/*
** Copyright 2009, 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 com.android.server.accessibility;
import android.Manifest;
import android.accessibilityservice.AccessibilityService;
import android.accessibilityservice.AccessibilityServiceInfo;
import android.accessibilityservice.IAccessibilityServiceConnection;
import android.accessibilityservice.IEventListener;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.database.ContentObserver;
import android.graphics.Rect;
import android.net.Uri;
import android.os.Binder;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.provider.Settings;
import android.text.TextUtils;
import android.text.TextUtils.SimpleStringSplitter;
import android.util.Slog;
import android.util.SparseArray;
import android.view.IWindow;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.IAccessibilityInteractionConnection;
import android.view.accessibility.IAccessibilityInteractionConnectionCallback;
import android.view.accessibility.IAccessibilityManager;
import android.view.accessibility.IAccessibilityManagerClient;
import com.android.internal.content.PackageMonitor;
import com.android.internal.os.HandlerCaller;
import com.android.internal.os.HandlerCaller.SomeArgs;
import com.android.server.wm.WindowManagerService;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* This class is instantiated by the system as a system level service and can be
* accessed only by the system. The task of this service is to be a centralized
* event dispatch for {@link AccessibilityEvent}s generated across all processes
* on the device. Events are dispatched to {@link AccessibilityService}s.
*
* @hide
*/
public class AccessibilityManagerService extends IAccessibilityManager.Stub
implements HandlerCaller.Callback {
private static final boolean DEBUG = false;
private static final String LOG_TAG = "AccessibilityManagerService";
private static final String FUNCTION_REGISTER_EVENT_LISTENER =
"registerEventListener";
private static int sIdCounter = 0;
private static final int OWN_PROCESS_ID = android.os.Process.myPid();
private static final int DO_SET_SERVICE_INFO = 10;
private static int sNextWindowId;
final HandlerCaller mCaller;
final Context mContext;
final Object mLock = new Object();
final List<Service> mServices = new ArrayList<Service>();
final List<IAccessibilityManagerClient> mClients =
new ArrayList<IAccessibilityManagerClient>();
final Map<ComponentName, Service> mComponentNameToServiceMap = new HashMap<ComponentName, Service>();
private final List<AccessibilityServiceInfo> mInstalledServices = new ArrayList<AccessibilityServiceInfo>();
private final Set<ComponentName> mEnabledServices = new HashSet<ComponentName>();
private final SparseArray<AccessibilityConnectionWrapper> mWindowIdToInteractionConnectionWrapperMap =
new SparseArray<AccessibilityConnectionWrapper>();
private final SparseArray<IBinder> mWindowIdToWindowTokenMap = new SparseArray<IBinder>();
private final SimpleStringSplitter mStringColonSplitter = new SimpleStringSplitter(':');
private PackageManager mPackageManager;
private int mHandledFeedbackTypes = 0;
private boolean mIsAccessibilityEnabled;
private AccessibilityInputFilter mInputFilter;
private boolean mHasInputFilter;
private final List<AccessibilityServiceInfo> mEnabledServicesForFeedbackTempList = new ArrayList<AccessibilityServiceInfo>();
private boolean mIsTouchExplorationEnabled;
private final WindowManagerService mWindowManagerService;
private final SecurityPolicy mSecurityPolicy;
/**
* Handler for delayed event dispatch.
*/
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message message) {
Service service = (Service) message.obj;
int eventType = message.arg1;
synchronized (mLock) {
notifyEventListenerLocked(service, eventType);
}
}
};
/**
* Creates a new instance.
*
* @param context A {@link Context} instance.
*/
public AccessibilityManagerService(Context context) {
mContext = context;
mPackageManager = mContext.getPackageManager();
mCaller = new HandlerCaller(context, this);
mWindowManagerService = (WindowManagerService) ServiceManager.getService(
Context.WINDOW_SERVICE);
mSecurityPolicy = new SecurityPolicy();
registerPackageChangeAndBootCompletedBroadcastReceiver();
registerSettingsContentObservers();
}
/**
* Registers a {@link BroadcastReceiver} for the events of
* adding/changing/removing/restarting a package and boot completion.
