Touch exploration feature, event bubling, refactor

1. Added an Input Filter that interprets the touch screen motion
   events to perfrom accessibility exploration. One finger explores.
   Tapping within a given time and distance slop on the last exlopred
   location does click and long press, respectively. Two fingers close
   and in the same diretion drag. Multiple finglers or two fingers in
   different directions or two fingers too far away are delegated to
   the view hierarchy. Non moving fingers "accidentally grabbed the
   device for the scrren" are ignored.

2. Added accessibility events for hover enter, hover exit, touch
   exoloration gesture start, and end. Accessibility hover events
   are fired by the hover pipeline. An accessibility event is
   dispatched up the view tree and the topmost view fires it.
   Thus predecessors can augment the fired event. An accessibility
   event has several records and a predecessor can optionally
   modify, delete, and add such to the event.

3. Added onPopulateAccessibilityEvent and refactored the existing
   accessibility code to use it.

4. Added API for querying the currently enabled accessibility services
   by feedback type.

Change-Id: Iea2258c07ffae9491071825d966dc453b07e5134

4 files changed, 590 insertions, 333 deletions

diff --git a/core/java/android/view/accessibility/AccessibilityEvent.java b/core/java/android/view/accessibility/AccessibilityEvent.java
index 9af19b8..11c9392 100644
--- a/core/java/android/view/accessibility/AccessibilityEvent.java
+++ b/core/java/android/view/accessibility/AccessibilityEvent.java
@@ -21,13 +21,26 @@ import android.os.Parcelable;
 import android.text.TextUtils;
 
 import java.util.ArrayList;
-import java.util.List;
 
 /**
  * This class represents accessibility events that are sent by the system when
  * something notable happens in the user interface. For example, when a
  * {@link android.widget.Button} is clicked, a {@link android.view.View} is focused, etc.
  * <p>
+ * An accessibility event is fired by an individual view which populates the event with
+ * a record for its state and requests from its parent to send the event to interested
+ * parties. The parent can optionally add a record for itself before dispatching a similar
+ * request to its parent. A parent can also choose not to respect the request for sending
+ * an event. The accessibility event is sent by the topmost view in the view tree.
+ * Therefore, an {@link android.accessibilityservice.AccessibilityService} can explore
+ * all records in an accessibility event to obtain more information about the context
+ * in which the event was fired.
+ * <p>
+ * A client can add, remove, and modify records. The getters and setters for individual
+ * properties operate on the current record which can be explicitly set by the client. By
+ * default current is the first record. Thus, querying a record would require setting
+ * it as the current one and interacting with the property getters and setters.
+ * <p>
  * This class represents various semantically different accessibility event
  * types. Each event type has associated a set of related properties. In other
  * words, each event type is characterized via a subset of the properties exposed
@@ -145,7 +158,7 @@ import java.util.List;
  * @see android.view.accessibility.AccessibilityManager
  * @see android.accessibilityservice.AccessibilityService
  */
-public final class AccessibilityEvent implements Parcelable {
+public final class AccessibilityEvent extends AccessibilityRecord implements Parcelable {
 
     /**
      * Invalid selection/focus position.
@@ -207,6 +220,26 @@ public final class AccessibilityEvent implements Parcelable {
     public static final int TYPE_NOTIFICATION_STATE_CHANGED = 0x00000040;
 
     /**
+     * Represents the event of a hover enter over a {@link android.view.View}.
+     */
+    public static final int TYPE_VIEW_HOVER_ENTER = 0x00000080;
+
+    /**
+     * Represents the event of a hover exit over a {@link android.view.View}.
+     */
+    public static final int TYPE_VIEW_HOVER_EXIT = 0x00000100;
+
+    /**
+     * Represents the event of starting a touch exploration gesture.
+     */
+    public static final int TYPE_TOUCH_EXPLORATION_GESTURE_START = 0x00000200;
+
+    /**
+     * Represents the event of ending a touch exploration gesture.
+     */
+    public static final int TYPE_TOUCH_EXPLORATION_GESTURE_END = 0x00000400;
+
+    /**
      * Mask for {@link AccessibilityEvent} all types.
      *
      * @see #TYPE_VIEW_CLICKED
@@ -219,116 +252,53 @@ public final class AccessibilityEvent implements Parcelable {
      */
     public static final int TYPES_ALL_MASK = 0xFFFFFFFF;
 
