TouchDelegate

public class TouchDelegate
extends Object

java.lang.Object
   ↳ android.view.TouchDelegate


Helper class to handle situations where you want a view to have a larger touch area than its actual view bounds. The view whose touch area is changed is called the delegate view. This class should be used by an ancestor of the delegate. To use a TouchDelegate, first create an instance that specifies the bounds that should be mapped to the delegate and the delegate view itself.

The ancestor should then forward all of its touch events received in its View.onTouchEvent(MotionEvent) to onTouchEvent(android.view.MotionEvent).

Summary

Constants

int ABOVE

The touchable region of the View extends above its actual extent.

int BELOW

The touchable region of the View extends below its actual extent.

int TO_LEFT

The touchable region of the View extends to the left of its actual extent.

int TO_RIGHT

The touchable region of the View extends to the right of its actual extent.

Public constructors

TouchDelegate(Rect bounds, View delegateView)

Constructor

Public methods

AccessibilityNodeInfo.TouchDelegateInfo getTouchDelegateInfo()

Return a TouchDelegateInfo mapping from regions (in view coordinates) to delegated views for accessibility usage.

boolean onTouchEvent(MotionEvent event)

Forward touch events to the delegate view if the event is within the bounds specified in the constructor.

boolean onTouchExplorationHoverEvent(MotionEvent event)

Forward hover events to the delegate view if the event is within the bounds specified in the constructor and touch exploration is enabled.

Inherited methods

Constants

ABOVE

Added in API level 1
public static final int ABOVE

The touchable region of the View extends above its actual extent.

Constant Value: 1 (0x00000001)

BELOW

Added in API level 1
public static final int BELOW

The touchable region of the View extends below its actual extent.

Constant Value: 2 (0x00000002)

TO_LEFT

Added in API level 1
public static final int TO_LEFT

The touchable region of the View extends to the left of its actual extent.

Constant Value: 4 (0x00000004)

TO_RIGHT

Added in API level 1
public static final int TO_RIGHT

The touchable region of the View extends to the right of its actual extent.

Constant Value: 8 (0x00000008)

Public constructors

TouchDelegate

Added in API level 1
public TouchDelegate (Rect bounds, 
                View delegateView)

Constructor

Parameters
bounds Rect: Bounds in local coordinates of the containing view that should be mapped to the delegate view

delegateView View: The view that should receive motion events

Public methods

getTouchDelegateInfo

Added in API level 29
public AccessibilityNodeInfo.TouchDelegateInfo getTouchDelegateInfo ()

Return a TouchDelegateInfo mapping from regions (in view coordinates) to delegated views for accessibility usage.

Returns
AccessibilityNodeInfo.TouchDelegateInfo A TouchDelegateInfo. This value cannot be null.

onTouchEvent

Added in API level 1
public boolean onTouchEvent (MotionEvent event)

Forward touch events to the delegate view if the event is within the bounds specified in the constructor.

Parameters
event MotionEvent: The touch event to forward This value cannot be null.

Returns
boolean True if the event was consumed by the delegate, false otherwise.

onTouchExplorationHoverEvent

Added in API level 29
public boolean onTouchExplorationHoverEvent (MotionEvent event)

Forward hover events to the delegate view if the event is within the bounds specified in the constructor and touch exploration is enabled.

This method is provided for accessibility purposes so touch exploration, which is commonly used by screen readers, can properly place accessibility focus on views that use touch delegates. Therefore, touch exploration must be enabled for hover events to be dispatched through the delegate.

Parameters
event MotionEvent: The hover event to forward This value cannot be null.

Returns
boolean True if the event was consumed by the delegate, false otherwise.