1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server.accessibility; 18 19 import android.os.Binder; 20 import android.os.RemoteException; 21 import android.util.Slog; 22 import android.view.MagnificationSpec; 23 import android.view.accessibility.AccessibilityNodeInfo; 24 import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction; 25 import android.view.accessibility.IAccessibilityInteractionConnection; 26 import android.view.accessibility.IAccessibilityInteractionConnectionCallback; 27 import com.android.internal.annotations.GuardedBy; 28 29 import java.util.ArrayList; 30 import java.util.List; 31 import java.util.concurrent.atomic.AtomicInteger; 32 33 /** 34 * If we are stripping and/or replacing the actions from a window, we need to intercept the 35 * nodes heading back to the service and swap out the actions. 36 */ 37 public class ActionReplacingCallback extends IAccessibilityInteractionConnectionCallback.Stub { 38 private static final boolean DEBUG = false; 39 private static final String LOG_TAG = "ActionReplacingCallback"; 40 41 private final IAccessibilityInteractionConnectionCallback mServiceCallback; 42 private final IAccessibilityInteractionConnection mConnectionWithReplacementActions; 43 private final int mInteractionId; 44 private final Object mLock = new Object(); 45 46 @GuardedBy("mLock") 47 List<AccessibilityNodeInfo> mNodesWithReplacementActions; 48 49 @GuardedBy("mLock") 50 List<AccessibilityNodeInfo> mNodesFromOriginalWindow; 51 52 @GuardedBy("mLock") 53 AccessibilityNodeInfo mNodeFromOriginalWindow; 54 55 // Keep track of whether or not we've been called back for a single node 56 @GuardedBy("mLock") 57 boolean mSingleNodeCallbackHappened; 58 59 // Keep track of whether or not we've been called back for multiple node 60 @GuardedBy("mLock") 61 boolean mMultiNodeCallbackHappened; 62 63 // We shouldn't get any more callbacks after we've called back the original service, but 64 // keep track to make sure we catch such strange things 65 @GuardedBy("mLock") 66 boolean mDone; 67 68 public ActionReplacingCallback(IAccessibilityInteractionConnectionCallback serviceCallback, 69 IAccessibilityInteractionConnection connectionWithReplacementActions, 70 int interactionId, int interrogatingPid, long interrogatingTid) { 71 mServiceCallback = serviceCallback; 72 mConnectionWithReplacementActions = connectionWithReplacementActions; 73 mInteractionId = interactionId; 74 75 // Request the root node of the replacing window 76 final long identityToken = Binder.clearCallingIdentity(); 77 try { 78 mConnectionWithReplacementActions.findAccessibilityNodeInfoByAccessibilityId( 79 AccessibilityNodeInfo.ROOT_NODE_ID, null, interactionId + 1, this, 0, 80 interrogatingPid, interrogatingTid, null, null); 81 } catch (RemoteException re) { 82 if (DEBUG) { 83 Slog.e(LOG_TAG, "Error calling findAccessibilityNodeInfoByAccessibilityId()"); 84 } 85 // Pretend we already got a (null) list of replacement nodes 86 mMultiNodeCallbackHappened = true; 87 } finally { 88 Binder.restoreCallingIdentity(identityToken); 89 } 90 } 91 92 @Override 93 public void setFindAccessibilityNodeInfoResult(AccessibilityNodeInfo info, int interactionId) { 94 boolean readyForCallback; 95 synchronized(mLock) { 96 if (interactionId == mInteractionId) { 97 mNodeFromOriginalWindow = info; 98 } else { 99 Slog.e(LOG_TAG, "Callback with unexpected interactionId"); 100 return; 101 } 102 103 mSingleNodeCallbackHappened = true; 104 readyForCallback = mMultiNodeCallbackHappened; 105 } 106 if (readyForCallback) { 107 replaceInfoActionsAndCallService(); 108 } 109 } 110 111 @Override 112 public void setFindAccessibilityNodeInfosResult(List<AccessibilityNodeInfo> infos, 113 int interactionId) { 114 boolean callbackForSingleNode; 115 boolean callbackForMultipleNodes; 116 synchronized(mLock) { 117 if (interactionId == mInteractionId) { 118 mNodesFromOriginalWindow = infos; 119 } else if (interactionId == mInteractionId + 1) { 120 mNodesWithReplacementActions = infos; 121 } else { 122 Slog.e(LOG_TAG, "Callback with unexpected interactionId"); 123 return; 124 } 125 callbackForSingleNode = mSingleNodeCallbackHappened; 126 callbackForMultipleNodes = mMultiNodeCallbackHappened; 127 mMultiNodeCallbackHappened = true; 128 } 129 if (callbackForSingleNode) { 130 replaceInfoActionsAndCallService(); 131 } 132 if (callbackForMultipleNodes) { 133 replaceInfosActionsAndCallService(); 134 } 135 } 136 137 @Override 138 public void setPerformAccessibilityActionResult(boolean succeeded, int interactionId) 139 throws RemoteException { 140 // There's no reason to use this class when performing actions. Do something reasonable. 