Reconcile with jb-dev - do not mergetools_r21

Change-Id: Ib87793fb3dc051968e2e1683476b217f7118712a

3 files changed, 1591 insertions, 15 deletions

diff --git a/src/com/android/videoeditor/KenBurnsActivity.java b/src/com/android/videoeditor/KenBurnsActivity.java
index cb9fa0c..37a6808 100755
--- a/src/com/android/videoeditor/KenBurnsActivity.java
+++ b/src/com/android/videoeditor/KenBurnsActivity.java
@@ -326,13 +326,7 @@ public class KenBurnsActivity extends Activity {
         mImageView.setEventListener(new ImageViewTouchBase.ImageTouchEventListener() {
             @Override
             public boolean onImageTouchEvent(MotionEvent ev) {
-                if (null != mScaleGestureDetector) {
-                    mScaleGestureDetector.onTouchEvent(ev);
-                    if (mScaleGestureDetector.isInProgress()) {
-                        return true;
-                    }
-                }
-
+                mScaleGestureDetector.onTouchEvent(ev);
                 mGestureDetector.onTouchEvent(ev);
                 return true;
             }
diff --git a/src/com/android/videoeditor/widgets/HorizontalScrollView.java b/src/com/android/videoeditor/widgets/HorizontalScrollView.java
new file mode 100644
index 0000000..0687b0f
--- /dev/null
+++ b/src/com/android/videoeditor/widgets/HorizontalScrollView.java
@@ -0,0 +1,1588 @@
+/*
+ * Copyright (C) 2009 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 com.android.videoeditor.widgets;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.os.Bundle;
+import android.util.AttributeSet;
+import android.view.FocusFinder;
+import android.view.InputDevice;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+import android.view.VelocityTracker;
+import android.view.View;
+import android.view.ViewConfiguration;
+import android.view.ViewDebug;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.animation.AnimationUtils;
+import android.widget.EdgeEffect;
+import android.widget.FrameLayout;
+import android.widget.OverScroller;
+
+import java.util.List;
+
+/**
+ * Layout container for a view hierarchy that can be scrolled by the user,
+ * allowing it to be larger than the physical display.  A HorizontalScrollView
+ * is a {@link FrameLayout}, meaning you should place one child in it
+ * containing the entire contents to scroll; this child may itself be a layout
+ * manager with a complex hierarchy of objects.  A child that is often used
+ * is a {@link LinearLayout} in a horizontal orientation, presenting a horizontal
+ * array of top-level items that the user can scroll through.
+ *
+ * <p>The {@link TextView} class also
+ * takes care of its own scrolling, so does not require a HorizontalScrollView, but
+ * using the two together is possible to achieve the effect of a text view
+ * within a larger container.
+ *
+ * <p>HorizontalScrollView only supports horizontal scrolling. For vertical scrolling,
+ * use either {@link ScrollView} or {@link ListView}.
+ *
+ * @attr ref android.R.styleable#HorizontalScrollView_fillViewport
+ */
+public class HorizontalScrollView extends FrameLayout {
+    private static final int ANIMATED_SCROLL_GAP = 250;
+
+    private static final float MAX_SCROLL_FACTOR = 0.5f;
+
+
+    private long mLastScroll;
+
+    private final Rect mTempRect = new Rect();
+    private OverScroller mScroller;
+    private EdgeEffect mEdgeGlowLeft;
+    private EdgeEffect mEdgeGlowRight;
+
+    /**
+     * X position of the last focal point.
+     */
+    private int mLastFocusX;
+
+    /**
+     * True if the value of mLastFocusX is still valid.
+     */
+    private boolean mHasLastFocusX;
+
+    /**
+     * True when the layout has changed but the traversal has not come through yet.
+     * Ideally the view hierarchy would keep track of this for us.
+     */
+    private boolean mIsLayoutDirty = true;
+
+    /**
+     * The child to give focus to in the event that a child has requested focus while the
+     * layout is dirty. This prevents the scroll from being wrong if the child has not been
+     * laid out before requesting focus.
+     */
+    private View mChildToScrollTo = null;
+
+    /**
+     * True if the user is currently dragging this ScrollView around. This is
+     * not the same as 'is being flinged', which can be checked by
+     * mScroller.isFinished() (flinging begins when the user lifts his finger).
+     */
+    private boolean mIsBeingDragged = false;
+
+    /**
+     * Determines speed during touch scrolling
+     */
+    private VelocityTracker mVelocityTracker;
+
+    /**
+     * When set to true, the scroll view measure its child to make it fill the currently
+     * visible area.
+     */
+    @ViewDebug.ExportedProperty(category = "layout")
+    private boolean mFillViewport;
+
+    /**
+     * Whether arrow scrolling is animated.
+     */
+    private boolean mSmoothScrollingEnabled = true;
+
+    private int mTouchSlop;
+    private int mMinimumVelocity;
+    private int mMaximumVelocity;
+
+    private int mOverscrollDistance;
+    private int mOverflingDistance;
+
+    public HorizontalScrollView(Context context) {
+        this(context, null);
+    }
+
+    public HorizontalScrollView(Context context, AttributeSet attrs) {
+        this(context, attrs, com.android.internal.R.attr.horizontalScrollViewStyle);
+    }
+
+    public HorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        initScrollView();
+
+        TypedArray a = context.obtainStyledAttributes(attrs,
+                android.R.styleable.HorizontalScrollView, defStyle, 0);
+
+        setFillViewport(a.getBoolean(android.R.styleable.HorizontalScrollView_fillViewport, false));
+
+        a.recycle();
+    }
+
+    @Override
+    protected float getLeftFadingEdgeStrength() {
+        if (getChildCount() == 0) {
+            return 0.0f;
+        }
+
+        final int length = getHorizontalFadingEdgeLength();
+        if (mScrollX < length) {
+            return mScrollX / (float) length;
+        }
+
+        return 1.0f;
+    }
+
+    @Override
+    protected float getRightFadingEdgeStrength() {
+        if (getChildCount() == 0) {
+            return 0.0f;
+        }
+
+        final int length = getHorizontalFadingEdgeLength();
+        final int rightEdge = getWidth() - mPaddingRight;
+        final int span = getChildAt(0).getRight() - mScrollX - rightEdge;
+        if (span < length) {
+            return span / (float) length;
+        }
+
+        return 1.0f;
+    }
+
+    /**
+     * @return The maximum amount this scroll view will scroll in response to
+     *   an arrow event.
