Merge change 1371 into donut

* changes:
  Fixes #1596240. Optimize invalidate/draw passes by marking opaque views and avoiding drawing them. Whenever a View requests an invalidate its parent check whether the view is opaque or not. When the view is not opaque, the framework behaves as it used to. However, when a view is opaque, the parent marks itself as being dirty because of an opaque view. Its parent then does the same, and so on. When the framework then starts drawing the views, it does not draw views marked as dirty opaque. If a view is dirty opaque and receives an invalidate request from a non-opaque view, it then clears the dirty opaque flag and behaves as before.

core/java/android/view/View.java

@@ -849,6 +849,28 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
      */
     public static final int HAPTIC_FEEDBACK_ENABLED = 0x10000000;
 
+    /**
+     * View flag indicating whether this view was invalidated (fully or partially.)
+     *
+     * @hide
+     */
+    static final int DIRTY = 0x20000000;
+
+    /**
+     * View flag indicating whether this view was invalidated by an opaque
+     * invalidate request.
+     *
+     * @hide
+     */
+    static final int DIRTY_OPAQUE = 0x40000000;
+
+    /**
+     * Mask for {@link #DIRTY} and {@link #DIRTY_OPAQUE}.
+     *
+     * @hide
+     */
+    static final int DIRTY_MASK = 0x60000000;
+
     /**
      * Use with {@link #focusSearch}. Move focus to the previous selectable
      * item.
@@ -4521,6 +4543,23 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
         }
     }
 
+    /**
+     * Indicates whether this View is opaque. An opaque View guarantees that it will
+     * draw all the pixels overlapping its bounds using a fully opaque color.
+     *
+     * Subclasses of View should override this method whenever possible to indicate
+     * whether an instance is opaque. Opaque Views are treated in a special way by
+     * the View hierarchy, possibly allowing it to perform optimizations during
+     * invalidate/draw passes.
+     * 
+     * @return True if this View is guaranteed to be fully opaque, false otherwise.
+     *
+     * @hide Pending API council approval
+     */
+    public boolean isOpaque() {
+        return mBGDrawable != null && mBGDrawable.getOpacity() == PixelFormat.OPAQUE;
+    }
+
     /**
      * @return A handler associated with the thread running the View. This
      * handler can be used to pump events in the UI events queue.
@@ -5687,7 +5726,7 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
             final int restoreCount = canvas.save();
             canvas.translate(-mScrollX, -mScrollY);
 
-            mPrivateFlags |= DRAWN;
+            mPrivateFlags = (mPrivateFlags & ~DIRTY_MASK) | DRAWN; 
 
             // Fast path for layouts with no backgrounds
             if ((mPrivateFlags & SKIP_DRAW) == SKIP_DRAW) {
@@ -5875,7 +5914,10 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
             ViewDebug.trace(this, ViewDebug.HierarchyTraceType.DRAW);
         }
 
-        mPrivateFlags |= DRAWN;                    
+        final boolean dirtyOpaque = (mPrivateFlags & DIRTY_MASK) == DIRTY_OPAQUE;
+        mPrivateFlags = (mPrivateFlags & ~DIRTY_MASK) | DRAWN;
+
+        if (dirtyOpaque) android.util.Log.d("View", "Skipping draw in " + this);
 
         /*
          * Draw traversal performs several drawing steps which must be executed
@@ -5892,22 +5934,24 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
         // Step 1, draw the background, if needed
         int saveCount;
 
-        final Drawable background = mBGDrawable;
-        if (background != null) {
-            final int scrollX = mScrollX;
-            final int scrollY = mScrollY;
+        if (!dirtyOpaque) {
+            final Drawable background = mBGDrawable;
+            if (background != null) {
+                final int scrollX = mScrollX;
+                final int scrollY = mScrollY;
 
-            if (mBackgroundSizeChanged) {
-                background.setBounds(0, 0,  mRight - mLeft, mBottom - mTop);
-                mBackgroundSizeChanged = false;
-            }
+                if (mBackgroundSizeChanged) {
+                    background.setBounds(0, 0,  mRight - mLeft, mBottom - mTop);
+                    mBackgroundSizeChanged = false;
+                }
 
