/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.v4.view;
import android.os.Build;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
/**
* Helper for accessing {@link View.AccessibilityDelegate} introduced after
* API level 4 in a backwards compatible fashion.
*/
public class AccessibilityDelegateCompat {
static interface AccessibilityDelegateImpl {
public Object newAccessiblityDelegateDefaultImpl();
public Object newAccessiblityDelegateBridge(AccessibilityDelegateCompat listener);
public boolean dispatchPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event);
public void onInitializeAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event);
public void onInitializeAccessibilityNodeInfo(Object delegate, View host,
AccessibilityNodeInfoCompat info);
public void onPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event);
public boolean onRequestSendAccessibilityEvent(Object delegate, ViewGroup host, View child,
AccessibilityEvent event);
public void sendAccessibilityEvent(Object delegate, View host, int eventType);
public void sendAccessibilityEventUnchecked(Object delegate, View host,
AccessibilityEvent event);
}
static class AccessibilityDelegateStubImpl implements AccessibilityDelegateImpl {
public Object newAccessiblityDelegateDefaultImpl() {
return null;
}
public Object newAccessiblityDelegateBridge(AccessibilityDelegateCompat listener) {
return null;
}
public boolean dispatchPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
return false;
}
public void onInitializeAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
}
public void onInitializeAccessibilityNodeInfo(Object delegate, View host,
AccessibilityNodeInfoCompat info) {
}
public void onPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
}
public boolean onRequestSendAccessibilityEvent(Object delegate, ViewGroup host, View child,
AccessibilityEvent event) {
return true;
}
public void sendAccessibilityEvent(Object delegate, View host, int eventType) {
}
public void sendAccessibilityEventUnchecked(Object delegate, View host,
AccessibilityEvent event) {
}
}
static class AccessibilityDelegateIcsImpl extends AccessibilityDelegateStubImpl {
@Override
public Object newAccessiblityDelegateDefaultImpl() {
return AccessibilityDelegateCompatIcs.newAccessibilityDelegateDefaultImpl();
}
@Override
public Object newAccessiblityDelegateBridge(final AccessibilityDelegateCompat compat) {
return AccessibilityDelegateCompatIcs.newAccessibilityDelegateBridge(
new AccessibilityDelegateCompatIcs.AccessibilityDelegateBridge() {
@Override
public boolean dispatchPopulateAccessibilityEvent(View host,
AccessibilityEvent event) {
return compat.dispatchPopulateAccessibilityEvent(host, event);
}
@Override
public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
compat.onInitializeAccessibilityEvent(host, event);
}
@Override
public void onInitializeAccessibilityNodeInfo(View host, Object info) {
compat.onInitializeAccessibilityNodeInfo(host,
new AccessibilityNodeInfoCompat(info));
}
@Override
public void onPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
compat.onPopulateAccessibilityEvent(host, event);
}
@Override
public boolean onRequestSendAccessibilityEvent(ViewGroup host, View child,
AccessibilityEvent event) {
return compat.onRequestSendAccessibilityEvent(host, child, event);
}
@Override
public void sendAccessibilityEvent(View host, int eventType) {
compat.sendAccessibilityEvent(host, eventType);
}
@Override
public void sendAccessibilityEventUnchecked(View host, AccessibilityEvent event) {
compat.sendAccessibilityEventUnchecked(host, event);
}
});
}
@Override
public boolean dispatchPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
return AccessibilityDelegateCompatIcs.dispatchPopulateAccessibilityEvent(delegate,
host, event);
}
@Override
public void onInitializeAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
AccessibilityDelegateCompatIcs.onInitializeAccessibilityEvent(delegate, host, event);
}
@Override
public void onInitializeAccessibilityNodeInfo(Object delegate, View host,
AccessibilityNodeInfoCompat info) {
AccessibilityDelegateCompatIcs.onInitializeAccessibilityNodeInfo(delegate, host,
info.getImpl());
}
@Override
public void onPopulateAccessibilityEvent(Object delegate, View host,
AccessibilityEvent event) {
AccessibilityDelegateCompatIcs.onPopulateAccessibilityEvent(delegate, host, event);
}
@Override
public boolean onRequestSendAccessibilityEvent(Object delegate, ViewGroup host, View child,
AccessibilityEvent event) {
return AccessibilityDelegateCompatIcs.onRequestSendAccessibilityEvent(delegate, host,
child, event);
}
@Override
public void sendAccessibilityEvent(Object delegate, View host, int eventType) {
AccessibilityDelegateCompatIcs.sendAccessibilityEvent(delegate, host, eventType);
}
@Override
public void sendAccessibilityEventUnchecked(Object delegate, View host,
AccessibilityEvent event) {
AccessibilityDelegateCompatIcs.sendAccessibilityEventUnchecked(delegate, host, event);
}
}
private static final AccessibilityDelegateImpl IMPL;
private static final Object DEFAULT_DELEGATE;
static {
if (Build.VERSION.SDK_INT >= 14) { // ICS
IMPL = new AccessibilityDelegateIcsImpl();
} else {
IMPL = new AccessibilityDelegateStubImpl();
}
DEFAULT_DELEGATE = IMPL.newAccessiblityDelegateDefaultImpl();
}
final Object mBridge;
/**
* Creates a new instance.