*/
private void registerPackageChangeAndBootCompletedBroadcastReceiver() {
Context context = mContext;
PackageMonitor monitor = new PackageMonitor() {
@Override
public void onSomePackagesChanged() {
synchronized (mLock) {
populateAccessibilityServiceListLocked();
manageServicesLocked();
}
}
@Override
public void onPackageRemoved(String packageName, int uid) {
synchronized (mLock) {
Iterator<ComponentName> it = mEnabledServices.iterator();
while (it.hasNext()) {
ComponentName comp = it.next();
String compPkg = comp.getPackageName();
if (compPkg.equals(packageName)) {
it.remove();
updateEnabledAccessibilitySerivcesSettingLocked(mEnabledServices);
return;
}
}
}
}
@Override
public boolean onHandleForceStop(Intent intent, String[] packages,
int uid, boolean doit) {
synchronized (mLock) {
boolean changed = false;
Iterator<ComponentName> it = mEnabledServices.iterator();
while (it.hasNext()) {
ComponentName comp = it.next();
String compPkg = comp.getPackageName();
for (String pkg : packages) {
if (compPkg.equals(pkg)) {
if (!doit) {
return true;
}
it.remove();
changed = true;
}
}
}
if (changed) {
updateEnabledAccessibilitySerivcesSettingLocked(mEnabledServices);
}
return false;
}
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction() == Intent.ACTION_BOOT_COMPLETED) {
synchronized (mLock) {
populateAccessibilityServiceListLocked();
// get accessibility enabled setting on boot
mIsAccessibilityEnabled = Settings.Secure.getInt(
mContext.getContentResolver(),
Settings.Secure.ACCESSIBILITY_ENABLED, 0) == 1;
manageServicesLocked();
// get touch exploration enabled setting on boot
mIsTouchExplorationEnabled = Settings.Secure.getInt(
mContext.getContentResolver(),
Settings.Secure.TOUCH_EXPLORATION_ENABLED, 0) == 1;
updateInputFilterLocked();
sendStateToClientsLocked();
}
return;
}
super.onReceive(context, intent);
}
private void updateEnabledAccessibilitySerivcesSettingLocked(
Set<ComponentName> enabledServices) {
Iterator<ComponentName> it = enabledServices.iterator();
StringBuilder str = new StringBuilder();
while (it.hasNext()) {
if (str.length() > 0) {
str.append(':');
}
str.append(it.next().flattenToShortString());
}
Settings.Secure.putString(mContext.getContentResolver(),
Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,
str.toString());
}
};
// package changes
monitor.register(context, true);
// boot completed
IntentFilter bootFiler = new IntentFilter(Intent.ACTION_BOOT_COMPLETED);
mContext.registerReceiver(monitor, bootFiler);
}
/**
* {@link ContentObserver}s for {@link Settings.Secure#ACCESSIBILITY_ENABLED}
* and {@link Settings.Secure#ENABLED_ACCESSIBILITY_SERVICES} settings.
*/
private void registerSettingsContentObservers() {
ContentResolver contentResolver = mContext.getContentResolver();
Uri accessibilityEnabledUri = Settings.Secure.getUriFor(
Settings.Secure.ACCESSIBILITY_ENABLED);
contentResolver.registerContentObserver(accessibilityEnabledUri, false,
new ContentObserver(new Handler()) {
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
synchronized (mLock) {
handleAccessibilityEnabledSettingChangedLocked();
}
}
});
Uri touchExplorationRequestedUri = Settings.Secure.getUriFor(
Settings.Secure.TOUCH_EXPLORATION_ENABLED);
contentResolver.registerContentObserver(touchExplorationRequestedUri, false,
new ContentObserver(new Handler()) {
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
synchronized (mLock) {
mIsTouchExplorationEnabled = Settings.Secure.getInt(
mContext.getContentResolver(),
Settings.Secure.TOUCH_EXPLORATION_ENABLED, 0) == 1;
updateInputFilterLocked();
sendStateToClientsLocked();
}
}
});
Uri accessibilityServicesUri =
Settings.Secure.getUriFor(Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES);
contentResolver.registerContentObserver(accessibilityServicesUri, false,
new ContentObserver(new Handler()) {
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
synchronized (mLock) {
manageServicesLocked();
}
}
});
}
public int addClient(IAccessibilityManagerClient client) throws RemoteException {
synchronized (mLock) {
final IAccessibilityManagerClient addedClient = client;
mClients.add(addedClient);
// Clients are registered all the time until their process is
// killed, therefore we do not have a corresponding unlinkToDeath.
client.asBinder().linkToDeath(new DeathRecipient() {
public void binderDied() {
synchronized (mLock) {
addedClient.asBinder().unlinkToDeath(this, 0);
mClients.remove(addedClient);
}
}
}, 0);
return getState();
}
}
public boolean sendAccessibilityEvent(AccessibilityEvent event) {
synchronized (mLock) {
if (mSecurityPolicy.canDispatchAccessibilityEvent(event)) {
mSecurityPolicy.updateRetrievalAllowingWindowAndEventSourceLocked(event);
notifyAccessibilityServicesDelayedLocked(event, false);
notifyAccessibilityServicesDelayedLocked(event, true);
}
}
event.recycle();
mHandledFeedbackTypes = 0;
return (OWN_PROCESS_ID != Binder.getCallingPid());
}
public List<AccessibilityServiceInfo> getInstalledAccessibilityServiceList() {
synchronized (mLock) {
return mInstalledServices;
}
}
public List<AccessibilityServiceInfo> getEnabledAccessibilityServiceList(int feedbackType) {
List<AccessibilityServiceInfo> result = mEnabledServicesForFeedbackTempList;
result.clear();
List<Service> services = mServices;
synchronized (mLock) {
while (feedbackType != 0) {
final int feedbackTypeBit = (1 << Integer.numberOfTrailingZeros(feedbackType));
feedbackType &= ~feedbackTypeBit;
final int serviceCount = services.size();
for (int i = 0; i < serviceCount; i++) {
Service service = services.get(i);
if ((service.mFeedbackType & feedbackTypeBit) != 0) {
result.add(service.mAccessibilityServiceInfo);
}
}
}
}
return result;
}
public void interrupt() {
synchronized (mLock) {
for (int i = 0, count = mServices.size(); i < count; i++) {
Service service = mServices.get(i);
try {
service.mServiceInterface.onInterrupt();
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error during sending interrupt request to "
+ service.mService, re);
}
}
}
}
public void executeMessage(Message message) {
switch (message.what) {
case DO_SET_SERVICE_INFO: {
SomeArgs arguments = ((SomeArgs) message.obj);
AccessibilityServiceInfo info = (AccessibilityServiceInfo) arguments.arg1;
Service service = (Service) arguments.arg2;
synchronized (mLock) {
// If the XML manifest had data to configure the service its info
// should be already set. In such a case update only the dynamically
// configurable properties.
