+     * <p><strong>Note:</strong> do not invoke this method from
+     * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
+     * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
+     */
+    public void removeAllViewsInLayout() {
+        final int count = mChildrenCount;
+        if (count <= 0) {
+            return;
+        }
+
+        final View[] children = mChildren;
+        mChildrenCount = 0;
+
+        final View focused = mFocused;
+        final boolean detach = mAttachInfo != null;
+        boolean clearChildFocus = false;
+
+        needGlobalAttributesUpdate(false);
+
+        for (int i = count - 1; i >= 0; i--) {
+            final View view = children[i];
+
+            if (mTransition != null) {
+                mTransition.removeChild(this, view);
+            }
+
+            if (view == focused) {
+                view.unFocus(null);
+                clearChildFocus = true;
+            }
+
+            view.clearAccessibilityFocus();
+
+            cancelTouchTarget(view);
+            cancelHoverTarget(view);
+
+            if (view.getAnimation() != null ||
+                    (mTransitioningViews != null && mTransitioningViews.contains(view))) {
+                addDisappearingView(view);
+            } else if (detach) {
+               view.dispatchDetachedFromWindow();
+            }
+
+            if (view.hasTransientState()) {
+                childHasTransientStateChanged(view, false);
+            }
+
+            dispatchViewRemoved(view);
+
+            view.mParent = null;
+            children[i] = null;
+        }
+
+        if (mDefaultFocus != null) {
+            clearDefaultFocus(mDefaultFocus);
+        }
+        if (mFocusedInCluster != null) {
+            clearFocusedInCluster(mFocusedInCluster);
+        }
+        if (clearChildFocus) {
+            clearChildFocus(focused);
+            if (!rootViewRequestFocus()) {
+                notifyGlobalFocusCleared(focused);
+            }
+        }
+    }
+
+    /**
+     * Finishes the removal of a detached view. This method will dispatch the detached from
+     * window event and notify the hierarchy change listener.
+     * <p>
+     * This method is intended to be lightweight and makes no assumptions about whether the
+     * parent or child should be redrawn. Proper use of this method will include also making
+     * any appropriate {@link #requestLayout()} or {@link #invalidate()} calls.
+     * For example, callers can {@link #post(Runnable) post} a {@link Runnable}
+     * which performs a {@link #requestLayout()} on the next frame, after all detach/remove
+     * calls are finished, causing layout to be run prior to redrawing the view hierarchy.
+     *
+     * @param child the child to be definitely removed from the view hierarchy
+     * @param animate if true and the view has an animation, the view is placed in the
+     *                disappearing views list, otherwise, it is detached from the window
+     *
+     * @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
+     * @see #detachAllViewsFromParent()
+     * @see #detachViewFromParent(View)
+     * @see #detachViewFromParent(int)
+     */
+    protected void removeDetachedView(View child, boolean animate) {
+        if (mTransition != null) {
+            mTransition.removeChild(this, child);
+        }
+
+        if (child == mFocused) {
+            child.clearFocus();
+        }
+        if (child == mDefaultFocus) {
+            clearDefaultFocus(child);
+        }
+        if (child == mFocusedInCluster) {
+            clearFocusedInCluster(child);
+        }
+
+        child.clearAccessibilityFocus();
+
+        cancelTouchTarget(child);
+        cancelHoverTarget(child);
+
+        if ((animate && child.getAnimation() != null) ||
+                (mTransitioningViews != null && mTransitioningViews.contains(child))) {
+            addDisappearingView(child);
+        } else if (child.mAttachInfo != null) {
+            child.dispatchDetachedFromWindow();
+        }
+
+        if (child.hasTransientState()) {
+            childHasTransientStateChanged(child, false);
+        }
+
+        dispatchViewRemoved(child);
+    }
+
+    /**
+     * Attaches a view to this view group. Attaching a view assigns this group as the parent,
+     * sets the layout parameters and puts the view in the list of children so that
+     * it can be retrieved by calling {@link #getChildAt(int)}.
+     * <p>
+     * This method is intended to be lightweight and makes no assumptions about whether the
+     * parent or child should be redrawn. Proper use of this method will include also making
+     * any appropriate {@link #requestLayout()} or {@link #invalidate()} calls.
+     * For example, callers can {@link #post(Runnable) post} a {@link Runnable}
+     * which performs a {@link #requestLayout()} on the next frame, after all detach/attach
+     * calls are finished, causing layout to be run prior to redrawing the view hierarchy.
+     * <p>
+     * This method should be called only for views which were detached from their parent.
+     *
+     * @param child the child to attach
+     * @param index the index at which the child should be attached
+     * @param params the layout parameters of the child
+     *
+     * @see #removeDetachedView(View, boolean)
+     * @see #detachAllViewsFromParent()
+     * @see #detachViewFromParent(View)
+     * @see #detachViewFromParent(int)
+     */
+    protected void attachViewToParent(View child, int index, LayoutParams params) {
+        child.mLayoutParams = params;
+
+        if (index < 0) {
+            index = mChildrenCount;
+        }
+
+        addInArray(child, index);
+
+        child.mParent = this;
+        child.mPrivateFlags = (child.mPrivateFlags & ~PFLAG_DIRTY_MASK
+                        & ~PFLAG_DRAWING_CACHE_VALID)
+                | PFLAG_DRAWN | PFLAG_INVALIDATED;
+        this.mPrivateFlags |= PFLAG_INVALIDATED;
+
+        if (child.hasFocus()) {
+            requestChildFocus(child, child.findFocus());
+        }
+        dispatchVisibilityAggregated(isAttachedToWindow() && getWindowVisibility() == VISIBLE
+                && isShown());
+    }
+
+    /**
+     * Detaches a view from its parent. Detaching a view should be followed
+     * either by a call to
+     * {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
+     * or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
+     * temporary; reattachment or removal should happen within the same drawing cycle as
+     * detachment. When a view is detached, its parent is null and cannot be retrieved by a
+     * call to {@link #getChildAt(int)}.
+     *
+     * @param child the child to detach
+     *
+     * @see #detachViewFromParent(int)
+     * @see #detachViewsFromParent(int, int)
+     * @see #detachAllViewsFromParent()
+     * @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
+     * @see #removeDetachedView(View, boolean)
+     */
+    protected void detachViewFromParent(View child) {
+        removeFromArray(indexOfChild(child));
+    }
+
+    /**
+     * Detaches a view from its parent. Detaching a view should be followed
+     * either by a call to
+     * {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
+     * or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
+     * temporary; reattachment or removal should happen within the same drawing cycle as
+     * detachment. When a view is detached, its parent is null and cannot be retrieved by a
+     * call to {@link #getChildAt(int)}.
+     *
+     * @param index the index of the child to detach
+     *
+     * @see #detachViewFromParent(View)
+     * @see #detachAllViewsFromParent()
+     * @see #detachViewsFromParent(int, int)
+     * @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
+     * @see #removeDetachedView(View, boolean)
+     */
+    protected void detachViewFromParent(int index) {
+        removeFromArray(index);
+    }
+
+    /**
+     * Detaches a range of views from their parents. Detaching a view should be followed
+     * either by a call to
+     * {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
+     * or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
+     * temporary; reattachment or removal should happen within the same drawing cycle as
+     * detachment. When a view is detached, its parent is null and cannot be retrieved by a
+     * call to {@link #getChildAt(int)}.
+     *
+     * @param start the first index of the childrend range to detach
+     * @param count the number of children to detach
+     *
+     * @see #detachViewFromParent(View)
+     * @see #detachViewFromParent(int)
+     * @see #detachAllViewsFromParent()
+     * @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
+     * @see #removeDetachedView(View, boolean)
+     */
+    protected void detachViewsFromParent(int start, int count) {
+        removeFromArray(start, count);
+    }
+
+    /**
+     * Detaches all views from the parent. Detaching a view should be followed
+     * either by a call to
+     * {@link #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)}
+     * or a call to {@link #removeDetachedView(View, boolean)}. Detachment should only be
+     * temporary; reattachment or removal should happen within the same drawing cycle as
+     * detachment. When a view is detached, its parent is null and cannot be retrieved by a
+     * call to {@link #getChildAt(int)}.
+     *
+     * @see #detachViewFromParent(View)
+     * @see #detachViewFromParent(int)
+     * @see #detachViewsFromParent(int, int)
+     * @see #attachViewToParent(View, int, android.view.ViewGroup.LayoutParams)
+     * @see #removeDetachedView(View, boolean)
+     */
+    protected void detachAllViewsFromParent() {
+        final int count = mChildrenCount;
+        if (count <= 0) {
+            return;
+        }
+
+        final View[] children = mChildren;
+        mChildrenCount = 0;
+
+        for (int i = count - 1; i >= 0; i--) {
+            children[i].mParent = null;
+            children[i] = null;
+        }
+    }
+
+    @Override
+    @CallSuper
+    public void onDescendantInvalidated(@NonNull View child, @NonNull View target) {
+        /*
+         * HW-only, Rect-ignoring damage codepath
+         *
+         * We don't deal with rectangles here, since RenderThread native code computes damage for
+         * everything drawn by HWUI (and SW layer / drawing cache doesn't keep track of damage area)
+         */
+
+        // if set, combine the animation flag into the parent
+        mPrivateFlags |= (target.mPrivateFlags & PFLAG_DRAW_ANIMATION);
+
+        if ((target.mPrivateFlags & ~PFLAG_DIRTY_MASK) != 0) {
+            // We lazily use PFLAG_DIRTY, since computing opaque isn't worth the potential
+            // optimization in provides in a DisplayList world.
+            mPrivateFlags = (mPrivateFlags & ~PFLAG_DIRTY_MASK) | PFLAG_DIRTY;
+
+            // simplified invalidateChildInParent behavior: clear cache validity to be safe...
+            mPrivateFlags &= ~PFLAG_DRAWING_CACHE_VALID;
+        }
+
+        // ... and mark inval if in software layer that needs to repaint (hw handled in native)
+        if (mLayerType == LAYER_TYPE_SOFTWARE) {
+            // Layered parents should be invalidated. Escalate to a full invalidate (and note that
+            // we do this after consuming any relevant flags from the originating descendant)
+            mPrivateFlags |= PFLAG_INVALIDATED | PFLAG_DIRTY;
+            target = this;
+        }
+
+        if (mParent != null) {
+            mParent.onDescendantInvalidated(this, target);
+        }
+    }
+
+
+    /**
+     * Don't call or override this method. It is used for the implementation of
+     * the view hierarchy.
+     *
+     * @deprecated Use {@link #onDescendantInvalidated(View, View)} instead to observe updates to
+     * draw state in descendants.
+     */
+    @Deprecated
+    @Override
+    public final void invalidateChild(View child, final Rect dirty) {
+        final AttachInfo attachInfo = mAttachInfo;
+        if (attachInfo != null && attachInfo.mHardwareAccelerated) {
+            // HW accelerated fast path
+            onDescendantInvalidated(child, child);
+            return;
+        }
+
+        ViewParent parent = this;
+        if (attachInfo != null) {
+            // If the child is drawing an animation, we want to copy this flag onto
+            // ourselves and the parent to make sure the invalidate request goes
+            // through
+            final boolean drawAnimation = (child.mPrivateFlags & PFLAG_DRAW_ANIMATION) != 0;
+
+            // Check whether the child that requests the invalidate is fully opaque
+            // Views being animated or transformed are not considered opaque because we may
+            // be invalidating their old position and need the parent to paint behind them.
