[SuwLib] Refactor out TemplateLayout

Refactor TemplateLayout as a base class for SetupWizardLayout, which
is a generic layout that takes the "android:layout", inflates that as
a template and put its children in the "container".

Change-Id: Id7977787ffa6cdb5df7a4cb8172ce1fa6a52ed45

3 files changed, 227 insertions, 129 deletions

diff --git a/library/main/src/com/android/setupwizardlib/SetupWizardLayout.java b/library/main/src/com/android/setupwizardlib/SetupWizardLayout.java
index 9caff6c..73cc1bd 100644
--- a/library/main/src/com/android/setupwizardlib/SetupWizardLayout.java
+++ b/library/main/src/com/android/setupwizardlib/SetupWizardLayout.java
@@ -36,64 +36,47 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewStub;
-import android.view.ViewTreeObserver;
-import android.widget.FrameLayout;
 import android.widget.TextView;
 
-import com.android.setupwizardlib.annotations.Keep;
 import com.android.setupwizardlib.util.RequireScrollHelper;
 import com.android.setupwizardlib.view.BottomScrollView;
 import com.android.setupwizardlib.view.Illustration;
 import com.android.setupwizardlib.view.NavigationBar;
 
-public class SetupWizardLayout extends FrameLayout {
+public class SetupWizardLayout extends TemplateLayout {
 
     private static final String TAG = "SetupWizardLayout";
 
-    /**
-     * The container of the actual content. This will be a view in the template, which child views
-     * will be added to when {@link #addView(android.view.View)} is called. This will be the layout
-     * in the template that has the ID of {@link #getContainerId()}. For the default implementation
-     * of SetupWizardLayout, that would be @id/suw_layout_content.
-     */
-    private ViewGroup mContainer;
-
     public SetupWizardLayout(Context context) {
-        super(context);
-        init(0, null, R.attr.suwLayoutTheme);
+        super(context, 0, 0);
+        init(null, R.attr.suwLayoutTheme);
     }
 
     public SetupWizardLayout(Context context, int template) {
-        super(context);
-        init(template, null, R.attr.suwLayoutTheme);
+        this(context, template, 0);
+    }
+
+    public SetupWizardLayout(Context context, int template, int containerId) {
+        super(context, template, containerId);
+        init(null, R.attr.suwLayoutTheme);
     }
 
     public SetupWizardLayout(Context context, AttributeSet attrs) {
         super(context, attrs);
-        init(0, attrs, R.attr.suwLayoutTheme);
+        init(attrs, R.attr.suwLayoutTheme);
     }
 
     @TargetApi(VERSION_CODES.HONEYCOMB)
     public SetupWizardLayout(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
-        init(0, attrs, defStyleAttr);
-    }
-
-    @TargetApi(VERSION_CODES.HONEYCOMB)
-    public SetupWizardLayout(Context context, int template, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-        init(template, attrs, defStyleAttr);
+        init(attrs, defStyleAttr);
     }
 
     // All the constructors delegate to this init method. The 3-argument constructor is not
     // available in LinearLayout before v11, so call super with the exact same arguments.
-    private void init(int template, AttributeSet attrs, int defStyleAttr) {
+    private void init(AttributeSet attrs, int defStyleAttr) {
         final TypedArray a = getContext().obtainStyledAttributes(attrs,
                 R.styleable.SuwSetupWizardLayout, defStyleAttr, 0);
-        if (template == 0) {
-            template = a.getResourceId(R.styleable.SuwSetupWizardLayout_android_layout, 0);
-        }
-        inflateTemplate(template);
 
         // Set the background from XML, either directly or built from a bitmap tile
         final Drawable background =
@@ -174,52 +157,19 @@ public class SetupWizardLayout extends FrameLayout {
     }
 