141 mServiceCallback.setPerformAccessibilityActionResult(succeeded, interactionId); 142 } 143 144 private void replaceInfoActionsAndCallService() { 145 final AccessibilityNodeInfo nodeToReturn; 146 synchronized (mLock) { 147 if (mDone) { 148 if (DEBUG) { 149 Slog.e(LOG_TAG, "Extra callback"); 150 } 151 return; 152 } 153 if (mNodeFromOriginalWindow != null) { 154 replaceActionsOnInfoLocked(mNodeFromOriginalWindow); 155 } 156 recycleReplaceActionNodesLocked(); 157 nodeToReturn = mNodeFromOriginalWindow; 158 mDone = true; 159 } 160 try { 161 mServiceCallback.setFindAccessibilityNodeInfoResult(nodeToReturn, mInteractionId); 162 } catch (RemoteException re) { 163 if (DEBUG) { 164 Slog.e(LOG_TAG, "Failed to setFindAccessibilityNodeInfoResult"); 165 } 166 } 167 } 168 169 private void replaceInfosActionsAndCallService() { 170 final List<AccessibilityNodeInfo> nodesToReturn; 171 synchronized (mLock) { 172 if (mDone) { 173 if (DEBUG) { 174 Slog.e(LOG_TAG, "Extra callback"); 175 } 176 return; 177 } 178 if (mNodesFromOriginalWindow != null) { 179 for (int i = 0; i < mNodesFromOriginalWindow.size(); i++) { 180 replaceActionsOnInfoLocked(mNodesFromOriginalWindow.get(i)); 181 } 182 } 183 recycleReplaceActionNodesLocked(); 184 nodesToReturn = (mNodesFromOriginalWindow == null) 185 ? null : new ArrayList<>(mNodesFromOriginalWindow); 186 mDone = true; 187 } 188 try { 189 mServiceCallback.setFindAccessibilityNodeInfosResult(nodesToReturn, mInteractionId); 190 } catch (RemoteException re) { 191 if (DEBUG) { 192 Slog.e(LOG_TAG, "Failed to setFindAccessibilityNodeInfosResult"); 193 } 194 } 195 } 196 197 @GuardedBy("mLock") 198 private void replaceActionsOnInfoLocked(AccessibilityNodeInfo info) { 199 info.removeAllActions(); 200 info.setClickable(false); 201 info.setFocusable(false); 202 info.setContextClickable(false); 203 info.setScrollable(false); 204 info.setLongClickable(false); 205 info.setDismissable(false); 206 // We currently only replace actions for the root node 207 if ((info.getSourceNodeId() == AccessibilityNodeInfo.ROOT_NODE_ID) 208 && mNodesWithReplacementActions != null) { 209 // This list should always contain a single node with the root ID 210 for (int i = 0; i < mNodesWithReplacementActions.size(); i++) { 211 AccessibilityNodeInfo nodeWithReplacementActions = 212 mNodesWithReplacementActions.get(i); 213 if (nodeWithReplacementActions.getSourceNodeId() 214 == AccessibilityNodeInfo.ROOT_NODE_ID) { 215 List<AccessibilityAction> actions = nodeWithReplacementActions.getActionList(); 216 if (actions != null) { 217 for (int j = 0; j < actions.size(); j++) { 218 info.addAction(actions.get(j)); 219 } 220 // The PIP needs to be able to take accessibility focus 221 info.addAction(AccessibilityAction.ACTION_ACCESSIBILITY_FOCUS); 222 info.addAction(AccessibilityAction.ACTION_CLEAR_ACCESSIBILITY_FOCUS); 223 } 224 info.setClickable(nodeWithReplacementActions.isClickable()); 225 info.setFocusable(nodeWithReplacementActions.isFocusable()); 226 info.setContextClickable(nodeWithReplacementActions.isContextClickable()); 227 info.setScrollable(nodeWithReplacementActions.isScrollable()); 228 info.setLongClickable(nodeWithReplacementActions.isLongClickable()); 229 info.setDismissable(nodeWithReplacementActions.isDismissable()); 230 } 231 } 232 } 233 } 234 235 @GuardedBy("mLock") 236 private void recycleReplaceActionNodesLocked() { 237 if (mNodesWithReplacementActions == null) return; 238 for (int i = mNodesWithReplacementActions.size() - 1; i >= 0; i--) { 239 AccessibilityNodeInfo nodeWithReplacementAction = mNodesWithReplacementActions.get(i); 240 nodeWithReplacementAction.recycle(); 241 } 242 mNodesWithReplacementActions = null; 243 } 244 } 245