AccessibilityServiceInfo oldInfo = service.mAccessibilityServiceInfo;
if (oldInfo != null) {
oldInfo.updateDynamicallyConfigurableProperties(info);
service.setDynamicallyConfigurableProperties(oldInfo);
} else {
service.setDynamicallyConfigurableProperties(info);
}
}
} return;
default:
Slog.w(LOG_TAG, "Unknown message type: " + message.what);
}
}
public int addAccessibilityInteractionConnection(IWindow windowToken,
IAccessibilityInteractionConnection connection) throws RemoteException {
synchronized (mLock) {
final IWindow addedWindowToken = windowToken;
final IAccessibilityInteractionConnection addedConnection = connection;
final int windowId = sNextWindowId++;
AccessibilityConnectionWrapper wrapper = new AccessibilityConnectionWrapper(windowId,
connection);
wrapper.linkToDeath();
mWindowIdToWindowTokenMap.put(windowId, addedWindowToken.asBinder());
mWindowIdToInteractionConnectionWrapperMap.put(windowId, wrapper);
if (DEBUG) {
Slog.i(LOG_TAG, "Adding interaction connection to windowId: " + windowId);
}
return windowId;
}
}
public void removeAccessibilityInteractionConnection(IWindow windowToken) {
synchronized (mLock) {
final int count = mWindowIdToWindowTokenMap.size();
for (int i = 0; i < count; i++) {
if (mWindowIdToWindowTokenMap.valueAt(i) == windowToken.asBinder()) {
final int windowId = mWindowIdToWindowTokenMap.keyAt(i);
AccessibilityConnectionWrapper wrapper =
mWindowIdToInteractionConnectionWrapperMap.get(windowId);
wrapper.unlinkToDeath();
removeAccessibilityInteractionConnectionLocked(windowId);
return;
}
}
}
}
public void registerEventListener(IEventListener listener) {
mSecurityPolicy.enforceCallingPermission(Manifest.permission.RETRIEVE_WINDOW_CONTENT,
FUNCTION_REGISTER_EVENT_LISTENER);
ComponentName componentName = new ComponentName("foo.bar",
"AutomationAccessibilityService");
synchronized (mLock) {
// If an automation services is connected to the system all services are stopped
// so the automation one is the only one running. Settings are not changed so when
// the automation service goes away the state is restored from the settings.
// Disable all services.
final int runningServiceCount = mServices.size();
for (int i = 0; i < runningServiceCount; i++) {
Service runningService = mServices.get(i);
runningService.unbind();
}
// If necessary enable accessibility and announce that.
if (!mIsAccessibilityEnabled) {
mIsAccessibilityEnabled = true;
sendStateToClientsLocked();
}
}
// Hook the automation service up.
AccessibilityServiceInfo accessibilityServiceInfo = new AccessibilityServiceInfo();
accessibilityServiceInfo.eventTypes = AccessibilityEvent.TYPES_ALL_MASK;
accessibilityServiceInfo.feedbackType = AccessibilityServiceInfo.FEEDBACK_GENERIC;
Service service = new Service(componentName, accessibilityServiceInfo, true);
service.onServiceConnected(componentName, listener.asBinder());
}
/**
* Removes an AccessibilityInteractionConnection.
*
* @param windowId The id of the window to which the connection is targeted.
*/
private void removeAccessibilityInteractionConnectionLocked(int windowId) {
mWindowIdToWindowTokenMap.remove(windowId);
mWindowIdToInteractionConnectionWrapperMap.remove(windowId);
if (DEBUG) {
Slog.i(LOG_TAG, "Removing interaction connection to windowId: " + windowId);
}
}
/**
* Populates the cached list of installed {@link AccessibilityService}s.
*/
private void populateAccessibilityServiceListLocked() {
mInstalledServices.clear();
List<ResolveInfo> installedServices = mPackageManager.queryIntentServices(
new Intent(AccessibilityService.SERVICE_INTERFACE),
PackageManager.GET_SERVICES | PackageManager.GET_META_DATA);
for (int i = 0, count = installedServices.size(); i < count; i++) {
ResolveInfo resolveInfo = installedServices.get(i);
AccessibilityServiceInfo accessibilityServiceInfo;
try {
accessibilityServiceInfo = new AccessibilityServiceInfo(resolveInfo, mContext);
mInstalledServices.add(accessibilityServiceInfo);
} catch (XmlPullParserException xppe) {
Slog.e(LOG_TAG, "Error while initializing AccessibilityServiceInfo", xppe);
} catch (IOException ioe) {
Slog.e(LOG_TAG, "Error while initializing AccessibilityServiceInfo", ioe);
}
}
}
/**
* Performs {@link AccessibilityService}s delayed notification. The delay is configurable
* and denotes the period after the last event before notifying the service.
