private void onAnimationStopped() {
            if (onAnimationComplete != null) {
              onAnimationComplete.run();
            }
            setAnimating(false);
            getDetector().restartGesture();
          }
ZoomableController that adds animation capabilities to DefaultZoomableController using standard
Android animation classes
samples/zoomable/src/main/java/com/facebook/samples/zoomable/AnimatedZoomableController.java