+     */
+    public int getMaxScrollAmount() {
+        return (int) (MAX_SCROLL_FACTOR * (mRight - mLeft));
+    }
+
+
+    private void initScrollView() {
+        mScroller = new OverScroller(getContext());
+        setFocusable(true);
+        setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
+        setWillNotDraw(false);
+        final ViewConfiguration configuration = ViewConfiguration.get(mContext);
+        mTouchSlop = configuration.getScaledTouchSlop();
+        mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
+        mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
+        mOverscrollDistance = configuration.getScaledOverscrollDistance();
+        mOverflingDistance = configuration.getScaledOverflingDistance();
+    }
+
+    @Override
+    public void addView(View child) {
+        if (getChildCount() > 0) {
+            throw new IllegalStateException("HorizontalScrollView can host only one direct child");
+        }
+
+        super.addView(child);
+    }
+
+    @Override
+    public void addView(View child, int index) {
+        if (getChildCount() > 0) {
+            throw new IllegalStateException("HorizontalScrollView can host only one direct child");
+        }
+
+        super.addView(child, index);
+    }
+
+    @Override
+    public void addView(View child, ViewGroup.LayoutParams params) {
+        if (getChildCount() > 0) {
+            throw new IllegalStateException("HorizontalScrollView can host only one direct child");
+        }
+
+        super.addView(child, params);
+    }
+
+    @Override
+    public void addView(View child, int index, ViewGroup.LayoutParams params) {
+        if (getChildCount() > 0) {
+            throw new IllegalStateException("HorizontalScrollView can host only one direct child");
+        }
+
+        super.addView(child, index, params);
+    }
+
+    /**
+     * @return Returns true this HorizontalScrollView can be scrolled
+     */
+    private boolean canScroll() {
+        View child = getChildAt(0);
+        if (child != null) {
+            int childWidth = child.getWidth();
+            return getWidth() < childWidth + mPaddingLeft + mPaddingRight ;
+        }
+        return false;
+    }
+
+    /**
+     * Indicates whether this HorizontalScrollView's content is stretched to
+     * fill the viewport.
+     *
+     * @return True if the content fills the viewport, false otherwise.
+     *
+     * @attr ref android.R.styleable#HorizontalScrollView_fillViewport
+     */
+    public boolean isFillViewport() {
+        return mFillViewport;
+    }
+
+    /**
+     * Indicates this HorizontalScrollView whether it should stretch its content width
+     * to fill the viewport or not.
+     *
+     * @param fillViewport True to stretch the content's width to the viewport's
+     *        boundaries, false otherwise.
+     *
+     * @attr ref android.R.styleable#HorizontalScrollView_fillViewport
+     */
+    public void setFillViewport(boolean fillViewport) {
+        if (fillViewport != mFillViewport) {
+            mFillViewport = fillViewport;
+            requestLayout();
+        }
+    }
+
+    /**
+     * @return Whether arrow scrolling will animate its transition.
+     */
+    public boolean isSmoothScrollingEnabled() {
+        return mSmoothScrollingEnabled;
+    }
+
+    /**
+     * Set whether arrow scrolling will animate its transition.
+     * @param smoothScrollingEnabled whether arrow scrolling will animate its transition
+     */
+    public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) {
+        mSmoothScrollingEnabled = smoothScrollingEnabled;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        if (!mFillViewport) {
+            return;
+        }
+
+        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
+        if (widthMode == MeasureSpec.UNSPECIFIED) {
+            return;
+        }
+
+        if (getChildCount() > 0) {
+            final View child = getChildAt(0);
+            int width = getMeasuredWidth();
+            if (child.getMeasuredWidth() < width) {
+                final FrameLayout.LayoutParams lp = (LayoutParams) child.getLayoutParams();
+
+                int childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec, mPaddingTop
+                        + mPaddingBottom, lp.height);
+                width -= mPaddingLeft;
+                width -= mPaddingRight;
+                int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
+
+                child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+            }
+        }
+    }
+
+    @Override
+    public boolean dispatchKeyEvent(KeyEvent event) {
+        // Let the focused view and/or our descendants get the key first
+        return super.dispatchKeyEvent(event) || executeKeyEvent(event);
+    }
+
+    /**
+     * You can call this function yourself to have the scroll view perform
+     * scrolling from a key event, just as if the event had been dispatched to
+     * it by the view hierarchy.
+     *
+     * @param event The key event to execute.
+     * @return Return true if the event was handled, else false.
+     */
+    public boolean executeKeyEvent(KeyEvent event) {
+        mTempRect.setEmpty();
+
+        if (!canScroll()) {
+            if (isFocused()) {
+                View currentFocused = findFocus();
+                if (currentFocused == this) currentFocused = null;
+                View nextFocused = FocusFinder.getInstance().findNextFocus(this,
+                        currentFocused, View.FOCUS_RIGHT);
+                return nextFocused != null && nextFocused != this &&
+                        nextFocused.requestFocus(View.FOCUS_RIGHT);
+            }
+            return false;
+        }
+
+        boolean handled = false;
+        if (event.getAction() == KeyEvent.ACTION_DOWN) {
+            switch (event.getKeyCode()) {
+                case KeyEvent.KEYCODE_DPAD_LEFT:
+                    if (!event.isAltPressed()) {
+                        handled = arrowScroll(View.FOCUS_LEFT);
+                    } else {
+                        handled = fullScroll(View.FOCUS_LEFT);
+                    }
+                    break;
+                case KeyEvent.KEYCODE_DPAD_RIGHT:
+                    if (!event.isAltPressed()) {
+                        handled = arrowScroll(View.FOCUS_RIGHT);
+                    } else {
+                        handled = fullScroll(View.FOCUS_RIGHT);
+                    }
+                    break;
+                case KeyEvent.KEYCODE_SPACE:
+                    pageScroll(event.isShiftPressed() ? View.FOCUS_LEFT : View.FOCUS_RIGHT);
+                    break;
+            }
+        }
+
+        return handled;
+    }
+
+    private boolean inChild(int x, int y) {
+        if (getChildCount() > 0) {
+            final int scrollX = mScrollX;
+            final View child = getChildAt(0);
+            return !(y < child.getTop()
+                    || y >= child.getBottom()
+                    || x < child.getLeft() - scrollX
+                    || x >= child.getRight() - scrollX);
+        }
+        return false;
+    }
+
+    private void initOrResetVelocityTracker() {
+        if (mVelocityTracker == null) {
+            mVelocityTracker = VelocityTracker.obtain();
+        } else {
+            mVelocityTracker.clear();
+        }
+    }
+
+    private void initVelocityTrackerIfNotExists() {
+        if (mVelocityTracker == null) {
+            mVelocityTracker = VelocityTracker.obtain();
+        }
+    }
+
+    private void recycleVelocityTracker() {
+        if (mVelocityTracker != null) {
+            mVelocityTracker.recycle();
+            mVelocityTracker = null;
+        }
+    }
+
+    private static int getFocusX(MotionEvent ev) {
+        final int action = ev.getAction();
+        final boolean pointerUp =
+                (action & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_UP;
+        final int skipIndex = pointerUp ? ev.getActionIndex() : -1;
+
+        // Determine focal point
+        float sumX = 0;
+        final int count = ev.getPointerCount();
+        for (int i = 0; i < count; i++) {
+            if (skipIndex == i) continue;
+            sumX += ev.getX(i);
+        }
+        final int div = pointerUp ? count - 1 : count;
+        final float focusX = sumX / div;
+        return (int) focusX;
+    }
+
+    @Override
+    public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
+        if (disallowIntercept) {
+            recycleVelocityTracker();
+        }
+        super.requestDisallowInterceptTouchEvent(disallowIntercept);
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        /*
+         * This method JUST determines whether we want to intercept the motion.
