Fixed a bug where notifications shadows were blinking out

Bug: 22567770
Change-Id: I2d335241a287d0c64e659221994f19b7c13eccd3

Author: Selim Cinek

packages/SystemUI/src/com/android/systemui/statusbar/ExpandableView.java

@@ -374,7 +374,11 @@ public boolean areChildrenExpanded() {
     }
 
     private void updateClipping() {
-        mClipRect.set(0, mClipTopOptimization, getWidth(), getActualHeight());
+        int top = mClipTopOptimization;
+        if (top >= getActualHeight()) {
+            top = getActualHeight() - 1;
+        }
+        mClipRect.set(0, top, getWidth(), getActualHeight());
         setClipBounds(mClipRect);
     }
 

packages/SystemUI/src/com/android/systemui/statusbar/stack/StackScrollAlgorithm.java

@@ -413,7 +413,9 @@ private void updatePositionsForState(StackScrollState resultState,
         ExpandableNotificationRow topHeadsUpEntry = ambientState.getTopHeadsUpEntry();
 
         int childCount = algorithmState.visibleChildren.size();
-        int numberOfElementsCompletelyIn = (int) algorithmState.itemsInTopStack;
+        int numberOfElementsCompletelyIn = algorithmState.partialInTop == 1.0f
+                ? algorithmState.lastTopStackIndex
+                : (int) algorithmState.itemsInTopStack;
         for (int i = 0; i < childCount; i++) {
             ExpandableView child = algorithmState.visibleChildren.get(i);
             StackViewState childViewState = resultState.getViewStateForView(child);