/** TransformationCallback methods */
 protected void getParentTransform(Matrix transform) {
   if (mTransformCallback != null) {
     mTransformCallback.getTransform(transform);
   } else {
     transform.reset();
   }
 }
 @Override
 public void getRootBounds(RectF bounds) {
   if (mTransformCallback != null) {
     mTransformCallback.getRootBounds(bounds);
   } else {
     bounds.set(getBounds());
   }
 }
 /** TransformationCallback methods */
 @Override
 public void getTransform(Matrix transform) {
   if (mTransformCallback != null) {
     mTransformCallback.getTransform(transform);
   } else {
     transform.reset();
   }
 }