Merge "Revert "Revert "Fix notification group dismissal fade animation""" into tm-qpr-dev

packages/SystemUI/src/com/android/systemui/statusbar/notification/row/ExpandableNotificationRow.java

@@ -1511,7 +1511,7 @@ public class ExpandableNotificationRow extends ActivatableNotificationView
             l.setAlpha(alpha);
         }
         if (mChildrenContainer != null) {
-            mChildrenContainer.setAlpha(alpha);
+            mChildrenContainer.setContentAlpha(alpha);
         }
     }
 

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

@@ -494,6 +494,20 @@ public class NotificationChildrenContainer extends ViewGroup
         return mAttachedChildren;
     }
 
+    /**
+     * Sets the alpha on the content, while leaving the background of the container itself as is.
+     *
+     * @param alpha alpha value to apply to the content
+     */
+    public void setContentAlpha(float alpha) {
+        for (int i = 0; i < mNotificationHeader.getChildCount(); i++) {
+            mNotificationHeader.getChildAt(i).setAlpha(alpha);
+        }
+        for (ExpandableNotificationRow child : getAttachedChildren()) {
+            child.setContentAlpha(alpha);
+        }
+    }
+
     /**
      * To be called any time the rows have been updated
      */