*
* @param event The event.
* @param isDefault True to notify default listeners, not default services.
*/
private void notifyAccessibilityServicesDelayedLocked(AccessibilityEvent event,
boolean isDefault) {
try {
for (int i = 0, count = mServices.size(); i < count; i++) {
Service service = mServices.get(i);
if (service.mIsDefault == isDefault) {
if (canDispathEventLocked(service, event, mHandledFeedbackTypes)) {
mHandledFeedbackTypes |= service.mFeedbackType;
notifyAccessibilityServiceDelayedLocked(service, event);
}
}
}
} catch (IndexOutOfBoundsException oobe) {
// An out of bounds exception can happen if services are going away
// as the for loop is running. If that happens, just bail because
// there are no more services to notify.
return;
}
}
/**
* Performs an {@link AccessibilityService} delayed notification. The delay is configurable
* and denotes the period after the last event before notifying the service.
*
* @param service The service.
* @param event The event.
*/
private void notifyAccessibilityServiceDelayedLocked(Service service,
AccessibilityEvent event) {
synchronized (mLock) {
final int eventType = event.getEventType();
// Make a copy since during dispatch it is possible the event to
// be modified to remove its source if the receiving service does
// not have permission to access the window content.
AccessibilityEvent newEvent = AccessibilityEvent.obtain(event);
AccessibilityEvent oldEvent = service.mPendingEvents.get(eventType);
service.mPendingEvents.put(eventType, newEvent);
final int what = eventType | (service.mId << 16);
if (oldEvent != null) {
mHandler.removeMessages(what);
oldEvent.recycle();
}
Message message = mHandler.obtainMessage(what, service);
message.arg1 = eventType;
mHandler.sendMessageDelayed(message, service.mNotificationTimeout);
}
}
/**
* Notifies a service for a scheduled event given the event type.
*
* @param service The service.
* @param eventType The type of the event to dispatch.
*/
private void notifyEventListenerLocked(Service service, int eventType) {
IEventListener listener = service.mServiceInterface;
// If the service died/was disabled while the message for dispatching
// the accessibility event was propagating the listener may be null.
if (listener == null) {
return;
}
AccessibilityEvent event = service.mPendingEvents.get(eventType);
// Check for null here because there is a concurrent scenario in which this
// happens: 1) A binder thread calls notifyAccessibilityServiceDelayedLocked
// which posts a message for dispatching an event. 2) The message is pulled
// from the queue by the handler on the service thread and the latter is
// just about to acquire the lock and call this method. 3) Now another binder
// thread acquires the lock calling notifyAccessibilityServiceDelayedLocked
// so the service thread waits for the lock; 4) The binder thread replaces
// the event with a more recent one (assume the same event type) and posts a
// dispatch request releasing the lock. 5) Now the main thread is unblocked and
// dispatches the event which is removed from the pending ones. 6) And ... now
// the service thread handles the last message posted by the last binder call
// but the event is already dispatched and hence looking it up in the pending
// ones yields null. This check is much simpler that keeping count for each
// event type of each service to catch such a scenario since only one message
// is processed at a time.
if (event == null) {
return;
}
service.mPendingEvents.remove(eventType);
try {
if (mSecurityPolicy.canRetrieveWindowContent(service)) {
event.setConnectionId(service.mId);
} else {
event.setSource(null);
}
event.setSealed(true);
listener.onAccessibilityEvent(event);
event.recycle();
if (DEBUG) {
Slog.i(LOG_TAG, "Event " + event + " sent to " + listener);
}
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error during sending " + event + " to " + service.mService, re);
}
}
/**
* Adds a service.
*
* @param service The service to add.
*/
private void tryAddServiceLocked(Service service) {
try {
if (mServices.contains(service) || !service.isConfigured()) {
return;
}
service.linkToOwnDeath();
mServices.add(service);
mComponentNameToServiceMap.put(service.mComponentName, service);
updateInputFilterLocked();
} catch (RemoteException e) {
/* do nothing */
}
}
/**
* Removes a service.
*
* @param service The service.
* @return True if the service was removed, false otherwise.
*/
private boolean tryRemoveServiceLocked(Service service) {
final boolean removed = mServices.remove(service);
if (!removed) {
return false;
}
mComponentNameToServiceMap.remove(service.mComponentName);
mHandler.removeMessages(service.mId);
service.unlinkToOwnDeath();
service.dispose();
updateInputFilterLocked();
return removed;
}
/**
* Determines if given event can be dispatched to a service based on the package of the
* event source and already notified services for that event type. Specifically, a
* service is notified if it is interested in events from the package and no other service
* providing the same feedback type has been notified. Exception are services the
* provide generic feedback (feedback type left as a safety net for unforeseen feedback
* types) which are always notified.
*
* @param service The potential receiver.
* @param event The event.
* @param handledFeedbackTypes The feedback types for which services have been notified.
* @return True if the listener should be notified, false otherwise.
