Callback

Kotlin |Java

abstract class Callback

kotlin.Any
↳	android.view.WindowInsetsAnimation.Callback

Interface that allows the application to listen to animation events for windows that cause insets.

Summary

Constants
static Int	`DISPATCH_MODE_CONTINUE_ON_SUBTREE` Return value for `getDispatchMode()`: Dispatching of animation events should continue in the view hierarchy.
static Int	`DISPATCH_MODE_STOP` Return value for `getDispatchMode()`: Dispatching of animation events should stop at this level in the view hierarchy, and no animation events should be dispatch to the subtree of the view hierarchy.

Public constructors
`Callback(dispatchMode: Int)` Creates a new `WindowInsetsAnimation` callback with the given `dispatch mode`.

Public methods
Int	`getDispatchMode()` Retrieves the dispatch mode of this listener.
open Unit	`onEnd(animation: WindowInsetsAnimation)` Called when an insets animation has ended.
open Unit	`onPrepare(animation: WindowInsetsAnimation)` Called when an insets animation is about to start and before the views have been laid out in the end state of the animation.
abstract WindowInsets	`onProgress(insets: WindowInsets, runningAnimations: MutableList<WindowInsetsAnimation!>)` Called when the insets change as part of running an animation.
open WindowInsetsAnimation.Bounds	`onStart(animation: WindowInsetsAnimation, bounds: WindowInsetsAnimation.Bounds)` Called when an insets animation gets started.

Constants

DISPATCH_MODE_CONTINUE_ON_SUBTREE

Added in API level 30

static val DISPATCH_MODE_CONTINUE_ON_SUBTREE: Int

Return value for getDispatchMode(): Dispatching of animation events should continue in the view hierarchy.

Value: 1

DISPATCH_MODE_STOP

Added in API level 30

static val DISPATCH_MODE_STOP: Int

Return value for getDispatchMode(): Dispatching of animation events should stop at this level in the view hierarchy, and no animation events should be dispatch to the subtree of the view hierarchy.

Value: 0

Public constructors

Callback

Added in API level 30

Callback(dispatchMode: Int)

Creates a new WindowInsetsAnimation callback with the given dispatch mode.

Parameters
`dispatchMode`	Int: The dispatch mode for this callback. See `getDispatchMode()`. Value is `android.view.WindowInsetsAnimation.Callback#DISPATCH_MODE_STOP`, or `android.view.WindowInsetsAnimation.Callback#DISPATCH_MODE_CONTINUE_ON_SUBTREE`

Public methods

getDispatchMode

Added in API level 30

fun getDispatchMode(): Int

Retrieves the dispatch mode of this listener. Dispatch of the all animation events is hierarchical: It will starts at the root of the view hierarchy and then traverse it and invoke the callback of the specific View that is being traversed. The method may return either DISPATCH_MODE_CONTINUE_ON_SUBTREE to indicate that animation events should be propagated to the subtree of the view hierarchy, or DISPATCH_MODE_STOP to stop dispatching. In that case, all animation callbacks related to the animation passed in will be stopped from propagating to the subtree of the hierarchy.

Also note that DISPATCH_MODE_STOP behaves the same way as returning WindowInsets#CONSUMED during the regular insets dispatch in View#onApplyWindowInsets.

Return
`Int`	Either `DISPATCH_MODE_CONTINUE_ON_SUBTREE` to indicate that dispatching of animation events will continue to the subtree of the view hierarchy, or `DISPATCH_MODE_STOP` to indicate that animation events will stop dispatching. Value is `android.view.WindowInsetsAnimation.Callback#DISPATCH_MODE_STOP`, or `android.view.WindowInsetsAnimation.Callback#DISPATCH_MODE_CONTINUE_ON_SUBTREE`

onEnd

Added in API level 30

open fun onEnd(animation: WindowInsetsAnimation): Unit

Called when an insets animation has ended.