-            if ((scrollX | scrollY) == 0) {
-                background.draw(canvas);
-            } else {
-                canvas.translate(scrollX, scrollY);
-                background.draw(canvas);
-                canvas.translate(-scrollX, -scrollY);
+                if ((scrollX | scrollY) == 0) {
+                    background.draw(canvas);
+                } else {
+                    canvas.translate(scrollX, scrollY);
+                    background.draw(canvas);
+                    canvas.translate(-scrollX, -scrollY);
+                }
             }
         }
 
@@ -5917,7 +5961,7 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
         boolean verticalEdges = (viewFlags & FADING_EDGE_VERTICAL) != 0;
         if (!verticalEdges && !horizontalEdges) {
             // Step 3, draw the content
-            onDraw(canvas);
+            if (!dirtyOpaque) onDraw(canvas);
 
             // Step 4, draw the children
             dispatchDraw(canvas);
@@ -6020,7 +6064,7 @@ public class View implements Drawable.Callback, KeyEvent.Callback {
         }
 
         // Step 3, draw the content
-        onDraw(canvas);
+        if (!dirtyOpaque) onDraw(canvas);
 
         // Step 4, draw the children
         dispatchDraw(canvas);

core/java/android/view/ViewGroup.java

@@ -1796,7 +1796,7 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
             boolean preventRequestLayout) {
         child.mParent = null;
         addViewInner(child, index, params, preventRequestLayout);
-        child.mPrivateFlags |= DRAWN;
+        child.mPrivateFlags = (child.mPrivateFlags & ~DIRTY_MASK) | DRAWN;
         return true;
     }
 
@@ -2210,7 +2210,7 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
         addInArray(child, index);
 
         child.mParent = this;
-        child.mPrivateFlags |= DRAWN;
+        child.mPrivateFlags = (child.mPrivateFlags & ~DIRTY_MASK) | DRAWN;
 
         if (child.hasFocus()) {
             requestChildFocus(child, child.findFocus());
@@ -2320,15 +2320,33 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
             // ourselves and the parent to make sure the invalidate request goes
             // through
             final boolean drawAnimation = (child.mPrivateFlags & DRAW_ANIMATION) == DRAW_ANIMATION;
-    
+
+            // Check whether the child that requests the invalidate is fully opaque
+            final boolean isOpaque = child.isOpaque();
+            // Mark the child as dirty, using the appropriate flag
+            // Make sure we do not set both flags at the same time
+            final int opaqueFlag = isOpaque ? DIRTY_OPAQUE : DIRTY;
+
             do {
+                View view = null;
+                if (parent instanceof View) {
+                    view = (View) parent;
+                }
+
                 if (drawAnimation) {
-                    if (parent instanceof View) {
-                        ((View) parent).mPrivateFlags |= DRAW_ANIMATION;
+                    if (view != null) {
+                        view.mPrivateFlags |= DRAW_ANIMATION;
                     } else if (parent instanceof ViewRoot) {
                         ((ViewRoot) 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 && (view.mPrivateFlags & DIRTY_MASK) != DIRTY) {
+                    view.mPrivateFlags = (view.mPrivateFlags & ~DIRTY_MASK) | opaqueFlag;
+                }
+
                 parent = parent.invalidateChildInParent(location, dirty);
             } while (parent != null);
         }

core/java/android/view/ViewRoot.java

@@ -539,6 +539,7 @@ public final class ViewRoot extends Handler implements ViewParent,
             }
             dirty = mTempRect;
         }
+        // TODO: When doing a union with mDirty != empty, we must cancel all the DIRTY_OPAQUE flags
         mDirty.union(dirty);
         if (!mWillDrawSoon) {
             scheduleTraversals();

core/java/android/widget/AbsListView.java

@@ -1947,7 +1947,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 if (y != mLastY) {
                     deltaY -= mMotionCorrection;
                     int incrementalDeltaY = mLastY != Integer.MIN_VALUE ? y - mLastY : deltaY;
-                    trackMotionScroll(deltaY, incrementalDeltaY);
+                    trackMotionScroll(deltaY, incrementalDeltaY, true);
 