-    private static final int MAX_POOL_SIZE = 2;
+    private static final int MAX_POOL_SIZE = 10;
     private static final Object mPoolLock = new Object();
     private static AccessibilityEvent sPool;
     private static int sPoolSize;
 
-    private static final int CHECKED = 0x00000001;
-    private static final int ENABLED = 0x00000002;
-    private static final int PASSWORD = 0x00000004;
-    private static final int FULL_SCREEN = 0x00000080;
-
     private AccessibilityEvent mNext;
+    private boolean mIsInPool;
 
     private int mEventType;
-    private int mBooleanProperties;
-    private int mCurrentItemIndex;
-    private int mItemCount;
-    private int mFromIndex;
-    private int mAddedCount;
-    private int mRemovedCount;
-
-    private long mEventTime;
-
-    private CharSequence mClassName;
     private CharSequence mPackageName;
-    private CharSequence mContentDescription;
-    private CharSequence mBeforeText;
-
-    private Parcelable mParcelableData;
-
-    private final List<CharSequence> mText = new ArrayList<CharSequence>();
+    private long mEventTime;
 
-    private boolean mIsInPool;
+    private final ArrayList<AccessibilityRecord> mRecords = new ArrayList<AccessibilityRecord>();
 
     /*
      * Hide constructor from clients.
      */
     private AccessibilityEvent() {
-        mCurrentItemIndex = INVALID_POSITION;
-    }
-
-    /**
-     * Gets if the source is checked.
-     *
-     * @return True if the view is checked, false otherwise.
-     */
-    public boolean isChecked() {
-        return getBooleanProperty(CHECKED);
-    }
-
-    /**
-     * Sets if the source is checked.
-     *
-     * @param isChecked True if the view is checked, false otherwise.
-     */
-    public void setChecked(boolean isChecked) {
-        setBooleanProperty(CHECKED, isChecked);
-    }
 
-    /**
-     * Gets if the source is enabled.
-     *
-     * @return True if the view is enabled, false otherwise.
-     */
-    public boolean isEnabled() {
-        return getBooleanProperty(ENABLED);
-    }
-
-    /**
-     * Sets if the source is enabled.
-     *
-     * @param isEnabled True if the view is enabled, false otherwise.
-     */
-    public void setEnabled(boolean isEnabled) {
-        setBooleanProperty(ENABLED, isEnabled);
-    }
-
-    /**
-     * Gets if the source is a password field.
-     *
-     * @return True if the view is a password field, false otherwise.
-     */
-    public boolean isPassword() {
-        return getBooleanProperty(PASSWORD);
     }
 
     /**
-     * Sets if the source is a password field.
+     * Gets the number of records contained in the event.
      *
-     * @param isPassword True if the view is a password field, false otherwise.
+     * @return The number of records.
      */
-    public void setPassword(boolean isPassword) {
-        setBooleanProperty(PASSWORD, isPassword);
+    public int getRecordCount() {
+        return mRecords.size();
     }
 
     /**
-     * Sets if the source is taking the entire screen.
+     * Appends an {@link AccessibilityRecord} to the end of event records.
      *
-     * @param isFullScreen True if the source is full screen, false otherwise.
+     * @param record The record to append.
      */
-    public void setFullScreen(boolean isFullScreen) {
-        setBooleanProperty(FULL_SCREEN, isFullScreen);
+    public void appendRecord(AccessibilityRecord record) {
+        mRecords.add(record);
     }
 
     /**
-     * Gets if the source is taking the entire screen.
+     * Gets the records at a given index.
      *
-     * @return True if the source is full screen, false otherwise.
+     * @param index The index.
+     * @return The records at the specified index.
      */
-    public boolean isFullScreen() {
-        return getBooleanProperty(FULL_SCREEN);
+    public AccessibilityRecord getRecord(int index) {
+        return mRecords.get(index);
     }
 
     /**
@@ -350,96 +320,6 @@ public final class AccessibilityEvent implements Parcelable {
     }
 