+            Matrix childMatrix = child.getMatrix();
+            final boolean isOpaque = child.isOpaque() && !drawAnimation &&
+                    child.getAnimation() == null && childMatrix.isIdentity();
+            // Mark the child as dirty, using the appropriate flag
+            // Make sure we do not set both flags at the same time
+            int opaqueFlag = isOpaque ? PFLAG_DIRTY_OPAQUE : PFLAG_DIRTY;
+
+            if (child.mLayerType != LAYER_TYPE_NONE) {
+                mPrivateFlags |= PFLAG_INVALIDATED;
+                mPrivateFlags &= ~PFLAG_DRAWING_CACHE_VALID;
+            }
+
+            final int[] location = attachInfo.mInvalidateChildLocation;
+            location[CHILD_LEFT_INDEX] = child.mLeft;
+            location[CHILD_TOP_INDEX] = child.mTop;
+            if (!childMatrix.isIdentity() ||
+                    (mGroupFlags & ViewGroup.FLAG_SUPPORT_STATIC_TRANSFORMATIONS) != 0) {
+                RectF boundingRect = attachInfo.mTmpTransformRect;
+                boundingRect.set(dirty);
+                Matrix transformMatrix;
+                if ((mGroupFlags & ViewGroup.FLAG_SUPPORT_STATIC_TRANSFORMATIONS) != 0) {
+                    Transformation t = attachInfo.mTmpTransformation;
+                    boolean transformed = getChildStaticTransformation(child, t);
+                    if (transformed) {
+                        transformMatrix = attachInfo.mTmpMatrix;
+                        transformMatrix.set(t.getMatrix());
+                        if (!childMatrix.isIdentity()) {
+                            transformMatrix.preConcat(childMatrix);
+                        }
+                    } else {
+                        transformMatrix = childMatrix;
+                    }
+                } else {
+                    transformMatrix = childMatrix;
+                }
+                transformMatrix.mapRect(boundingRect);
+                dirty.set((int) Math.floor(boundingRect.left),
+                        (int) Math.floor(boundingRect.top),
+                        (int) Math.ceil(boundingRect.right),
+                        (int) Math.ceil(boundingRect.bottom));
+            }
+
+            do {
+                View view = null;
+                if (parent instanceof View) {
+                    view = (View) parent;
+                }
+
+                if (drawAnimation) {
+                    if (view != null) {
+                        view.mPrivateFlags |= PFLAG_DRAW_ANIMATION;
+                    } else if (parent instanceof ViewRootImpl) {
+                        ((ViewRootImpl) parent).mIsAnimating = true;
+                    }
+                }
+
+                // If the parent is dirty opaque or not dirty, mark it dirty with the opaque
+                // flag coming from the child that initiated the invalidate
+                if (view != null) {
+                    if ((view.mViewFlags & FADING_EDGE_MASK) != 0 &&
+                            view.getSolidColor() == 0) {
+                        opaqueFlag = PFLAG_DIRTY;
+                    }
+                    if ((view.mPrivateFlags & PFLAG_DIRTY_MASK) != PFLAG_DIRTY) {
+                        view.mPrivateFlags = (view.mPrivateFlags & ~PFLAG_DIRTY_MASK) | opaqueFlag;
+                    }
+                }
+
+                parent = parent.invalidateChildInParent(location, dirty);
+                if (view != null) {
+                    // Account for transform on current parent
+                    Matrix m = view.getMatrix();
+                    if (!m.isIdentity()) {
+                        RectF boundingRect = attachInfo.mTmpTransformRect;
+                        boundingRect.set(dirty);
+                        m.mapRect(boundingRect);
+                        dirty.set((int) Math.floor(boundingRect.left),
+                                (int) Math.floor(boundingRect.top),
+                                (int) Math.ceil(boundingRect.right),
+                                (int) Math.ceil(boundingRect.bottom));
+                    }
+                }
+            } while (parent != null);
+        }
+    }
+
+    /**
+     * Don't call or override this method. It is used for the implementation of
+     * the view hierarchy.
+     *
+     * This implementation returns null if this ViewGroup does not have a parent,
+     * if this ViewGroup is already fully invalidated or if the dirty rectangle
+     * does not intersect with this ViewGroup's bounds.
+     *
+     * @deprecated Use {@link #onDescendantInvalidated(View, View)} instead to observe updates to
+     * draw state in descendants.
+     */
+    @Deprecated
+    @Override
+    public ViewParent invalidateChildInParent(final int[] location, final Rect dirty) {
+        if ((mPrivateFlags & (PFLAG_DRAWN | PFLAG_DRAWING_CACHE_VALID)) != 0) {
+            // either DRAWN, or DRAWING_CACHE_VALID
+            if ((mGroupFlags & (FLAG_OPTIMIZE_INVALIDATE | FLAG_ANIMATION_DONE))
+                    != FLAG_OPTIMIZE_INVALIDATE) {
+                dirty.offset(location[CHILD_LEFT_INDEX] - mScrollX,
+                        location[CHILD_TOP_INDEX] - mScrollY);
+                if ((mGroupFlags & FLAG_CLIP_CHILDREN) == 0) {
+                    dirty.union(0, 0, mRight - mLeft, mBottom - mTop);
+                }
+
+                final int left = mLeft;
+                final int top = mTop;
+
+                if ((mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN) {
+                    if (!dirty.intersect(0, 0, mRight - left, mBottom - top)) {
+                        dirty.setEmpty();
+                    }
+                }
+
+                location[CHILD_LEFT_INDEX] = left;
+                location[CHILD_TOP_INDEX] = top;
+            } else {
+
+                if ((mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN) {
+                    dirty.set(0, 0, mRight - mLeft, mBottom - mTop);
+                } else {
+                    // in case the dirty rect extends outside the bounds of this container
+                    dirty.union(0, 0, mRight - mLeft, mBottom - mTop);
+                }
+                location[CHILD_LEFT_INDEX] = mLeft;
+                location[CHILD_TOP_INDEX] = mTop;
+
+                mPrivateFlags &= ~PFLAG_DRAWN;
+            }
+            mPrivateFlags &= ~PFLAG_DRAWING_CACHE_VALID;
+            if (mLayerType != LAYER_TYPE_NONE) {
+                mPrivateFlags |= PFLAG_INVALIDATED;
+            }
+
+            return mParent;
+        }
+
+        return null;
+    }
+
+    /**
+     * Offset a rectangle that is in a descendant's coordinate
+     * space into our coordinate space.
+     * @param descendant A descendant of this view
+     * @param rect A rectangle defined in descendant's coordinate space.
+     */
+    public final void offsetDescendantRectToMyCoords(View descendant, Rect rect) {
+        offsetRectBetweenParentAndChild(descendant, rect, true, false);
+    }
+
+    /**
+     * Offset a rectangle that is in our coordinate space into an ancestor's
+     * coordinate space.
+     * @param descendant A descendant of this view
+     * @param rect A rectangle defined in descendant's coordinate space.
+     */
+    public final void offsetRectIntoDescendantCoords(View descendant, Rect rect) {
+        offsetRectBetweenParentAndChild(descendant, rect, false, false);
+    }
+
+    /**
+     * Helper method that offsets a rect either from parent to descendant or
+     * descendant to parent.
+     */
+    void offsetRectBetweenParentAndChild(View descendant, Rect rect,
+            boolean offsetFromChildToParent, boolean clipToBounds) {
+
+        // already in the same coord system :)
+        if (descendant == this) {
+            return;
+        }
+
+        ViewParent theParent = descendant.mParent;
+
+        // search and offset up to the parent
+        while ((theParent != null)
+                && (theParent instanceof View)
+                && (theParent != this)) {
+
+            if (offsetFromChildToParent) {
+                rect.offset(descendant.mLeft - descendant.mScrollX,
+                        descendant.mTop - descendant.mScrollY);
+                if (clipToBounds) {
+                    View p = (View) theParent;
+                    boolean intersected = rect.intersect(0, 0, p.mRight - p.mLeft,
+                            p.mBottom - p.mTop);
+                    if (!intersected) {
+                        rect.setEmpty();
+                    }
+                }
+            } else {
+                if (clipToBounds) {
+                    View p = (View) theParent;
+                    boolean intersected = rect.intersect(0, 0, p.mRight - p.mLeft,
+                            p.mBottom - p.mTop);
+                    if (!intersected) {
+                        rect.setEmpty();
+                    }
+                }
+                rect.offset(descendant.mScrollX - descendant.mLeft,
+                        descendant.mScrollY - descendant.mTop);
+            }
+
+            descendant = (View) theParent;
+            theParent = descendant.mParent;
+        }
+
+        // now that we are up to this view, need to offset one more time
+        // to get into our coordinate space
+        if (theParent == this) {
+            if (offsetFromChildToParent) {
+                rect.offset(descendant.mLeft - descendant.mScrollX,
+                        descendant.mTop - descendant.mScrollY);
+            } else {
+                rect.offset(descendant.mScrollX - descendant.mLeft,
+                        descendant.mScrollY - descendant.mTop);
+            }
+        } else {
+            throw new IllegalArgumentException("parameter must be a descendant of this view");
+        }
+    }
+
+    /**
+     * Offset the vertical location of all children of this view by the specified number of pixels.
+     *
+     * @param offset the number of pixels to offset
+     *
+     * @hide
+     */
+    public void offsetChildrenTopAndBottom(int offset) {
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        boolean invalidate = false;
+
+        for (int i = 0; i < count; i++) {
+            final View v = children[i];
+            v.mTop += offset;
+            v.mBottom += offset;
+            if (v.mRenderNode != null) {
+                invalidate = true;
+                v.mRenderNode.offsetTopAndBottom(offset);
+            }
+        }
+
+        if (invalidate) {
+            invalidateViewProperty(false, false);
+        }
+        notifySubtreeAccessibilityStateChangedIfNeeded();
+    }
+
+    @Override
+    public boolean getChildVisibleRect(View child, Rect r, android.graphics.Point offset) {
+        return getChildVisibleRect(child, r, offset, false);
+    }
+
+    /**
+     * @param forceParentCheck true to guarantee that this call will propagate to all ancestors,
+     *      false otherwise
+     *
+     * @hide
+     */
+    public boolean getChildVisibleRect(
+            View child, Rect r, android.graphics.Point offset, boolean forceParentCheck) {
+        // It doesn't make a whole lot of sense to call this on a view that isn't attached,
+        // but for some simple tests it can be useful. If we don't have attach info this
+        // will allocate memory.
+        final RectF rect = mAttachInfo != null ? mAttachInfo.mTmpTransformRect : new RectF();
+        rect.set(r);
+
+        if (!child.hasIdentityMatrix()) {
+            child.getMatrix().mapRect(rect);
+        }
+
+        final int dx = child.mLeft - mScrollX;
+        final int dy = child.mTop - mScrollY;
+
+        rect.offset(dx, dy);
+
+        if (offset != null) {
+            if (!child.hasIdentityMatrix()) {
+                float[] position = mAttachInfo != null ? mAttachInfo.mTmpTransformLocation
+                        : new float[2];
+                position[0] = offset.x;
+                position[1] = offset.y;
+                child.getMatrix().mapPoints(position);
+                offset.x = Math.round(position[0]);
+                offset.y = Math.round(position[1]);
+            }
+            offset.x += dx;
+            offset.y += dy;
+        }
+
+        final int width = mRight - mLeft;
+        final int height = mBottom - mTop;
+
+        boolean rectIsVisible = true;
+        if (mParent == null ||
+                (mParent instanceof ViewGroup && ((ViewGroup) mParent).getClipChildren())) {
+            // Clip to bounds.
+            rectIsVisible = rect.intersect(0, 0, width, height);
+        }
+
+        if ((forceParentCheck || rectIsVisible)
+                && (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) {
+            // Clip to padding.
+            rectIsVisible = rect.intersect(mPaddingLeft, mPaddingTop,
+                    width - mPaddingRight, height - mPaddingBottom);
+        }
+
+        if ((forceParentCheck || rectIsVisible) && mClipBounds != null) {
+            // Clip to clipBounds.
+            rectIsVisible = rect.intersect(mClipBounds.left, mClipBounds.top, mClipBounds.right,
+                    mClipBounds.bottom);
+        }
+        r.set((int) Math.floor(rect.left), (int) Math.floor(rect.top),
+                (int) Math.ceil(rect.right), (int) Math.ceil(rect.bottom));
+
+        if ((forceParentCheck || rectIsVisible) && mParent != null) {
+            if (mParent instanceof ViewGroup) {
+                rectIsVisible = ((ViewGroup) mParent)
+                        .getChildVisibleRect(this, r, offset, forceParentCheck);
+            } else {
+                rectIsVisible = mParent.getChildVisibleRect(this, r, offset);
+            }
+        }
+        return rectIsVisible;
+    }
+
+    @Override
+    public final void layout(int l, int t, int r, int b) {
+        if (!mSuppressLayout && (mTransition == null || !mTransition.isChangingLayout())) {
+            if (mTransition != null) {
+                mTransition.layoutChange(this);
+            }
+            super.layout(l, t, r, b);
+        } else {
+            // record the fact that we noop'd it; request layout when transition finishes
+            mLayoutCalledWhileSuppressed = true;
+        }
+    }
+
+    @Override
+    protected abstract void onLayout(boolean changed,
+            int l, int t, int r, int b);
+
+    /**
+     * Indicates whether the view group has the ability to animate its children
+     * after the first layout.
+     *
+     * @return true if the children can be animated, false otherwise
+     */
+    protected boolean canAnimate() {
+        return mLayoutAnimationController != null;
+    }
+
+    /**
+     * Runs the layout animation. Calling this method triggers a relayout of
+     * this view group.
+     */
+    public void startLayoutAnimation() {
+        if (mLayoutAnimationController != null) {
+            mGroupFlags |= FLAG_RUN_ANIMATION;
+            requestLayout();
+        }
+    }
+
+    /**
+     * Schedules the layout animation to be played after the next layout pass
+     * of this view group. This can be used to restart the layout animation
+     * when the content of the view group changes or when the activity is
+     * paused and resumed.
+     */
+    public void scheduleLayoutAnimation() {
+        mGroupFlags |= FLAG_RUN_ANIMATION;
+    }
+
+    /**
+     * Sets the layout animation controller used to animate the group's
+     * children after the first layout.
+     *
+     * @param controller the animation controller
+     */
+    public void setLayoutAnimation(LayoutAnimationController controller) {
+        mLayoutAnimationController = controller;
+        if (mLayoutAnimationController != null) {
+            mGroupFlags |= FLAG_RUN_ANIMATION;
+        }
+    }
+
+    /**
+     * Returns the layout animation controller used to animate the group's
+     * children.
+     *
+     * @return the current animation controller
+     */
+    public LayoutAnimationController getLayoutAnimation() {
+        return mLayoutAnimationController;
+    }
+
+    /**
+     * Indicates whether the children's drawing cache is used during a layout
+     * animation. By default, the drawing cache is enabled but this will prevent
+     * nested layout animations from working. To nest animations, you must disable
+     * the cache.