*/
private boolean canDispathEventLocked(Service service, AccessibilityEvent event,
int handledFeedbackTypes) {
if (!service.isConfigured()) {
return false;
}
int eventType = event.getEventType();
if ((service.mEventTypes & eventType) != eventType) {
return false;
}
Set<String> packageNames = service.mPackageNames;
CharSequence packageName = event.getPackageName();
if (packageNames.isEmpty() || packageNames.contains(packageName)) {
int feedbackType = service.mFeedbackType;
if ((handledFeedbackTypes & feedbackType) != feedbackType
|| feedbackType == AccessibilityServiceInfo.FEEDBACK_GENERIC) {
return true;
}
}
return false;
}
/**
* Manages services by starting enabled ones and stopping disabled ones.
*/
private void manageServicesLocked() {
unbindAutomationService();
populateEnabledServicesLocked(mEnabledServices);
final int enabledInstalledServicesCount = updateServicesStateLocked(mInstalledServices,
mEnabledServices);
// No enabled installed services => disable accessibility to avoid
// sending accessibility events with no recipient across processes.
if (mIsAccessibilityEnabled && enabledInstalledServicesCount == 0) {
Settings.Secure.putInt(mContext.getContentResolver(),
Settings.Secure.ACCESSIBILITY_ENABLED, 0);
}
}
/**
* Unbinds all bound services.
*/
private void unbindAllServicesLocked() {
List<Service> services = mServices;
for (int i = 0, count = services.size(); i < count; i++) {
Service service = services.get(i);
if (service.unbind()) {
i--;
count--;
}
}
}
/**
* Unbinds the automation service if such is running.
*/
private void unbindAutomationService() {
List<Service> runningServices = mServices;
int runningServiceCount = mServices.size();
for (int i = 0; i < runningServiceCount; i++) {
Service service = runningServices.get(i);
if (service.mIsAutomation) {
service.unbind();
return;
}
}
}
/**
* Populates a list with the {@link ComponentName}s of all enabled
* {@link AccessibilityService}s.
*
* @param enabledServices The list.
*/
private void populateEnabledServicesLocked(Set<ComponentName> enabledServices) {
enabledServices.clear();
String servicesValue = Settings.Secure.getString(mContext.getContentResolver(),
Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES);
if (servicesValue != null) {
TextUtils.SimpleStringSplitter splitter = mStringColonSplitter;
splitter.setString(servicesValue);
while (splitter.hasNext()) {
String str = splitter.next();
if (str == null || str.length() <= 0) {
continue;
}
ComponentName enabledService = ComponentName.unflattenFromString(str);
if (enabledService != null) {
enabledServices.add(enabledService);
}
}
}
}
/**
* Updates the state of each service by starting (or keeping running) enabled ones and
* stopping the rest.
*
* @param installedServices All installed {@link AccessibilityService}s.
* @param enabledServices The {@link ComponentName}s of the enabled services.
* @return The number of enabled installed services.
*/
private int updateServicesStateLocked(List<AccessibilityServiceInfo> installedServices,
Set<ComponentName> enabledServices) {
Map<ComponentName, Service> componentNameToServiceMap = mComponentNameToServiceMap;
boolean isEnabled = mIsAccessibilityEnabled;
int enabledInstalledServices = 0;
for (int i = 0, count = installedServices.size(); i < count; i++) {
AccessibilityServiceInfo installedService = installedServices.get(i);
ComponentName componentName = ComponentName.unflattenFromString(
installedService.getId());
Service service = componentNameToServiceMap.get(componentName);
if (isEnabled) {
if (enabledServices.contains(componentName)) {
if (service == null) {
service = new Service(componentName, installedService, false);
}
service.bind();
enabledInstalledServices++;
} else {
if (service != null) {
service.unbind();
}
}
} else {
if (service != null) {
service.unbind();
}
}
}
return enabledInstalledServices;
}
/**
* Sends the state to the clients.
*/
private void sendStateToClientsLocked() {
final int state = getState();
for (int i = 0, count = mClients.size(); i < count; i++) {
try {
mClients.get(i).setState(state);
} catch (RemoteException re) {
mClients.remove(i);
count--;
i--;
}
}
}
/**
* Gets the current state as a set of flags.
*
* @return The state.
*/
private int getState() {
int state = 0;
if (mIsAccessibilityEnabled) {
state |= AccessibilityManager.STATE_FLAG_ACCESSIBILITY_ENABLED;
}
// Touch exploration relies on enabled accessibility.
if (mIsAccessibilityEnabled && mIsTouchExplorationEnabled) {
state |= AccessibilityManager.STATE_FLAG_TOUCH_EXPLORATION_ENABLED;
}
return state;
}
/**
* Updates the touch exploration state.
*/
private void updateInputFilterLocked() {
if (mIsAccessibilityEnabled && mIsTouchExplorationEnabled) {
if (!mHasInputFilter) {
mHasInputFilter = true;
if (mInputFilter == null) {
mInputFilter = new AccessibilityInputFilter(mContext);
}
mWindowManagerService.setInputFilter(mInputFilter);
}
return;
}
if (mHasInputFilter) {
mHasInputFilter = false;
mWindowManagerService.setInputFilter(null);
}
}
/**
* Updated the state based on the accessibility enabled setting.