     /**
-     * Gets the number of items that can be visited.
-     *
-     * @return The number of items.
-     */
-    public int getItemCount() {
-        return mItemCount;
-    }
-
-    /**
-     * Sets the number of items that can be visited.
-     *
-     * @param itemCount The number of items.
-     */
-    public void setItemCount(int itemCount) {
-        mItemCount = itemCount;
-    }
-
-    /**
-     * Gets the index of the source in the list of items the can be visited.
-     *
-     * @return The current item index.
-     */
-    public int getCurrentItemIndex() {
-        return mCurrentItemIndex;
-    }
-
-    /**
-     * Sets the index of the source in the list of items that can be visited.
-     *
-     * @param currentItemIndex The current item index.
-     */
-    public void setCurrentItemIndex(int currentItemIndex) {
-        mCurrentItemIndex = currentItemIndex;
-    }
-
-    /**
-     * Gets the index of the first character of the changed sequence.
-     *
-     * @return The index of the first character.
-     */
-    public int getFromIndex() {
-        return mFromIndex;
-    }
-
-    /**
-     * Sets the index of the first character of the changed sequence.
-     *
-     * @param fromIndex The index of the first character.
-     */
-    public void setFromIndex(int fromIndex) {
-        mFromIndex = fromIndex;
-    }
-
-    /**
-     * Gets the number of added characters.
-     *
-     * @return The number of added characters.
-     */
-    public int getAddedCount() {
-        return mAddedCount;
-    }
-
-    /**
-     * Sets the number of added characters.
-     *
-     * @param addedCount The number of added characters.
-     */
-    public void setAddedCount(int addedCount) {
-        mAddedCount = addedCount;
-    }
-
-    /**
-     * Gets the number of removed characters.
-     *
-     * @return The number of removed characters.
-     */
-    public int getRemovedCount() {
-        return mRemovedCount;
-    }
-
-    /**
-     * Sets the number of removed characters.
-     *
-     * @param removedCount The number of removed characters.
-     */
-    public void setRemovedCount(int removedCount) {
-        mRemovedCount = removedCount;
-    }
-
-    /**
      * Gets the time in which this event was sent.
      *
      * @return The event time.
@@ -458,24 +338,6 @@ public final class AccessibilityEvent implements Parcelable {
     }
 
     /**
-     * Gets the class name of the source.
-     *
-     * @return The class name.
-     */
-    public CharSequence getClassName() {
-        return mClassName;
-    }
-
-    /**
-     * Sets the class name of the source.
-     *
-     * @param className The lass name.
-     */
-    public void setClassName(CharSequence className) {
-        mClassName = className;
-    }
-
-    /**
      * Gets the package name of the source.
      *
      * @return The package name.
@@ -494,70 +356,6 @@ public final class AccessibilityEvent implements Parcelable {
     }
 
     /**
-     * Gets the text of the event. The index in the list represents the priority
-     * of the text. Specifically, the lower the index the higher the priority.
-     *
-     * @return The text.
-     */
-    public List<CharSequence> getText() {
-        return mText;
-    }
-
-    /**
-     * Sets the text before a change.
-     *
-     * @return The text before the change.
-     */
-    public CharSequence getBeforeText() {
-        return mBeforeText;
-    }
-
-    /**
-     * Sets the text before a change.
-     *
-     * @param beforeText The text before the change.
-     */
-    public void setBeforeText(CharSequence beforeText) {
-        mBeforeText = beforeText;
-    }
-
-    /**
-     * Gets the description of the source.
-     *
-     * @return The description.
-     */
-    public CharSequence getContentDescription() {
-        return mContentDescription;
-    }
-
-    /**
-     * Sets the description of the source.
-     *
-     * @param contentDescription The description.
-     */
-    public void setContentDescription(CharSequence contentDescription) {
-        mContentDescription = contentDescription;
-    }
-
-    /**
-     * Gets the {@link Parcelable} data.
-     *
-     * @return The parcelable data.
-     */
-    public Parcelable getParcelableData() {
-        return mParcelableData;
-    }
-
-    /**
-     * Sets the {@link Parcelable} data of the event.
-     *
-     * @param parcelableData The parcelable data.
-     */
-    public void setParcelableData(Parcelable parcelableData) {
-        mParcelableData = parcelableData;
-    }
-
-    /**
      * Returns a cached instance if such is available or a new one is
      * instantiated with type property set.
      *
@@ -595,11 +393,11 @@ public final class AccessibilityEvent implements Parcelable {
      * <p>
      * <b>Note: You must not touch the object after calling this function.</b>
      */
+    @Override
     public void recycle() {
         if (mIsInPool) {
             return;
         }
-
         clear();
         synchronized (mPoolLock) {
             if (sPoolSize <= MAX_POOL_SIZE) {
@@ -614,44 +412,15 @@ public final class AccessibilityEvent implements Parcelable {
     /**
      * Clears the state of this instance.
      */
-    private void clear() {
+    @Override
+    protected void clear() {
+        super.clear();
         mEventType = 0;
-        mBooleanProperties = 0;
-        mCurrentItemIndex = INVALID_POSITION;
-        mItemCount = 0;
-        mFromIndex = 0;
-        mAddedCount = 0;
-        mRemovedCount = 0;
-        mEventTime = 0;
-        mClassName = null;
         mPackageName = null;
-        mContentDescription = null;
-        mBeforeText = null;
-        mParcelableData = null;
-        mText.clear();
-    }
-
-    /**
-     * Gets the value of a boolean property.
-     *
-     * @param property The property.
-     * @return The value.
-     */
-    private boolean getBooleanProperty(int property) {
-        return (mBooleanProperties & property) == property;
-    }
-
-    /**
-     * Sets a boolean property.
-     *
-     * @param property The property.
-     * @param value The value.
-     */
-    private void setBooleanProperty(int property, boolean value) {
-        if (value) {
-            mBooleanProperties |= property;
-        } else {
-            mBooleanProperties &= ~property;
+        mEventTime = 0;
+        while (!mRecords.isEmpty()) {
+            AccessibilityRecord record = mRecords.remove(0);
+            record.recycle();
         }
     }
 
