added in version 22.1.0
belongs to Maven artifact com.android.support:customview:28.0.0-alpha1

ExploreByTouchHelper

public abstract class ExploreByTouchHelper
extends AccessibilityDelegateCompat

java.lang.Object
↳	android.support.v4.view.AccessibilityDelegateCompat
	↳	android.support.v4.widget.ExploreByTouchHelper

ExploreByTouchHelper is a utility class for implementing accessibility support in custom Views that represent a collection of View-like logical items. It extends AccessibilityNodeProviderCompat and simplifies many aspects of providing information to accessibility services and managing accessibility focus.

Clients should override abstract methods on this class and attach it to the host view using setAccessibilityDelegate(View, AccessibilityDelegateCompat):

 class MyCustomView extends View {
     private MyVirtualViewHelper mVirtualViewHelper;

     public MyCustomView(Context context, ...) {
         ...
         mVirtualViewHelper = new MyVirtualViewHelper(this);
         ViewCompat.setAccessibilityDelegate(this, mVirtualViewHelper);
     }

     @Override
     public boolean dispatchHoverEvent(MotionEvent event) {
       return mHelper.dispatchHoverEvent(this, event)
           || super.dispatchHoverEvent(event);
     }

     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
       return mHelper.dispatchKeyEvent(event)
           || super.dispatchKeyEvent(event);
     }

     @Override
     public boolean onFocusChanged(boolean gainFocus, int direction,
         Rect previouslyFocusedRect) {
       super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
       mHelper.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
     }
 }
 mAccessHelper = new MyExploreByTouchHelper(someView);
 ViewCompat.setAccessibilityDelegate(someView, mAccessHelper);

Summary

Constants
`int`	`HOST_ID` Virtual node identifier value for the host view's node.
`int`	`INVALID_ID` Virtual node identifier value for invalid nodes.

Public constructors
`ExploreByTouchHelper(View host)` Constructs a new helper that can expose a virtual view hierarchy for the specified host view.

Public methods
`final boolean`	`clearKeyboardFocusForVirtualView(int virtualViewId)` Attempts to clear keyboard focus from a virtual view.
`final boolean`	`dispatchHoverEvent(MotionEvent event)` Delegates hover events from the host view.
`final boolean`	`dispatchKeyEvent(KeyEvent event)` Delegates key events from the host view.
`final int`	`getAccessibilityFocusedVirtualViewId()`
`AccessibilityNodeProviderCompat`	`getAccessibilityNodeProvider(View host)` Gets the provider for managing a virtual view hierarchy rooted at this View and reported to `AccessibilityService`s that explore the window content.
`int`	`getFocusedVirtualView()` This method was deprecated in API level 24.1.0. Use `getAccessibilityFocusedVirtualViewId()`.
`final int`	`getKeyboardFocusedVirtualViewId()`
`final void`	`invalidateRoot()` Notifies the accessibility framework that the properties of the parent view have changed.
`final void`	`invalidateVirtualView(int virtualViewId)` Notifies the accessibility framework that the properties of a particular item have changed.
`final void`	`invalidateVirtualView(int virtualViewId, int changeTypes)` Notifies the accessibility framework that the properties of a particular item have changed.
`final void`	`onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect)` Delegates focus changes from the host view.
`void`	`onInitializeAccessibilityEvent(View host, AccessibilityEvent event)` Initializes an `AccessibilityEvent` with information about the the host View which is the event source.
`void`	`onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)` Initializes an `AccessibilityNodeInfoCompat` with information about the host view.
`final boolean`	`requestKeyboardFocusForVirtualView(int virtualViewId)` Attempts to give keyboard focus to a virtual view.
`final boolean`	`sendEventForVirtualView(int virtualViewId, int eventType)` Populates an event of the specified type with information about an item and attempts to send it up through the view hierarchy.

Protected methods
`abstract int`	`getVirtualViewAt(float x, float y)` Provides a mapping between view-relative coordinates and logical items.
`abstract void`	`getVisibleVirtualViews(List<Integer> virtualViewIds)` Populates a list with the view's visible items.
`abstract boolean`	`onPerformActionForVirtualView(int virtualViewId, int action, Bundle arguments)` Performs the specified accessibility action on the item associated with the virtual view identifier.
`void`	`onPopulateEventForHost(AccessibilityEvent event)` Populates an `AccessibilityEvent` with information about the host view.
`void`	`onPopulateEventForVirtualView(int virtualViewId, AccessibilityEvent event)` Populates an `AccessibilityEvent` with information about the specified item.
`void`	`onPopulateNodeForHost(AccessibilityNodeInfoCompat node)` Populates an `AccessibilityNodeInfoCompat` with information about the host view.
`abstract void`	`onPopulateNodeForVirtualView(int virtualViewId, AccessibilityNodeInfoCompat node)` Populates an `AccessibilityNodeInfoCompat` with information about the specified item.
`void`	`onVirtualViewKeyboardFocusChanged(int virtualViewId, boolean hasFocus)` Called when the focus state of a virtual view changes.

Inherited methods

From class


  
    android.support.v4.view.AccessibilityDelegateCompat

From class


  
    java.lang.Object

Constants

HOST_ID

added in version 24.1.0

int HOST_ID

Virtual node identifier value for the host view's node.

Constant Value: -1 (0xffffffff)

INVALID_ID

added in version 22.1.0

int INVALID_ID

Virtual node identifier value for invalid nodes.

Constant Value: -2147483648 (0x80000000)

Public constructors