*/
private void handleAccessibilityEnabledSettingChangedLocked() {
mIsAccessibilityEnabled = Settings.Secure.getInt(
mContext.getContentResolver(),
Settings.Secure.ACCESSIBILITY_ENABLED, 0) == 1;
if (mIsAccessibilityEnabled) {
manageServicesLocked();
} else {
unbindAllServicesLocked();
}
updateInputFilterLocked();
sendStateToClientsLocked();
}
private class AccessibilityConnectionWrapper implements DeathRecipient {
private final int mWindowId;
private final IAccessibilityInteractionConnection mConnection;
public AccessibilityConnectionWrapper(int windowId,
IAccessibilityInteractionConnection connection) {
mWindowId = windowId;
mConnection = connection;
}
public void linkToDeath() throws RemoteException {
mConnection.asBinder().linkToDeath(this, 0);
}
public void unlinkToDeath() {
mConnection.asBinder().unlinkToDeath(this, 0);
}
@Override
public void binderDied() {
unlinkToDeath();
synchronized (mLock) {
removeAccessibilityInteractionConnectionLocked(mWindowId);
}
}
}
/**
* This class represents an accessibility service. It stores all per service
* data required for the service management, provides API for starting/stopping the
* service and is responsible for adding/removing the service in the data structures
* for service management. The class also exposes configuration interface that is
* passed to the service it represents as soon it is bound. It also serves as the
* connection for the service.
*/
class Service extends IAccessibilityServiceConnection.Stub
implements ServiceConnection, DeathRecipient {
int mId = 0;
AccessibilityServiceInfo mAccessibilityServiceInfo;
IBinder mService;
IEventListener mServiceInterface;
int mEventTypes;
int mFeedbackType;
Set<String> mPackageNames = new HashSet<String>();
boolean mIsDefault;
long mNotificationTimeout;
ComponentName mComponentName;
Intent mIntent;
boolean mCanRetrieveScreenContent;
boolean mIsAutomation;
final Rect mTempBounds = new Rect();
// the events pending events to be dispatched to this service
final SparseArray<AccessibilityEvent> mPendingEvents =
new SparseArray<AccessibilityEvent>();
public Service(ComponentName componentName,
AccessibilityServiceInfo accessibilityServiceInfo, boolean isAutomation) {
mId = sIdCounter++;
mComponentName = componentName;
mAccessibilityServiceInfo = accessibilityServiceInfo;
mIsAutomation = isAutomation;
if (!isAutomation) {
mCanRetrieveScreenContent = accessibilityServiceInfo.getCanRetrieveWindowContent();
mIntent = new Intent().setComponent(mComponentName);
mIntent.putExtra(Intent.EXTRA_CLIENT_LABEL,
com.android.internal.R.string.accessibility_binding_label);
mIntent.putExtra(Intent.EXTRA_CLIENT_INTENT, PendingIntent.getActivity(
mContext, 0, new Intent(Settings.ACTION_ACCESSIBILITY_SETTINGS), 0));
} else {
mCanRetrieveScreenContent = true;
}
setDynamicallyConfigurableProperties(accessibilityServiceInfo);
}
public void setDynamicallyConfigurableProperties(AccessibilityServiceInfo info) {
mEventTypes = info.eventTypes;
mFeedbackType = info.feedbackType;
String[] packageNames = info.packageNames;
if (packageNames != null) {
mPackageNames.addAll(Arrays.asList(packageNames));
}
mNotificationTimeout = info.notificationTimeout;
mIsDefault = (info.flags & AccessibilityServiceInfo.DEFAULT) != 0;
synchronized (mLock) {
tryAddServiceLocked(this);
}
}
/**
* Binds to the accessibility service.
*
* @return True if binding is successful.
*/
public boolean bind() {
if (!mIsAutomation && mService == null) {
return mContext.bindService(mIntent, this, Context.BIND_AUTO_CREATE);
}
return false;
}
/**
* Unbinds form the accessibility service and removes it from the data
* structures for service management.
*
* @return True if unbinding is successful.
*/
public boolean unbind() {
if (mService != null) {
synchronized (mLock) {
tryRemoveServiceLocked(this);
}
if (!mIsAutomation) {
mContext.unbindService(this);
}
return true;
}
return false;
}
/**
* Returns if the service is configured i.e. at least event types of interest
* and feedback type must be set.
*
* @return True if the service is configured, false otherwise.
