Fire "dreaming started" and "dreaming stopped" broadcasts. (f4f6b4c8) · Commits · e / os / android_frameworks_base

api/current.txt

+2 −0

Original line number	Diff line number	Diff line
		@@ -20289,6 +20289,8 @@ package android.service.dreams {
		method public void setContentView(android.view.View);
		method public void setContentView(android.view.View, android.view.ViewGroup.LayoutParams);
		method public void setInteractive(boolean);
		field public static final java.lang.String ACTION_DREAMING_STARTED = "android.intent.action.DREAMING_STARTED";
		field public static final java.lang.String ACTION_DREAMING_STOPPED = "android.intent.action.DREAMING_STOPPED";
		field public static final java.lang.String METADATA_NAME_CONFIG_ACTIVITY = "android.service.dreams.config_activity";
		field public static final java.lang.String SERVICE_INTERFACE = "android.service.dreams.Dream";
		}

core/java/android/service/dreams/Dream.java

+160 −90

Original line number	Diff line number	Diff line
		@@ -22,7 +22,6 @@ import android.content.Intent;
		import android.graphics.drawable.ColorDrawable;
		import android.os.Handler;
		import android.os.IBinder;
		import android.os.RemoteException;
		import android.os.ServiceManager;
		import android.util.Slog;
		import android.view.ActionMode;
		@@ -40,11 +39,15 @@ import android.view.accessibility.AccessibilityEvent;
		import com.android.internal.policy.PolicyManager;

		/**
		* Extend this class to implement a custom screensaver.
		* Extend this class to implement a custom Dream.
		*
		* <p>Dreams are interactive screensavers launched when a charging device is idle, or docked in a
		* desk dock. Dreams provide another modality for apps to express themselves, tailored for
		* an exhibition/lean-back experience.</p>
		*/
		public class Dream extends Service implements Window.Callback {
		private final static boolean DEBUG = true;
		private final static String TAG = "Dream";
		private final String TAG = Dream.class.getSimpleName() + "[" + getClass().getSimpleName() + "]";

		/**
		* The {@link Intent} that must be declared as handled by the service.
		@@ -60,28 +63,43 @@ public class Dream extends Service implements Window.Callback {
		public static final String METADATA_NAME_CONFIG_ACTIVITY =
		"android.service.dreams.config_activity";

		private Window mWindow;
		/**
		* Broadcast Action: Sent after the system starts dreaming.
		*
		* <p class="note">This is a protected intent that can only be sent by the system.
		* It is only sent to registered receivers.</p>
		*/
		@SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
		public static final String ACTION_DREAMING_STARTED = "android.intent.action.DREAMING_STARTED";

		/**
		* Broadcast Action: Sent after the system stops dreaming.
		*
		* <p class="note">This is a protected intent that can only be sent by the system.
		* It is only sent to registered receivers.</p>
		*/
		@SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
		public static final String ACTION_DREAMING_STOPPED = "android.intent.action.DREAMING_STOPPED";

		private final Handler mHandler = new Handler();
		private IBinder mWindowToken;
		private Window mWindow;
		private WindowManager mWindowManager;
		private IDreamManager mSandman;

		private boolean mInteractive;

		final Handler mHandler = new Handler();

		boolean mFinished = false;
		private boolean mFinished;

