ViewTreeObserver

addOnDrawListener

fun addOnDrawListener(listener: ViewTreeObserver.OnDrawListener!): Unit

Register a callback to be invoked when the view tree is about to be drawn.

Note: this method cannot be invoked from android.view.ViewTreeObserver.OnDrawListener#onDraw().

addOnGlobalFocusChangeListener

fun addOnGlobalFocusChangeListener(listener: ViewTreeObserver.OnGlobalFocusChangeListener!): Unit

addOnGlobalLayoutListener

fun addOnGlobalLayoutListener(listener: ViewTreeObserver.OnGlobalLayoutListener!): Unit

Register a callback to be invoked when the global layout state or the visibility of views within the view tree changes

addOnPreDrawListener

fun addOnPreDrawListener(listener: ViewTreeObserver.OnPreDrawListener!): Unit

Register a callback to be invoked when the view tree is about to be drawn

addOnScrollChangedListener

fun addOnScrollChangedListener(listener: ViewTreeObserver.OnScrollChangedListener!): Unit

Register a callback to be invoked when a view has been scrolled.

addOnSystemGestureExclusionRectsChangedListener

fun addOnSystemGestureExclusionRectsChangedListener(listener: Consumer<MutableList<Rect!>!>): Unit

Add a listener to be notified when the tree's transformed gesture exclusion rects change. This could be the result of an animation or other layout change, or a view calling View.setSystemGestureExclusionRects(List).

addOnTouchModeChangeListener

fun addOnTouchModeChangeListener(listener: ViewTreeObserver.OnTouchModeChangeListener!): Unit

Register a callback to be invoked when the invoked when the touch mode changes.

addOnWindowAttachListener

fun addOnWindowAttachListener(listener: ViewTreeObserver.OnWindowAttachListener!): Unit

Register a callback to be invoked when the view hierarchy is attached to a window.

addOnWindowFocusChangeListener

fun addOnWindowFocusChangeListener(listener: ViewTreeObserver.OnWindowFocusChangeListener!): Unit

Register a callback to be invoked when the window focus state within the view tree changes.

addOnWindowVisibilityChangeListener

fun addOnWindowVisibilityChangeListener(listener: ViewTreeObserver.OnWindowVisibilityChangeListener): Unit

Register a callback to be invoked when the window visibility changes.

dispatchOnDraw

fun dispatchOnDraw(): Unit

Notifies registered listeners that the drawing pass is about to start.

dispatchOnGlobalLayout

fun dispatchOnGlobalLayout(): Unit

Notifies registered listeners that a global layout happened. This can be called manually if you are forcing a layout on a View or a hierarchy of Views that are not attached to a Window or in the GONE state.

dispatchOnPreDraw

fun dispatchOnPreDraw(): Boolean

Notifies registered listeners that the drawing pass is about to start. If a listener returns true, then the drawing pass is canceled and rescheduled. This can be called manually if you are forcing the drawing on a View or a hierarchy of Views that are not attached to a Window or in the GONE state.

isAlive

fun isAlive(): Boolean

Indicates whether this ViewTreeObserver is alive. When an observer is not alive, any call to a method (except this one) will throw an exception. If an application keeps a long-lived reference to this ViewTreeObserver, it should always check for the result of this method before calling any other method.

registerFrameCommitCallback

fun registerFrameCommitCallback(callback: Runnable): Unit

Adds a frame commit callback. This callback will be invoked when the current rendering content has been rendered into a frame and submitted to the swap chain. The frame may not currently be visible on the display when this is invoked, but it has been submitted. This callback is useful in combination with PixelCopy to capture the current rendered content of the UI reliably. Note: Only works with hardware rendering. Does nothing otherwise.

removeGlobalOnLayoutListener

fun removeGlobalOnLayoutListener(victim: ViewTreeObserver.OnGlobalLayoutListener!): Unit

Deprecated: Use #removeOnGlobalLayoutListener instead

Remove a previously installed global layout callback

removeOnDrawListener

fun removeOnDrawListener(victim: ViewTreeObserver.OnDrawListener!): Unit

Remove a previously installed pre-draw callback.

Note: this method cannot be invoked from android.view.ViewTreeObserver.OnDrawListener#onDraw().

removeOnGlobalFocusChangeListener

fun removeOnGlobalFocusChangeListener(victim: ViewTreeObserver.OnGlobalFocusChangeListener!): Unit

Remove a previously installed focus change callback.

removeOnGlobalLayoutListener

fun removeOnGlobalLayoutListener(victim: ViewTreeObserver.OnGlobalLayoutListener!): Unit

Remove a previously installed global layout callback

removeOnPreDrawListener

fun removeOnPreDrawListener(victim: ViewTreeObserver.OnPreDrawListener!): Unit

Remove a previously installed pre-draw callback

removeOnScrollChangedListener

fun removeOnScrollChangedListener(victim: ViewTreeObserver.OnScrollChangedListener!): Unit

Remove a previously installed scroll-changed callback

removeOnSystemGestureExclusionRectsChangedListener

fun removeOnSystemGestureExclusionRectsChangedListener(listener: Consumer<MutableList<Rect!>!>): Unit

Unsubscribe the given listener from gesture exclusion rect changes.

removeOnTouchModeChangeListener

fun removeOnTouchModeChangeListener(victim: ViewTreeObserver.OnTouchModeChangeListener!): Unit

Remove a previously installed touch mode change callback

removeOnWindowAttachListener

fun removeOnWindowAttachListener(victim: ViewTreeObserver.OnWindowAttachListener!): Unit

Remove a previously installed window attach callback.

removeOnWindowFocusChangeListener

fun removeOnWindowFocusChangeListener(victim: ViewTreeObserver.OnWindowFocusChangeListener!): Unit

Remove a previously installed window focus change callback.

removeOnWindowVisibilityChangeListener

fun removeOnWindowVisibilityChangeListener(victim: ViewTreeObserver.OnWindowVisibilityChangeListener): Unit

Remove a previously installed window visibility callback.

unregisterFrameCommitCallback

fun unregisterFrameCommitCallback(callback: Runnable): Boolean

Attempts to remove the given callback from the list of pending frame complete callbacks.