Parameters
`animation`	WindowInsetsAnimation: The animation that has ended. This will be the same instance as passed into `onStart` This value cannot be `null`.

onPrepare

Added in API level 30

open fun onPrepare(animation: WindowInsetsAnimation): Unit

Called when an insets animation is about to start and before the views have been laid out in the end state of the animation. The ordering of events during an insets animation is the following:

Application calls WindowInsetsController#hide(int), WindowInsetsController#show(int), WindowInsetsController#controlWindowInsetsAnimation
onPrepare is called on the view hierarchy listeners
View#onApplyWindowInsets will be called with the end state of the animation
View hierarchy gets laid out according to the changes the application has requested due to the new insets being dispatched
onStart is called before the view hierarchy gets drawn in the new laid out state
onProgress is called immediately after with the animation start state
The frame gets drawn.

This ordering allows the application to inspect the end state after the animation has finished, and then revert to the starting state of the animation in the first onProgress callback by using post-layout view properties like View#setX and related methods.

Note that the animation might be cancelled before onStart is dispatched. On S and later, onEnd is immediately dispatched without an onStart in that case. On R, no callbacks are dispatched after onPrepare for such an animation.

Note: If the animation is application controlled by using WindowInsetsController#controlWindowInsetsAnimation, the end state of the animation is undefined as the application may decide on the end state only by passing in shown parameter when calling WindowInsetsAnimationController#finish. In this situation, the system will dispatch the insets in the opposite visibility state before the animation starts. Example: When controlling the input method with WindowInsetsController#controlWindowInsetsAnimation and the input method is currently showing, View#onApplyWindowInsets will receive a WindowInsets instance for which WindowInsets#isVisible will return false for WindowInsets.Type#ime.

Parameters
`animation`	WindowInsetsAnimation: The animation that is about to start. This value cannot be `null`.

onProgress

Added in API level 30

abstract fun onProgress(
    insets: WindowInsets, 
    runningAnimations: MutableList<WindowInsetsAnimation!>
): WindowInsets

Called when the insets change as part of running an animation. Note that even if multiple animations for different types are running, there will only be one progress callback per frame. The insets passed as an argument represents the overall state and will include all types, regardless of whether they are animating or not.

Note that insets dispatch is hierarchical: It will start at the root of the view hierarchy, and then traverse it and invoke the callback of the specific View being traversed. The method may return a modified instance by calling WindowInsets#inset(int, int, int, int) to indicate that a part of the insets have been used to offset or clip its children, and the children shouldn't worry about that part anymore. Furthermore, if getDispatchMode() returns DISPATCH_MODE_STOP, children of this view will not receive the callback anymore.

Parameters
`insets`	WindowInsets: The current insets. This value cannot be `null`.
`runningAnimations`	MutableList<WindowInsetsAnimation!>: The currently running animations. This value cannot be `null`.

Return
`WindowInsets`	The insets to dispatch to the subtree of the hierarchy. This value cannot be `null`.

onStart

Added in API level 30

open fun onStart(
    animation: WindowInsetsAnimation, 
    bounds: WindowInsetsAnimation.Bounds
): WindowInsetsAnimation.Bounds

Called when an insets animation gets started.

Note that, like onProgress, dispatch of the animation start event is hierarchical: It will starts at the root of the view hierarchy and then traverse it and invoke the callback of the specific View that is being traversed. The method may return a modified instance of the bounds by calling Bounds#inset to indicate that a part of the insets have been used to offset or clip its children, and the children shouldn't worry about that part anymore. Furthermore, if getDispatchMode() returns DISPATCH_MODE_STOP, children of this view will not receive the callback anymore.

Parameters
`animation`	WindowInsetsAnimation: The animation that is about to start. This value cannot be `null`.
`bounds`	WindowInsetsAnimation.Bounds: The bounds in which animation happens. This value cannot be `null`.

Return
`WindowInsetsAnimation.Bounds`	The animation representing the part of the insets that should be dispatched to the subtree of the hierarchy. This value cannot be `null`.