Add check for no children in VIew hosting virtual view tree.

1. For accessibility purposes View may report a virtual tree
   rooted at them to convey the logical structure they draw.
   These are usually custom Views. Such views cannot have
   children and this patch adds a check for that.

bug:6022217

Change-Id: I3795a613b4aef1a7ec5810db8584a11b648870f2

1 files changed, 9 insertions, 0 deletions

diff --git a/core/java/android/view/ViewGroup.java b/core/java/android/view/ViewGroup.java
index c68d77d..2848e88 100644
--- a/core/java/android/view/ViewGroup.java
+++ b/core/java/android/view/ViewGroup.java
@@ -2669,6 +2669,15 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
         return child.draw(canvas, this, drawingTime);
     }
 
+    @Override
+    public void requestLayout() {
+        if (mChildrenCount > 0 && getAccessibilityNodeProvider() != null) {
+            throw new IllegalStateException("Views with AccessibilityNodeProvider"
+                    + " can't have children.");
+        }
+        super.requestLayout();
+    }
+
     /**
      * 
      * @param enabled True if children should be drawn with layers, false otherwise.