/* * 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 findAccessibilityNodeInfosByText( String text, int virtualViewId) { List compatInfos = compat.findAccessibilityNodeInfosByText(text, virtualViewId); List infos = new ArrayList(); 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 findAccessibilityNodeInfosByText( String text, int virtualViewId) { List compatInfos = compat.findAccessibilityNodeInfosByText(text, virtualViewId); List infos = new ArrayList(); 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 virtualViewId * or the host View itself if virtualViewId equals to {@link View#NO_ID}. *

* 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. *

*

* 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. *

* * @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 virtualViewId or the host View itself * if virtualViewId 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 virtualViewId or the host View itself * virtualViewId 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 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; } }