Merge "Fix hidden EmptyShadeView" into sc-dev am: 2458c8f8c6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15340910

Change-Id: Ic642c0a2a0b6bb3613edee6b4dc49b0e2f061f58

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

@@ -157,15 +157,13 @@ public class StackScrollAlgorithm {
         // After the shelf has updated its yTranslation, explicitly set alpha=0 for view below shelf
         // to skip rendering them in the hardware layer. We do not set them invisible because that
         // runs invalidate & onDraw when these views return onscreen, which is more expensive.
+        if (shelf.getViewState().hidden) {
+            // When the shelf is hidden, it won't clip views, so we don't hide rows
+            return;
+        }
         final float shelfTop = shelf.getViewState().yTranslation;
 
         for (ExpandableView view : algorithmState.visibleChildren) {
-            if (view instanceof ExpandableNotificationRow) {
-                ExpandableNotificationRow row = (ExpandableNotificationRow) view;
-                if (row.isHeadsUp() || row.isHeadsUpAnimatingAway()) {
-                    continue;
-                }
-            }
             final float viewTop = view.getViewState().yTranslation;
             if (viewTop >= shelfTop) {
                 view.getViewState().alpha = 0;