@@ -662,38 +431,82 @@ public final class AccessibilityEvent implements Parcelable {
      */
     public void initFromParcel(Parcel parcel) {
         mEventType = parcel.readInt();
-        mBooleanProperties = parcel.readInt();
-        mCurrentItemIndex = parcel.readInt();
-        mItemCount = parcel.readInt();
-        mFromIndex = parcel.readInt();
-        mAddedCount = parcel.readInt();
-        mRemovedCount = parcel.readInt();
-        mEventTime = parcel.readLong();
-        mClassName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
         mPackageName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
-        mContentDescription = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
-        mBeforeText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
-        mParcelableData = parcel.readParcelable(null);
-        parcel.readList(mText, null);
+        mEventTime = parcel.readLong();
+        readAccessibilityRecordFromParcel(this, parcel);
+
+        // Read the records.
+        final int recordCount = parcel.readInt();
+        for (int i = 0; i < recordCount; i++) {
+            AccessibilityRecord record = AccessibilityRecord.obtain();
+            readAccessibilityRecordFromParcel(record, parcel);
+            mRecords.add(record);
+        }
     }
 
+    /**
+     * Reads an {@link AccessibilityRecord} from a parcel.
+     *
+     * @param record The record to initialize.
+     * @param parcel The parcel to read from.
+     */
+    private void readAccessibilityRecordFromParcel(AccessibilityRecord record,
+            Parcel parcel) {
+        record.mBooleanProperties = parcel.readInt();
+        record.mCurrentItemIndex = parcel.readInt();
+        record.mItemCount = parcel.readInt();
+        record.mFromIndex = parcel.readInt();
+        record.mAddedCount = parcel.readInt();
+        record.mRemovedCount = parcel.readInt();
+        record.mClassName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
+        record.mContentDescription = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
+        record.mBeforeText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
+        record.mParcelableData = parcel.readParcelable(null);
+        parcel.readList(record.mText, null);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
     public void writeToParcel(Parcel parcel, int flags) {
         parcel.writeInt(mEventType);
-        parcel.writeInt(mBooleanProperties);
-        parcel.writeInt(mCurrentItemIndex);
-        parcel.writeInt(mItemCount);
-        parcel.writeInt(mFromIndex);
-        parcel.writeInt(mAddedCount);
-        parcel.writeInt(mRemovedCount);
-        parcel.writeLong(mEventTime);
-        TextUtils.writeToParcel(mClassName, parcel, 0);
         TextUtils.writeToParcel(mPackageName, parcel, 0);
-        TextUtils.writeToParcel(mContentDescription, parcel, 0);
-        TextUtils.writeToParcel(mBeforeText, parcel, 0);
-        parcel.writeParcelable(mParcelableData, flags);
-        parcel.writeList(mText);
+        parcel.writeLong(mEventTime);
+        writeAccessibilityRecordToParcel(this, parcel, flags);
+
+        // Write the records.
+        final int recordCount = getRecordCount();
+        parcel.writeInt(recordCount);
+        for (int i = 0; i < recordCount; i++) {
+            AccessibilityRecord record = mRecords.get(i);
+            writeAccessibilityRecordToParcel(record, parcel, flags);
+        }
+    }
+
+    /**
+     * Writes an {@link AccessibilityRecord} to a parcel.