     @Override
-    public void addView(View child, int index, ViewGroup.LayoutParams params) {
-        mContainer.addView(child, index, params);
-    }
-
-    private void addViewInternal(View child) {
-        super.addView(child, -1, generateDefaultLayoutParams());
-    }
-
-    private void inflateTemplate(int templateResource) {
-        final LayoutInflater inflater = LayoutInflater.from(getContext());
-        final View templateRoot = onInflateTemplate(inflater, templateResource);
-        addViewInternal(templateRoot);
-
-        mContainer = (ViewGroup) findViewById(getContainerId());
-        onTemplateInflated();
-    }
-
-    /**
-     * This method inflates the template. Subclasses can override this method to customize the
-     * template inflation, or change to a different default template. The root of the inflated
-     * layout should be returned, and not added to the view hierarchy.
-     *
-     * @param inflater A LayoutInflater to inflate the template.
-     * @param template The resource ID of the template to be inflated, or 0 if no template is
-     *                 specified.
-     * @return Root of the inflated layout.
-     */
     protected View onInflateTemplate(LayoutInflater inflater, int template) {
         if (template == 0) {
             template = R.layout.suw_template;
         }
-        return inflater.inflate(template, this, false);
-    }
-
-    /**
-     * This is called after the template has been inflated and added to the view hierarchy.
-     * Subclasses can implement this method to modify the template as necessary, such as caching
-     * views retrieved from findViewById, or other view operations that need to be done in code.
-     * You can think of this as {@link android.view.View#onFinishInflate()} but for inflation of the
-     * template instead of for child views.
-     */
-    protected void onTemplateInflated() {
+        return super.onInflateTemplate(inflater, template);
     }
 
-    protected int getContainerId() {
-        return R.id.suw_layout_content;
+    @Override
+    protected ViewGroup findContainer(int containerId) {
+        if (containerId == 0) {
+            containerId = R.id.suw_layout_content;
+        }
+        return super.findContainer(containerId);
     }
 
     public NavigationBar getNavigationBar() {
@@ -426,53 +376,6 @@ public class SetupWizardLayout extends FrameLayout {
         }
     }
 
-    /* Animator support */
-
-    private float mXFraction;
-    private ViewTreeObserver.OnPreDrawListener mPreDrawListener;
-
-    /**
-     * Set the X translation as a fraction of the width of this view. Make sure this method is not
-     * stripped out by proguard when using ObjectAnimator. You may need to add
-     *     -keep @com.android.setupwizardlib.annotations.Keep class *
-     * to your proguard configuration if you are seeing mysterious MethodNotFoundExceptions at
-     * runtime.
-     */
-    @Keep
-    public void setXFraction(float fraction) {
-        mXFraction = fraction;
-        final int width = getWidth();
-        if (width != 0) {
-            setTranslationX(width * fraction);
-        } else {
-            // If we haven't done a layout pass yet, wait for one and then set the fraction before
-            // the draw occurs using an OnPreDrawListener. Don't call translationX until we know
-            // getWidth() has a reliable, non-zero value or else we will see the fragment flicker on
-            // screen.
-            if (mPreDrawListener == null) {
-                mPreDrawListener = new ViewTreeObserver.OnPreDrawListener() {
-                    @Override
-                    public boolean onPreDraw() {
-                        getViewTreeObserver().removeOnPreDrawListener(mPreDrawListener);
-                        setXFraction(mXFraction);
-                        return true;
-                    }
-                };
-                getViewTreeObserver().addOnPreDrawListener(mPreDrawListener);
-            }
-        }
-    }
-
-    /**
-     * Return the X translation as a fraction of the width, as previously set in setXFraction.
-     *
-     * @see #setXFraction(float)
-     */
-    @Keep
-    public float getXFraction() {
-        return mXFraction;
-    }
-
     /* Misc */
 
     protected static class SavedState extends BaseSavedState {
diff --git a/library/main/src/com/android/setupwizardlib/SetupWizardListLayout.java b/library/main/src/com/android/setupwizardlib/SetupWizardListLayout.java
index 7165f39..36dcdea 100644
--- a/library/main/src/com/android/setupwizardlib/SetupWizardListLayout.java
+++ b/library/main/src/com/android/setupwizardlib/SetupWizardListLayout.java
@@ -22,6 +22,7 @@ import android.os.Build.VERSION_CODES;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
+import android.view.ViewGroup;
 import android.widget.ListAdapter;
 import android.widget.ListView;
 