                     // Check to see if we have bumped into the scroll limit
                     View motionView = this.getChildAt(mMotionPosition - mFirstPosition);
@@ -2286,7 +2286,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 delta = Math.max(-(getHeight() - mPaddingBottom - mPaddingTop - 1), delta);
             }
 
-            trackMotionScroll(delta, delta);
+            trackMotionScroll(delta, delta, false);
 
             // Check to see if we have bumped into the scroll limit
             View motionView = getChildAt(mMotionPosition - mFirstPosition);
@@ -2299,6 +2299,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             }
 
             if (more) {
+                invalidate();
                 mLastFlingY = y;
                 post(this);
             } else {
@@ -2323,6 +2324,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
 
     private void clearScrollingCache() {
         if (mCachingStarted) {
+            mCachingStarted = false;
             setChildrenDrawnWithCacheEnabled(false);
             if ((mPersistentDrawingCache & PERSISTENT_SCROLLING_CACHE) == 0) {
                 setChildrenDrawingCacheEnabled(false);
@@ -2330,7 +2332,6 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             if (!isAlwaysDrawnWithCacheEnabled()) {
                 invalidate();
             }
-            mCachingStarted = false;
         }
     }
 
@@ -2340,8 +2341,9 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
      * @param deltaY Amount to offset mMotionView. This is the accumulated delta since the motion
      *        began. Positive numbers mean the user's finger is moving down the screen.
      * @param incrementalDeltaY Change in deltaY from the previous event.
+     * @param invalidate True to make this method call invalidate(), false otherwise.
      */
-    void trackMotionScroll(int deltaY, int incrementalDeltaY) {
+    void trackMotionScroll(int deltaY, int incrementalDeltaY, boolean invalidate) {
         final int childCount = getChildCount();
         if (childCount == 0) {
             return;
@@ -2375,7 +2377,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         if (spaceAbove >= absIncrementalDeltaY && spaceBelow >= absIncrementalDeltaY) {
             hideSelector();
             offsetChildrenTopAndBottom(incrementalDeltaY);
-            invalidate();
+            if (invalidate) invalidate();
             mMotionViewNewTop = mMotionViewOriginalTop + deltaY;
         } else {
             final int firstPosition = mFirstPosition;
@@ -2453,7 +2455,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 mFirstPosition += count;
             }
 
-            invalidate();
+            if (invalidate) invalidate();
             fillGap(down);
             mBlockLayoutRequests = false;
 
@@ -2788,7 +2790,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         int screenHeight = getResources().getDisplayMetrics().heightPixels;
         final int[] xy = new int[2];
         getLocationOnScreen(xy);
-        // TODO: The 20 below should come from the theme and be expressed in dip
+        // TODO: The 20 below should come from the theme
         // TODO: And the gravity should be defined in the theme as well
         final int bottomGap = screenHeight - xy[1] - getHeight() + (int) (mDensityScale * 20);
         if (!mPopup.isShowing()) {

core/java/android/widget/ListView.java

@@ -20,6 +20,7 @@ import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.Rect;
+import android.graphics.PixelFormat;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.ColorDrawable;
 import android.os.Parcel;
@@ -113,7 +114,11 @@ public class ListView extends AbsListView {
 
     Drawable mDivider;
     int mDividerHeight;
+
+    private boolean mIsCacheColorOpaque;
+    private boolean mDividerIsOpaque;
     private boolean mClipDivider;
+
     private boolean mHeaderDividersEnabled;
     private boolean mFooterDividersEnabled;
 
@@ -2776,6 +2781,17 @@ public class ListView extends AbsListView {
         return mItemsCanFocus;
     }
 
+    @Override
+    public boolean isOpaque() {
+        return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque) || super.isOpaque();
+    }
+
+    @Override
+    public void setCacheColorHint(int color) {
+        mIsCacheColorOpaque = (color >>> 24) == 0xFF;
+        super.setCacheColorHint(color);
+    }
+
     @Override
     protected void dispatchDraw(Canvas canvas) {
         // Draw the dividers
@@ -2897,6 +2913,7 @@ public class ListView extends AbsListView {
             mClipDivider = false;
         }
         mDivider = divider;
+        mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE;
         requestLayoutIfNecessary();
     }