+     *
+     * @return true if the animation cache is enabled, false otherwise
+     *
+     * @see #setAnimationCacheEnabled(boolean)
+     * @see View#setDrawingCacheEnabled(boolean)
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Caching behavior of children may be controlled through {@link View#setLayerType(int, Paint)}.
+     */
+    @Deprecated
+    public boolean isAnimationCacheEnabled() {
+        return (mGroupFlags & FLAG_ANIMATION_CACHE) == FLAG_ANIMATION_CACHE;
+    }
+
+    /**
+     * Enables or disables the children's drawing cache during a layout animation.
+     * By default, the drawing cache is enabled but this will prevent nested
+     * layout animations from working. To nest animations, you must disable the
+     * cache.
+     *
+     * @param enabled true to enable the animation cache, false otherwise
+     *
+     * @see #isAnimationCacheEnabled()
+     * @see View#setDrawingCacheEnabled(boolean)
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Caching behavior of children may be controlled through {@link View#setLayerType(int, Paint)}.
+     */
+    @Deprecated
+    public void setAnimationCacheEnabled(boolean enabled) {
+        setBooleanFlag(FLAG_ANIMATION_CACHE, enabled);
+    }
+
+    /**
+     * Indicates whether this ViewGroup will always try to draw its children using their
+     * drawing cache. By default this property is enabled.
+     *
+     * @return true if the animation cache is enabled, false otherwise
+     *
+     * @see #setAlwaysDrawnWithCacheEnabled(boolean)
+     * @see #setChildrenDrawnWithCacheEnabled(boolean)
+     * @see View#setDrawingCacheEnabled(boolean)
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Child views may no longer have their caching behavior disabled by parents.
+     */
+    @Deprecated
+    public boolean isAlwaysDrawnWithCacheEnabled() {
+        return (mGroupFlags & FLAG_ALWAYS_DRAWN_WITH_CACHE) == FLAG_ALWAYS_DRAWN_WITH_CACHE;
+    }
+
+    /**
+     * Indicates whether this ViewGroup will always try to draw its children using their
+     * drawing cache. This property can be set to true when the cache rendering is
+     * slightly different from the children's normal rendering. Renderings can be different,
+     * for instance, when the cache's quality is set to low.
+     *
+     * When this property is disabled, the ViewGroup will use the drawing cache of its
+     * children only when asked to. It's usually the task of subclasses to tell ViewGroup
+     * when to start using the drawing cache and when to stop using it.
+     *
+     * @param always true to always draw with the drawing cache, false otherwise
+     *
+     * @see #isAlwaysDrawnWithCacheEnabled()
+     * @see #setChildrenDrawnWithCacheEnabled(boolean)
+     * @see View#setDrawingCacheEnabled(boolean)
+     * @see View#setDrawingCacheQuality(int)
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Child views may no longer have their caching behavior disabled by parents.
+     */
+    @Deprecated
+    public void setAlwaysDrawnWithCacheEnabled(boolean always) {
+        setBooleanFlag(FLAG_ALWAYS_DRAWN_WITH_CACHE, always);
+    }
+
+    /**
+     * Indicates whether the ViewGroup is currently drawing its children using
+     * their drawing cache.
+     *
+     * @return true if children should be drawn with their cache, false otherwise
+     *
+     * @see #setAlwaysDrawnWithCacheEnabled(boolean)
+     * @see #setChildrenDrawnWithCacheEnabled(boolean)
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Child views may no longer be forced to cache their rendering state by their parents.
+     * Use {@link View#setLayerType(int, Paint)} on individual Views instead.
+     */
+    @Deprecated
+    protected boolean isChildrenDrawnWithCacheEnabled() {
+        return (mGroupFlags & FLAG_CHILDREN_DRAWN_WITH_CACHE) == FLAG_CHILDREN_DRAWN_WITH_CACHE;
+    }
+
+    /**
+     * Tells the ViewGroup to draw its children using their drawing cache. This property
+     * is ignored when {@link #isAlwaysDrawnWithCacheEnabled()} is true. A child's drawing cache
+     * will be used only if it has been enabled.
+     *
+     * Subclasses should call this method to start and stop using the drawing cache when
+     * they perform performance sensitive operations, like scrolling or animating.
+     *
+     * @param enabled true if children should be drawn with their cache, false otherwise
+     *
+     * @see #setAlwaysDrawnWithCacheEnabled(boolean)
+     * @see #isChildrenDrawnWithCacheEnabled()
+     *
+     * @deprecated As of {@link android.os.Build.VERSION_CODES#M}, this property is ignored.
+     * Child views may no longer be forced to cache their rendering state by their parents.
+     * Use {@link View#setLayerType(int, Paint)} on individual Views instead.
+     */
+    @Deprecated
+    protected void setChildrenDrawnWithCacheEnabled(boolean enabled) {
+        setBooleanFlag(FLAG_CHILDREN_DRAWN_WITH_CACHE, enabled);
+    }
+
+    /**
+     * Indicates whether the ViewGroup is drawing its children in the order defined by
+     * {@link #getChildDrawingOrder(int, int)}.
+     *
+     * @return true if children drawing order is defined by {@link #getChildDrawingOrder(int, int)},
+     *         false otherwise
+     *
+     * @see #setChildrenDrawingOrderEnabled(boolean)
+     * @see #getChildDrawingOrder(int, int)
+     */
+    @ViewDebug.ExportedProperty(category = "drawing")
+    protected boolean isChildrenDrawingOrderEnabled() {
+        return (mGroupFlags & FLAG_USE_CHILD_DRAWING_ORDER) == FLAG_USE_CHILD_DRAWING_ORDER;
+    }
+
+    /**
+     * Tells the ViewGroup whether to draw its children in the order defined by the method
+     * {@link #getChildDrawingOrder(int, int)}.
+     * <p>
+     * Note that {@link View#getZ() Z} reordering, done by {@link #dispatchDraw(Canvas)},
+     * will override custom child ordering done via this method.
+     *
+     * @param enabled true if the order of the children when drawing is determined by
+     *        {@link #getChildDrawingOrder(int, int)}, false otherwise
+     *
+     * @see #isChildrenDrawingOrderEnabled()
+     * @see #getChildDrawingOrder(int, int)
+     */
+    protected void setChildrenDrawingOrderEnabled(boolean enabled) {
+        setBooleanFlag(FLAG_USE_CHILD_DRAWING_ORDER, enabled);
+    }
+
+    private boolean hasBooleanFlag(int flag) {
+        return (mGroupFlags & flag) == flag;
+    }
+
+    private void setBooleanFlag(int flag, boolean value) {
+        if (value) {
+            mGroupFlags |= flag;
+        } else {
+            mGroupFlags &= ~flag;
+        }
+    }
+
+    /**
+     * Returns an integer indicating what types of drawing caches are kept in memory.
+     *
+     * @see #setPersistentDrawingCache(int)
+     * @see #setAnimationCacheEnabled(boolean)
+     *
+     * @return one or a combination of {@link #PERSISTENT_NO_CACHE},
+     *         {@link #PERSISTENT_ANIMATION_CACHE}, {@link #PERSISTENT_SCROLLING_CACHE}
+     *         and {@link #PERSISTENT_ALL_CACHES}
+     */
+    @ViewDebug.ExportedProperty(category = "drawing", mapping = {
+        @ViewDebug.IntToString(from = PERSISTENT_NO_CACHE,        to = "NONE"),
+        @ViewDebug.IntToString(from = PERSISTENT_ANIMATION_CACHE, to = "ANIMATION"),
+        @ViewDebug.IntToString(from = PERSISTENT_SCROLLING_CACHE, to = "SCROLLING"),
+        @ViewDebug.IntToString(from = PERSISTENT_ALL_CACHES,      to = "ALL")
+    })
+    public int getPersistentDrawingCache() {
+        return mPersistentDrawingCache;
+    }
+
+    /**
+     * Indicates what types of drawing caches should be kept in memory after
+     * they have been created.
+     *
+     * @see #getPersistentDrawingCache()
+     * @see #setAnimationCacheEnabled(boolean)
+     *
+     * @param drawingCacheToKeep one or a combination of {@link #PERSISTENT_NO_CACHE},
+     *        {@link #PERSISTENT_ANIMATION_CACHE}, {@link #PERSISTENT_SCROLLING_CACHE}
+     *        and {@link #PERSISTENT_ALL_CACHES}
+     */
+    public void setPersistentDrawingCache(int drawingCacheToKeep) {
+        mPersistentDrawingCache = drawingCacheToKeep & PERSISTENT_ALL_CACHES;
+    }
+
+    private void setLayoutMode(int layoutMode, boolean explicitly) {
+        mLayoutMode = layoutMode;
+        setBooleanFlag(FLAG_LAYOUT_MODE_WAS_EXPLICITLY_SET, explicitly);
+    }
+
+    /**
+     * Recursively traverse the view hierarchy, resetting the layoutMode of any
+     * descendants that had inherited a different layoutMode from a previous parent.
+     * Recursion terminates when a descendant's mode is:
+     * <ul>
+     *     <li>Undefined</li>
+     *     <li>The same as the root node's</li>
+     *     <li>A mode that had been explicitly set</li>
+     * <ul/>
+     * The first two clauses are optimizations.
+     * @param layoutModeOfRoot
+     */
+    @Override
+    void invalidateInheritedLayoutMode(int layoutModeOfRoot) {
+        if (mLayoutMode == LAYOUT_MODE_UNDEFINED ||
+            mLayoutMode == layoutModeOfRoot ||
+            hasBooleanFlag(FLAG_LAYOUT_MODE_WAS_EXPLICITLY_SET)) {
+            return;
+        }
+        setLayoutMode(LAYOUT_MODE_UNDEFINED, false);
+
+        // apply recursively
+        for (int i = 0, N = getChildCount(); i < N; i++) {
+            getChildAt(i).invalidateInheritedLayoutMode(layoutModeOfRoot);
+        }
+    }
+
+    /**
+     * Returns the basis of alignment during layout operations on this ViewGroup:
+     * either {@link #LAYOUT_MODE_CLIP_BOUNDS} or {@link #LAYOUT_MODE_OPTICAL_BOUNDS}.
+     * <p>
+     * If no layoutMode was explicitly set, either programmatically or in an XML resource,
+     * the method returns the layoutMode of the view's parent ViewGroup if such a parent exists,
+     * otherwise the method returns a default value of {@link #LAYOUT_MODE_CLIP_BOUNDS}.
+     *
+     * @return the layout mode to use during layout operations
+     *
+     * @see #setLayoutMode(int)
+     */
+    public int getLayoutMode() {
+        if (mLayoutMode == LAYOUT_MODE_UNDEFINED) {
+            int inheritedLayoutMode = (mParent instanceof ViewGroup) ?
+                    ((ViewGroup) mParent).getLayoutMode() : LAYOUT_MODE_DEFAULT;
+            setLayoutMode(inheritedLayoutMode, false);
+        }
+        return mLayoutMode;
+    }
+
+    /**
+     * Sets the basis of alignment during the layout of this ViewGroup.
+     * Valid values are either {@link #LAYOUT_MODE_CLIP_BOUNDS} or
+     * {@link #LAYOUT_MODE_OPTICAL_BOUNDS}.
+     *
+     * @param layoutMode the layout mode to use during layout operations
+     *
+     * @see #getLayoutMode()
+     * @attr ref android.R.styleable#ViewGroup_layoutMode
+     */
+    public void setLayoutMode(int layoutMode) {
+        if (mLayoutMode != layoutMode) {
+            invalidateInheritedLayoutMode(layoutMode);
+            setLayoutMode(layoutMode, layoutMode != LAYOUT_MODE_UNDEFINED);
+            requestLayout();
+        }
+    }
+
+    /**
+     * Returns a new set of layout parameters based on the supplied attributes set.
+     *
+     * @param attrs the attributes to build the layout parameters from
+     *
+     * @return an instance of {@link android.view.ViewGroup.LayoutParams} or one
+     *         of its descendants
+     */
+    public LayoutParams generateLayoutParams(AttributeSet attrs) {
+        return new LayoutParams(getContext(), attrs);
+    }
+
+    /**
+     * Returns a safe set of layout parameters based on the supplied layout params.
+     * When a ViewGroup is passed a View whose layout params do not pass the test of
+     * {@link #checkLayoutParams(android.view.ViewGroup.LayoutParams)}, this method
+     * is invoked. This method should return a new set of layout params suitable for
+     * this ViewGroup, possibly by copying the appropriate attributes from the
+     * specified set of layout params.
+     *
+     * @param p The layout parameters to convert into a suitable set of layout parameters
+     *          for this ViewGroup.
+     *
+     * @return an instance of {@link android.view.ViewGroup.LayoutParams} or one
+     *         of its descendants
+     */
+    protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
+        return p;
+    }
+
+    /**
+     * Returns a set of default layout parameters. These parameters are requested
+     * when the View passed to {@link #addView(View)} has no layout parameters
+     * already set. If null is returned, an exception is thrown from addView.
