Improving performance of state transitions

- Caching CellLayouts to bitmaps when they're small again
- Enabling hardware layers on customize tray/all apps during transition

Change-Id: Ia4f5f7b608a9d013ed48b990551fd1b9de503b32

src/com/android/launcher2/CachedViewGroup.java

@@ -26,6 +26,7 @@ import android.graphics.Paint;
 import android.graphics.Rect;
 import android.graphics.Bitmap.Config;
 import android.graphics.PorterDuff.Mode;
+import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -52,6 +53,15 @@ public class CachedViewGroup extends ViewGroup implements VisibilityChangedListe
 
     public CachedViewGroup(Context context) {
         super(context);
+        init();
+    }
+
+    public CachedViewGroup(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        init();
+    }
+
+    private void init() {
         mBackgroundRect = new Rect();
         mCacheRect = new Rect();
         final Resources res = getResources();
@@ -124,14 +134,13 @@ public class CachedViewGroup extends ViewGroup implements VisibilityChangedListe
         float alpha = getAlpha();
         setAlpha(1.0f);
         isUpdatingCache = true;
-        draw(mCacheCanvas);
+        drawChildren(mCacheCanvas);
         isUpdatingCache = false;
         setAlpha(alpha);
 
         mIsCacheDirty = false;
     }
 
-
     public void drawChildren(Canvas canvas) {
         super.dispatchDraw(canvas);
     }
@@ -148,11 +157,6 @@ public class CachedViewGroup extends ViewGroup implements VisibilityChangedListe
         invalidateCache();
     }
 
-    public void removeViewWithoutMarkingCells(View view) {
-        super.removeView(view);
-        invalidateCache();
-    }
-
     @Override
     public void removeView(View view) {
         super.removeView(view);

src/com/android/launcher2/CellLayout.java

@@ -50,7 +50,7 @@ import android.view.animation.LayoutAnimationController;
 
 import java.util.Arrays;
 
-public class CellLayout extends ViewGroup {
+public class CellLayout extends CachedViewGroup {
     static final String TAG = "CellLayout";
 
     private int mCellWidth;
@@ -363,14 +363,6 @@ public class CellLayout extends ViewGroup {
         }
     }
 
-    public void disableCacheUpdates() {
-        mChildren.disableCacheUpdates();
-    }
-
-    public void enableCacheUpdates() {
-        mChildren.enableCacheUpdates();
-    }
-
     @Override
     protected void onDraw(Canvas canvas) {
         // When we're large, we are either drawn in a "hover" state (ie when dragging an item to
@@ -542,7 +534,7 @@ public class CellLayout extends ViewGroup {
     }
 
     public void removeViewWithoutMarkingCells(View view) {
-        mChildren.removeViewWithoutMarkingCells(view);
+        mChildren.removeView(view);
     }
 
     @Override

src/com/android/launcher2/CellLayoutChildren.java

@@ -18,11 +18,12 @@ package com.android.launcher2;
 
 import android.app.WallpaperManager;
 import android.content.Context;
-import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.view.View;
+import android.view.ViewGroup;
+import android.view.View.MeasureSpec;
 
-public class CellLayoutChildren extends CachedViewGroup {
+public class CellLayoutChildren extends ViewGroup {
     static final String TAG = "CellLayoutChildren";
 
     // These are temporary variables to prevent having to allocate a new object just to
@@ -94,7 +95,6 @@ public class CellLayoutChildren extends CachedViewGroup {
 
     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
-        super.onLayout(changed, l, t, r, b);
         int count = getChildCount();
         for (int i = 0; i < count; i++) {
             final View child = getChildAt(i);

src/com/android/launcher2/Launcher.java

@@ -2783,10 +2783,12 @@ public final class Launcher extends Activity
                     PropertyValuesHolder.ofFloat("alpha", 1.0f, 0.0f));
             alphaAnim.setDuration(res.getInteger(R.integer.config_allAppsFadeOutTime));
             alphaAnim.setInterpolator(new DecelerateInterpolator(2.0f));
+            fromView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
             alphaAnim.addListener(new AnimatorListenerAdapter() {
                 @Override
                 public void onAnimationEnd(Animator animation) {
                     fromView.setVisibility(View.GONE);
+                    fromView.setLayerType(View.LAYER_TYPE_NONE, null);
                 }
             });