*/
public AccessibilityDelegateCompat() {
mBridge = IMPL.newAccessiblityDelegateBridge(this);
}
/**
* @return The wrapped bridge implementation.
*/
Object getBridge() {
return mBridge;
}
/**
* Sends an accessibility event of the given type. If accessibility is not
* enabled this method has no effect.
* <p>
* The default implementation behaves as {@link View#sendAccessibilityEvent(int)
* View#sendAccessibilityEvent(int)} for the case of no accessibility delegate
* been set.
* </p>
*
* @param host The View hosting the delegate.
* @param eventType The type of the event to send.
*
* @see View#sendAccessibilityEvent(int) View#sendAccessibilityEvent(int)
*/
public void sendAccessibilityEvent(View host, int eventType) {
IMPL.sendAccessibilityEvent(DEFAULT_DELEGATE, host, eventType);
}
/**
* Sends an accessibility event. This method behaves exactly as
* {@link #sendAccessibilityEvent(View, int)} but takes as an argument an
* empty {@link AccessibilityEvent} and does not perform a check whether
* accessibility is enabled.
* <p>
* The default implementation behaves as
* {@link View#sendAccessibilityEventUnchecked(AccessibilityEvent)
* View#sendAccessibilityEventUnchecked(AccessibilityEvent)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param event The event to send.
*
* @see View#sendAccessibilityEventUnchecked(AccessibilityEvent)
* View#sendAccessibilityEventUnchecked(AccessibilityEvent)
*/
public void sendAccessibilityEventUnchecked(View host, AccessibilityEvent event) {
IMPL.sendAccessibilityEventUnchecked(DEFAULT_DELEGATE, host, event);
}
/**
* Dispatches an {@link AccessibilityEvent} to the host {@link View} first and then
* to its children for adding their text content to the event.
* <p>
* The default implementation behaves as
* {@link View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
* View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param event The event.
* @return True if the event population was completed.
*
* @see View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
* View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
*/
public boolean dispatchPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
return IMPL.dispatchPopulateAccessibilityEvent(DEFAULT_DELEGATE, host, event);
}
/**
* Gives a chance to the host View to populate the accessibility event with its
* text content.
* <p>
* The default implementation behaves as
* {@link ViewCompat#onPopulateAccessibilityEvent(View, AccessibilityEvent)
* ViewCompat#onPopulateAccessibilityEvent(AccessibilityEvent)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param event The accessibility event which to populate.
*
* @see ViewCompat#onPopulateAccessibilityEvent(View ,AccessibilityEvent)
* ViewCompat#onPopulateAccessibilityEvent(View, AccessibilityEvent)
*/
public void onPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
IMPL.onPopulateAccessibilityEvent(DEFAULT_DELEGATE, host, event);
}
/**
* Initializes an {@link AccessibilityEvent} with information about the
* the host View which is the event source.
* <p>
* The default implementation behaves as
* {@link ViewCompat#onInitializeAccessibilityEvent(View v, AccessibilityEvent event)
* ViewCompat#onInitalizeAccessibilityEvent(View v, AccessibilityEvent event)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param event The event to initialize.
*
* @see ViewCompat#onInitializeAccessibilityEvent(View, AccessibilityEvent)
* ViewCompat#onInitializeAccessibilityEvent(View, AccessibilityEvent)
*/
public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
IMPL.onInitializeAccessibilityEvent(DEFAULT_DELEGATE, host, event);
}
/**
* Initializes an {@link AccessibilityNodeInfoCompat} with information about the host view.
* <p>
* The default implementation behaves as
* {@link ViewCompat#onInitializeAccessibilityNodeInfo(View, AccessibilityNodeInfoCompat)
* ViewCompat#onInitializeAccessibilityNodeInfo(View, AccessibilityNodeInfoCompat)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param info The instance to initialize.
*
* @see ViewCompat#onInitializeAccessibilityNodeInfo(View, AccessibilityNodeInfoCompat)
* ViewCompat#onInitializeAccessibilityNodeInfo(View, AccessibilityNodeInfoCompat)
*/
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
IMPL.onInitializeAccessibilityNodeInfo(DEFAULT_DELEGATE, host, info);
}
/**
* Called when a child of the host View has requested sending an
* {@link AccessibilityEvent} and gives an opportunity to the parent (the host)
* to augment the event.
* <p>
* The default implementation behaves as
* {@link ViewGroupCompat#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)
* ViewGroupCompat#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)} for
* the case of no accessibility delegate been set.
* </p>
*
* @param host The View hosting the delegate.
* @param child The child which requests sending the event.
* @param event The event to be sent.
* @return True if the event should be sent
*
* @see ViewGroupCompat#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)
* ViewGroupCompat#onRequestSendAccessibilityEvent(ViewGroup, View, AccessibilityEvent)
*/
public boolean onRequestSendAccessibilityEvent(ViewGroup host, View child,
AccessibilityEvent event) {
return IMPL.onRequestSendAccessibilityEvent(DEFAULT_DELEGATE, host, child, event);
}
}