+     *
+     * @param record The record to write.
+     * @param parcel The parcel to which to write.
+     */
+    private void writeAccessibilityRecordToParcel(AccessibilityRecord record, Parcel parcel,
+            int flags) {
+        parcel.writeInt(record.mBooleanProperties);
+        parcel.writeInt(record.mCurrentItemIndex);
+        parcel.writeInt(record.mItemCount);
+        parcel.writeInt(record.mFromIndex);
+        parcel.writeInt(record.mAddedCount);
+        parcel.writeInt(record.mRemovedCount);
+        TextUtils.writeToParcel(record.mClassName, parcel, flags);
+        TextUtils.writeToParcel(record.mContentDescription, parcel, flags);
+        TextUtils.writeToParcel(record.mBeforeText, parcel, flags);
+        parcel.writeParcelable(record.mParcelableData, flags);
+        parcel.writeList(record.mText);
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public int describeContents() {
         return 0;
     }
@@ -701,24 +514,21 @@ public final class AccessibilityEvent implements Parcelable {
     @Override
     public String toString() {
         StringBuilder builder = new StringBuilder();
-        builder.append(super.toString());
         builder.append("; EventType: " + mEventType);
         builder.append("; EventTime: " + mEventTime);
-        builder.append("; ClassName: " + mClassName);
         builder.append("; PackageName: " + mPackageName);
-        builder.append("; Text: " + mText);
-        builder.append("; ContentDescription: " + mContentDescription);
-        builder.append("; ItemCount: " + mItemCount);
-        builder.append("; CurrentItemIndex: " + mCurrentItemIndex);
-        builder.append("; IsEnabled: " + isEnabled());
-        builder.append("; IsPassword: " + isPassword());
-        builder.append("; IsChecked: " + isChecked());
-        builder.append("; IsFullScreen: " + isFullScreen());
-        builder.append("; BeforeText: " + mBeforeText);
-        builder.append("; FromIndex: " + mFromIndex);
-        builder.append("; AddedCount: " + mAddedCount);
-        builder.append("; RemovedCount: " + mRemovedCount);
-        builder.append("; ParcelableData: " + mParcelableData);
+        builder.append(" \n{\n");
+        builder.append(super.toString());
+        builder.append("\n");
+        for (int i = 0; i < mRecords.size(); i++) {
+            AccessibilityRecord record = mRecords.get(i);
+            builder.append("  Record ");
+            builder.append(i);
+            builder.append(":");
+            builder.append(record.toString());
+            builder.append("\n");
+        }
+        builder.append("}\n");
         return builder.toString();
     }
 
diff --git a/core/java/android/view/accessibility/AccessibilityManager.java b/core/java/android/view/accessibility/AccessibilityManager.java
index 22cb0d4..dd77193 100644
--- a/core/java/android/view/accessibility/AccessibilityManager.java
+++ b/core/java/android/view/accessibility/AccessibilityManager.java
@@ -16,6 +16,8 @@
 
 package android.view.accessibility;
 
+import android.accessibilityservice.AccessibilityService;
+import android.accessibilityservice.AccessibilityServiceInfo;
 import android.content.Context;
 import android.content.pm.ServiceInfo;
 import android.os.Binder;
@@ -44,6 +46,8 @@ import java.util.List;
  * @see android.content.Context#getSystemService
  */
 public final class AccessibilityManager {
+    private static final boolean DEBUG = false;
+
     private static final String LOG_TAG = "AccessibilityManager";
 
