/*
* Copyright (C) 2012 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.accessibility;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
/**
* Helper for accessing {@link android.view.accessibility.AccessibilityNodeProvider}
* introduced after API level 4 in a backwards compatible fashion.
*/
public class AccessibilityNodeProviderCompat {
interface AccessibilityNodeProviderImpl {
public Object newAccessibilityNodeProviderBridge(AccessibilityNodeProviderCompat compat);
}
static class AccessibilityNodeProviderStubImpl implements AccessibilityNodeProviderImpl {
@Override
public Object newAccessibilityNodeProviderBridge(AccessibilityNodeProviderCompat compat) {
return null;
}
}
static class AccessibilityNodeProviderJellyBeanImpl extends AccessibilityNodeProviderStubImpl {
@Override
public Object newAccessibilityNodeProviderBridge(
final AccessibilityNodeProviderCompat compat) {
return AccessibilityNodeProviderCompatJellyBean.newAccessibilityNodeProviderBridge(
new AccessibilityNodeProviderCompatJellyBean.AccessibilityNodeInfoBridge() {
@Override
public boolean performAction(int virtualViewId, int action,
Bundle arguments) {
return compat.performAction(virtualViewId, action, arguments);
}
@Override
public List<Object> findAccessibilityNodeInfosByText(
String text, int virtualViewId) {
List<AccessibilityNodeInfoCompat> compatInfos =
compat.findAccessibilityNodeInfosByText(text, virtualViewId);
List<Object> infos = new ArrayList<Object>();
final int infoCount = compatInfos.size();
for (int i = 0; i < infoCount; i++) {
AccessibilityNodeInfoCompat infoCompat = compatInfos.get(i);
infos.add(infoCompat.getInfo());
}
return infos;
}
@Override
public Object createAccessibilityNodeInfo(
int virtualViewId) {
final AccessibilityNodeInfoCompat compatInfo = compat
.createAccessibilityNodeInfo(virtualViewId);
if (compatInfo == null) {
return null;
} else {
return compatInfo.getInfo();
}
}
});
}
}
static class AccessibilityNodeProviderKitKatImpl extends AccessibilityNodeProviderStubImpl {
@Override
public Object newAccessibilityNodeProviderBridge(
final AccessibilityNodeProviderCompat compat) {
return AccessibilityNodeProviderCompatKitKat.newAccessibilityNodeProviderBridge(
new AccessibilityNodeProviderCompatKitKat.AccessibilityNodeInfoBridge() {
@Override
public boolean performAction(
int virtualViewId, int action, Bundle arguments) {
return compat.performAction(virtualViewId, action, arguments);
}
@Override
public List<Object> findAccessibilityNodeInfosByText(
String text, int virtualViewId) {
List<AccessibilityNodeInfoCompat> compatInfos =
compat.findAccessibilityNodeInfosByText(text, virtualViewId);
List<Object> infos = new ArrayList<Object>();
final int infoCount = compatInfos.size();
for (int i = 0; i < infoCount; i++) {
AccessibilityNodeInfoCompat infoCompat = compatInfos.get(i);
infos.add(infoCompat.getInfo());
}
return infos;
}
@Override
public Object createAccessibilityNodeInfo(int virtualViewId) {
final AccessibilityNodeInfoCompat compatInfo =
compat.createAccessibilityNodeInfo(virtualViewId);
if (compatInfo == null) {
return null;
} else {
return compatInfo.getInfo();
}
}
@Override
public Object findFocus(int focus) {
final AccessibilityNodeInfoCompat compatInfo = compat.findFocus(focus);
if (compatInfo == null) {
return null;
} else {
return compatInfo.getInfo();
}
}
});
}
}
private static final AccessibilityNodeProviderImpl IMPL;
private final Object mProvider;
static {
if (Build.VERSION.SDK_INT >= 19) { // KitKat
IMPL = new AccessibilityNodeProviderKitKatImpl();
} else if (Build.VERSION.SDK_INT >= 16) { // JellyBean
IMPL = new AccessibilityNodeProviderJellyBeanImpl();
} else {
IMPL = new AccessibilityNodeProviderStubImpl();
}
}
/**
* Creates a new instance.
*/
public AccessibilityNodeProviderCompat() {
mProvider = IMPL.newAccessibilityNodeProviderBridge(this);
}
/**
* Creates a new instance wrapping an
* {@link android.view.accessibility.AccessibilityNodeProvider}.
*
* @param provider The provider.
*/
public AccessibilityNodeProviderCompat(Object provider) {
mProvider = provider;
}
/**
* @return The wrapped {@link android.view.accessibility.AccessibilityNodeProvider}.
*/
public Object getProvider() {
return mProvider;
}
/**
* Returns an {@link AccessibilityNodeInfoCompat} representing a virtual view,
* i.e. a descendant of the host View, with the given <code>virtualViewId</code>
* or the host View itself if <code>virtualViewId</code> equals to {@link View#NO_ID}.
* <p>
* A virtual descendant is an imaginary View that is reported as a part of the view
* hierarchy for accessibility purposes. This enables custom views that draw complex
* content to report them selves as a tree of virtual views, thus conveying their
* logical structure.
* </p>
* <p>
* The implementer is responsible for obtaining an accessibility node info from the
* pool of reusable instances and setting the desired properties of the node info
* before returning it.
* </p>
*
* @param virtualViewId A client defined virtual view id.
* @return A populated {@link AccessibilityNodeInfoCompat} for a virtual descendant
* or the host View.
*
* @see AccessibilityNodeInfoCompat
*/
public AccessibilityNodeInfoCompat createAccessibilityNodeInfo(int virtualViewId) {
return null;
}
/**
* Performs an accessibility action on a virtual view, i.e. a descendant of the
* host View, with the given <code>virtualViewId</code> or the host View itself
* if <code>virtualViewId</code> equals to {@link View#NO_ID}.
*
* @param virtualViewId A client defined virtual view id.
* @param action The action to perform.
* @param arguments Optional arguments.
* @return True if the action was performed.
*
* @see #createAccessibilityNodeInfo(int)
* @see AccessibilityNodeInfoCompat
*/
public boolean performAction(int virtualViewId, int action, Bundle arguments) {
return false;
}
/**
* Finds {@link AccessibilityNodeInfoCompat}s by text. The match is case insensitive
* containment. The search is relative to the virtual view, i.e. a descendant of the
* host View, with the given <code>virtualViewId</code> or the host View itself
* <code>virtualViewId</code> equals to {@link View#NO_ID}.
*
* @param virtualViewId A client defined virtual view id which defined
* the root of the tree in which to perform the search.
* @param text The searched text.
* @return A list of node info.
*
* @see #createAccessibilityNodeInfo(int)
* @see AccessibilityNodeInfoCompat
*/
public List<AccessibilityNodeInfoCompat> findAccessibilityNodeInfosByText(String text,
int virtualViewId) {
return null;
}
/**
* Find the virtual view, i.e. a descendant of the host View, that has the
* specified focus type.
*
* @param focus The focus to find. One of
* {@link AccessibilityNodeInfoCompat#FOCUS_INPUT} or
* {@link AccessibilityNodeInfoCompat#FOCUS_ACCESSIBILITY}.
* @return The node info of the focused view or null.
* @see AccessibilityNodeInfoCompat#FOCUS_INPUT
* @see AccessibilityNodeInfoCompat#FOCUS_ACCESSIBILITY
*/
public AccessibilityNodeInfoCompat findFocus(int focus) {
return null;
}
}