+         * If we return true, onMotionEvent will be called and we do the actual
+         * scrolling there.
+         */
+
+        /*
+        * Shortcut the most recurring case: the user is in the dragging
+        * state and he is moving his finger.  We want to intercept this
+        * motion.
+        */
+        final int action = ev.getAction();
+        if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) {
+            return true;
+        }
+
+        switch (action & MotionEvent.ACTION_MASK) {
+            case MotionEvent.ACTION_MOVE: {
+                /*
+                 * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
+                 * whether the user has moved far enough from his original down touch.
+                 */
+
+                if (!mHasLastFocusX) {
+                    // If we don't have a valid mLastFocusX, the touch down wasn't
+                    // on content.
+                    break;
+                }
+
+                final int x = getFocusX(ev);
+                final int xDiff = (int) Math.abs(x - mLastFocusX);
+                if (xDiff > mTouchSlop) {
+                    mIsBeingDragged = true;
+                    mLastFocusX = x;
+                    initVelocityTrackerIfNotExists();
+                    mVelocityTracker.addMovement(ev);
+                    if (mParent != null) mParent.requestDisallowInterceptTouchEvent(true);
+                }
+                break;
+            }
+
+            case MotionEvent.ACTION_DOWN: {
+                final int x = (int) ev.getX();
+                if (!inChild((int) x, (int) ev.getY())) {
+                    mIsBeingDragged = false;
+                    recycleVelocityTracker();
+                    break;
+                }
+
+                /*
+                 * Remember location of down touch.
+                 */
+                mLastFocusX = getFocusX(ev);
+                mHasLastFocusX = true;
+
+                initOrResetVelocityTracker();
+                mVelocityTracker.addMovement(ev);
+
+                /*
+                * If being flinged and user touches the screen, initiate drag;
+                * otherwise don't.  mScroller.isFinished should be false when
+                * being flinged.
+                */
+                mIsBeingDragged = !mScroller.isFinished();
+                break;
+            }
+
+            case MotionEvent.ACTION_CANCEL:
+            case MotionEvent.ACTION_UP:
+                /* Release the drag */
+                mIsBeingDragged = false;
+                mHasLastFocusX = false;
+                if (mScroller.springBack(mScrollX, mScrollY, 0, getScrollRange(), 0, 0)) {
+                    postInvalidateOnAnimation();
+                }
+                break;
+            case MotionEvent.ACTION_POINTER_DOWN: {
+                mLastFocusX = getFocusX(ev);
+                mHasLastFocusX = true;
+                break;
+            }
+            case MotionEvent.ACTION_POINTER_UP:
+                onSecondaryPointerUp(ev);
+                mLastFocusX = getFocusX(ev);
+                break;
+        }
+
+        /*
+        * The only time we want to intercept motion events is if we are in the
+        * drag mode.
+        */
+        return mIsBeingDragged;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent ev) {
+        initVelocityTrackerIfNotExists();
+        mVelocityTracker.addMovement(ev);
+
+        final int action = ev.getAction();
+
+        switch (action & MotionEvent.ACTION_MASK) {
+            case MotionEvent.ACTION_DOWN: {
+                if (getChildCount() == 0) {
+                    return false;
+                }
+                if ((mIsBeingDragged = !mScroller.isFinished())) {
+                    final ViewParent parent = getParent();
+                    if (parent != null) {
+                        parent.requestDisallowInterceptTouchEvent(true);
+                    }
+                }
+
+                /*
+                 * If being flinged and user touches, stop the fling. isFinished
+                 * will be false if being flinged.
+                 */
+                if (!mScroller.isFinished()) {
+                    mScroller.abortAnimation();
+                }
+
+                // Remember where the motion event started
+                mLastFocusX = getFocusX(ev);
+                mHasLastFocusX = true;
+                break;
+            }
+            case MotionEvent.ACTION_MOVE:
+                final int x = getFocusX(ev);
+                int deltaX = mLastFocusX - x;
+                if (!mIsBeingDragged && Math.abs(deltaX) > mTouchSlop) {
+                    final ViewParent parent = getParent();
+                    if (parent != null) {
+                        parent.requestDisallowInterceptTouchEvent(true);
+                    }
+                    mIsBeingDragged = true;
+                    if (deltaX > 0) {
+                        deltaX -= mTouchSlop;
+                    } else {
+                        deltaX += mTouchSlop;
+                    }
+                }
+                if (mIsBeingDragged) {
+                    // Scroll to follow the motion event
+                    mLastFocusX = x;
+
+                    final int oldX = mScrollX;
+                    final int oldY = mScrollY;
+                    final int range = getScrollRange();
+                    final int overscrollMode = getOverScrollMode();
+                    final boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS ||
+                            (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);
+
+                    if (overScrollBy(deltaX, 0, mScrollX, 0, range, 0,
+                            mOverscrollDistance, 0, true)) {
+                        // Break our velocity if we hit a scroll barrier.