     static final Object sInstanceSync = new Object();
@@ -164,7 +168,7 @@ public final class AccessibilityManager {
             long identityToken = Binder.clearCallingIdentity();
             doRecycle = mService.sendAccessibilityEvent(event);
             Binder.restoreCallingIdentity(identityToken);
-            if (false) {
+            if (DEBUG) {
                 Log.i(LOG_TAG, event + " sent");
             }
         } catch (RemoteException re) {
@@ -185,7 +189,7 @@ public final class AccessibilityManager {
         }
         try {
             mService.interrupt();
-            if (false) {
+            if (DEBUG) {
                 Log.i(LOG_TAG, "Requested interrupt from all services");
             }
         } catch (RemoteException re) {
@@ -202,7 +206,33 @@ public final class AccessibilityManager {
         List<ServiceInfo> services = null;
         try {
             services = mService.getAccessibilityServiceList();
-            if (false) {
+            if (DEBUG) {
+                Log.i(LOG_TAG, "Installed AccessibilityServices " + services);
+            }
+        } catch (RemoteException re) {
+            Log.e(LOG_TAG, "Error while obtaining the installed AccessibilityServices. ", re);
+        }
+        return Collections.unmodifiableList(services);
+    }
+
+    /**
+     * Returns the {@link ServiceInfo}s of the enabled accessibility services
+     * for a given feedback type.
+     *
+     * @param feedbackType The type of feedback.
+     * @return An unmodifiable list with {@link ServiceInfo}s.
+     *
+     * @see AccessibilityServiceInfo#FEEDBACK_AUDIBLE
+     * @see AccessibilityServiceInfo#FEEDBACK_HAPTIC
+     * @see AccessibilityServiceInfo#FEEDBACK_SPOKEN
+     * @see AccessibilityServiceInfo#FEEDBACK_VISUAL
+     * @see AccessibilityServiceInfo#FEEDBACK_GENERIC
+     */
+    public List<ServiceInfo> getEnabledAccessibilityServiceList(int feedbackType) {
+        List<ServiceInfo> services = null;
+        try {
+            services = mService.getEnabledAccessibilityServiceList(feedbackType);
+            if (DEBUG) {
                 Log.i(LOG_TAG, "Installed AccessibilityServices " + services);
             }
         } catch (RemoteException re) {
diff --git a/core/java/android/view/accessibility/AccessibilityRecord.java b/core/java/android/view/accessibility/AccessibilityRecord.java
new file mode 100644
index 0000000..e095f43
--- /dev/null
+++ b/core/java/android/view/accessibility/AccessibilityRecord.java
@@ -0,0 +1,415 @@
+/*
+ * Copyright (C) 2011 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.view.accessibility;
+
+import android.os.Parcelable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Represents a record in an accessibility event. This class encapsulates
+ * the information for a {@link android.view.View}. Note that not all properties
+ * are applicable to all view types. For detailed information please refer to
+ * {@link AccessibilityEvent}.
+ *
+ * @see AccessibilityEvent
+ */
+public class AccessibilityRecord {
+
+    private static final int INVALID_POSITION = -1;
+
+    private static final int PROPERTY_CHECKED = 0x00000001;
+    private static final int PROPERTY_ENABLED = 0x00000002;
+    private static final int PROPERTY_PASSWORD = 0x00000004;
+    private static final int PROPERTY_FULL_SCREEN = 0x00000080;
+
+    private static final int MAX_POOL_SIZE = 10;
+    private static final Object mPoolLock = new Object();
+    private static AccessibilityRecord sPool;
+    private static int sPoolSize;
+
+    private AccessibilityRecord mNext;
+    private boolean mIsInPool;
+
+    protected int mBooleanProperties;
+    protected int mCurrentItemIndex;
+    protected int mItemCount;
+    protected int mFromIndex;
+    protected int mAddedCount;
+    protected int mRemovedCount;
+
+    protected CharSequence mClassName;
+    protected CharSequence mContentDescription;
+    protected CharSequence mBeforeText;
+    protected Parcelable mParcelableData;
+
+    protected final List<CharSequence> mText = new ArrayList<CharSequence>();
+
+    /*
+     * Hide constructor.
+     */
+    protected AccessibilityRecord() {
+
+    }
+
+    /**
+     * Gets if the source is checked.
+     *
+     * @return True if the view is checked, false otherwise.
+     */
+    public boolean isChecked() {
+        return getBooleanProperty(PROPERTY_CHECKED);
+    }
+
+    /**
+     * Sets if the source is checked.
+     *
+     * @param isChecked True if the view is checked, false otherwise.
+     */
+    public void setChecked(boolean isChecked) {
+        setBooleanProperty(PROPERTY_CHECKED, isChecked);
+    }
+
+    /**
+     * Gets if the source is enabled.
