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 AccessibilityServices 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