+                        mVelocityTracker.clear();
+                    }
+                    onScrollChanged(mScrollX, mScrollY, oldX, oldY);
+
+                    if (canOverscroll) {
+                        final int pulledToX = oldX + deltaX;
+                        if (pulledToX < 0) {
+                            mEdgeGlowLeft.onPull((float) deltaX / getWidth());
+                            if (!mEdgeGlowRight.isFinished()) {
+                                mEdgeGlowRight.onRelease();
+                            }
+                        } else if (pulledToX > range) {
+                            mEdgeGlowRight.onPull((float) deltaX / getWidth());
+                            if (!mEdgeGlowLeft.isFinished()) {
+                                mEdgeGlowLeft.onRelease();
+                            }
+                        }
+                        if (mEdgeGlowLeft != null
+                                && (!mEdgeGlowLeft.isFinished() || !mEdgeGlowRight.isFinished())) {
+                            postInvalidateOnAnimation();
+                        }
+                    }
+                }
+                break;
+            case MotionEvent.ACTION_UP:
+                if (mIsBeingDragged) {
+                    final VelocityTracker velocityTracker = mVelocityTracker;
+                    final int pointerId = ev.getPointerId(0);
+                    velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
+                    int initialVelocity = (int) velocityTracker.getXVelocity(pointerId);
+
+                    if (getChildCount() > 0) {
+                        if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
+                            fling(-initialVelocity);
+                        } else {
+                            if (mScroller.springBack(mScrollX, mScrollY, 0,
+                                    getScrollRange(), 0, 0)) {
+                                postInvalidateOnAnimation();
+                            }
+                        }
+                    }
+
+                    mHasLastFocusX = false;
+                    mIsBeingDragged = false;
+                    recycleVelocityTracker();
+
+                    if (mEdgeGlowLeft != null) {
+                        mEdgeGlowLeft.onRelease();
+                        mEdgeGlowRight.onRelease();
+                    }
+                }
+                break;
+            case MotionEvent.ACTION_CANCEL:
+                if (mIsBeingDragged && getChildCount() > 0) {
+                    if (mScroller.springBack(mScrollX, mScrollY, 0, getScrollRange(), 0, 0)) {
+                        postInvalidateOnAnimation();
+                    }
+                    mHasLastFocusX = false;
+                    mIsBeingDragged = false;
+                    recycleVelocityTracker();
+
+                    if (mEdgeGlowLeft != null) {
+                        mEdgeGlowLeft.onRelease();
+                        mEdgeGlowRight.onRelease();
+                    }
+                }
+                break;
+            case MotionEvent.ACTION_POINTER_UP:
+                onSecondaryPointerUp(ev);
+                break;
+        }
+        return true;
+    }
+
+    private void onSecondaryPointerUp(MotionEvent ev) {
+        mLastFocusX = getFocusX(ev);
+        mHasLastFocusX = true;
+        if (mVelocityTracker != null) {
+            mVelocityTracker.clear();
+        }
+    }
+
+    @Override
+    public boolean onGenericMotionEvent(MotionEvent event) {
+        if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
+            switch (event.getAction()) {
+                case MotionEvent.ACTION_SCROLL: {
+                    if (!mIsBeingDragged) {
+                        final float hscroll;
+                        if ((event.getMetaState() & KeyEvent.META_SHIFT_ON) != 0) {
+                            hscroll = -event.getAxisValue(MotionEvent.AXIS_VSCROLL);
+                        } else {
+                            hscroll = event.getAxisValue(MotionEvent.AXIS_HSCROLL);
+                        }
+                        if (hscroll != 0) {
+                            final int delta = (int) (hscroll * getHorizontalScrollFactor());
+                            final int range = getScrollRange();
+                            int oldScrollX = mScrollX;
+                            int newScrollX = oldScrollX + delta;
+                            if (newScrollX < 0) {
+                                newScrollX = 0;
+                            } else if (newScrollX > range) {
+                                newScrollX = range;
+                            }
+                            if (newScrollX != oldScrollX) {
+                                super.scrollTo(newScrollX, mScrollY);
+                                return true;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        return super.onGenericMotionEvent(event);
+    }
+
+    @Override
+    public boolean shouldDelayChildPressedState() {
+        return true;
+    }
+
+    @Override
+    protected void onOverScrolled(int scrollX, int scrollY,
+            boolean clampedX, boolean clampedY) {
+        // Treat animating scrolls differently; see #computeScroll() for why.
+        if (!mScroller.isFinished()) {
+            mScrollX = scrollX;
+            mScrollY = scrollY;
+            invalidateParentIfNeeded();
+            if (clampedX) {
+                mScroller.springBack(mScrollX, mScrollY, 0, getScrollRange(), 0, 0);
+            }
+        } else {
+            super.scrollTo(scrollX, scrollY);
+        }
+        
+        awakenScrollBars();
+    }
+
+    @Override
+    public boolean performAccessibilityAction(int action, Bundle arguments) {
+        if (super.performAccessibilityAction(action, arguments)) {
+            return true;
+        }
+        switch (action) {
+            case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
+                if (!isEnabled()) {
+                    return false;
+                }
+                final int viewportWidth = getWidth() - mPaddingLeft - mPaddingRight;
+                final int targetScrollX = Math.min(mScrollX + viewportWidth, getScrollRange());
+                if (targetScrollX != mScrollX) {
+                    smoothScrollTo(targetScrollX, 0);
+                    return true;
+                }
+            } return false;
+            case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
+                if (!isEnabled()) {
+                    return false;
+                }
+                final int viewportWidth = getWidth() - mPaddingLeft - mPaddingRight;
+                final int targetScrollX = Math.max(0, mScrollX - viewportWidth);
+                if (targetScrollX != mScrollX) {
+                    smoothScrollTo(targetScrollX, 0);
+                    return true;
+                }
+            } return false;
+        }
+        return false;
+    }
+
+    @Override
+    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfo(info);
+        info.setClassName(HorizontalScrollView.class.getName());
+        final int scrollRange = getScrollRange();
+        if (scrollRange > 0) {
+            info.setScrollable(true);
+            if (isEnabled() && mScrollX > 0) {
+                info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
+            }
+            if (isEnabled() && mScrollX < scrollRange) {
+                info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
+            }
+        }
+    }
+
+    @Override
+    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
+        super.onInitializeAccessibilityEvent(event);
+        event.setClassName(HorizontalScrollView.class.getName());
+        event.setScrollable(getScrollRange() > 0);
+        event.setScrollX(mScrollX);
+        event.setScrollY(mScrollY);
+        event.setMaxScrollX(getScrollRange());
+        event.setMaxScrollY(mScrollY);
+    }
+
+    private int getScrollRange() {
+        int scrollRange = 0;
+        if (getChildCount() > 0) {
+            View child = getChildAt(0);
+            scrollRange = Math.max(0,
+                    child.getWidth() - (getWidth() - mPaddingLeft - mPaddingRight));
+        }
+        return scrollRange;
+    }
+
+    /**
+     * <p>
+     * Finds the next focusable component that fits in this View's bounds
+     * (excluding fading edges) pretending that this View's left is located at
+     * the parameter left.
+     * </p>
+     *
+     * @param leftFocus          look for a candidate is the one at the left of the bounds
+     *                           if leftFocus is true, or at the right of the bounds if leftFocus
+     *                           is false
+     * @param left               the left offset of the bounds in which a focusable must be
+     *                           found (the fading edge is assumed to start at this position)
+     * @param preferredFocusable the View that has highest priority and will be
+     *                           returned if it is within my bounds (null is valid)
+     * @return the next focusable component in the bounds or null if none can be found
+     */
+    private View findFocusableViewInMyBounds(final boolean leftFocus,
+            final int left, View preferredFocusable) {
+        /*
+         * The fading edge's transparent side should be considered for focus
+         * since it's mostly visible, so we divide the actual fading edge length
+         * by 2.