*/
public boolean isConfigured() {
return (mEventTypes != 0 && mFeedbackType != 0 && mService != null);
}
public void setServiceInfo(AccessibilityServiceInfo info) {
mCaller.obtainMessageOO(DO_SET_SERVICE_INFO, info, this).sendToTarget();
}
public void onServiceConnected(ComponentName componentName, IBinder service) {
mService = service;
mServiceInterface = IEventListener.Stub.asInterface(service);
try {
mServiceInterface.setConnection(this, mId);
synchronized (mLock) {
tryAddServiceLocked(this);
}
} catch (RemoteException re) {
Slog.w(LOG_TAG, "Error while setting Controller for service: " + service, re);
}
}
public float findAccessibilityNodeInfoByViewIdInActiveWindow(int viewId,
int interactionId, IAccessibilityInteractionConnectionCallback callback,
long interrogatingTid)
throws RemoteException {
IAccessibilityInteractionConnection connection = null;
synchronized (mLock) {
mSecurityPolicy.enforceCanRetrieveWindowContent(this);
final boolean permissionGranted = mSecurityPolicy.canRetrieveWindowContent(this);
if (!permissionGranted) {
return 0;
} else {
connection = getConnectionToRetrievalAllowingWindowLocked();
if (connection == null) {
if (DEBUG) {
Slog.e(LOG_TAG, "No interaction connection to a retrieve "
+ "allowing window.");
}
return 0;
}
}
}
final int interrogatingPid = Binder.getCallingPid();
final long identityToken = Binder.clearCallingIdentity();
try {
connection.findAccessibilityNodeInfoByViewId(viewId, interactionId, callback,
interrogatingPid, interrogatingTid);
} catch (RemoteException re) {
if (DEBUG) {
Slog.e(LOG_TAG, "Error finding node.");
}
} finally {
Binder.restoreCallingIdentity(identityToken);
}
return getCompatibilityScale(mSecurityPolicy.getRetrievalAllowingWindowLocked());
}
public float findAccessibilityNodeInfosByViewTextInActiveWindow(
String text, int interactionId,
IAccessibilityInteractionConnectionCallback callback, long threadId)
throws RemoteException {
return findAccessibilityNodeInfosByViewText(text,
mSecurityPolicy.mRetrievalAlowingWindowId, View.NO_ID, interactionId, callback,
threadId);
}
public float findAccessibilityNodeInfosByViewText(String text,
int accessibilityWindowId, int accessibilityViewId, int interactionId,
IAccessibilityInteractionConnectionCallback callback, long interrogatingTid)
throws RemoteException {
IAccessibilityInteractionConnection connection = null;
synchronized (mLock) {
mSecurityPolicy.enforceCanRetrieveWindowContent(this);
final boolean permissionGranted =
mSecurityPolicy.canGetAccessibilityNodeInfoLocked(this, accessibilityWindowId);
if (!permissionGranted) {
return 0;
} else {
connection = getConnectionToRetrievalAllowingWindowLocked();
if (connection == null) {
if (DEBUG) {
Slog.e(LOG_TAG, "No interaction connection to focused window.");
}
return 0;
}
}
}
final int interrogatingPid = Binder.getCallingPid();
final long identityToken = Binder.clearCallingIdentity();
try {
connection.findAccessibilityNodeInfosByViewText(text, accessibilityViewId,
interactionId, callback, interrogatingPid, interrogatingTid);
} catch (RemoteException re) {
if (DEBUG) {
Slog.e(LOG_TAG, "Error finding node.");
}
} finally {
Binder.restoreCallingIdentity(identityToken);
}
return getCompatibilityScale(accessibilityWindowId);
}
public float findAccessibilityNodeInfoByAccessibilityId(int accessibilityWindowId,
int accessibilityViewId, int interactionId,
IAccessibilityInteractionConnectionCallback callback, long interrogatingTid)
throws RemoteException {
IAccessibilityInteractionConnection connection = null;
synchronized (mLock) {
mSecurityPolicy.enforceCanRetrieveWindowContent(this);
final boolean permissionGranted =
mSecurityPolicy.canGetAccessibilityNodeInfoLocked(this, accessibilityWindowId);
if (!permissionGranted) {
return 0;
} else {
AccessibilityConnectionWrapper wrapper =
mWindowIdToInteractionConnectionWrapperMap.get(accessibilityWindowId);
if (wrapper == null) {
if (DEBUG) {
Slog.e(LOG_TAG, "No interaction connection to window: "
+ accessibilityWindowId);
}
return 0;
}
connection = wrapper.mConnection;
}
}
final int interrogatingPid = Binder.getCallingPid();
final long identityToken = Binder.clearCallingIdentity();
try {
connection.findAccessibilityNodeInfoByAccessibilityId(accessibilityViewId,
interactionId, callback, interrogatingPid, interrogatingTid);
} catch (RemoteException re) {
if (DEBUG) {
Slog.e(LOG_TAG, "Error requesting node with accessibilityViewId: "
+ accessibilityViewId);
}
} finally {
Binder.restoreCallingIdentity(identityToken);
}
return getCompatibilityScale(accessibilityWindowId);
}
public boolean performAccessibilityAction(int accessibilityWindowId,
int accessibilityViewId, int action, int interactionId,
IAccessibilityInteractionConnectionCallback callback, long interrogatingTid) {
IAccessibilityInteractionConnection connection = null;
synchronized (mLock) {
final boolean permissionGranted = mSecurityPolicy.canPerformActionLocked(this,
accessibilityWindowId, action);
if (!permissionGranted) {
return false;
} else {
AccessibilityConnectionWrapper wrapper =
mWindowIdToInteractionConnectionWrapperMap.get(accessibilityWindowId);
if (wrapper == null) {
if (DEBUG) {
Slog.e(LOG_TAG, "No interaction connection to window: "
+ accessibilityWindowId);
}
return false;
}
connection = wrapper.mConnection;
}
}
final int interrogatingPid = Binder.getCallingPid();
final long identityToken = Binder.clearCallingIdentity();
try {
connection.performAccessibilityAction(accessibilityViewId, action, interactionId,
callback, interrogatingPid, interrogatingTid);
} catch (RemoteException re) {
if (DEBUG) {
Slog.e(LOG_TAG, "Error requesting node with accessibilityViewId: "
+ accessibilityViewId);
}
} finally {
Binder.restoreCallingIdentity(identityToken);
}
return true;
}
public void onServiceDisconnected(ComponentName componentName) {
/* do nothing - #binderDied takes care */
}
public void linkToOwnDeath() throws RemoteException {
mService.linkToDeath(this, 0);
}
public void unlinkToOwnDeath() {
mService.unlinkToDeath(this, 0);
}
public void dispose() {
try {
// Clear the proxy in the other process so this
// IAccessibilityServiceConnection can be garbage collected.
