Speedup the accessibility window querying APIs and clean up.

1. Now when an interrogating client requires an AccessibilibtyNodeInfo
   we aggressively prefetch all the predecessors of that node and its
   descendants. The number of fetched nodes in one call is limited to
   keep the APIs responsive. The prefetched nodes infos are cached in
   the client process. The node info cache is invalidated partially or
   completely based on the fired accessibility events. For example,
   TYPE_WINDOW_STATE_CHANGED event clears the cache while
   TYPE_VIEW_FOCUSED removed the focused node from the cache, etc.
   Note that the cache is only for the currently active window.
   The ViewRootImple also keeps track of only the ids of the node
   infos it has sent to each querying process to avoid duplicating
   work. Usually only one process will query the screen content
   but we support the general case. Also all the caches are
   automatically invalidated so not additional bookkeeping is
   required. This simple strategy leads to 10X improving the
   speed of the querying APIs.

2. The Monkey and UI test automation framework  were registering a
   raw event listener for accessibility events and hence perform
   connection and cache management in similar way to an AccessibilityService.
   This is fragile and requires the implementer to know internal framework
   stuff. Now the functionality required by the Monkey and the UI automation
   is encapsulated in a new UiTestAutomationBridge class. To enable this
   was requited some refactoring of AccessibilityService.

3. Removed the *doSomethiong*InActiveWindow methods from the
   AccessibilityInteractionClient and the AccessibilityInteractionConnection.
   The function of these methods is implemented by the not *InActiveWindow
   version while passing appropriate constants.

4. Updated the internal window Querying tests to use the new
   UiTestAutomationBridge.

5. If the ViewRootImple was not initialized the querying APIs of
   the IAccessibilityInteractionConnection implementation were
   returning immediately without calling the callback with null.
   This was causing the client side to wait until it times out. Now
   the client is notified as soon as the call fails.

6. Added a check to guarantee that Views with AccessibilityNodeProvider
   do not have children.

bug:5879530

Change-Id: I3ee43718748fec6e570992c7073c8f6f1fc269b3

Author: sganov

core/java/android/accessibilityservice/AccessibilityService.java

@@ -17,8 +17,10 @@
 package android.accessibilityservice;
 
 import android.app.Service;
+import android.content.Context;
 import android.content.Intent;
 import android.os.IBinder;
+import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
 import android.util.Log;
@@ -218,10 +220,17 @@ public abstract class AccessibilityService extends Service {
 
     private static final String LOG_TAG = "AccessibilityService";
 
-    private AccessibilityServiceInfo mInfo;
+    interface Callbacks {
+        public void onAccessibilityEvent(AccessibilityEvent event);
+        public void onInterrupt();
+        public void onServiceConnected();
+        public void onSetConnectionId(int connectionId);
+    }
 
     private int mConnectionId;
 
+    private AccessibilityServiceInfo mInfo;
+
     /**
      * Callback for {@link android.view.accessibility.AccessibilityEvent}s.
      *
@@ -282,27 +291,49 @@ private void sendServiceInfo() {
      */
     @Override
     public final IBinder onBind(Intent intent) {
-        return new IEventListenerWrapper(this);
+        return new IEventListenerWrapper(this, getMainLooper(), new Callbacks() {
+            @Override
+            public void onServiceConnected() {
+                AccessibilityService.this.onServiceConnected();
+            }
+
+            @Override
+            public void onInterrupt() {
+                AccessibilityService.this.onInterrupt();
+            }
+
+            @Override
+            public void onAccessibilityEvent(AccessibilityEvent event) {
+                AccessibilityService.this.onAccessibilityEvent(event);
+            }
+
+            @Override
+            public void onSetConnectionId( int connectionId) {
+                mConnectionId = connectionId;
+            }
+        });
     }
 
     /**
      * Implements the internal {@link IEventListener} interface to convert
      * incoming calls to it back to calls on an {@link AccessibilityService}.
      */
-    class IEventListenerWrapper extends IEventListener.Stub
+    static class IEventListenerWrapper extends IEventListener.Stub
             implements HandlerCaller.Callback {
 
+        static final int NO_ID = -1;
+
         private static final int DO_SET_SET_CONNECTION = 10;
         private static final int DO_ON_INTERRUPT = 20;
         private static final int DO_ON_ACCESSIBILITY_EVENT = 30;
 
         private final HandlerCaller mCaller;
 
-        private final AccessibilityService mTarget;
+        private final Callbacks mCallback;
 
-        public IEventListenerWrapper(AccessibilityService context) {
-            mTarget = context;
-            mCaller = new HandlerCaller(context, this);
+        public IEventListenerWrapper(Context context, Looper looper, Callbacks callback) {
+            mCallback = callback;
+            mCaller = new HandlerCaller(context, looper, this);
         }
 
         public void setConnection(IAccessibilityServiceConnection connection, int connectionId) {
@@ -326,12 +357,13 @@ public void executeMessage(Message message) {
                 case DO_ON_ACCESSIBILITY_EVENT :
                     AccessibilityEvent event = (AccessibilityEvent) message.obj;
                     if (event != null) {
-                        mTarget.onAccessibilityEvent(event);
+                        AccessibilityInteractionClient.getInstance().onAccessibilityEvent(event);
+                        mCallback.onAccessibilityEvent(event);
                         event.recycle();
                     }
                     return;
                 case DO_ON_INTERRUPT :
-                    mTarget.onInterrupt();
+                    mCallback.onInterrupt();
                     return;
                 case DO_SET_SET_CONNECTION :
                     final int connectionId = message.arg1;
@@ -340,12 +372,11 @@ public void executeMessage(Message message) {
                     if (connection != null) {
                         AccessibilityInteractionClient.getInstance().addConnection(connectionId,
                                 connection);
-                        mConnectionId = connectionId;
-                        mTarget.onServiceConnected();
+                        mCallback.onSetConnectionId(connectionId);
+                        mCallback.onServiceConnected();
                     } else {
                         AccessibilityInteractionClient.getInstance().removeConnection(connectionId);
-                        mConnectionId = AccessibilityInteractionClient.NO_ID;
-                        // TODO: Do we need a onServiceDisconnected callback?
+                        mCallback.onSetConnectionId(AccessibilityInteractionClient.NO_ID);
                     }
                     return;
                 default :