+     *
+     * @return a set of default layout parameters or null
+     */
+    protected LayoutParams generateDefaultLayoutParams() {
+        return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
+    }
+
+    @Override
+    protected void debug(int depth) {
+        super.debug(depth);
+        String output;
+
+        if (mFocused != null) {
+            output = debugIndent(depth);
+            output += "mFocused";
+            Log.d(VIEW_LOG_TAG, output);
+            mFocused.debug(depth + 1);
+        }
+        if (mDefaultFocus != null) {
+            output = debugIndent(depth);
+            output += "mDefaultFocus";
+            Log.d(VIEW_LOG_TAG, output);
+            mDefaultFocus.debug(depth + 1);
+        }
+        if (mFocusedInCluster != null) {
+            output = debugIndent(depth);
+            output += "mFocusedInCluster";
+            Log.d(VIEW_LOG_TAG, output);
+            mFocusedInCluster.debug(depth + 1);
+        }
+        if (mChildrenCount != 0) {
+            output = debugIndent(depth);
+            output += "{";
+            Log.d(VIEW_LOG_TAG, output);
+        }
+        int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            View child = mChildren[i];
+            child.debug(depth + 1);
+        }
+
+        if (mChildrenCount != 0) {
+            output = debugIndent(depth);
+            output += "}";
+            Log.d(VIEW_LOG_TAG, output);
+        }
+    }
+
+    /**
+     * Returns the position in the group of the specified child view.
+     *
+     * @param child the view for which to get the position
+     * @return a positive integer representing the position of the view in the
+     *         group, or -1 if the view does not exist in the group
+     */
+    public int indexOfChild(View child) {
+        final int count = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < count; i++) {
+            if (children[i] == child) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /**
+     * Returns the number of children in the group.
+     *
+     * @return a positive integer representing the number of children in
+     *         the group
+     */
+    public int getChildCount() {
+        return mChildrenCount;
+    }
+
+    /**
+     * Returns the view at the specified position in the group.
+     *
+     * @param index the position at which to get the view from
+     * @return the view at the specified position or null if the position
+     *         does not exist within the group
+     */
+    public View getChildAt(int index) {
+        if (index < 0 || index >= mChildrenCount) {
+            return null;
+        }
+        return mChildren[index];
+    }
+
+    /**
+     * Ask all of the children of this view to measure themselves, taking into
+     * account both the MeasureSpec requirements for this view and its padding.
+     * We skip children that are in the GONE state The heavy lifting is done in
+     * getChildMeasureSpec.
+     *
+     * @param widthMeasureSpec The width requirements for this view
+     * @param heightMeasureSpec The height requirements for this view
+     */
+    protected void measureChildren(int widthMeasureSpec, int heightMeasureSpec) {
+        final int size = mChildrenCount;
+        final View[] children = mChildren;
+        for (int i = 0; i < size; ++i) {
+            final View child = children[i];
+            if ((child.mViewFlags & VISIBILITY_MASK) != GONE) {
+                measureChild(child, widthMeasureSpec, heightMeasureSpec);
+            }
+        }
+    }
+
+    /**
+     * Ask one of the children of this view to measure itself, taking into
+     * account both the MeasureSpec requirements for this view and its padding.
+     * The heavy lifting is done in getChildMeasureSpec.
+     *
+     * @param child The child to measure
+     * @param parentWidthMeasureSpec The width requirements for this view
+     * @param parentHeightMeasureSpec The height requirements for this view
+     */
+    protected void measureChild(View child, int parentWidthMeasureSpec,
+            int parentHeightMeasureSpec) {
+        final LayoutParams lp = child.getLayoutParams();
+
+        final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
+                mPaddingLeft + mPaddingRight, lp.width);
+        final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
+                mPaddingTop + mPaddingBottom, lp.height);
+
+        child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+    }
+
+    /**
+     * Ask one of the children of this view to measure itself, taking into
+     * account both the MeasureSpec requirements for this view and its padding
+     * and margins. The child must have MarginLayoutParams The heavy lifting is
+     * done in getChildMeasureSpec.
+     *
+     * @param child The child to measure
+     * @param parentWidthMeasureSpec The width requirements for this view
+     * @param widthUsed Extra space that has been used up by the parent
+     *        horizontally (possibly by other children of the parent)
+     * @param parentHeightMeasureSpec The height requirements for this view
+     * @param heightUsed Extra space that has been used up by the parent
+     *        vertically (possibly by other children of the parent)
+     */
+    protected void measureChildWithMargins(View child,
+            int parentWidthMeasureSpec, int widthUsed,
+            int parentHeightMeasureSpec, int heightUsed) {
+        final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
+
+        final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
+                mPaddingLeft + mPaddingRight + lp.leftMargin + lp.rightMargin
+                        + widthUsed, lp.width);
+        final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
+                mPaddingTop + mPaddingBottom + lp.topMargin + lp.bottomMargin
+                        + heightUsed, lp.height);
+
+        child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+    }
+
+    /**
+     * Does the hard part of measureChildren: figuring out the MeasureSpec to
+     * pass to a particular child. This method figures out the right MeasureSpec
+     * for one dimension (height or width) of one child view.
+     *
+     * The goal is to combine information from our MeasureSpec with the
+     * LayoutParams of the child to get the best possible results. For example,
+     * if the this view knows its size (because its MeasureSpec has a mode of
+     * EXACTLY), and the child has indicated in its LayoutParams that it wants
+     * to be the same size as the parent, the parent should ask the child to
+     * layout given an exact size.
+     *
+     * @param spec The requirements for this view
+     * @param padding The padding of this view for the current dimension and
+     *        margins, if applicable
+     * @param childDimension How big the child wants to be in the current
+     *        dimension
+     * @return a MeasureSpec integer for the child
+     */
+    public static int getChildMeasureSpec(int spec, int padding, int childDimension) {
+        int specMode = MeasureSpec.getMode(spec);
+        int specSize = MeasureSpec.getSize(spec);
+
+        int size = Math.max(0, specSize - padding);
+
+        int resultSize = 0;
+        int resultMode = 0;
+
+        switch (specMode) {
+        // Parent has imposed an exact size on us
+        case MeasureSpec.EXACTLY:
+            if (childDimension >= 0) {
+                resultSize = childDimension;
+                resultMode = MeasureSpec.EXACTLY;
+            } else if (childDimension == LayoutParams.MATCH_PARENT) {
+                // Child wants to be our size. So be it.
+                resultSize = size;
+                resultMode = MeasureSpec.EXACTLY;
+            } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+                // Child wants to determine its own size. It can't be
+                // bigger than us.
+                resultSize = size;
+                resultMode = MeasureSpec.AT_MOST;
+            }
+            break;
+
+        // Parent has imposed a maximum size on us
+        case MeasureSpec.AT_MOST:
+            if (childDimension >= 0) {
+                // Child wants a specific size... so be it
+                resultSize = childDimension;
+                resultMode = MeasureSpec.EXACTLY;
+            } else if (childDimension == LayoutParams.MATCH_PARENT) {
+                // Child wants to be our size, but our size is not fixed.
+                // Constrain child to not be bigger than us.
+                resultSize = size;
+                resultMode = MeasureSpec.AT_MOST;
+            } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+                // Child wants to determine its own size. It can't be
+                // bigger than us.
+                resultSize = size;
+                resultMode = MeasureSpec.AT_MOST;
+            }
+            break;
+
+        // Parent asked to see how big we want to be
+        case MeasureSpec.UNSPECIFIED:
+            if (childDimension >= 0) {
+                // Child wants a specific size... let him have it
+                resultSize = childDimension;
+                resultMode = MeasureSpec.EXACTLY;
+            } else if (childDimension == LayoutParams.MATCH_PARENT) {
+                // Child wants to be our size... find out how big it should
+                // be
+                resultSize = View.sUseZeroUnspecifiedMeasureSpec ? 0 : size;
+                resultMode = MeasureSpec.UNSPECIFIED;
+            } else if (childDimension == LayoutParams.WRAP_CONTENT) {
+                // Child wants to determine its own size.... find out how
+                // big it should be
+                resultSize = View.sUseZeroUnspecifiedMeasureSpec ? 0 : size;
+                resultMode = MeasureSpec.UNSPECIFIED;
+            }
+            break;
+        }
+        //noinspection ResourceType
+        return MeasureSpec.makeMeasureSpec(resultSize, resultMode);
+    }
+
+
+    /**
+     * Removes any pending animations for views that have been removed. Call
+     * this if you don't want animations for exiting views to stack up.
+     */
+    public void clearDisappearingChildren() {
+        final ArrayList<View> disappearingChildren = mDisappearingChildren;
+        if (disappearingChildren != null) {
+            final int count = disappearingChildren.size();
+            for (int i = 0; i < count; i++) {
+                final View view = disappearingChildren.get(i);
+                if (view.mAttachInfo != null) {
+                    view.dispatchDetachedFromWindow();
+                }
+                view.clearAnimation();
+            }
+            disappearingChildren.clear();
+            invalidate();
+        }
+    }
+
+    /**
+     * Add a view which is removed from mChildren but still needs animation
+     *
+     * @param v View to add
+     */
+    private void addDisappearingView(View v) {
+        ArrayList<View> disappearingChildren = mDisappearingChildren;
+
+        if (disappearingChildren == null) {
+            disappearingChildren = mDisappearingChildren = new ArrayList<View>();
+        }
+
+        disappearingChildren.add(v);
+    }
+
+    /**
+     * Cleanup a view when its animation is done. This may mean removing it from
+     * the list of disappearing views.
+     *
+     * @param view The view whose animation has finished
+     * @param animation The animation, cannot be null
+     */
+    void finishAnimatingView(final View view, Animation animation) {
+        final ArrayList<View> disappearingChildren = mDisappearingChildren;
+        if (disappearingChildren != null) {
+            if (disappearingChildren.contains(view)) {
+                disappearingChildren.remove(view);
+
+                if (view.mAttachInfo != null) {
+                    view.dispatchDetachedFromWindow();
+                }
+
+                view.clearAnimation();
+                mGroupFlags |= FLAG_INVALIDATE_REQUIRED;
+            }
+        }
+
+        if (animation != null && !animation.getFillAfter()) {
+            view.clearAnimation();
+        }
+
+        if ((view.mPrivateFlags & PFLAG_ANIMATION_STARTED) == PFLAG_ANIMATION_STARTED) {
+            view.onAnimationEnd();
+            // Should be performed by onAnimationEnd() but this avoid an infinite loop,
+            // so we'd rather be safe than sorry
+            view.mPrivateFlags &= ~PFLAG_ANIMATION_STARTED;
+            // Draw one more frame after the animation is done
+            mGroupFlags |= FLAG_INVALIDATE_REQUIRED;
+        }
+    }
+
+    /**
+     * Utility function called by View during invalidation to determine whether a view that
+     * is invisible or gone should still be invalidated because it is being transitioned (and
+     * therefore still needs to be drawn).
+     */
+    boolean isViewTransitioning(View view) {
+        return (mTransitioningViews != null && mTransitioningViews.contains(view));
+    }
+
+    /**
+     * This method tells the ViewGroup that the given View object, which should have this
+     * ViewGroup as its parent,
+     * should be kept around  (re-displayed when the ViewGroup draws its children) even if it
+     * is removed from its parent. This allows animations, such as those used by
+     * {@link android.app.Fragment} and {@link android.animation.LayoutTransition} to animate
+     * the removal of views. A call to this method should always be accompanied by a later call
+     * to {@link #endViewTransition(View)}, such as after an animation on the View has finished,
+     * so that the View finally gets removed.
+     *
+     * @param view The View object to be kept visible even if it gets removed from its parent.
+     */
+    public void startViewTransition(View view) {
+        if (view.mParent == this) {
+            if (mTransitioningViews == null) {
+                mTransitioningViews = new ArrayList<View>();
+            }
+            mTransitioningViews.add(view);
+        }
+    }
+
+    /**
+     * This method should always be called following an earlier call to
+     * {@link #startViewTransition(View)}. The given View is finally removed from its parent
+     * and will no longer be displayed. Note that this method does not perform the functionality
+     * of removing a view from its parent; it just discontinues the display of a View that
+     * has previously been removed.
+     *
+     * @return view The View object that has been removed but is being kept around in the visible
+     * hierarchy by an earlier call to {@link #startViewTransition(View)}.