+         */
+        final int fadingEdgeLength = getHorizontalFadingEdgeLength() / 2;
+        final int leftWithoutFadingEdge = left + fadingEdgeLength;
+        final int rightWithoutFadingEdge = left + getWidth() - fadingEdgeLength;
+
+        if ((preferredFocusable != null)
+                && (preferredFocusable.getLeft() < rightWithoutFadingEdge)
+                && (preferredFocusable.getRight() > leftWithoutFadingEdge)) {
+            return preferredFocusable;
+        }
+
+        return findFocusableViewInBounds(leftFocus, leftWithoutFadingEdge,
+                rightWithoutFadingEdge);
+    }
+
+    /**
+     * <p>
+     * Finds the next focusable component that fits in the specified bounds.
+     * </p>
+     *
+     * @param leftFocus look for a candidate is the one at the left of the bounds
+     *                  if leftFocus is true, or at the right of the bounds if
+     *                  leftFocus is false
+     * @param left      the left offset of the bounds in which a focusable must be
+     *                  found
+     * @param right     the right offset of the bounds in which a focusable must
+     *                  be found
+     * @return the next focusable component in the bounds or null if none can
+     *         be found
+     */
+    private View findFocusableViewInBounds(boolean leftFocus, int left, int right) {
+
+        List<View> focusables = getFocusables(View.FOCUS_FORWARD);
+        View focusCandidate = null;
+
+        /*
+         * A fully contained focusable is one where its left is below the bound's
+         * left, and its right is above the bound's right. A partially
+         * contained focusable is one where some part of it is within the
+         * bounds, but it also has some part that is not within bounds.  A fully contained
+         * focusable is preferred to a partially contained focusable.
+         */
+        boolean foundFullyContainedFocusable = false;
+
+        int count = focusables.size();
+        for (int i = 0; i < count; i++) {
+            View view = focusables.get(i);
+            int viewLeft = view.getLeft();
+            int viewRight = view.getRight();
+
+            if (left < viewRight && viewLeft < right) {
+                /*
+                 * the focusable is in the target area, it is a candidate for
+                 * focusing
+                 */
+
+                final boolean viewIsFullyContained = (left < viewLeft) &&
+                        (viewRight < right);
+
+                if (focusCandidate == null) {
+                    /* No candidate, take this one */
+                    focusCandidate = view;
+                    foundFullyContainedFocusable = viewIsFullyContained;
+                } else {
+                    final boolean viewIsCloserToBoundary =
+                            (leftFocus && viewLeft < focusCandidate.getLeft()) ||
+                                    (!leftFocus && viewRight > focusCandidate.getRight());
+
+                    if (foundFullyContainedFocusable) {
+                        if (viewIsFullyContained && viewIsCloserToBoundary) {
+                            /*
+                             * We're dealing with only fully contained views, so
+                             * it has to be closer to the boundary to beat our
+                             * candidate
+                             */
+                            focusCandidate = view;
+                        }
+                    } else {
+                        if (viewIsFullyContained) {
+                            /* Any fully contained view beats a partially contained view */
+                            focusCandidate = view;
+                            foundFullyContainedFocusable = true;
+                        } else if (viewIsCloserToBoundary) {
+                            /*
+                             * Partially contained view beats another partially
+                             * contained view if it's closer
+                             */
+                            focusCandidate = view;
+                        }
+                    }
+                }
+            }
+        }
+
+        return focusCandidate;
+    }
+
+    /**
+     * <p>Handles scrolling in response to a "page up/down" shortcut press. This
+     * method will scroll the view by one page left or right and give the focus
+     * to the leftmost/rightmost component in the new visible area. If no
+     * component is a good candidate for focus, this scrollview reclaims the
+     * focus.</p>
+     *
+     * @param direction the scroll direction: {@link android.view.View#FOCUS_LEFT}
+     *                  to go one page left or {@link android.view.View#FOCUS_RIGHT}
+     *                  to go one page right
+     * @return true if the key event is consumed by this method, false otherwise
+     */
+    public boolean pageScroll(int direction) {
+        boolean right = direction == View.FOCUS_RIGHT;
+        int width = getWidth();
+
+        if (right) {
+            mTempRect.left = getScrollX() + width;
+            int count = getChildCount();
+            if (count > 0) {
+                View view = getChildAt(0);
+                if (mTempRect.left + width > view.getRight()) {
+                    mTempRect.left = view.getRight() - width;
+                }
+            }
+        } else {
+            mTempRect.left = getScrollX() - width;
+            if (mTempRect.left < 0) {
+                mTempRect.left = 0;
+            }
+        }
+        mTempRect.right = mTempRect.left + width;
+
+        return scrollAndFocus(direction, mTempRect.left, mTempRect.right);
+    }
+
+    /**
+     * <p>Handles scrolling in response to a "home/end" shortcut press. This
+     * method will scroll the view to the left or right and give the focus
+     * to the leftmost/rightmost component in the new visible area. If no
+     * component is a good candidate for focus, this scrollview reclaims the
+     * focus.</p>
+     *
+     * @param direction the scroll direction: {@link android.view.View#FOCUS_LEFT}
+     *                  to go the left of the view or {@link android.view.View#FOCUS_RIGHT}
+     *                  to go the right
+     * @return true if the key event is consumed by this method, false otherwise
+     */
+    public boolean fullScroll(int direction) {
+        boolean right = direction == View.FOCUS_RIGHT;
+        int width = getWidth();
+
+        mTempRect.left = 0;
+        mTempRect.right = width;
+
+        if (right) {
+            int count = getChildCount();
+            if (count > 0) {
+                View view = getChildAt(0);
+                mTempRect.right = view.getRight();
+                mTempRect.left = mTempRect.right - width;
+            }
+        }
+
+        return scrollAndFocus(direction, mTempRect.left, mTempRect.right);
+    }
+
+    /**
+     * <p>Scrolls the view to make the area defined by <code>left</code> and
+     * <code>right</code> visible. This method attempts to give the focus
+     * to a component visible in this area. If no component can be focused in
+     * the new visible area, the focus is reclaimed by this scrollview.</p>
+     *
+     * @param direction the scroll direction: {@link android.view.View#FOCUS_LEFT}
+     *                  to go left {@link android.view.View#FOCUS_RIGHT} to right
+     * @param left     the left offset of the new area to be made visible
+     * @param right    the right offset of the new area to be made visible
+     * @return true if the key event is consumed by this method, false otherwise
+     */
+    private boolean scrollAndFocus(int direction, int left, int right) {
+        boolean handled = true;
+
+        int width = getWidth();
+        int containerLeft = getScrollX();
+        int containerRight = containerLeft + width;
+        boolean goLeft = direction == View.FOCUS_LEFT;
+
+        View newFocused = findFocusableViewInBounds(goLeft, left, right);
+        if (newFocused == null) {
+            newFocused = this;
+        }
+
+        if (left >= containerLeft && right <= containerRight) {
+            handled = false;
+        } else {
+            int delta = goLeft ? (left - containerLeft) : (right - containerRight);
+            doScrollX(delta);
+        }
+
+        if (newFocused != findFocus()) newFocused.requestFocus(direction);
+
+        return handled;
+    }
+
+    /**
+     * Handle scrolling in response to a left or right arrow click.
