Summary: Methods | Inherited Methods

OneShotPreDrawListener

Kotlin |Java

public final class OneShotPreDrawListener
extends Object implements ViewTreeObserver.OnPreDrawListener, View.OnAttachStateChangeListener

java.lang.Object
↳	androidx.core.view.OneShotPreDrawListener

An OnPreDrawListener that will remove itself after one OnPreDraw call. Typical usage is:


     OneShotPreDrawListener.add(view, () -> { view.doSomething(); })

The onPreDraw always returns true.

The listener will also remove itself from the ViewTreeObserver when the view is detached from the view hierarchy. In that case, the Runnable will never be executed.

Summary

Public methods
`static OneShotPreDrawListener`	`add(View view, Runnable runnable)` Creates a OneShotPreDrawListener and adds it to view's ViewTreeObserver.
`boolean`	`onPreDraw()`
`void`	`onViewAttachedToWindow(View v)`
`void`	`onViewDetachedFromWindow(View v)`
`void`	`removeListener()` Removes the listener from the ViewTreeObserver.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

From interface


        
          android.view.ViewTreeObserver.OnPreDrawListener

abstract boolean onPreDraw()

From interface


        
          android.view.View.OnAttachStateChangeListener

`abstract void`	`onViewAttachedToWindow(View arg0)`
`abstract void`	`onViewDetachedFromWindow(View arg0)`

Public methods

add

public static OneShotPreDrawListener add (View view, 
                Runnable runnable)

Creates a OneShotPreDrawListener and adds it to view's ViewTreeObserver.

Parameters
`view`	`View`: The view whose ViewTreeObserver the OnPreDrawListener should listen.
`runnable`	`Runnable`: The Runnable to execute in the OnPreDraw (once)

Returns
`OneShotPreDrawListener`	The added OneShotPreDrawListener. It can be removed prior to the onPreDraw by calling `removeListener()`.

onPreDraw

public boolean onPreDraw ()

Returns
`boolean`

onViewAttachedToWindow

public void onViewAttachedToWindow (View v)

Parameters
`v`	`View`

onViewDetachedFromWindow

public void onViewDetachedFromWindow (View v)

Parameters
`v`	`View`

removeListener

public void removeListener ()

Removes the listener from the ViewTreeObserver. This is useful to call if the callback should be removed prior to onPreDraw().