+     */
+    public void endViewTransition(View view) {
+        if (mTransitioningViews != null) {
+            mTransitioningViews.remove(view);
+            final ArrayList<View> disappearingChildren = mDisappearingChildren;
+            if (disappearingChildren != null && disappearingChildren.contains(view)) {
+                disappearingChildren.remove(view);
+                if (mVisibilityChangingChildren != null &&
+                        mVisibilityChangingChildren.contains(view)) {
+                    mVisibilityChangingChildren.remove(view);
+                } else {
+                    if (view.mAttachInfo != null) {
+                        view.dispatchDetachedFromWindow();
+                    }
+                    if (view.mParent != null) {
+                        view.mParent = null;
+                    }
+                }
+                invalidate();
+            }
+        }
+    }
+
+    private LayoutTransition.TransitionListener mLayoutTransitionListener =
+            new LayoutTransition.TransitionListener() {
+        @Override
+        public void startTransition(LayoutTransition transition, ViewGroup container,
+                View view, int transitionType) {
+            // We only care about disappearing items, since we need special logic to keep
+            // those items visible after they've been 'removed'
+            if (transitionType == LayoutTransition.DISAPPEARING) {
+                startViewTransition(view);
+            }
+        }
+
+        @Override
+        public void endTransition(LayoutTransition transition, ViewGroup container,
+                View view, int transitionType) {
+            if (mLayoutCalledWhileSuppressed && !transition.isChangingLayout()) {
+                requestLayout();
+                mLayoutCalledWhileSuppressed = false;
+            }
+            if (transitionType == LayoutTransition.DISAPPEARING && mTransitioningViews != null) {
+                endViewTransition(view);
+            }
+        }
+    };
+
+    /**
+     * Tells this ViewGroup to suppress all layout() calls until layout
+     * suppression is disabled with a later call to suppressLayout(false).
+     * When layout suppression is disabled, a requestLayout() call is sent
+     * if layout() was attempted while layout was being suppressed.
+     *
+     * @hide
+     */
+    public void suppressLayout(boolean suppress) {
+        mSuppressLayout = suppress;
+        if (!suppress) {
+            if (mLayoutCalledWhileSuppressed) {
+                requestLayout();
+                mLayoutCalledWhileSuppressed = false;
+            }
+        }
+    }
+
+    /**
+     * Returns whether layout calls on this container are currently being
+     * suppressed, due to an earlier call to {@link #suppressLayout(boolean)}.
+     *
+     * @return true if layout calls are currently suppressed, false otherwise.
+     *
+     * @hide
+     */
+    public boolean isLayoutSuppressed() {
+        return mSuppressLayout;
+    }
+
+    @Override
+    public boolean gatherTransparentRegion(Region region) {
+        // If no transparent regions requested, we are always opaque.
+        final boolean meOpaque = (mPrivateFlags & View.PFLAG_REQUEST_TRANSPARENT_REGIONS) == 0;
+        if (meOpaque && region == null) {
+            // The caller doesn't care about the region, so stop now.
+            return true;
+        }
+        super.gatherTransparentRegion(region);
+        // Instead of naively traversing the view tree, we have to traverse according to the Z
+        // order here. We need to go with the same order as dispatchDraw().
+        // One example is that after surfaceView punch a hole, we will still allow other views drawn
+        // on top of that hole. In this case, those other views should be able to cut the
+        // transparent region into smaller area.
+        final int childrenCount = mChildrenCount;
+        boolean noneOfTheChildrenAreTransparent = true;
+        if (childrenCount > 0) {
+            final ArrayList<View> preorderedList = buildOrderedChildList();
+            final boolean customOrder = preorderedList == null
+                    && isChildrenDrawingOrderEnabled();
+            final View[] children = mChildren;
+            for (int i = 0; i < childrenCount; i++) {
+                final int childIndex = getAndVerifyPreorderedIndex(childrenCount, i, customOrder);
+                final View child = getAndVerifyPreorderedView(preorderedList, children, childIndex);
+                if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE || child.getAnimation() != null) {
+                    if (!child.gatherTransparentRegion(region)) {
+                        noneOfTheChildrenAreTransparent = false;
+                    }
+                }
+            }
+            if (preorderedList != null) preorderedList.clear();
+        }
+        return meOpaque || noneOfTheChildrenAreTransparent;
+    }
+
+    @Override
+    public void requestTransparentRegion(View child) {
+        if (child != null) {
+            child.mPrivateFlags |= View.PFLAG_REQUEST_TRANSPARENT_REGIONS;
+            if (mParent != null) {
+                mParent.requestTransparentRegion(this);
+            }
+        }
+    }
+
+    @Override
+    public WindowInsets dispatchApplyWindowInsets(WindowInsets insets) {
+        insets = super.dispatchApplyWindowInsets(insets);
+        if (!insets.isConsumed()) {
+            final int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                insets = getChildAt(i).dispatchApplyWindowInsets(insets);
+                if (insets.isConsumed()) {
+                    break;
+                }
+            }
+        }
+        return insets;
+    }
+
+    /**
+     * Returns the animation listener to which layout animation events are
+     * sent.
+     *
+     * @return an {@link android.view.animation.Animation.AnimationListener}
+     */
+    public Animation.AnimationListener getLayoutAnimationListener() {
+        return mAnimationListener;
+    }
+
+    @Override
+    protected void drawableStateChanged() {
+        super.drawableStateChanged();
+
+        if ((mGroupFlags & FLAG_NOTIFY_CHILDREN_ON_DRAWABLE_STATE_CHANGE) != 0) {
+            if ((mGroupFlags & FLAG_ADD_STATES_FROM_CHILDREN) != 0) {
+                throw new IllegalStateException("addStateFromChildren cannot be enabled if a"
+                        + " child has duplicateParentState set to true");
+            }
+
+            final View[] children = mChildren;
+            final int count = mChildrenCount;
+
+            for (int i = 0; i < count; i++) {
+                final View child = children[i];
+                if ((child.mViewFlags & DUPLICATE_PARENT_STATE) != 0) {
+                    child.refreshDrawableState();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void jumpDrawablesToCurrentState() {
+        super.jumpDrawablesToCurrentState();
+        final View[] children = mChildren;
+        final int count = mChildrenCount;
+        for (int i = 0; i < count; i++) {
+            children[i].jumpDrawablesToCurrentState();
+        }
+    }
+
+    @Override
+    protected int[] onCreateDrawableState(int extraSpace) {
+        if ((mGroupFlags & FLAG_ADD_STATES_FROM_CHILDREN) == 0) {
+            return super.onCreateDrawableState(extraSpace);
+        }
+
+        int need = 0;
+        int n = getChildCount();
+        for (int i = 0; i < n; i++) {
+            int[] childState = getChildAt(i).getDrawableState();
+
+            if (childState != null) {
+                need += childState.length;
+            }
+        }
+
+        int[] state = super.onCreateDrawableState(extraSpace + need);
+
+        for (int i = 0; i < n; i++) {
+            int[] childState = getChildAt(i).getDrawableState();
+
+            if (childState != null) {
+                state = mergeDrawableStates(state, childState);
+            }
+        }
+
+        return state;
+    }
+
+    /**
+     * Sets whether this ViewGroup's drawable states also include
+     * its children's drawable states.  This is used, for example, to
+     * make a group appear to be focused when its child EditText or button
+     * is focused.
+     */
+    public void setAddStatesFromChildren(boolean addsStates) {
+        if (addsStates) {
+            mGroupFlags |= FLAG_ADD_STATES_FROM_CHILDREN;
+        } else {
+            mGroupFlags &= ~FLAG_ADD_STATES_FROM_CHILDREN;
+        }
+
+        refreshDrawableState();
+    }
+
+    /**
+     * Returns whether this ViewGroup's drawable states also include
+     * its children's drawable states.  This is used, for example, to
+     * make a group appear to be focused when its child EditText or button
+     * is focused.
+     */
+    public boolean addStatesFromChildren() {
+        return (mGroupFlags & FLAG_ADD_STATES_FROM_CHILDREN) != 0;
+    }
+
+    /**
+     * If {@link #addStatesFromChildren} is true, refreshes this group's
+     * drawable state (to include the states from its children).
+     */
+    @Override
+    public void childDrawableStateChanged(View child) {
+        if ((mGroupFlags & FLAG_ADD_STATES_FROM_CHILDREN) != 0) {
+            refreshDrawableState();
+        }
+    }
+
+    /**
+     * Specifies the animation listener to which layout animation events must
+     * be sent. Only
+     * {@link android.view.animation.Animation.AnimationListener#onAnimationStart(Animation)}
+     * and
+     * {@link android.view.animation.Animation.AnimationListener#onAnimationEnd(Animation)}
+     * are invoked.
+     *
+     * @param animationListener the layout animation listener
+     */
+    public void setLayoutAnimationListener(Animation.AnimationListener animationListener) {
+        mAnimationListener = animationListener;
+    }
+
+    /**
+     * This method is called by LayoutTransition when there are 'changing' animations that need
+     * to start after the layout/setup phase. The request is forwarded to the ViewAncestor, who
+     * starts all pending transitions prior to the drawing phase in the current traversal.
+     *
+     * @param transition The LayoutTransition to be started on the next traversal.
+     *
+     * @hide
+     */
+    public void requestTransitionStart(LayoutTransition transition) {
+        ViewRootImpl viewAncestor = getViewRootImpl();
+        if (viewAncestor != null) {
+            viewAncestor.requestTransitionStart(transition);
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean resolveRtlPropertiesIfNeeded() {
+        final boolean result = super.resolveRtlPropertiesIfNeeded();
+        // We dont need to resolve the children RTL properties if nothing has changed for the parent
+        if (result) {
+            int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                final View child = getChildAt(i);
+                if (child.isLayoutDirectionInherited()) {
+                    child.resolveRtlPropertiesIfNeeded();
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean resolveLayoutDirection() {
+        final boolean result = super.resolveLayoutDirection();
+        if (result) {
+            int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                final View child = getChildAt(i);
+                if (child.isLayoutDirectionInherited()) {
+                    child.resolveLayoutDirection();
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean resolveTextDirection() {
+        final boolean result = super.resolveTextDirection();
+        if (result) {
+            int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                final View child = getChildAt(i);
+                if (child.isTextDirectionInherited()) {
+                    child.resolveTextDirection();
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public boolean resolveTextAlignment() {
+        final boolean result = super.resolveTextAlignment();
+        if (result) {
+            int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                final View child = getChildAt(i);
+                if (child.isTextAlignmentInherited()) {
+                    child.resolveTextAlignment();
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resolvePadding() {
+        super.resolvePadding();
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isLayoutDirectionInherited() && !child.isPaddingResolved()) {
+                child.resolvePadding();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    protected void resolveDrawables() {
+        super.resolveDrawables();
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isLayoutDirectionInherited() && !child.areDrawablesResolved()) {
+                child.resolveDrawables();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resolveLayoutParams() {
+        super.resolveLayoutParams();
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            child.resolveLayoutParams();
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resetResolvedLayoutDirection() {
+        super.resetResolvedLayoutDirection();
+
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isLayoutDirectionInherited()) {
+                child.resetResolvedLayoutDirection();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resetResolvedTextDirection() {
+        super.resetResolvedTextDirection();
+
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isTextDirectionInherited()) {
+                child.resetResolvedTextDirection();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resetResolvedTextAlignment() {
+        super.resetResolvedTextAlignment();
+
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isTextAlignmentInherited()) {
+                child.resetResolvedTextAlignment();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public void resetResolvedPadding() {
+        super.resetResolvedPadding();
+
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isLayoutDirectionInherited()) {
+                child.resetResolvedPadding();
+            }
+        }
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    protected void resetResolvedDrawables() {
+        super.resetResolvedDrawables();
+
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.isLayoutDirectionInherited()) {
+                child.resetResolvedDrawables();
+            }
+        }
+    }
+
+    /**
+     * Return true if the pressed state should be delayed for children or descendants of this
+     * ViewGroup. Generally, this should be done for containers that can scroll, such as a List.
+     * This prevents the pressed state from appearing when the user is actually trying to scroll
+     * the content.
+     *
+     * The default implementation returns true for compatibility reasons. Subclasses that do
+     * not scroll should generally override this method and return false.
+     */
+    public boolean shouldDelayChildPressedState() {
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
+        return false;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void onNestedScrollAccepted(View child, View target, int axes) {
+        mNestedScrollAxes = axes;
+    }
+
+    /**
+     * @inheritDoc
+     *
+     * <p>The default implementation of onStopNestedScroll calls
+     * {@link #stopNestedScroll()} to halt any recursive nested scrolling in progress.</p>
+     */
+    @Override
+    public void onStopNestedScroll(View child) {
+        // Stop any recursive nested scrolling.
+        stopNestedScroll();
+        mNestedScrollAxes = 0;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
+            int dxUnconsumed, int dyUnconsumed) {
+        // Re-dispatch up the tree by default
+        dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, null);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
+        // Re-dispatch up the tree by default
+        dispatchNestedPreScroll(dx, dy, consumed, null);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
+        // Re-dispatch up the tree by default
+        return dispatchNestedFling(velocityX, velocityY, consumed);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
+        // Re-dispatch up the tree by default
+        return dispatchNestedPreFling(velocityX, velocityY);
+    }
+
+    /**
+     * Return the current axes of nested scrolling for this ViewGroup.