core/java/android/accessibilityservice/IAccessibilityServiceConnection.aidl

@@ -32,8 +32,13 @@ interface IAccessibilityServiceConnection {
     /**
      * Finds an {@link AccessibilityNodeInfo} by accessibility id.
      *
-     * @param accessibilityWindowId A unique window id.
-     * @param accessibilityNodeId A unique view id or virtual descendant id.
+     * @param accessibilityWindowId A unique window id. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ACTIVE_WINDOW_ID}
+     *     to query the currently active window.
+     * @param accessibilityNodeId A unique view id or virtual descendant id from
+     *     where to start the search. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ROOT_NODE_ID}
+     *     to start from the root.
      * @param interactionId The id of the interaction for matching with the callback result.
      * @param callback Callback which to receive the result.
      * @param threadId The id of the calling thread.
@@ -46,57 +51,58 @@ interface IAccessibilityServiceConnection {
     /**
      * Finds {@link AccessibilityNodeInfo}s by View text. The match is case
      * insensitive containment. The search is performed in the window whose
-     * id is specified and starts from the View whose accessibility id is
+     * id is specified and starts from the node whose accessibility id is
      * specified.
      *
-     * @param text The searched text.
-     * @param accessibilityWindowId A unique window id.
+     * @param accessibilityWindowId A unique window id. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ACTIVE_WINDOW_ID}
+     *     to query the currently active window.
      * @param accessibilityNodeId A unique view id or virtual descendant id from
-     *        where to start the search. Use {@link android.view.View#NO_ID} to start from the root.
-     * @param interactionId The id of the interaction for matching with the callback result.
-     * @param callback Callback which to receive the result.
-     * @param threadId The id of the calling thread.
-     * @return The current window scale, where zero means a failure.
-     */
-    float findAccessibilityNodeInfosByText(String text, int accessibilityWindowId,
-        long accessibilityNodeId, int interractionId,
-        IAccessibilityInteractionConnectionCallback callback, long threadId);
-
-    /**
-     * Finds {@link AccessibilityNodeInfo}s by View text. The match is case
-     * insensitive containment. The search is performed in the currently
-     * active window and start from the root View in the window.
-     *
+     *     where to start the search. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ROOT_NODE_ID}
+     *     to start from the root.
      * @param text The searched text.
-     * @param accessibilityId The id of the view from which to start searching.
-     *        Use {@link android.view.View#NO_ID} to start from the root.
      * @param interactionId The id of the interaction for matching with the callback result.
      * @param callback Callback which to receive the result.
      * @param threadId The id of the calling thread.
      * @return The current window scale, where zero means a failure.
      */
-    float findAccessibilityNodeInfosByTextInActiveWindow(String text,
-        int interactionId, IAccessibilityInteractionConnectionCallback callback,
+    float findAccessibilityNodeInfosByText(int accessibilityWindowId, long accessibilityNodeId,
+        String text, int interactionId, IAccessibilityInteractionConnectionCallback callback,
         long threadId);
 
     /**
-     * Finds an {@link AccessibilityNodeInfo} by View id. The search is performed
-     * in the currently active window and starts from the root View in the window.
+     * Finds an {@link AccessibilityNodeInfo} by View id. The search is performed in
+     * the window whose id is specified and starts from the node whose accessibility
+     * id is specified.
      *
+     * @param accessibilityWindowId A unique window id. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ACTIVE_WINDOW_ID}
+     *     to query the currently active window.
+     * @param accessibilityNodeId A unique view id or virtual descendant id from
+     *     where to start the search. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ROOT_NODE_ID}
+     *     to start from the root.
      * @param id The id of the node.
      * @param interactionId The id of the interaction for matching with the callback result.
      * @param callback Callback which to receive the result.
      * @param threadId The id of the calling thread.
      * @return The current window scale, where zero means a failure.
      */
-    float findAccessibilityNodeInfoByViewIdInActiveWindow(int viewId, int interactionId,
-        IAccessibilityInteractionConnectionCallback callback, long threadId);
+    float findAccessibilityNodeInfoByViewId(int accessibilityWindowId, long accessibilityNodeId,
+        int viewId, int interactionId, IAccessibilityInteractionConnectionCallback callback,
+        long threadId);
 
     /**
      * Performs an accessibility action on an {@link AccessibilityNodeInfo}.
      *
-     * @param accessibilityWindowId The id of the window.
-     * @param accessibilityNodeId A unique view id or virtual descendant id.
+     * @param accessibilityWindowId A unique window id. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ACTIVE_WINDOW_ID}
+     *     to query the currently active window.
+     * @param accessibilityNodeId A unique view id or virtual descendant id from
+     *     where to start the search. Use
+     *     {@link com.android.server.accessibility.AccessibilityManagerService#ROOT_NODE_ID}
+     *     to start from the root.
      * @param action The action to perform.
      * @param interactionId The id of the interaction for matching with the callback result.
      * @param callback Callback which to receive the result.