+     *
+     * @return True if the view is enabled, false otherwise.
+     */
+    public boolean isEnabled() {
+        return getBooleanProperty(PROPERTY_ENABLED);
+    }
+
+    /**
+     * Sets if the source is enabled.
+     *
+     * @param isEnabled True if the view is enabled, false otherwise.
+     */
+    public void setEnabled(boolean isEnabled) {
+        setBooleanProperty(PROPERTY_ENABLED, isEnabled);
+    }
+
+    /**
+     * Gets if the source is a password field.
+     *
+     * @return True if the view is a password field, false otherwise.
+     */
+    public boolean isPassword() {
+        return getBooleanProperty(PROPERTY_PASSWORD);
+    }
+
+    /**
+     * Sets if the source is a password field.
+     *
+     * @param isPassword True if the view is a password field, false otherwise.
+     */
+    public void setPassword(boolean isPassword) {
+        setBooleanProperty(PROPERTY_PASSWORD, isPassword);
+    }
+
+    /**
+     * Sets if the source is taking the entire screen.
+     *
+     * @param isFullScreen True if the source is full screen, false otherwise.
+     */
+    public void setFullScreen(boolean isFullScreen) {
+        setBooleanProperty(PROPERTY_FULL_SCREEN, isFullScreen);
+    }
+
+    /**
+     * Gets if the source is taking the entire screen.
+     *
+     * @return True if the source is full screen, false otherwise.
+     */
+    public boolean isFullScreen() {
+        return getBooleanProperty(PROPERTY_FULL_SCREEN);
+    }
+
+    /**
+     * Gets the number of items that can be visited.
+     *
+     * @return The number of items.
+     */
+    public int getItemCount() {
+        return mItemCount;
+    }
+
+    /**
+     * Sets the number of items that can be visited.
+     *
+     * @param itemCount The number of items.
+     */
+    public void setItemCount(int itemCount) {
+        mItemCount = itemCount;
+    }
+
+    /**
+     * Gets the index of the source in the list of items the can be visited.
+     *
+     * @return The current item index.
+     */
+    public int getCurrentItemIndex() {
+        return mCurrentItemIndex;
+    }
+
+    /**
+     * Sets the index of the source in the list of items that can be visited.
+     *
+     * @param currentItemIndex The current item index.
+     */
+    public void setCurrentItemIndex(int currentItemIndex) {
+        mCurrentItemIndex = currentItemIndex;
+    }
+
+    /**
+     * Gets the index of the first character of the changed sequence.
+     *
+     * @return The index of the first character.
+     */
+    public int getFromIndex() {
+        return mFromIndex;
+    }
+
+    /**
+     * Sets the index of the first character of the changed sequence.
+     *
+     * @param fromIndex The index of the first character.
+     */
+    public void setFromIndex(int fromIndex) {
+        mFromIndex = fromIndex;
+    }
+
+    /**
+     * Gets the number of added characters.
+     *
+     * @return The number of added characters.
+     */
+    public int getAddedCount() {
+        return mAddedCount;
+    }
+
+    /**
+     * Sets the number of added characters.
+     *
+     * @param addedCount The number of added characters.
+     */
+    public void setAddedCount(int addedCount) {
+        mAddedCount = addedCount;
+    }
+
+    /**
+     * Gets the number of removed characters.
+     *
+     * @return The number of removed characters.
+     */
+    public int getRemovedCount() {
+        return mRemovedCount;
+    }
+
+    /**
+     * Sets the number of removed characters.
+     *
+     * @param removedCount The number of removed characters.
+     */
+    public void setRemovedCount(int removedCount) {
+        mRemovedCount = removedCount;
+    }
+
+    /**
+     * Gets the class name of the source.
+     *
+     * @return The class name.
+     */
+    public CharSequence getClassName() {
+        return mClassName;
+    }
+
+    /**
+     * Sets the class name of the source.
+     *
+     * @param className The lass name.
+     */
+    public void setClassName(CharSequence className) {
+        mClassName = className;
+    }
+
+    /**
+     * Gets the text of the event. The index in the list represents the priority
+     * of the text. Specifically, the lower the index the higher the priority.
+     *
+     * @return The text.
+     */
+    public List<CharSequence> getText() {
+        return mText;
+    }
+
+    /**
+     * Sets the text before a change.
+     *
+     * @return The text before the change.
+     */
+    public CharSequence getBeforeText() {
+        return mBeforeText;
+    }
+
+    /**
+     * Sets the text before a change.
+     *
+     * @param beforeText The text before the change.
+     */
