material-sheet-fab/src/main/java/com/gordonwong/materialsheetfab/animations/OverlayAnimation.java
public void hide(long duration, final AnimationListener listener) {
		overlay.animate().alpha(0).setDuration(duration).setInterpolator(interpolator)
				.setListener(new AnimatorListenerAdapter() {
					@Override
					public void onAnimationStart(Animator animation) {
						if (listener != null) {
							listener.onStart();
						}
					}

					@Override
					public void onAnimationEnd(Animator animation) {
						overlay.setVisibility(View.GONE);
						if (listener != null) {
							listener.onEnd();
						}
					}
				}).start();
	}
public void hide(long duration, final AnimationListener listener) {
		overlay.animate().alpha(0).setDuration(duration).setInterpolator(interpolator)
				.setListener(new AnimatorListenerAdapter() {
					@Override
					public void onAnimationStart(Animator animation) {
						if (listener != null) {
							listener.onStart();
						}
					}

					@Override
					public void onAnimationEnd(Animator animation) {
						overlay.setVisibility(View.GONE);
						if (listener != null) {
							listener.onEnd();
						}
					}
				}).start();
	}
Hides the overlay.

@param duration Duration of the animation in milliseconds. Use 0 for no animation.
@param listener Listener for animation events.