@@ -31,11 +32,15 @@ public class SetupWizardListLayout extends SetupWizardLayout {
     private ListView mListView;
 
     public SetupWizardListLayout(Context context) {
-        super(context);
+        this(context, 0, 0);
     }
 
     public SetupWizardListLayout(Context context, int template) {
-        super(context, template);
+        this(context, template, 0);
+    }
+
+    public SetupWizardListLayout(Context context, int template, int containerId) {
+        super(context, template, containerId);
     }
 
     public SetupWizardListLayout(Context context, AttributeSet attrs) {
@@ -47,28 +52,25 @@ public class SetupWizardListLayout extends SetupWizardLayout {
         super(context, attrs, defStyleAttr);
     }
 
-    @TargetApi(VERSION_CODES.HONEYCOMB)
-    public SetupWizardListLayout(Context context, int template, AttributeSet attrs,
-            int defStyleAttr) {
-        super(context, template, attrs, defStyleAttr);
-    }
-
     @Override
     protected View onInflateTemplate(LayoutInflater inflater, int template) {
         if (template == 0) {
             template = R.layout.suw_list_template;
         }
-        return inflater.inflate(template, this, false);
+        return super.onInflateTemplate(inflater, template);
     }
 
     @Override
-    protected void onTemplateInflated() {
-        mListView = (ListView) findViewById(android.R.id.list);
+    protected ViewGroup findContainer(int containerId) {
+        if (containerId == 0) {
+            containerId = android.R.id.list;
+        }
+        return super.findContainer(containerId);
     }
 
     @Override
-    protected int getContainerId() {
-        return android.R.id.list;
+    protected void onTemplateInflated() {
+        mListView = (ListView) findViewById(android.R.id.list);
     }
 
