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 View
s 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 |
int
|
getFocusedVirtualView()
This method was deprecated
in API level 24.1.0.
Use |
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 |
void
|
onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)
Initializes an |
final
boolean
|
|