AccessibilityRequestPreparer
  public
  
  
  abstract
  class
  AccessibilityRequestPreparer
  
    extends Object
  
  
  
  
  
  
| java.lang.Object | |
| ↳ | android.view.accessibility.AccessibilityRequestPreparer | 
Object responsible to ensuring that a View is prepared to meet a synchronous request for
 accessibility data.
 
 Because accessibility requests arrive to Views synchronously on the UI thread, a View
 that requires information from other processes can struggle to meet those requests. Registering
 an instance of this class with AccessibilityManager allows a View to be notified when
 a request is about to be made, and to asynchronously inform the accessibility system when it is
 ready to meet the request.
 
 Note: This class should only be needed in exceptional situations where a
 View cannot otherwise synchronously meet the request for accessibility data.
Summary
| Constants | |
|---|---|
| int | REQUEST_TYPE_EXTRA_DATA
 | 
| Public constructors | |
|---|---|
| 
      AccessibilityRequestPreparer(View view, int requestTypes)
       | |
| Public methods | |
|---|---|
| 
        
        
        
        
        
        View | 
      getView()
      Get the view this object was created with. | 
| 
        abstract
        
        
        
        
        void | 
      onPrepareExtraData(int virtualViewId, String extraDataKey, Bundle args, Message preparationFinishedMessage)
      Callback to allow preparation for filling extra data. | 
| Inherited methods | |
|---|---|
Constants
REQUEST_TYPE_EXTRA_DATA
public static final int REQUEST_TYPE_EXTRA_DATA
Constant Value: 1 (0x00000001)
Public constructors
AccessibilityRequestPreparer
public AccessibilityRequestPreparer (View view, int requestTypes)
| Parameters | |
|---|---|
| view | View: The view whose requests need preparation. It must be attached to a
 window. This object will retain a weak reference to this view, and will unregister itself
 from AccessibilityManager if the view is detached from a window. It will not re-register
 itself. | 
| requestTypes | int: The types of requests that require preparation. Different types may
 be ORed together.
 Value is either0orREQUEST_TYPE_EXTRA_DATA | 
| Throws | |
|---|---|
| IllegalStateException | if the view is not attached to a window. | 
Public methods
getView
public View getView ()
Get the view this object was created with.
| Returns | |
|---|---|
| View | The view this object was created with, or nullif the weak reference held
 to the view is no longer valid. | 
onPrepareExtraData
public abstract void onPrepareExtraData (int virtualViewId, 
                String extraDataKey, 
                Bundle args, 
                Message preparationFinishedMessage)Callback to allow preparation for filling extra data. Only called back if REQUEST_TYPE_EXTRA_DATA is requested.
| Parameters | |
|---|---|
| virtualViewId | int: The ID of a virtual child node, if theViewfor this preparer
 supports virtual descendents, orAccessibilityNodeProvider.HOST_VIEW_IDif the request is for the view itself. | 
| extraDataKey | String: The extra data key for the request | 
| args | Bundle: The arguments for the request | 
| preparationFinishedMessage | Message: A message that must be sent to its target when preparations
 are complete. | 
See also:
