diff --git a/core/java/android/os/RemoteCallbackList.java b/core/java/android/os/RemoteCallbackList.java
index b74af16..d02a320 100644
--- a/core/java/android/os/RemoteCallbackList.java
+++ b/core/java/android/os/RemoteCallbackList.java
@@ -304,4 +304,25 @@
         
         mBroadcastCount = -1;
     }
+
+    /**
+     * Returns the number of registered callbacks. Note that the number of registered
+     * callbacks may differ from the value returned by {@link #beginBroadcast()} since
+     * the former returns the number of callbacks registered at the time of the call
+     * and the second the number of callback to which the broadcast will be delivered.
+     * <p>
+     * This function is useful to decide whether to schedule a broadcast if this
+     * requires doing some work which otherwise would not be performed.
+     * </p>
+     *
+     * @return The size.
+     */
+    public int getRegisteredCallbackCount() {
+        synchronized (mCallbacks) {
+            if (mKilled) {
+                return 0;
+            }
+            return mCallbacks.size();
+        }
+    }
 }
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 6b4bc76..d7ae441 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -3400,6 +3400,46 @@
             "accessibility_web_content_key_bindings";
 
         /**
+         * Setting that specifies whether the display magnification is enabled.
+         * Display magnifications allows the user to zoom in the display content
+         * and is targeted to low vision users. The current magnification scale
+         * is controlled by {@link #ACCESSIBILITY_DISPLAY_MAGNIFICATION_SCALE}.
+         *
+         * @hide
+         */
+        public static final String ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED =
+                "accessibility_display_magnification_enabled";
+
+        /**
+         * Setting that specifies what the display magnification scale is.
+         * Display magnifications allows the user to zoom in the display
+         * content and is targeted to low vision users. Whether a display
+         * magnification is performed is controlled by
+         * {@link #ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED}
+         *
+         * @hide
+         */
+        public static final String ACCESSIBILITY_DISPLAY_MAGNIFICATION_SCALE =
+                "accessibility_display_magnification_scale";
+
+        /**
+         * Setting that specifies whether the display magnification should be
+         * automatically updated. If this fearture is enabled the system will
+         * exit magnification mode or pan the viewport when a context change
+         * occurs. For example, on staring a new activity or rotating the screen,
+         * the system may zoom out so the user can see the new context he is in.
+         * Another example is on showing a window that is not visible in the
+         * magnified viewport the system may pan the viewport to make the window
+         * the has popped up so the user knows that the context has changed.
+         * Whether a screen magnification is performed is controlled by
+         * {@link #ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED}
+         *
+         * @hide
+         */
+        public static final String ACCESSIBILITY_DISPLAY_MAGNIFICATION_AUTO_UPDATE =
+                "accessibility_display_magnification_auto_update";
+
+        /**
          * The timout for considering a press to be a long press in milliseconds.
          * @hide
          */
@@ -4806,6 +4846,9 @@
             PARENTAL_CONTROL_ENABLED,
             PARENTAL_CONTROL_REDIRECT_URL,
             USB_MASS_STORAGE_ENABLED,
+            ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED,
+            ACCESSIBILITY_DISPLAY_MAGNIFICATION_SCALE,
+            ACCESSIBILITY_DISPLAY_MAGNIFICATION_AUTO_UPDATE,
             ACCESSIBILITY_SCRIPT_INJECTION,
             BACKUP_AUTO_RESTORE,
             ENABLED_ACCESSIBILITY_SERVICES,
diff --git a/core/java/android/view/IDisplayContentChangeListener.aidl b/core/java/android/view/IDisplayContentChangeListener.aidl
new file mode 100644
index 0000000..8f23ff6
--- /dev/null
+++ b/core/java/android/view/IDisplayContentChangeListener.aidl
@@ -0,0 +1,32 @@
+/*
+** Copyright 2012, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License")
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.view;
+
+import android.os.IBinder;
+import android.view.WindowInfo;
+import android.graphics.Rect;
+
+/**
+ * Interface for observing content changes on a display.
+ *
+ * {@hide}
+ */
+oneway interface IDisplayContentChangeListener {
+    void onWindowTransition(int displayId, int transition, in WindowInfo info);
+    void onRectangleOnScreenRequested(int displayId, in Rect rectangle, boolean immediate);
+    void onRotationChanged(int rotation);
+}
diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index 7f2de50..b9f3942 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -26,6 +26,7 @@
 import android.graphics.Rect;
 import android.os.IRemoteCallback;
 import android.view.IApplicationToken;
+import android.view.IDisplayContentChangeListener;
 import android.view.IOnKeyguardExitResult;
 import android.view.IRotationWatcher;
 import android.view.IWindowSession;
@@ -34,7 +35,8 @@
 import android.view.MotionEvent;
 import android.view.InputChannel;
 import android.view.InputDevice;
-import  android.view.IInputFilter;
+import android.view.IInputFilter;
+import android.view.WindowInfo;
 
 /**
  * System private interface to the window manager.
@@ -214,11 +216,6 @@
     IBinder getFocusedWindowToken();
 
     /**
-     * Gets the frame on the screen of the window given its token.
-     */
-    boolean getWindowFrame(IBinder token, out Rect outBounds);
-
-    /**
      * Gets the compatibility scale of e window given its token.
      */
     float getWindowCompatibilityScale(IBinder windowToken);
@@ -227,4 +224,29 @@
      * Sets an input filter for manipulating the input event stream.
      */
     void setInputFilter(in IInputFilter filter);
+
+    /**
+     * Sets the scale and offset for implementing accessibility magnification.
+     */
+    void magnifyDisplay(int dipslayId, float scale, float offsetX, float offsetY);
+
+    /**
+     * Adds a listener for display content changes.
+     */
+    void addDisplayContentChangeListener(int displayId, IDisplayContentChangeListener listener);
+
+    /**
+     * Removes a listener for display content changes.
+     */
+    void removeDisplayContentChangeListener(int displayId, IDisplayContentChangeListener listener);
+
+    /**
+     * Gets the info for a window given its token.
+     */
+    WindowInfo getWindowInfo(IBinder token);
+
+    /**
+     * Gets the infos for all visible windows.
+     */
+    void getVisibleWindowsForDisplay(int displayId, out List<WindowInfo> outInfos);
 }
diff --git a/core/java/android/view/IWindowSession.aidl b/core/java/android/view/IWindowSession.aidl
index c5d9255..ff9dcce 100644
--- a/core/java/android/view/IWindowSession.aidl
+++ b/core/java/android/view/IWindowSession.aidl
@@ -180,4 +180,9 @@
 
     void setUniverseTransform(IBinder window, float alpha, float offx, float offy,
             float dsdx, float dtdx, float dsdy, float dtdy);
+
+    /**
+     * Notifies that a rectangle on the screen has been requested.
+     */
+    void onRectangleOnScreenRequested(IBinder token, in Rect rectangle, boolean immediate);
 }
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index fc5629e..e5d72ab 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -6259,6 +6259,11 @@
             if (viewRootImpl != null) {
                 viewRootImpl.setAccessibilityFocus(this, null);
             }
+            if (mAttachInfo != null) {
+                Rect rectangle = mAttachInfo.mTmpInvalRect;
+                getDrawingRect(rectangle);
+                requestRectangleOnScreen(rectangle);
+            }
             invalidate();
             sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
             notifyAccessibilityStateChanged();
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index ffd495e..a4c0235 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -4649,9 +4649,19 @@
         // ViewAncestor never intercepts touch event, so this can be a no-op
     }
 
-    public boolean requestChildRectangleOnScreen(View child, Rect rectangle,
-            boolean immediate) {
-        return scrollToRectOrFocus(rectangle, immediate);
+    public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
+        final boolean scrolled = scrollToRectOrFocus(rectangle, immediate);
+        if (rectangle != null) {
+            mTempRect.set(rectangle);
+            mTempRect.offset(0, -mCurScrollY);
+            mTempRect.offset(mAttachInfo.mWindowLeft, mAttachInfo.mWindowTop);
+            try {
+                mWindowSession.onRectangleOnScreenRequested(mWindow, mTempRect, immediate);
+            } catch (RemoteException re) {
+                /* ignore */
+            }
+        }
+        return scrolled;
     }
 