     public ListView getListView() {
diff --git a/library/main/src/com/android/setupwizardlib/TemplateLayout.java b/library/main/src/com/android/setupwizardlib/TemplateLayout.java
new file mode 100644
index 0000000..1596674
--- /dev/null
+++ b/library/main/src/com/android/setupwizardlib/TemplateLayout.java
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2015 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.setupwizardlib;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.os.Build;
+import android.os.Build.VERSION_CODES;
+import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
+import android.widget.FrameLayout;
+
+import com.android.setupwizardlib.annotations.Keep;
+
+/**
+ * A generic template class that inflates a template, provided in the constructor or in
+ * android:layout through XML, and adds its children to a "container" in the template. When
+ * inflating this layout from XML, the {@code android:layout} and {@code suwContainer} attributes
+ * are required.
+ */
+public class TemplateLayout extends FrameLayout {
+
+    /**
+     * The container of the actual content. This will be a view in the template, which child views
+     * will be added to when {@link #addView(View)} is called.
+     */
+    private ViewGroup mContainer;
+
+    public TemplateLayout(Context context, int template, int containerId) {
+        super(context);
+        init(template, containerId, null, R.attr.suwLayoutTheme);
+    }
+
+    public TemplateLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(0, 0, attrs, R.attr.suwLayoutTheme);
+    }
+
+    @TargetApi(VERSION_CODES.HONEYCOMB)
+    public TemplateLayout(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(0, 0, attrs, defStyleAttr);
+    }
+
+    // All the constructors delegate to this init method. The 3-argument constructor is not
+    // available in LinearLayout before v11, so call super with the exact same arguments.
+    private void init(int template, int containerId, AttributeSet attrs, int defStyleAttr) {
+        final TypedArray a = getContext().obtainStyledAttributes(attrs,
+                R.styleable.SuwTemplateLayout, defStyleAttr, 0);
+        if (template == 0) {
+            template = a.getResourceId(R.styleable.SuwTemplateLayout_android_layout, 0);
+        }
+        if (containerId == 0) {
+            containerId = a.getResourceId(R.styleable.SuwTemplateLayout_suwContainer, 0);
+        }
+        inflateTemplate(template, containerId);
+
+        a.recycle();
+    }
+
+    @Override
+    public void addView(View child, int index, ViewGroup.LayoutParams params) {
+        mContainer.addView(child, index, params);
+    }
+
+    private void addViewInternal(View child) {
+        super.addView(child, -1, generateDefaultLayoutParams());
+    }
+
+    private void inflateTemplate(int templateResource, int containerId) {
+        final LayoutInflater inflater = LayoutInflater.from(getContext());
+        final View templateRoot = onInflateTemplate(inflater, templateResource);
+        addViewInternal(templateRoot);
+
+        mContainer = findContainer(containerId);
+        if (mContainer == null) {
+            throw new IllegalArgumentException("Container cannot be null in TemplateLayout");
+        }
+        onTemplateInflated();
+    }
+
+    /**
+     * This method inflates the template. Subclasses can override this method to customize the
+     * template inflation, or change to a different default template. The root of the inflated
+     * layout should be returned, and not added to the view hierarchy.
+     *
+     * @param inflater A LayoutInflater to inflate the template.
+     * @param template The resource ID of the template to be inflated, or 0 if no template is
+     *                 specified.
+     * @return Root of the inflated layout.
+     */
+    protected View onInflateTemplate(LayoutInflater inflater, int template) {
+        if (template == 0) {
+            throw new IllegalArgumentException("android:layout not specified for TemplateLayout");
+        }
+        return inflater.inflate(template, this, false);
+    }
+
+    protected ViewGroup findContainer(int containerId) {
+        if (containerId == 0) {
+            // Maintain compatibility with the deprecated way of specifying container ID.
+            containerId = getContainerId();
+        }
+        return (ViewGroup) findViewById(containerId);
+    }
+
+    /**
+     * This is called after the template has been inflated and added to the view hierarchy.
+     * Subclasses can implement this method to modify the template as necessary, such as caching
+     * views retrieved from findViewById, or other view operations that need to be done in code.
+     * You can think of this as {@link View#onFinishInflate()} but for inflation of the
+     * template instead of for child views.
+     */
+    protected void onTemplateInflated() {
+    }
+
+    /**
+     * @return ID of the default container for this layout. This will be used to find the container
+     * ViewGroup, which all children views of this layout will be placed in.
+     * @deprecated Use the constructor with containerId argument instead.
+     */
+    @Deprecated
+    protected int getContainerId() {
+        return 0;
+    }
+
+    /* Animator support */
+
+    private float mXFraction;
+    private ViewTreeObserver.OnPreDrawListener mPreDrawListener;
+
+    /**
+     * Set the X translation as a fraction of the width of this view. Make sure this method is not
+     * stripped out by proguard when using ObjectAnimator. You may need to add
+     *     -keep @com.android.setupwizardlib.annotations.Keep class *
+     * to your proguard configuration if you are seeing mysterious MethodNotFoundExceptions at
+     * runtime.
+     */
+    @Keep
+    @TargetApi(VERSION_CODES.HONEYCOMB)
+    public void setXFraction(float fraction) {
+        mXFraction = fraction;
+        final int width = getWidth();
+        if (width != 0) {
+            setTranslationX(width * fraction);
+        } else {
+            // If we haven't done a layout pass yet, wait for one and then set the fraction before
+            // the draw occurs using an OnPreDrawListener. Don't call translationX until we know
+            // getWidth() has a reliable, non-zero value or else we will see the fragment flicker on
+            // screen.
+            if (mPreDrawListener == null) {
+                mPreDrawListener = new ViewTreeObserver.OnPreDrawListener() {
+                    @Override
+                    public boolean onPreDraw() {
+                        getViewTreeObserver().removeOnPreDrawListener(mPreDrawListener);
+                        setXFraction(mXFraction);
+                        return true;
+                    }
+                };
+                getViewTreeObserver().addOnPreDrawListener(mPreDrawListener);
+            }
+        }
+    }
+
+    /**
+     * Return the X translation as a fraction of the width, as previously set in setXFraction.
+     *
+     * @see #setXFraction(float)
+     */
+    @Keep
+    @TargetApi(VERSION_CODES.HONEYCOMB)
+    public float getXFraction() {
+        return mXFraction;
+    }
+}