+     *
+     * @param direction The direction corresponding to the arrow key that was
+     *                  pressed
+     * @return True if we consumed the event, false otherwise
+     */
+    public boolean arrowScroll(int direction) {
+
+        View currentFocused = findFocus();
+        if (currentFocused == this) currentFocused = null;
+
+        View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
+
+        final int maxJump = getMaxScrollAmount();
+
+        if (nextFocused != null && isWithinDeltaOfScreen(nextFocused, maxJump)) {
+            nextFocused.getDrawingRect(mTempRect);
+            offsetDescendantRectToMyCoords(nextFocused, mTempRect);
+            int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+            doScrollX(scrollDelta);
+            nextFocused.requestFocus(direction);
+        } else {
+            // no new focus
+            int scrollDelta = maxJump;
+
+            if (direction == View.FOCUS_LEFT && getScrollX() < scrollDelta) {
+                scrollDelta = getScrollX();
+            } else if (direction == View.FOCUS_RIGHT && getChildCount() > 0) {
+
+                int daRight = getChildAt(0).getRight();
+
+                int screenRight = getScrollX() + getWidth();
+
+                if (daRight - screenRight < maxJump) {
+                    scrollDelta = daRight - screenRight;
+                }
+            }
+            if (scrollDelta == 0) {
+                return false;
+            }
+            doScrollX(direction == View.FOCUS_RIGHT ? scrollDelta : -scrollDelta);
+        }
+
+        if (currentFocused != null && currentFocused.isFocused()
+                && isOffScreen(currentFocused)) {
+            // previously focused item still has focus and is off screen, give
+            // it up (take it back to ourselves)
+            // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are
+            // sure to
+            // get it)
+            final int descendantFocusability = getDescendantFocusability();  // save
+            setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
+            requestFocus();
+            setDescendantFocusability(descendantFocusability);  // restore
+        }
+        return true;
+    }
+
+    /**
+     * @return whether the descendant of this scroll view is scrolled off
+     *  screen.
+     */
+    private boolean isOffScreen(View descendant) {
+        return !isWithinDeltaOfScreen(descendant, 0);
+    }
+
+    /**
+     * @return whether the descendant of this scroll view is within delta
+     *  pixels of being on the screen.
+     */
+    private boolean isWithinDeltaOfScreen(View descendant, int delta) {
+        descendant.getDrawingRect(mTempRect);
+        offsetDescendantRectToMyCoords(descendant, mTempRect);
+
+        return (mTempRect.right + delta) >= getScrollX()
+                && (mTempRect.left - delta) <= (getScrollX() + getWidth());
+    }
+
+    /**
+     * Smooth scroll by a X delta
+     *
+     * @param delta the number of pixels to scroll by on the X axis
+     */
+    private void doScrollX(int delta) {
+        if (delta != 0) {
+            if (mSmoothScrollingEnabled) {
+                smoothScrollBy(delta, 0);
+            } else {
+                scrollBy(delta, 0);
+            }
+        }
+    }
+
+    /**
+     * Like {@link View#scrollBy}, but scroll smoothly instead of immediately.
+     *
+     * @param dx the number of pixels to scroll by on the X axis
+     * @param dy the number of pixels to scroll by on the Y axis
+     */
+    public final void smoothScrollBy(int dx, int dy) {
+        if (getChildCount() == 0) {
+            // Nothing to do.
+            return;
+        }
+        long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll;
+        if (duration > ANIMATED_SCROLL_GAP) {
+            final int width = getWidth() - mPaddingRight - mPaddingLeft;
+            final int right = getChildAt(0).getWidth();
+            final int maxX = Math.max(0, right - width);
+            final int scrollX = mScrollX;
+            dx = Math.max(0, Math.min(scrollX + dx, maxX)) - scrollX;
+
+            mScroller.startScroll(scrollX, mScrollY, dx, 0);
+            postInvalidateOnAnimation();
+        } else {
+            if (!mScroller.isFinished()) {
+                mScroller.abortAnimation();
+            }
+            scrollBy(dx, dy);
+        }
+        mLastScroll = AnimationUtils.currentAnimationTimeMillis();
+    }
+
+    /**
+     * Like {@link #scrollTo}, but scroll smoothly instead of immediately.
+     *
+     * @param x the position where to scroll on the X axis
+     * @param y the position where to scroll on the Y axis
+     */
+    public final void smoothScrollTo(int x, int y) {
+        smoothScrollBy(x - mScrollX, y - mScrollY);
+    }
+
+    /**
+     * <p>The scroll range of a scroll view is the overall width of all of its
+     * children.</p>
+     */
+    @Override
+    protected int computeHorizontalScrollRange() {
+        final int count = getChildCount();
+        final int contentWidth = getWidth() - mPaddingLeft - mPaddingRight;
+        if (count == 0) {
+            return contentWidth;
+        }
+
+        int scrollRange = getChildAt(0).getRight();
+        final int scrollX = mScrollX;
+        final int overscrollRight = Math.max(0, scrollRange - contentWidth);
+        if (scrollX < 0) {
+            scrollRange -= scrollX;
+        } else if (scrollX > overscrollRight) {
+            scrollRange += scrollX - overscrollRight;
+        }
+
+        return scrollRange;
+    }
+
+    @Override
+    protected int computeHorizontalScrollOffset() {
+        return Math.max(0, super.computeHorizontalScrollOffset());
+    }
+
+    @Override
+    protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
+        ViewGroup.LayoutParams lp = child.getLayoutParams();
+
+        int childWidthMeasureSpec;
+        int childHeightMeasureSpec;
+
+        childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec, mPaddingTop
+                + mPaddingBottom, lp.height);
+
+        childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
+
+        child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+    }
+
+    @Override
+    protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed,
+            int parentHeightMeasureSpec, int heightUsed) {
+        final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
+
+        final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
+                mPaddingTop + mPaddingBottom + lp.topMargin + lp.bottomMargin
+                        + heightUsed, lp.height);
+        final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
+                lp.leftMargin + lp.rightMargin, MeasureSpec.UNSPECIFIED);
+
+        child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+    }
+
+    @Override
+    public void computeScroll() {
+        if (mScroller.computeScrollOffset()) {
+            // This is called at drawing time by ViewGroup.  We don't want to
+            // re-show the scrollbars at this point, which scrollTo will do,
+            // so we replicate most of scrollTo here.