     public void childHasTransientStateChanged(View child, boolean hasTransientState) {
diff --git a/core/java/android/view/WindowInfo.aidl b/core/java/android/view/WindowInfo.aidl
new file mode 100644
index 0000000..23e927a
--- /dev/null
+++ b/core/java/android/view/WindowInfo.aidl
@@ -0,0 +1,20 @@
+/*
+**
+** Copyright 2012, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License")
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.view;
+
+parcelable WindowInfo;
diff --git a/core/java/android/view/WindowInfo.java b/core/java/android/view/WindowInfo.java
new file mode 100644
index 0000000..00875ae
--- /dev/null
+++ b/core/java/android/view/WindowInfo.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.view;
+
+import android.graphics.Rect;
+import android.os.IBinder;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Information the state of a window.
+ *
+ * @hide
+ */
+public class WindowInfo implements Parcelable {
+
+    private static final int MAX_POOL_SIZE = 20;
+
+    private static int UNDEFINED = -1;
+
+    private static Object sPoolLock = new Object();
+    private static WindowInfo sPool;
+    private static int sPoolSize;
+
+    private WindowInfo mNext;
+    private boolean mInPool;
+
+    public IBinder token;
+
+    public final Rect frame = new Rect();
+
+    public final Rect touchableRegion = new Rect();
+
+    public int type;
+
+    public float compatibilityScale;
+
+    public boolean visible;
+
+    public int displayId;
+
+    private WindowInfo() {
+        /* do nothing - reduce visibility */
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel parcel, int flags) {
+        parcel.writeStrongBinder(token);
+        parcel.writeParcelable(frame, 0);
+        parcel.writeParcelable(touchableRegion, 0);
+        parcel.writeInt(type);
+        parcel.writeFloat(compatibilityScale);
+        parcel.writeInt(visible ? 1 : 0);
+        parcel.writeInt(displayId);
+        recycle();
+    }
+
+    private void initFromParcel(Parcel parcel) {
+        token = parcel.readStrongBinder();
+        frame.set((Rect) parcel.readParcelable(null));
+        touchableRegion.set((Rect) parcel.readParcelable(null));
+        type = parcel.readInt();
+        compatibilityScale = parcel.readFloat();
+        visible = (parcel.readInt() == 1);
+        displayId = parcel.readInt();
+    }
+
+    public static WindowInfo obtain(WindowInfo other) {
+        WindowInfo info = obtain();
+        info.token = other.token;
+        info.frame.set(other.frame);
+        info.touchableRegion.set(other.touchableRegion);
+        info.type = other.type;
+        info.displayId = other.displayId;
+        info.compatibilityScale = other.compatibilityScale;
+        info.visible = other.visible;
+        return info;
+    }
+
+    public static WindowInfo obtain() {
+        synchronized (sPoolLock) {
+            if (sPoolSize > 0) {
+                WindowInfo info = sPool;
+                sPool = info.mNext;
+                info.mNext = null;
+                info.mInPool = false;
+                sPoolSize--;
+                return info;
+            } else {
+                return new WindowInfo();
+            }
+        }
+    }
+
+    public void recycle() {
+        if (mInPool) {
+            throw new IllegalStateException("Already recycled.");
+        }
+        clear();
+        synchronized (sPoolLock) {
+            if (sPoolSize < MAX_POOL_SIZE) {
+                mNext = sPool;
+                sPool = this;
+                mInPool = true;
+                sPoolSize++;
+            }
+        }
+    }
+
+    private void clear() {
+        token = null;
+        frame.setEmpty();
+        touchableRegion.setEmpty();
+        type = UNDEFINED;
+        displayId = UNDEFINED;
+        visible = false;
+    }
+
+    /**
+     * @see Parcelable.Creator
+     */
+    public static final Parcelable.Creator<WindowInfo> CREATOR =
+            new Parcelable.Creator<WindowInfo>() {
+        public WindowInfo createFromParcel(Parcel parcel) {
+            WindowInfo info = WindowInfo.obtain();
+            info.initFromParcel(parcel);
+            return info;
+        }
+
+        public WindowInfo[] newArray(int size) {
+            return new WindowInfo[size];
+        }
+    };
+}
diff --git a/core/java/android/view/WindowManager.java b/core/java/android/view/WindowManager.java
index 7412f39..fa2d4e8 100644
--- a/core/java/android/view/WindowManager.java
+++ b/core/java/android/view/WindowManager.java
@@ -205,7 +205,8 @@
             @ViewDebug.IntToString(from = TYPE_HIDDEN_NAV_CONSUMER, to = "TYPE_HIDDEN_NAV_CONSUMER"),
             @ViewDebug.IntToString(from = TYPE_DREAM, to = "TYPE_DREAM"),
             @ViewDebug.IntToString(from = TYPE_NAVIGATION_BAR_PANEL, to = "TYPE_NAVIGATION_BAR_PANEL"),
-            @ViewDebug.IntToString(from = TYPE_DISPLAY_OVERLAY, to = "TYPE_DISPLAY_OVERLAY")
+            @ViewDebug.IntToString(from = TYPE_DISPLAY_OVERLAY, to = "TYPE_DISPLAY_OVERLAY"),
+            @ViewDebug.IntToString(from = TYPE_MAGNIFICATION_OVERLAY, to = "TYPE_MAGNIFICATION_OVERLAY")
         })
         public int type;
     