+    public void setBeforeText(CharSequence beforeText) {
+        mBeforeText = beforeText;
+    }
+
+    /**
+     * Gets the description of the source.
+     *
+     * @return The description.
+     */
+    public CharSequence getContentDescription() {
+        return mContentDescription;
+    }
+
+    /**
+     * Sets the description of the source.
+     *
+     * @param contentDescription The description.
+     */
+    public void setContentDescription(CharSequence contentDescription) {
+        mContentDescription = contentDescription;
+    }
+
+    /**
+     * Gets the {@link Parcelable} data.
+     *
+     * @return The parcelable data.
+     */
+    public Parcelable getParcelableData() {
+        return mParcelableData;
+    }
+
+    /**
+     * Sets the {@link Parcelable} data of the event.
+     *
+     * @param parcelableData The parcelable data.
+     */
+    public void setParcelableData(Parcelable parcelableData) {
+        mParcelableData = parcelableData;
+    }
+
+    /**
+     * Gets the value of a boolean property.
+     *
+     * @param property The property.
+     * @return The value.
+     */
+    public boolean getBooleanProperty(int property) {
+        return (mBooleanProperties & property) == property;
+    }
+
+    /**
+     * Sets a boolean property.
+     *
+     * @param property The property.
+     * @param value The value.
+     */
+    private void setBooleanProperty(int property, boolean value) {
+        if (value) {
+            mBooleanProperties |= property;
+        } else {
+            mBooleanProperties &= ~property;
+        }
+    }
+
+    /**
+     * Returns a cached instance if such is available or a new one is
+     * instantiated.
+     *
+     * @return An instance.
+     */
+    protected static AccessibilityRecord obtain() {
+        synchronized (mPoolLock) {
+            if (sPool != null) {
+                AccessibilityRecord record = sPool;
+                sPool = sPool.mNext;
+                sPoolSize--;
+                record.mNext = null;
+                record.mIsInPool = false;
+                return record;
+            }
+            return new AccessibilityRecord();
+        }
+    }
+
+    /**
+     * Return an instance back to be reused.
+     * <p>
+     * <b>Note: You must not touch the object after calling this function.</b>
+     */
+    public void recycle() {
+        if (mIsInPool) {
+            return;
+        }
+        clear();
+        synchronized (mPoolLock) {
+            if (sPoolSize <= MAX_POOL_SIZE) {
+                mNext = sPool;
+                sPool = this;
+                mIsInPool = true;
+                sPoolSize++;
+            }
+        }
+    }
+
+    /**
+     * Clears the state of this instance.
+     */
+    protected void clear() {
+        mBooleanProperties = 0;
+        mCurrentItemIndex = INVALID_POSITION;
+        mItemCount = 0;
+        mFromIndex = 0;
+        mAddedCount = 0;
+        mRemovedCount = 0;
+        mClassName = null;
+        mContentDescription = null;
+        mBeforeText = null;
+        mParcelableData = null;
+        mText.clear();
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append(" [ ClassName: " + mClassName);
+        builder.append("; Text: " + mText);
+        builder.append("; ContentDescription: " + mContentDescription);
+        builder.append("; ItemCount: " + mItemCount);
+        builder.append("; CurrentItemIndex: " + mCurrentItemIndex);
+        builder.append("; IsEnabled: " + getBooleanProperty(PROPERTY_ENABLED));
+        builder.append("; IsPassword: " + getBooleanProperty(PROPERTY_PASSWORD));
+        builder.append("; IsChecked: " + getBooleanProperty(PROPERTY_CHECKED));
+        builder.append("; IsFullScreen: " + getBooleanProperty(PROPERTY_FULL_SCREEN));
+        builder.append("; BeforeText: " + mBeforeText);
+        builder.append("; FromIndex: " + mFromIndex);
+        builder.append("; AddedCount: " + mAddedCount);
+        builder.append("; RemovedCount: " + mRemovedCount);
+        builder.append("; ParcelableData: " + mParcelableData);
+        builder.append(" ]");
+        return builder.toString();
+    }
+}
diff --git a/core/java/android/view/accessibility/IAccessibilityManager.aidl b/core/java/android/view/accessibility/IAccessibilityManager.aidl
index 7633569..aaaae32 100644
--- a/core/java/android/view/accessibility/IAccessibilityManager.aidl
+++ b/core/java/android/view/accessibility/IAccessibilityManager.aidl
@@ -35,5 +35,7 @@ interface IAccessibilityManager {
 
     List<ServiceInfo> getAccessibilityServiceList();
 
+    List<ServiceInfo> getEnabledAccessibilityServiceList(int feedbackType);
+
     void interrupt();
 }