mServiceInterface.setConnection(null, mId);
} catch (RemoteException re) {
/* ignore */
}
mService = null;
mServiceInterface = null;
}
public void binderDied() {
synchronized (mLock) {
unlinkToOwnDeath();
tryRemoveServiceLocked(this);
// We no longer have an automation service, so restore
// the state based on values in the settings database.
if (mIsAutomation) {
handleAccessibilityEnabledSettingChangedLocked();
}
}
}
private IAccessibilityInteractionConnection getConnectionToRetrievalAllowingWindowLocked() {
final int windowId = mSecurityPolicy.getRetrievalAllowingWindowLocked();
if (DEBUG) {
Slog.i(LOG_TAG, "Trying to get interaction connection to windowId: " + windowId);
}
AccessibilityConnectionWrapper wrapper =
mWindowIdToInteractionConnectionWrapperMap.get(windowId);
return (wrapper != null) ? wrapper.mConnection : null;
}
private float getCompatibilityScale(int windowId) {
IBinder windowToken = mWindowIdToWindowTokenMap.get(windowId);
return mWindowManagerService.getWindowCompatibilityScale(windowToken);
}
}
final class SecurityPolicy {
private static final int VALID_ACTIONS = AccessibilityNodeInfo.ACTION_FOCUS
| AccessibilityNodeInfo.ACTION_CLEAR_FOCUS | AccessibilityNodeInfo.ACTION_SELECT
| AccessibilityNodeInfo.ACTION_CLEAR_SELECTION;
private static final int RETRIEVAL_ALLOWING_EVENT_TYPES =
AccessibilityEvent.TYPE_VIEW_CLICKED | AccessibilityEvent.TYPE_VIEW_FOCUSED
| AccessibilityEvent.TYPE_VIEW_HOVER_ENTER | AccessibilityEvent.TYPE_VIEW_HOVER_EXIT
| AccessibilityEvent.TYPE_VIEW_LONG_CLICKED | AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED
| AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED | AccessibilityEvent.TYPE_VIEW_SELECTED
| AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED
| AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED
| AccessibilityEvent.TYPE_VIEW_SCROLLED;
private static final int RETRIEVAL_ALLOWING_WINDOW_CHANGE_EVENT_TYPES =
AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED | AccessibilityEvent.TYPE_VIEW_HOVER_ENTER
| AccessibilityEvent.TYPE_VIEW_HOVER_EXIT;
private int mRetrievalAlowingWindowId;
private boolean canDispatchAccessibilityEvent(AccessibilityEvent event) {
// Send window changed event only for the retrieval allowing window.
return (event.getEventType() != AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED
|| event.getWindowId() == mRetrievalAlowingWindowId);
}
public void updateRetrievalAllowingWindowAndEventSourceLocked(AccessibilityEvent event) {
final int windowId = event.getWindowId();
final int eventType = event.getEventType();
if ((eventType & RETRIEVAL_ALLOWING_WINDOW_CHANGE_EVENT_TYPES) != 0) {
mRetrievalAlowingWindowId = windowId;
}
if ((eventType & RETRIEVAL_ALLOWING_EVENT_TYPES) == 0) {
event.setSource(null);
}
}
public int getRetrievalAllowingWindowLocked() {
return mRetrievalAlowingWindowId;
}
public boolean canGetAccessibilityNodeInfoLocked(Service service, int windowId) {
return canRetrieveWindowContent(service) && isRetrievalAllowingWindow(windowId);
}
public boolean canPerformActionLocked(Service service, int windowId, int action) {
return canRetrieveWindowContent(service)
&& isRetrievalAllowingWindow(windowId)
&& isActionPermitted(action);
}
public boolean canRetrieveWindowContent(Service service) {
return service.mCanRetrieveScreenContent;
}
public void enforceCanRetrieveWindowContent(Service service) throws RemoteException {
// This happens due to incorrect registration so make it apparent.
if (!canRetrieveWindowContent(service)) {
Slog.e(LOG_TAG, "Accessibility serivce " + service.mComponentName + " does not " +
"declare android:canRetrieveWindowContent.");
throw new RemoteException();
}
}
private boolean isRetrievalAllowingWindow(int windowId) {
return (mRetrievalAlowingWindowId == windowId);
}
private boolean isActionPermitted(int action) {
return (VALID_ACTIONS & action) != 0;
}
private void enforceCallingPermission(String permission, String function) {
if (OWN_PROCESS_ID == Binder.getCallingPid()) {
return;
}
final int permissionStatus = mContext.checkCallingPermission(permission);
if (permissionStatus != PackageManager.PERMISSION_GRANTED) {
throw new SecurityException("You do not have " + permission
+ " required to call " + function);
}
}
}
}