+     *
+     * <p>A ViewGroup returning something other than {@link #SCROLL_AXIS_NONE} is currently
+     * acting as a nested scrolling parent for one or more descendant views in the hierarchy.</p>
+     *
+     * @return Flags indicating the current axes of nested scrolling
+     * @see #SCROLL_AXIS_HORIZONTAL
+     * @see #SCROLL_AXIS_VERTICAL
+     * @see #SCROLL_AXIS_NONE
+     */
+    public int getNestedScrollAxes() {
+        return mNestedScrollAxes;
+    }
+
+    /** @hide */
+    protected void onSetLayoutParams(View child, LayoutParams layoutParams) {
+        requestLayout();
+    }
+
+    /** @hide */
+    @Override
+    public void captureTransitioningViews(List<View> transitioningViews) {
+        if (getVisibility() != View.VISIBLE) {
+            return;
+        }
+        if (isTransitionGroup()) {
+            transitioningViews.add(this);
+        } else {
+            int count = getChildCount();
+            for (int i = 0; i < count; i++) {
+                View child = getChildAt(i);
+                child.captureTransitioningViews(transitioningViews);
+            }
+        }
+    }
+
+    /** @hide */
+    @Override
+    public void findNamedViews(Map<String, View> namedElements) {
+        if (getVisibility() != VISIBLE && mGhostView == null) {
+            return;
+        }
+        super.findNamedViews(namedElements);
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            View child = getChildAt(i);
+            child.findNamedViews(namedElements);
+        }
+    }
+
+    /**
+     * LayoutParams are used by views to tell their parents how they want to be
+     * laid out. See
+     * {@link android.R.styleable#ViewGroup_Layout ViewGroup Layout Attributes}
+     * for a list of all child view attributes that this class supports.
+     *
+     * <p>
+     * The base LayoutParams class just describes how big the view wants to be
+     * for both width and height. For each dimension, it can specify one of:
+     * <ul>
+     * <li>FILL_PARENT (renamed MATCH_PARENT in API Level 8 and higher), which
+     * means that the view wants to be as big as its parent (minus padding)
+     * <li> WRAP_CONTENT, which means that the view wants to be just big enough
+     * to enclose its content (plus padding)
+     * <li> an exact number
+     * </ul>
+     * There are subclasses of LayoutParams for different subclasses of
+     * ViewGroup. For example, AbsoluteLayout has its own subclass of
+     * LayoutParams which adds an X and Y value.</p>
+     *
+     * <div class="special reference">
+     * <h3>Developer Guides</h3>
+     * <p>For more information about creating user interface layouts, read the
+     * <a href="{@docRoot}guide/topics/ui/declaring-layout.html">XML Layouts</a> developer
+     * guide.</p></div>
+     *
+     * @attr ref android.R.styleable#ViewGroup_Layout_layout_height
+     * @attr ref android.R.styleable#ViewGroup_Layout_layout_width
+     */
+    public static class LayoutParams {
+        /**
+         * Special value for the height or width requested by a View.
+         * FILL_PARENT means that the view wants to be as big as its parent,
+         * minus the parent's padding, if any. This value is deprecated
+         * starting in API Level 8 and replaced by {@link #MATCH_PARENT}.
+         */
+        @SuppressWarnings({"UnusedDeclaration"})
+        @Deprecated
+        public static final int FILL_PARENT = -1;
+
+        /**
+         * Special value for the height or width requested by a View.
+         * MATCH_PARENT means that the view wants to be as big as its parent,
+         * minus the parent's padding, if any. Introduced in API Level 8.
+         */
+        public static final int MATCH_PARENT = -1;
+
+        /**
+         * Special value for the height or width requested by a View.
+         * WRAP_CONTENT means that the view wants to be just large enough to fit
+         * its own internal content, taking its own padding into account.
+         */
+        public static final int WRAP_CONTENT = -2;
+
+        /**
+         * Information about how wide the view wants to be. Can be one of the
+         * constants FILL_PARENT (replaced by MATCH_PARENT
+         * in API Level 8) or WRAP_CONTENT, or an exact size.
+         */
+        @ViewDebug.ExportedProperty(category = "layout", mapping = {
+            @ViewDebug.IntToString(from = MATCH_PARENT, to = "MATCH_PARENT"),
+            @ViewDebug.IntToString(from = WRAP_CONTENT, to = "WRAP_CONTENT")
+        })
+        public int width;
+
+        /**
+         * Information about how tall the view wants to be. Can be one of the
+         * constants FILL_PARENT (replaced by MATCH_PARENT
+         * in API Level 8) or WRAP_CONTENT, or an exact size.
+         */
+        @ViewDebug.ExportedProperty(category = "layout", mapping = {
+            @ViewDebug.IntToString(from = MATCH_PARENT, to = "MATCH_PARENT"),
+            @ViewDebug.IntToString(from = WRAP_CONTENT, to = "WRAP_CONTENT")
+        })
+        public int height;
+
+        /**
+         * Used to animate layouts.
+         */
+        public LayoutAnimationController.AnimationParameters layoutAnimationParameters;
+
+        /**
+         * Creates a new set of layout parameters. The values are extracted from
+         * the supplied attributes set and context. The XML attributes mapped
+         * to this set of layout parameters are:
+         *
+         * <ul>
+         *   <li><code>layout_width</code>: the width, either an exact value,
+         *   {@link #WRAP_CONTENT}, or {@link #FILL_PARENT} (replaced by
+         *   {@link #MATCH_PARENT} in API Level 8)</li>
+         *   <li><code>layout_height</code>: the height, either an exact value,
+         *   {@link #WRAP_CONTENT}, or {@link #FILL_PARENT} (replaced by
+         *   {@link #MATCH_PARENT} in API Level 8)</li>
+         * </ul>
+         *
+         * @param c the application environment
+         * @param attrs the set of attributes from which to extract the layout
+         *              parameters' values
+         */
+        public LayoutParams(Context c, AttributeSet attrs) {
+            TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.ViewGroup_Layout);
+            setBaseAttributes(a,
+                    R.styleable.ViewGroup_Layout_layout_width,
+                    R.styleable.ViewGroup_Layout_layout_height);
+            a.recycle();
+        }
+
+        /**
+         * Creates a new set of layout parameters with the specified width
+         * and height.
+         *
+         * @param width the width, either {@link #WRAP_CONTENT},
+         *        {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in
+         *        API Level 8), or a fixed size in pixels
+         * @param height the height, either {@link #WRAP_CONTENT},
+         *        {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in
+         *        API Level 8), or a fixed size in pixels
+         */
+        public LayoutParams(int width, int height) {
+            this.width = width;
+            this.height = height;
+        }
+
+        /**
+         * Copy constructor. Clones the width and height values of the source.
+         *
+         * @param source The layout params to copy from.
+         */
+        public LayoutParams(LayoutParams source) {
+            this.width = source.width;
+            this.height = source.height;
+        }
+
+        /**
+         * Used internally by MarginLayoutParams.
+         * @hide
+         */
+        LayoutParams() {
+        }
+
+        /**
+         * Extracts the layout parameters from the supplied attributes.
+         *
+         * @param a the style attributes to extract the parameters from
+         * @param widthAttr the identifier of the width attribute
+         * @param heightAttr the identifier of the height attribute
+         */
+        protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) {
+            width = a.getLayoutDimension(widthAttr, "layout_width");
+            height = a.getLayoutDimension(heightAttr, "layout_height");
+        }
+
+        /**
+         * Resolve layout parameters depending on the layout direction. Subclasses that care about
+         * layoutDirection changes should override this method. The default implementation does
+         * nothing.
+         *
+         * @param layoutDirection the direction of the layout
+         *
+         * {@link View#LAYOUT_DIRECTION_LTR}
+         * {@link View#LAYOUT_DIRECTION_RTL}
+         */
+        public void resolveLayoutDirection(int layoutDirection) {
+        }
+
+        /**
+         * Returns a String representation of this set of layout parameters.
+         *
+         * @param output the String to prepend to the internal representation
+         * @return a String with the following format: output +
+         *         "ViewGroup.LayoutParams={ width=WIDTH, height=HEIGHT }"
+         *
+         * @hide
+         */
+        public String debug(String output) {
+            return output + "ViewGroup.LayoutParams={ width="
+                    + sizeToString(width) + ", height=" + sizeToString(height) + " }";
+        }
+
+        /**
+         * Use {@code canvas} to draw suitable debugging annotations for these LayoutParameters.
+         *
+         * <p>This function is called automatically when the developer setting is enabled.<p/>
+         *
+         * <p>It is strongly advised to only call this function from debug builds as there is
+         * a risk of leaking unwanted layout information.<p/>
+         *
+         * @param view the view that contains these layout parameters
+         * @param canvas the canvas on which to draw
+         * @param paint the paint used to draw through
+         */
+        public void onDebugDraw(View view, Canvas canvas, Paint paint) {
+        }
+
+        /**
+         * Converts the specified size to a readable String.
+         *
+         * @param size the size to convert
+         * @return a String instance representing the supplied size
+         *
+         * @hide
+         */
+        protected static String sizeToString(int size) {
+            if (size == WRAP_CONTENT) {
+                return "wrap-content";
+            }
+            if (size == MATCH_PARENT) {
+                return "match-parent";
+            }
+            return String.valueOf(size);
+        }
+
+        /** @hide */
+        void encode(@NonNull ViewHierarchyEncoder encoder) {
+            encoder.beginObject(this);
+            encodeProperties(encoder);
+            encoder.endObject();
+        }
+
+        /** @hide */
+        protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) {
+            encoder.addProperty("width", width);
+            encoder.addProperty("height", height);
+        }
+    }
+
+    /**
+     * Per-child layout information for layouts that support margins.
+     * See
+     * {@link android.R.styleable#ViewGroup_MarginLayout ViewGroup Margin Layout Attributes}
+     * for a list of all child view attributes that this class supports.
+     *
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_margin
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginHorizontal
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginVertical
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginLeft
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginTop
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginRight
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginBottom
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
+     * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
+     */
+    public static class MarginLayoutParams extends ViewGroup.LayoutParams {
+        /**
+         * The left margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        public int leftMargin;
+
+        /**
+         * The top margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        public int topMargin;
+
+        /**
+         * The right margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        public int rightMargin;
+
+        /**
+         * The bottom margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        public int bottomMargin;
+
+        /**
+         * The start margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        private int startMargin = DEFAULT_MARGIN_RELATIVE;
+
+        /**
+         * The end margin in pixels of the child. Margin values should be positive.
+         * Call {@link ViewGroup#setLayoutParams(LayoutParams)} after reassigning a new value
+         * to this field.
+         */
+        @ViewDebug.ExportedProperty(category = "layout")
+        private int endMargin = DEFAULT_MARGIN_RELATIVE;
+
+        /**
+         * The default start and end margin.
+         * @hide
+         */
+        public static final int DEFAULT_MARGIN_RELATIVE = Integer.MIN_VALUE;
+
+        /**
+         * Bit  0: layout direction
+         * Bit  1: layout direction
+         * Bit  2: left margin undefined
+         * Bit  3: right margin undefined
+         * Bit  4: is RTL compatibility mode
+         * Bit  5: need resolution
+         *
+         * Bit 6 to 7 not used
+         *
+         * @hide
+         */
+        @ViewDebug.ExportedProperty(category = "layout", flagMapping = {
+                @ViewDebug.FlagToString(mask = LAYOUT_DIRECTION_MASK,
+                        equals = LAYOUT_DIRECTION_MASK, name = "LAYOUT_DIRECTION"),
+                @ViewDebug.FlagToString(mask = LEFT_MARGIN_UNDEFINED_MASK,
+                        equals = LEFT_MARGIN_UNDEFINED_MASK, name = "LEFT_MARGIN_UNDEFINED_MASK"),
+                @ViewDebug.FlagToString(mask = RIGHT_MARGIN_UNDEFINED_MASK,
+                        equals = RIGHT_MARGIN_UNDEFINED_MASK, name = "RIGHT_MARGIN_UNDEFINED_MASK"),
+                @ViewDebug.FlagToString(mask = RTL_COMPATIBILITY_MODE_MASK,
+                        equals = RTL_COMPATIBILITY_MODE_MASK, name = "RTL_COMPATIBILITY_MODE_MASK"),
+                @ViewDebug.FlagToString(mask = NEED_RESOLUTION_MASK,
+                        equals = NEED_RESOLUTION_MASK, name = "NEED_RESOLUTION_MASK")
+        }, formatToHexString = true)
+        byte mMarginFlags;
+
+        private static final int LAYOUT_DIRECTION_MASK = 0x00000003;
+        private static final int LEFT_MARGIN_UNDEFINED_MASK = 0x00000004;
+        private static final int RIGHT_MARGIN_UNDEFINED_MASK = 0x00000008;
+        private static final int RTL_COMPATIBILITY_MODE_MASK = 0x00000010;
+        private static final int NEED_RESOLUTION_MASK = 0x00000020;
+
+        private static final int DEFAULT_MARGIN_RESOLVED = 0;
+        private static final int UNDEFINED_MARGIN = DEFAULT_MARGIN_RELATIVE;
+
+        /**
+         * Creates a new set of layout parameters. The values are extracted from
+         * the supplied attributes set and context.
