ViewTreeObserver.WindowInsetsAnimationListener

public static interface ViewTreeObserver.WindowInsetsAnimationListener

Interface definition for a callback to be invoked when window insets animations prepare or end.

A window insets animation listener can be registered to observe when window insets animations are about to start (prepare) and when they end. These callbacks are executed on the UI thread.

Unlike WindowInsetsAnimation.Callback, which is designed for applications to synchronize their view layouts or draw frames with the animation on every frame, this listener only observes the preparation and completion of animations, but doesn't allow for frame-by-frame synchronization.

Because this listener does not perform frame-by-frame synchronization, registering only this listener without a corresponding WindowInsetsAnimation.Callback on the view hierarchy allows the window insets animation to run off-thread on the background animation thread. This avoids the performance overhead of running the animation on the main UI thread.

This listener does not have an equivalent to WindowInsetsAnimation.Callback.onStart or receive the animation bounds, because it is not intended for layout synchronization. To perform frame-synchronized layout changes or customize the animation bounds, register a WindowInsetsAnimation.Callback on the view hierarchy instead.

Summary

Public methods

public void onEnd (WindowInsetsAnimation animation)

public void onPrepare (WindowInsetsAnimation animation)