Merge "Enabling hardware layers while overscrolling widget pager" into jb-mr1-dev

core/res/res/layout/keyguard_transport_control_view.xml

@@ -20,7 +20,6 @@
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:gravity="center_horizontal"
-    android:layerType="hardware"
     android:id="@+id/keyguard_transport_control">
 
     <!-- FrameLayout used as scrim to show between album art and buttons -->

policy/src/com/android/internal/policy/impl/keyguard/KeyguardSubdivisionLayout.java

@@ -97,12 +97,14 @@ public class KeyguardSubdivisionLayout extends ViewGroup {
             leafs.clear();
             getLeafs(leafs, 1);
 
-            // We find the first leaf who's depth is not
+            // If the tree is complete, then we start a new level at the rightmost side.
             double r = log2(leafs.size());
             if (Math.ceil(r) == Math.floor(r)) {
                 return leafs.get(leafs.size() - 1);
             }
 
+            // Tree is not complete, find the first leaf who's depth is less than the depth of
+            // the tree.
             int treeDepth = depth();
             for (int i = leafs.size() - 1; i >= 0; i--) {
                 BiTree n = leafs.get(i);

policy/src/com/android/internal/policy/impl/keyguard/KeyguardWidgetFrame.java

@@ -91,7 +91,14 @@ public class KeyguardWidgetFrame extends FrameLayout {
 
             mForegroundAlpha = (int) Math.round((r * 255));
             mForegroundDrawable.setAlpha(mForegroundAlpha);
+            if (getLayerType() != LAYER_TYPE_HARDWARE) {
+                setLayerType(LAYER_TYPE_HARDWARE, null);
+            }
             invalidate();
+        } else {
+            if (getLayerType() != LAYER_TYPE_NONE) {
+                setLayerType(LAYER_TYPE_NONE, null);
+            }
         }
     }
 }