+         *
+         * @param c the application environment
+         * @param attrs the set of attributes from which to extract the layout
+         *              parameters' values
+         */
+        public MarginLayoutParams(Context c, AttributeSet attrs) {
+            super();
+
+            TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.ViewGroup_MarginLayout);
+            setBaseAttributes(a,
+                    R.styleable.ViewGroup_MarginLayout_layout_width,
+                    R.styleable.ViewGroup_MarginLayout_layout_height);
+
+            int margin = a.getDimensionPixelSize(
+                    com.android.internal.R.styleable.ViewGroup_MarginLayout_layout_margin, -1);
+            if (margin >= 0) {
+                leftMargin = margin;
+                topMargin = margin;
+                rightMargin= margin;
+                bottomMargin = margin;
+            } else {
+                int horizontalMargin = a.getDimensionPixelSize(
+                        R.styleable.ViewGroup_MarginLayout_layout_marginHorizontal, -1);
+                int verticalMargin = a.getDimensionPixelSize(
+                        R.styleable.ViewGroup_MarginLayout_layout_marginVertical, -1);
+
+                if (horizontalMargin >= 0) {
+                    leftMargin = horizontalMargin;
+                    rightMargin = horizontalMargin;
+                } else {
+                    leftMargin = a.getDimensionPixelSize(
+                            R.styleable.ViewGroup_MarginLayout_layout_marginLeft,
+                            UNDEFINED_MARGIN);
+                    if (leftMargin == UNDEFINED_MARGIN) {
+                        mMarginFlags |= LEFT_MARGIN_UNDEFINED_MASK;
+                        leftMargin = DEFAULT_MARGIN_RESOLVED;
+                    }
+                    rightMargin = a.getDimensionPixelSize(
+                            R.styleable.ViewGroup_MarginLayout_layout_marginRight,
+                            UNDEFINED_MARGIN);
+                    if (rightMargin == UNDEFINED_MARGIN) {
+                        mMarginFlags |= RIGHT_MARGIN_UNDEFINED_MASK;
+                        rightMargin = DEFAULT_MARGIN_RESOLVED;
+                    }
+                }
+
+                startMargin = a.getDimensionPixelSize(
+                        R.styleable.ViewGroup_MarginLayout_layout_marginStart,
+                        DEFAULT_MARGIN_RELATIVE);
+                endMargin = a.getDimensionPixelSize(
+                        R.styleable.ViewGroup_MarginLayout_layout_marginEnd,
+                        DEFAULT_MARGIN_RELATIVE);
+
+                if (verticalMargin >= 0) {
+                    topMargin = verticalMargin;
+                    bottomMargin = verticalMargin;
+                } else {
+                    topMargin = a.getDimensionPixelSize(
+                            R.styleable.ViewGroup_MarginLayout_layout_marginTop,
+                            DEFAULT_MARGIN_RESOLVED);
+                    bottomMargin = a.getDimensionPixelSize(
+                            R.styleable.ViewGroup_MarginLayout_layout_marginBottom,
+                            DEFAULT_MARGIN_RESOLVED);
+                }
+
+                if (isMarginRelative()) {
+                   mMarginFlags |= NEED_RESOLUTION_MASK;
+                }
+            }
+
+            final boolean hasRtlSupport = c.getApplicationInfo().hasRtlSupport();
+            final int targetSdkVersion = c.getApplicationInfo().targetSdkVersion;
+            if (targetSdkVersion < JELLY_BEAN_MR1 || !hasRtlSupport) {
+                mMarginFlags |= RTL_COMPATIBILITY_MODE_MASK;
+            }
+
+            // Layout direction is LTR by default
+            mMarginFlags |= LAYOUT_DIRECTION_LTR;
+
+            a.recycle();
+        }
+
+        public MarginLayoutParams(int width, int height) {
+            super(width, height);
+
+            mMarginFlags |= LEFT_MARGIN_UNDEFINED_MASK;
+            mMarginFlags |= RIGHT_MARGIN_UNDEFINED_MASK;
+
+            mMarginFlags &= ~NEED_RESOLUTION_MASK;
+            mMarginFlags &= ~RTL_COMPATIBILITY_MODE_MASK;
+        }
+
+        /**
+         * Copy constructor. Clones the width, height and margin values of the source.
+         *
+         * @param source The layout params to copy from.
+         */
+        public MarginLayoutParams(MarginLayoutParams source) {
+            this.width = source.width;
+            this.height = source.height;
+
+            this.leftMargin = source.leftMargin;
+            this.topMargin = source.topMargin;
+            this.rightMargin = source.rightMargin;
+            this.bottomMargin = source.bottomMargin;
+            this.startMargin = source.startMargin;
+            this.endMargin = source.endMargin;
+
+            this.mMarginFlags = source.mMarginFlags;
+        }
+
+        public MarginLayoutParams(LayoutParams source) {
+            super(source);
+
+            mMarginFlags |= LEFT_MARGIN_UNDEFINED_MASK;
+            mMarginFlags |= RIGHT_MARGIN_UNDEFINED_MASK;
+
+            mMarginFlags &= ~NEED_RESOLUTION_MASK;
+            mMarginFlags &= ~RTL_COMPATIBILITY_MODE_MASK;
+        }
+
+        /**
+         * @hide Used internally.
+         */
+        public final void copyMarginsFrom(MarginLayoutParams source) {
+            this.leftMargin = source.leftMargin;
+            this.topMargin = source.topMargin;
+            this.rightMargin = source.rightMargin;
+            this.bottomMargin = source.bottomMargin;
+            this.startMargin = source.startMargin;
+            this.endMargin = source.endMargin;
+
+            this.mMarginFlags = source.mMarginFlags;
+        }
+
+        /**
+         * Sets the margins, in pixels. A call to {@link android.view.View#requestLayout()} needs
+         * to be done so that the new margins are taken into account. Left and right margins may be
+         * overriden by {@link android.view.View#requestLayout()} depending on layout direction.
+         * Margin values should be positive.
+         *
+         * @param left the left margin size
+         * @param top the top margin size
+         * @param right the right margin size
+         * @param bottom the bottom margin size
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginLeft
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginTop
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginRight
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginBottom
+         */
+        public void setMargins(int left, int top, int right, int bottom) {
+            leftMargin = left;
+            topMargin = top;
+            rightMargin = right;
+            bottomMargin = bottom;
+            mMarginFlags &= ~LEFT_MARGIN_UNDEFINED_MASK;
+            mMarginFlags &= ~RIGHT_MARGIN_UNDEFINED_MASK;
+            if (isMarginRelative()) {
+                mMarginFlags |= NEED_RESOLUTION_MASK;
+            } else {
+                mMarginFlags &= ~NEED_RESOLUTION_MASK;
+            }
+        }
+
+        /**
+         * Sets the relative margins, in pixels. A call to {@link android.view.View#requestLayout()}
+         * needs to be done so that the new relative margins are taken into account. Left and right
+         * margins may be overriden by {@link android.view.View#requestLayout()} depending on layout
+         * direction. Margin values should be positive.
+         *
+         * @param start the start margin size
+         * @param top the top margin size
+         * @param end the right margin size
+         * @param bottom the bottom margin size
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginTop
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginBottom
+         *
+         * @hide
+         */
+        public void setMarginsRelative(int start, int top, int end, int bottom) {
+            startMargin = start;
+            topMargin = top;
+            endMargin = end;
+            bottomMargin = bottom;
+            mMarginFlags |= NEED_RESOLUTION_MASK;
+        }
+
+        /**
+         * Sets the relative start margin. Margin values should be positive.
+         *
+         * @param start the start margin size
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
+         */
+        public void setMarginStart(int start) {
+            startMargin = start;
+            mMarginFlags |= NEED_RESOLUTION_MASK;
+        }
+
+        /**
+         * Returns the start margin in pixels.
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
+         *
+         * @return the start margin in pixels.
+         */
+        public int getMarginStart() {
+            if (startMargin != DEFAULT_MARGIN_RELATIVE) return startMargin;
+            if ((mMarginFlags & NEED_RESOLUTION_MASK) == NEED_RESOLUTION_MASK) {
+                doResolveMargins();
+            }
+            switch(mMarginFlags & LAYOUT_DIRECTION_MASK) {
+                case View.LAYOUT_DIRECTION_RTL:
+                    return rightMargin;
+                case View.LAYOUT_DIRECTION_LTR:
+                default:
+                    return leftMargin;
+            }
+        }
+
+        /**
+         * Sets the relative end margin. Margin values should be positive.
+         *
+         * @param end the end margin size
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
+         */
+        public void setMarginEnd(int end) {
+            endMargin = end;
+            mMarginFlags |= NEED_RESOLUTION_MASK;
+        }
+
+        /**
+         * Returns the end margin in pixels.
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
+         *
+         * @return the end margin in pixels.
+         */
+        public int getMarginEnd() {
+            if (endMargin != DEFAULT_MARGIN_RELATIVE) return endMargin;
+            if ((mMarginFlags & NEED_RESOLUTION_MASK) == NEED_RESOLUTION_MASK) {
+                doResolveMargins();
+            }
+            switch(mMarginFlags & LAYOUT_DIRECTION_MASK) {
+                case View.LAYOUT_DIRECTION_RTL:
+                    return leftMargin;
+                case View.LAYOUT_DIRECTION_LTR:
+                default:
+                    return rightMargin;
+            }
+        }
+
+        /**
+         * Check if margins are relative.
+         *
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
+         * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
+         *
+         * @return true if either marginStart or marginEnd has been set.
+         */
+        public boolean isMarginRelative() {
+            return (startMargin != DEFAULT_MARGIN_RELATIVE || endMargin != DEFAULT_MARGIN_RELATIVE);
+        }
+
+        /**
+         * Set the layout direction
+         * @param layoutDirection the layout direction.
+         *        Should be either {@link View#LAYOUT_DIRECTION_LTR}
+         *                     or {@link View#LAYOUT_DIRECTION_RTL}.
+         */
+        public void setLayoutDirection(int layoutDirection) {
+            if (layoutDirection != View.LAYOUT_DIRECTION_LTR &&
+                    layoutDirection != View.LAYOUT_DIRECTION_RTL) return;
+            if (layoutDirection != (mMarginFlags & LAYOUT_DIRECTION_MASK)) {
+                mMarginFlags &= ~LAYOUT_DIRECTION_MASK;
+                mMarginFlags |= (layoutDirection & LAYOUT_DIRECTION_MASK);
+                if (isMarginRelative()) {
+                    mMarginFlags |= NEED_RESOLUTION_MASK;
+                } else {
+                    mMarginFlags &= ~NEED_RESOLUTION_MASK;
+                }
+            }
+        }
+
+        /**
+         * Retuns the layout direction. Can be either {@link View#LAYOUT_DIRECTION_LTR} or
+         * {@link View#LAYOUT_DIRECTION_RTL}.
+         *
+         * @return the layout direction.
+         */
+        public int getLayoutDirection() {
+            return (mMarginFlags & LAYOUT_DIRECTION_MASK);
+        }
+
+        /**
+         * This will be called by {@link android.view.View#requestLayout()}. Left and Right margins
+         * may be overridden depending on layout direction.
+         */
+        @Override
+        public void resolveLayoutDirection(int layoutDirection) {
+            setLayoutDirection(layoutDirection);
+
+            // No relative margin or pre JB-MR1 case or no need to resolve, just dont do anything
+            // Will use the left and right margins if no relative margin is defined.
+            if (!isMarginRelative() ||
+                    (mMarginFlags & NEED_RESOLUTION_MASK) != NEED_RESOLUTION_MASK) return;
+
+            // Proceed with resolution
+            doResolveMargins();
+        }
+
+        private void doResolveMargins() {
+            if ((mMarginFlags & RTL_COMPATIBILITY_MODE_MASK) == RTL_COMPATIBILITY_MODE_MASK) {
+                // if left or right margins are not defined and if we have some start or end margin
+                // defined then use those start and end margins.
+                if ((mMarginFlags & LEFT_MARGIN_UNDEFINED_MASK) == LEFT_MARGIN_UNDEFINED_MASK
+                        && startMargin > DEFAULT_MARGIN_RELATIVE) {
+                    leftMargin = startMargin;
+                }
+                if ((mMarginFlags & RIGHT_MARGIN_UNDEFINED_MASK) == RIGHT_MARGIN_UNDEFINED_MASK
+                        && endMargin > DEFAULT_MARGIN_RELATIVE) {
+                    rightMargin = endMargin;
+                }
+            } else {
+                // We have some relative margins (either the start one or the end one or both). So use
+                // them and override what has been defined for left and right margins. If either start
+                // or end margin is not defined, just set it to default "0".
+                switch(mMarginFlags & LAYOUT_DIRECTION_MASK) {
+                    case View.LAYOUT_DIRECTION_RTL:
+                        leftMargin = (endMargin > DEFAULT_MARGIN_RELATIVE) ?
+                                endMargin : DEFAULT_MARGIN_RESOLVED;
+                        rightMargin = (startMargin > DEFAULT_MARGIN_RELATIVE) ?
+                                startMargin : DEFAULT_MARGIN_RESOLVED;
+                        break;
+                    case View.LAYOUT_DIRECTION_LTR:
+                    default:
+                        leftMargin = (startMargin > DEFAULT_MARGIN_RELATIVE) ?
+                                startMargin : DEFAULT_MARGIN_RESOLVED;
+                        rightMargin = (endMargin > DEFAULT_MARGIN_RELATIVE) ?