@@ -467,6 +468,13 @@
         public static final int TYPE_DISPLAY_OVERLAY = FIRST_SYSTEM_WINDOW+26;
 
         /**
+         * Window type: Magnification overlay window. Used to highlight the magnified
+         * portion of a display when accessibility magnification is enabled.
+         * @hide
+         */
+        public static final int TYPE_MAGNIFICATION_OVERLAY = FIRST_SYSTEM_WINDOW+27;
+
+        /**
          * End of types of system windows.
          */
         public static final int LAST_SYSTEM_WINDOW      = 2999;
diff --git a/core/java/android/view/WindowManagerPolicy.java b/core/java/android/view/WindowManagerPolicy.java
index b059afc..75554da 100644
--- a/core/java/android/view/WindowManagerPolicy.java
+++ b/core/java/android/view/WindowManagerPolicy.java
@@ -1106,6 +1106,14 @@
     public void setLastInputMethodWindowLw(WindowState ime, WindowState target);
 
     /**
+     * Returns whether magnification can be applied to the given window type.
+     *
+     * @param attrs The window's LayoutParams.
+     * @return Whether magnification can be applied.
+     */
+    public boolean canMagnifyWindow(WindowManager.LayoutParams attrs);
+
+    /**
      * Print the WindowManagerPolicy's state into the given stream.
      *
      * @param prefix Text to print at the front of each line.
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index f5f1109..23a412f 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1285,6 +1285,12 @@
         android:description="@string/permdesc_retrieve_window_info"
         android:protectionLevel="signature" />
 
+    <!-- @hide Allows an application to magnify the content of a display. -->
+    <permission android:name="android.permission.MAGNIFY_DISPLAY"
+        android:label="@string/permlab_magnify_display"
+        android:description="@string/permdesc_magnify_display"
+        android:protectionLevel="signature" />
+
     <!-- Allows an application to watch and control how activities are
          started globally in the system.  Only for is in debugging
          (usually the monkey command). -->
diff --git a/core/res/res/drawable-nodpi/magnified_region_frame.9.png b/core/res/res/drawable-nodpi/magnified_region_frame.9.png
new file mode 100644
index 0000000..4cadefb
--- /dev/null
+++ b/core/res/res/drawable-nodpi/magnified_region_frame.9.png
Binary files differ
diff --git a/core/res/res/values/public.xml b/core/res/res/values/public.xml
index 2e639a1..4db8cd1 100644
--- a/core/res/res/values/public.xml
+++ b/core/res/res/values/public.xml
@@ -1261,6 +1261,7 @@
   <java-symbol type="drawable" name="jog_tab_right_sound_on" />
   <java-symbol type="drawable" name="jog_tab_target_green" />
   <java-symbol type="drawable" name="jog_tab_target_yellow" />
+  <java-symbol type="drawable" name="magnified_region_frame" />
   <java-symbol type="drawable" name="menu_background" />
   <java-symbol type="drawable" name="stat_sys_secure" />
   <java-symbol type="drawable" name="kg_widget_overscroll_layer_left" />
diff --git a/core/res/res/values/strings.xml b/core/res/res/values/strings.xml
index d2951bf..9f254b6 100755
--- a/core/res/res/values/strings.xml
+++ b/core/res/res/values/strings.xml
@@ -669,8 +669,15 @@
     <string name="permlab_filter_events">filter events</string>
     <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permdesc_filter_events">Allows an application to register an input filter
-        which filters the stream of all user events before they are dispatched. Malicious app
-        may control the system UI whtout user intervention.</string>
+            which filters the stream of all user events before they are dispatched. Malicious app
+            may control the system UI whtout user intervention.</string>
+
+    <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permlab_magnify_display">magnify display</string>
+    <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permdesc_magnify_display">Allows an application to magnify the content of a
+        display. Malicious apps may transform the display content in a way that renders the
+        device unusable.</string>
 
     <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permlab_shutdown">partial shutdown</string>