+            //
+            //         It's a little odd to call onScrollChanged from inside the drawing.
+            //
+            //         It is, except when you remember that computeScroll() is used to
+            //         animate scrolling. So unless we want to defer the onScrollChanged()
+            //         until the end of the animated scrolling, we don't really have a
+            //         choice here.
+            //
+            //         I agree.  The alternative, which I think would be worse, is to post
+            //         something and tell the subclasses later.  This is bad because there
+            //         will be a window where mScrollX/Y is different from what the app
+            //         thinks it is.
+            //
+            int oldX = mScrollX;
+            int oldY = mScrollY;
+            int x = mScroller.getCurrX();
+            int y = mScroller.getCurrY();
+
+            if (oldX != x || oldY != y) {
+                final int range = getScrollRange();
+                final int overscrollMode = getOverScrollMode();
+                final boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS ||
+                        (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);
+
+                overScrollBy(x - oldX, y - oldY, oldX, oldY, range, 0,
+                        mOverflingDistance, 0, false);
+                onScrollChanged(mScrollX, mScrollY, oldX, oldY);
+
+                if (canOverscroll) {
+                    if (x < 0 && oldX >= 0) {
+                        mEdgeGlowLeft.onAbsorb((int) mScroller.getCurrVelocity());
+                    } else if (x > range && oldX <= range) {
+                        mEdgeGlowRight.onAbsorb((int) mScroller.getCurrVelocity());
+                    }
+                }
+            }
+
+            if (!awakenScrollBars()) {
+                postInvalidateOnAnimation();
+            }
+        }
+    }
+
+    /**
+     * Scrolls the view to the given child.
+     *
+     * @param child the View to scroll to
+     */
+    private void scrollToChild(View child) {
+        child.getDrawingRect(mTempRect);
+
+        /* Offset from child's local coordinates to ScrollView coordinates */
+        offsetDescendantRectToMyCoords(child, mTempRect);
+
+        int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+
+        if (scrollDelta != 0) {
+            scrollBy(scrollDelta, 0);
+        }
+    }
+
+    /**
+     * If rect is off screen, scroll just enough to get it (or at least the
+     * first screen size chunk of it) on screen.
+     *
+     * @param rect      The rectangle.
+     * @param immediate True to scroll immediately without animation
+     * @return true if scrolling was performed
+     */
+    private boolean scrollToChildRect(Rect rect, boolean immediate) {
+        final int delta = computeScrollDeltaToGetChildRectOnScreen(rect);
+        final boolean scroll = delta != 0;
+        if (scroll) {
+            if (immediate) {
+                scrollBy(delta, 0);
+            } else {
+                smoothScrollBy(delta, 0);
+            }
+        }
+        return scroll;
+    }
+
+    /**
+     * Compute the amount to scroll in the X direction in order to get
+     * a rectangle completely on the screen (or, if taller than the screen,
+     * at least the first screen size chunk of it).
+     *
+     * @param rect The rect.
+     * @return The scroll delta.
+     */
+    protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
+        if (getChildCount() == 0) return 0;
+
+        int width = getWidth();
+        int screenLeft = getScrollX();
+        int screenRight = screenLeft + width;
+
+        int fadingEdge = getHorizontalFadingEdgeLength();
+
+        // leave room for left fading edge as long as rect isn't at very left
+        if (rect.left > 0) {
+            screenLeft += fadingEdge;
+        }
+
+        // leave room for right fading edge as long as rect isn't at very right
+        if (rect.right < getChildAt(0).getWidth()) {
+            screenRight -= fadingEdge;
+        }
+
+        int scrollXDelta = 0;
+
+        if (rect.right > screenRight && rect.left > screenLeft) {
+            // need to move right to get it in view: move right just enough so
+            // that the entire rectangle is in view (or at least the first
+            // screen size chunk).
+
+            if (rect.width() > width) {
+                // just enough to get screen size chunk on
+                scrollXDelta += (rect.left - screenLeft);
+            } else {
+                // get entire rect at right of screen
+                scrollXDelta += (rect.right - screenRight);
+            }
+
+            // make sure we aren't scrolling beyond the end of our content
+            int right = getChildAt(0).getRight();
+            int distanceToRight = right - screenRight;
+            scrollXDelta = Math.min(scrollXDelta, distanceToRight);
+
+        } else if (rect.left < screenLeft && rect.right < screenRight) {
+            // need to move right to get it in view: move right just enough so that
+            // entire rectangle is in view (or at least the first screen
+            // size chunk of it).
+
+            if (rect.width() > width) {
+                // screen size chunk
+                scrollXDelta -= (screenRight - rect.right);
+            } else {
+                // entire rect at left
+                scrollXDelta -= (screenLeft - rect.left);
+            }
+
+            // make sure we aren't scrolling any further than the left our content
+            scrollXDelta = Math.max(scrollXDelta, -getScrollX());
+        }
+        return scrollXDelta;
+    }
+
+    @Override
+    public void requestChildFocus(View child, View focused) {
+        if (!mIsLayoutDirty) {
+            scrollToChild(focused);
+        } else {
+            // The child may not be laid out yet, we can't compute the scroll yet
+            mChildToScrollTo = focused;
+        }
+        super.requestChildFocus(child, focused);
+    }
+
+
+    /**
+     * When looking for focus in children of a scroll view, need to be a little
+     * more careful not to give focus to something that is scrolled off screen.
+     *
+     * This is more expensive than the default {@link android.view.ViewGroup}
+     * implementation, otherwise this behavior might have been made the default.
+     */
+    @Override
+    protected boolean onRequestFocusInDescendants(int direction,
+            Rect previouslyFocusedRect) {
+
+        // convert from forward / backward notation to up / down / left / right
+        // (ugh).
+        if (direction == View.FOCUS_FORWARD) {
+            direction = View.FOCUS_RIGHT;
+        } else if (direction == View.FOCUS_BACKWARD) {
+            direction = View.FOCUS_LEFT;
+        }
+
+        final View nextFocus = previouslyFocusedRect == null ?