+                                endMargin : DEFAULT_MARGIN_RESOLVED;
+                        break;
+                }
+            }
+            mMarginFlags &= ~NEED_RESOLUTION_MASK;
+        }
+
+        /**
+         * @hide
+         */
+        public boolean isLayoutRtl() {
+            return ((mMarginFlags & LAYOUT_DIRECTION_MASK) == View.LAYOUT_DIRECTION_RTL);
+        }
+
+        @Override
+        public void onDebugDraw(View view, Canvas canvas, Paint paint) {
+            Insets oi = isLayoutModeOptical(view.mParent) ? view.getOpticalInsets() : Insets.NONE;
+
+            fillDifference(canvas,
+                    view.getLeft()   + oi.left,
+                    view.getTop()    + oi.top,
+                    view.getRight()  - oi.right,
+                    view.getBottom() - oi.bottom,
+                    leftMargin,
+                    topMargin,
+                    rightMargin,
+                    bottomMargin,
+                    paint);
+        }
+
+        /** @hide */
+        @Override
+        protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) {
+            super.encodeProperties(encoder);
+            encoder.addProperty("leftMargin", leftMargin);
+            encoder.addProperty("topMargin", topMargin);
+            encoder.addProperty("rightMargin", rightMargin);
+            encoder.addProperty("bottomMargin", bottomMargin);
+            encoder.addProperty("startMargin", startMargin);
+            encoder.addProperty("endMargin", endMargin);
+        }
+    }
+
+    /* Describes a touched view and the ids of the pointers that it has captured.
+     *
+     * This code assumes that pointer ids are always in the range 0..31 such that
+     * it can use a bitfield to track which pointer ids are present.
+     * As it happens, the lower layers of the input dispatch pipeline also use the
+     * same trick so the assumption should be safe here...
+     */
+    private static final class TouchTarget {
+        private static final int MAX_RECYCLED = 32;
+        private static final Object sRecycleLock = new Object[0];
+        private static TouchTarget sRecycleBin;
+        private static int sRecycledCount;
+
+        public static final int ALL_POINTER_IDS = -1; // all ones
+
+        // The touched child view.
+        public View child;
+
+        // The combined bit mask of pointer ids for all pointers captured by the target.
+        public int pointerIdBits;
+
+        // The next target in the target list.
+        public TouchTarget next;
+
+        private TouchTarget() {
+        }
+
+        public static TouchTarget obtain(@NonNull View child, int pointerIdBits) {
+            if (child == null) {
+                throw new IllegalArgumentException("child must be non-null");
+            }
+
+            final TouchTarget target;
+            synchronized (sRecycleLock) {
+                if (sRecycleBin == null) {
+                    target = new TouchTarget();
+                } else {
+                    target = sRecycleBin;
+                    sRecycleBin = target.next;
+                     sRecycledCount--;
+                    target.next = null;
+                }
+            }
+            target.child = child;
+            target.pointerIdBits = pointerIdBits;
+            return target;
+        }
+
+        public void recycle() {
+            if (child == null) {
+                throw new IllegalStateException("already recycled once");
+            }
+
+            synchronized (sRecycleLock) {
+                if (sRecycledCount < MAX_RECYCLED) {
+                    next = sRecycleBin;
+                    sRecycleBin = this;
+                    sRecycledCount += 1;
+                } else {
+                    next = null;
+                }
+                child = null;
+            }
+        }
+    }
+
+    /* Describes a hovered view. */
+    private static final class HoverTarget {
+        private static final int MAX_RECYCLED = 32;
+        private static final Object sRecycleLock = new Object[0];
+        private static HoverTarget sRecycleBin;
+        private static int sRecycledCount;
+
+        // The hovered child view.
+        public View child;
+
+        // The next target in the target list.
+        public HoverTarget next;
+
+        private HoverTarget() {
+        }
+
+        public static HoverTarget obtain(@NonNull View child) {
+            if (child == null) {
+                throw new IllegalArgumentException("child must be non-null");
+            }
+
+            final HoverTarget target;
+            synchronized (sRecycleLock) {
+                if (sRecycleBin == null) {
+                    target = new HoverTarget();
+                } else {
+                    target = sRecycleBin;
+                    sRecycleBin = target.next;
+                    sRecycledCount--;
+                    target.next = null;
+                }
+            }
+            target.child = child;
+            return target;
+        }
+
+        public void recycle() {
+            if (child == null) {
+                throw new IllegalStateException("already recycled once");
+            }
+
+            synchronized (sRecycleLock) {
+                if (sRecycledCount < MAX_RECYCLED) {
+                    next = sRecycleBin;
+                    sRecycleBin = this;
+                    sRecycledCount += 1;
+                } else {
+                    next = null;
+                }
+                child = null;
+            }
+        }
+    }
+
+    /**
+     * Pooled class that to hold the children for autifill.
+     */
+    static class ChildListForAutoFill extends ArrayList<View> {
+        private static final int MAX_POOL_SIZE = 32;
+
+        private static final Pools.SimplePool<ChildListForAutoFill> sPool =
+                new Pools.SimplePool<>(MAX_POOL_SIZE);
+
+        public static ChildListForAutoFill obtain() {
+            ChildListForAutoFill list = sPool.acquire();
+            if (list == null) {
+                list = new ChildListForAutoFill();
+            }
+            return list;
+        }
+
+        public void recycle() {
+            clear();
+            sPool.release(this);
+        }
+    }
+
+    /**
+     * Pooled class that orderes the children of a ViewGroup from start
+     * to end based on how they are laid out and the layout direction.
+     */
+    static class ChildListForAccessibility {
+
+        private static final int MAX_POOL_SIZE = 32;
+
+        private static final SynchronizedPool<ChildListForAccessibility> sPool =
+                new SynchronizedPool<ChildListForAccessibility>(MAX_POOL_SIZE);
+
+        private final ArrayList<View> mChildren = new ArrayList<View>();
+
+        private final ArrayList<ViewLocationHolder> mHolders = new ArrayList<ViewLocationHolder>();
+
+        public static ChildListForAccessibility obtain(ViewGroup parent, boolean sort) {
+            ChildListForAccessibility list = sPool.acquire();
+            if (list == null) {
+                list = new ChildListForAccessibility();
+            }
+            list.init(parent, sort);
+            return list;
+        }
+
+        public void recycle() {
+            clear();
+            sPool.release(this);
+        }
+
+        public int getChildCount() {
+            return mChildren.size();
+        }
+
+        public View getChildAt(int index) {
+            return mChildren.get(index);
+        }
+
+        private void init(ViewGroup parent, boolean sort) {
+            ArrayList<View> children = mChildren;
+            final int childCount = parent.getChildCount();
+            for (int i = 0; i < childCount; i++) {
+                View child = parent.getChildAt(i);
+                children.add(child);
+            }
+            if (sort) {
+                ArrayList<ViewLocationHolder> holders = mHolders;
+                for (int i = 0; i < childCount; i++) {
+                    View child = children.get(i);
+                    ViewLocationHolder holder = ViewLocationHolder.obtain(parent, child);
+                    holders.add(holder);
+                }
+                sort(holders);
+                for (int i = 0; i < childCount; i++) {
+                    ViewLocationHolder holder = holders.get(i);
+                    children.set(i, holder.mView);
+                    holder.recycle();
+                }
+                holders.clear();
+            }
+        }
+
+        private void sort(ArrayList<ViewLocationHolder> holders) {
+            // This is gross but the least risky solution. The current comparison
+            // strategy breaks transitivity but produces very good results. Coming
+            // up with a new strategy requires time which we do not have, so ...
+            try {
+                ViewLocationHolder.setComparisonStrategy(
+                        ViewLocationHolder.COMPARISON_STRATEGY_STRIPE);
+                Collections.sort(holders);
+            } catch (IllegalArgumentException iae) {
+                // Note that in practice this occurs extremely rarely in a couple
+                // of pathological cases.
+                ViewLocationHolder.setComparisonStrategy(
+                        ViewLocationHolder.COMPARISON_STRATEGY_LOCATION);
+                Collections.sort(holders);
+            }
+        }
+
+        private void clear() {
+            mChildren.clear();
+        }
+    }
+
+    /**
+     * Pooled class that holds a View and its location with respect to
+     * a specified root. This enables sorting of views based on their
+     * coordinates without recomputing the position relative to the root
+     * on every comparison.
+     */
+    static class ViewLocationHolder implements Comparable<ViewLocationHolder> {
+
+        private static final int MAX_POOL_SIZE = 32;
+
+        private static final SynchronizedPool<ViewLocationHolder> sPool =
+                new SynchronizedPool<ViewLocationHolder>(MAX_POOL_SIZE);
+
+        public static final int COMPARISON_STRATEGY_STRIPE = 1;
+
+        public static final int COMPARISON_STRATEGY_LOCATION = 2;
+
+        private static int sComparisonStrategy = COMPARISON_STRATEGY_STRIPE;
+
+        private final Rect mLocation = new Rect();
+
+        public View mView;
+
+        private int mLayoutDirection;
+
+        public static ViewLocationHolder obtain(ViewGroup root, View view) {
+            ViewLocationHolder holder = sPool.acquire();
+            if (holder == null) {
+                holder = new ViewLocationHolder();
+            }
+            holder.init(root, view);
+            return holder;
+        }
+
+        public static void setComparisonStrategy(int strategy) {
+            sComparisonStrategy = strategy;
+        }
+
+        public void recycle() {
+            clear();
+            sPool.release(this);
+        }
+
+        @Override
+        public int compareTo(ViewLocationHolder another) {
+            // This instance is greater than an invalid argument.
+            if (another == null) {
+                return 1;
+            }
+
+            if (sComparisonStrategy == COMPARISON_STRATEGY_STRIPE) {
+                // First is above second.
+                if (mLocation.bottom - another.mLocation.top <= 0) {
+                    return -1;
+                }
+                // First is below second.
+                if (mLocation.top - another.mLocation.bottom >= 0) {
+                    return 1;
+                }
+            }
+
+            // We are ordering left-to-right, top-to-bottom.
+            if (mLayoutDirection == LAYOUT_DIRECTION_LTR) {
+                final int leftDifference = mLocation.left - another.mLocation.left;
+                if (leftDifference != 0) {
+                    return leftDifference;
+                }
+            } else { // RTL
+                final int rightDifference = mLocation.right - another.mLocation.right;
+                if (rightDifference != 0) {
+                    return -rightDifference;
+                }
+            }
+            // We are ordering left-to-right, top-to-bottom.
+            final int topDifference = mLocation.top - another.mLocation.top;
+            if (topDifference != 0) {
+                return topDifference;
+            }
+            // Break tie by height.
+            final int heightDiference = mLocation.height() - another.mLocation.height();
+            if (heightDiference != 0) {
+                return -heightDiference;
+            }
+            // Break tie by width.
+            final int widthDiference = mLocation.width() - another.mLocation.width();
+            if (widthDiference != 0) {
+                return -widthDiference;
+            }
+            // Just break the tie somehow. The accessibliity ids are unique
+            // and stable, hence this is deterministic tie breaking.
+            return mView.getAccessibilityViewId() - another.mView.getAccessibilityViewId();
+        }
+
+        private void init(ViewGroup root, View view) {
+            Rect viewLocation = mLocation;
+            view.getDrawingRect(viewLocation);
+            root.offsetDescendantRectToMyCoords(view, viewLocation);
+            mView = view;
+            mLayoutDirection = root.getLayoutDirection();
+        }
+
+        private void clear() {
+            mView = null;
+            mLocation.set(0, 0, 0, 0);
+        }
+    }
+
+    private static void drawRect(Canvas canvas, Paint paint, int x1, int y1, int x2, int y2) {
+        if (sDebugLines== null) {
+            // TODO: This won't work with multiple UI threads in a single process
+            sDebugLines = new float[16];
+        }
+
+        sDebugLines[0] = x1;
+        sDebugLines[1] = y1;
+        sDebugLines[2] = x2;
+        sDebugLines[3] = y1;
+
+        sDebugLines[4] = x2;
+        sDebugLines[5] = y1;
+        sDebugLines[6] = x2;
+        sDebugLines[7] = y2;
+
+        sDebugLines[8] = x2;
+        sDebugLines[9] = y2;
+        sDebugLines[10] = x1;
+        sDebugLines[11] = y2;
+
+        sDebugLines[12] = x1;
+        sDebugLines[13] = y2;
+        sDebugLines[14] = x1;
+        sDebugLines[15] = y1;
+
+        canvas.drawLines(sDebugLines, paint);
+    }
+
+    /** @hide */
+    @Override
+    protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) {
+        super.encodeProperties(encoder);
+
+        encoder.addProperty("focus:descendantFocusability", getDescendantFocusability());
+        encoder.addProperty("drawing:clipChildren", getClipChildren());
+        encoder.addProperty("drawing:clipToPadding", getClipToPadding());
+        encoder.addProperty("drawing:childrenDrawingOrderEnabled", isChildrenDrawingOrderEnabled());
+        encoder.addProperty("drawing:persistentDrawingCache", getPersistentDrawingCache());
+
+        int n = getChildCount();
+        encoder.addProperty("meta:__childCount__", (short)n);
+        for (int i = 0; i < n; i++) {
+            encoder.addPropertyKey("meta:__child__" + i);
+            getChildAt(i).encode(encoder);
+        }
+    }
+}