+                FocusFinder.getInstance().findNextFocus(this, null, direction) :
+                FocusFinder.getInstance().findNextFocusFromRect(this,
+                        previouslyFocusedRect, direction);
+
+        if (nextFocus == null) {
+            return false;
+        }
+
+        if (isOffScreen(nextFocus)) {
+            return false;
+        }
+
+        return nextFocus.requestFocus(direction, previouslyFocusedRect);
+    }
+
+    @Override
+    public boolean requestChildRectangleOnScreen(View child, Rect rectangle,
+            boolean immediate) {
+        // offset into coordinate space of this scroll view
+        rectangle.offset(child.getLeft() - child.getScrollX(),
+                child.getTop() - child.getScrollY());
+
+        return scrollToChildRect(rectangle, immediate);
+    }
+
+    @Override
+    public void requestLayout() {
+        mIsLayoutDirty = true;
+        super.requestLayout();
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        super.onLayout(changed, l, t, r, b);
+        mIsLayoutDirty = false;
+        // Give a child focus if it needs it
+        if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) {
+                scrollToChild(mChildToScrollTo);
+        }
+        mChildToScrollTo = null;
+
+        // Calling this with the present values causes it to re-claim them
+        scrollTo(mScrollX, mScrollY);
+    }
+
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+
+        View currentFocused = findFocus();
+        if (null == currentFocused || this == currentFocused)
+            return;
+
+        final int maxJump = mRight - mLeft;
+
+        if (isWithinDeltaOfScreen(currentFocused, maxJump)) {
+            currentFocused.getDrawingRect(mTempRect);
+            offsetDescendantRectToMyCoords(currentFocused, mTempRect);
+            int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+            doScrollX(scrollDelta);
+        }
+    }
+
+    /**
+     * Return true if child is a descendant of parent, (or equal to the parent).
+     */
+    private static boolean isViewDescendantOf(View child, View parent) {
+        if (child == parent) {
+            return true;
+        }
+
+        final ViewParent theParent = child.getParent();
+        return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent);
+    }
+
+    /**
+     * Fling the scroll view
+     *
+     * @param velocityX The initial velocity in the X direction. Positive
+     *                  numbers mean that the finger/cursor is moving down the screen,
+     *                  which means we want to scroll towards the left.
+     */
+    public void fling(int velocityX) {
+        if (getChildCount() > 0) {
+            int width = getWidth() - mPaddingRight - mPaddingLeft;
+            int right = getChildAt(0).getWidth();
+
+            mScroller.fling(mScrollX, mScrollY, velocityX, 0, 0,
+                    Math.max(0, right - width), 0, 0, width/2, 0);
+
+            final boolean movingRight = velocityX > 0;
+
+            View currentFocused = findFocus();
+            View newFocused = findFocusableViewInMyBounds(movingRight,
+                    mScroller.getFinalX(), currentFocused);
+
+            if (newFocused == null) {
+                newFocused = this;
+            }
+
+            if (newFocused != currentFocused) {
+                newFocused.requestFocus(movingRight ? View.FOCUS_RIGHT : View.FOCUS_LEFT);
+            }
+
+            postInvalidateOnAnimation();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>This version also clamps the scrolling to the bounds of our child.
+     */
+    @Override
+    public void scrollTo(int x, int y) {
+        // we rely on the fact the View.scrollBy calls scrollTo.
+        if (getChildCount() > 0) {
+            View child = getChildAt(0);
+            x = clamp(x, getWidth() - mPaddingRight - mPaddingLeft, child.getWidth());
+            y = clamp(y, getHeight() - mPaddingBottom - mPaddingTop, child.getHeight());
+            if (x != mScrollX || y != mScrollY) {
+                super.scrollTo(x, y);
+            }
+        }
+    }
+
+    @Override
+    public void setOverScrollMode(int mode) {
+        if (mode != OVER_SCROLL_NEVER) {
+            if (mEdgeGlowLeft == null) {
+                Context context = getContext();
+                mEdgeGlowLeft = new EdgeEffect(context);
+                mEdgeGlowRight = new EdgeEffect(context);
+            }
+        } else {
+            mEdgeGlowLeft = null;
+            mEdgeGlowRight = null;
+        }
+        super.setOverScrollMode(mode);
+    }
+
+    @SuppressWarnings({"SuspiciousNameCombination"})
+    @Override
+    public void draw(Canvas canvas) {
+        super.draw(canvas);
+        if (mEdgeGlowLeft != null) {
+            final int scrollX = mScrollX;
+            if (!mEdgeGlowLeft.isFinished()) {
+                final int restoreCount = canvas.save();
+                final int height = getHeight() - mPaddingTop - mPaddingBottom;
+
+                canvas.rotate(270);
+                canvas.translate(-height + mPaddingTop, Math.min(0, scrollX));
+                mEdgeGlowLeft.setSize(height, getWidth());
+                if (mEdgeGlowLeft.draw(canvas)) {
+                    postInvalidateOnAnimation();
+                }
+                canvas.restoreToCount(restoreCount);
+            }
+            if (!mEdgeGlowRight.isFinished()) {
+                final int restoreCount = canvas.save();
+                final int width = getWidth();
+                final int height = getHeight() - mPaddingTop - mPaddingBottom;
+
+                canvas.rotate(90);
+                canvas.translate(-mPaddingTop,
+                        -(Math.max(getScrollRange(), scrollX) + width));
+                mEdgeGlowRight.setSize(height, width);
+                if (mEdgeGlowRight.draw(canvas)) {
+                    postInvalidateOnAnimation();
+                }
+                canvas.restoreToCount(restoreCount);
+            }
+        }
+    }
+
+    private static int clamp(int n, int my, int child) {
+        if (my >= child || n < 0) {
+            return 0;
+        }
+        if ((my + n) > child) {
+            return child - my;
+        }
+        return n;
+    }
+}
diff --git a/src/com/android/videoeditor/widgets/TimelineHorizontalScrollView.java b/src/com/android/videoeditor/widgets/TimelineHorizontalScrollView.java
index 2d93b3e..1b0fb89 100755
--- a/src/com/android/videoeditor/widgets/TimelineHorizontalScrollView.java
+++ b/src/com/android/videoeditor/widgets/TimelineHorizontalScrollView.java
@@ -32,7 +32,6 @@ import android.util.AttributeSet;
 import android.view.Display;
 import android.view.MotionEvent;
 import android.view.ScaleGestureDetector;
-import android.widget.HorizontalScrollView;
 
 /**
  * The timeline scroll view
@@ -124,19 +123,14 @@ public class TimelineHorizontalScrollView extends HorizontalScrollView {
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         mScaleDetector.onTouchEvent(ev);
-        return mScaleDetector.isInProgress() || super.onInterceptTouchEvent(ev);
+        return super.onInterceptTouchEvent(ev);
     }
 
     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         if (mEnableUserScrolling) {
             mScaleDetector.onTouchEvent(ev);
-
-            if (!mScaleDetector.isInProgress()) {
-                return super.onTouchEvent(ev);
-            } else {
-                return true;
-            }
+            return super.onTouchEvent(ev);
         } else {
             if (mScaleDetector.isInProgress()) {
                 final MotionEvent cancelEvent = MotionEvent.obtain(SystemClock.uptimeMillis(),