		// begin Window.Callback methods
		@Override
		public boolean dispatchKeyEvent(KeyEvent event) {
		// TODO: create more flexible version of mInteractive that allows use of KEYCODE_BACK
		if (!mInteractive) {
		if (DEBUG) Slog.v(TAG, "finishing on keyEvent");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on keyEvent");
		safelyFinish();
		return true;
		} else if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
		if (DEBUG) Slog.v(TAG, "finishing on back key");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on back key");
		safelyFinish();
		return true;
		}
		return mWindow.superDispatchKeyEvent(event);
		@@ -90,8 +108,8 @@ public class Dream extends Service implements Window.Callback {
		@Override
		public boolean dispatchKeyShortcutEvent(KeyEvent event) {
		if (!mInteractive) {
		if (DEBUG) Slog.v(TAG, "finishing on keyShortcutEvent");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on keyShortcutEvent");
		safelyFinish();
		return true;
		}
		return mWindow.superDispatchKeyShortcutEvent(event);
		@@ -102,8 +120,8 @@ public class Dream extends Service implements Window.Callback {
		// TODO: create more flexible version of mInteractive that allows clicks
		// but finish()es on any other kind of activity
		if (!mInteractive) {
		if (DEBUG) Slog.v(TAG, "finishing on touchEvent");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on touchEvent");
		safelyFinish();
		return true;
		}
		return mWindow.superDispatchTouchEvent(event);
		@@ -112,8 +130,8 @@ public class Dream extends Service implements Window.Callback {
		@Override
		public boolean dispatchTrackballEvent(MotionEvent event) {
		if (!mInteractive) {
		if (DEBUG) Slog.v(TAG, "finishing on trackballEvent");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on trackballEvent");
		safelyFinish();
		return true;
		}
		return mWindow.superDispatchTrackballEvent(event);
		@@ -122,8 +140,8 @@ public class Dream extends Service implements Window.Callback {
		@Override
		public boolean dispatchGenericMotionEvent(MotionEvent event) {
		if (!mInteractive) {
		if (DEBUG) Slog.v(TAG, "finishing on genericMotionEvent");
		finish();
		if (DEBUG) Slog.v(TAG, "Finishing on genericMotionEvent");
		safelyFinish();
		return true;
		}
		return mWindow.superDispatchGenericMotionEvent(event);
		@@ -214,28 +232,7 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* Called when this Dream is constructed. Place your initialization here.
		*
		* Subclasses must call through to the superclass implementation.
		*/
		@Override
		public void onCreate() {
		super.onCreate();

		if (DEBUG) Slog.v(TAG, "Dream created on thread " + Thread.currentThread().getId());

		mSandman = IDreamManager.Stub.asInterface(ServiceManager.getService("dreams"));
		}

		/**
		* Called when this Dream is started.
		*/
		public void onStart() {
		// hook for subclasses
		}

		/**
		* Inflate a layout resource and set it to be the content view for this Dream.
		* Inflates a layout resource and set it to be the content view for this Dream.
		* Behaves similarly to {@link android.app.Activity#setContentView(int)}.
		*
		* @param layoutResID Resource ID to be inflated.
		@@ -248,7 +245,7 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* Set a view to be the content view for this Dream.
		* Sets a view to be the content view for this Dream.
		* Behaves similarly to {@link android.app.Activity#setContentView(android.view.View)},
		* including using {@link ViewGroup.LayoutParams#MATCH_PARENT} as the layout height and width of the view.
		*
		@@ -262,7 +259,7 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* Set a view to be the content view for this Dream.
		* Sets a view to be the content view for this Dream.
		* Behaves similarly to
		* {@link android.app.Activity#setContentView(android.view.View, android.view.ViewGroup.LayoutParams)}.
		*
		@@ -277,7 +274,7 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* Add a view to the Dream's window, leaving other content views in place.
		* Adds a view to the Dream's window, leaving other content views in place.
		*
		* @param view The desired content to display.
		* @param params Layout parameters for the view.
		@@ -287,14 +284,20 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* @param mInteractive the mInteractive to set
		* Marks this dream as interactive to receive input events.
		*
		* <p>Non-interactive dreams (default) will dismiss on the first input event.</p>
		*
		* <p>Interactive dreams should call {@link #finish()} to dismiss themselves.</p>
		*
		* @param interactive True if this dream will handle input events.
		*/
		public void setInteractive(boolean mInteractive) {
		this.mInteractive = mInteractive;
		public void setInteractive(boolean interactive) {
		mInteractive = interactive;
		}

		/**
		* @return the mInteractive
		* Returns whether or not this dream is interactive.
		*/
		public boolean isInteractive() {
		return mInteractive;
		@@ -321,12 +324,27 @@ public class Dream extends Service implements Window.Callback {
		}

		/**
		* Called when this Dream is being removed from the screen and stopped.
		* Called when this Dream is constructed. Place your initialization here.
		*
		* Subclasses must call through to the superclass implementation.
		*/
		@Override
		public void onDestroy() {
		super.onDestroy();
		mWindowManager.removeView(mWindow.getDecorView());
		public void onCreate() {
		if (DEBUG) Slog.v(TAG, "onCreate() on thread " + Thread.currentThread().getId());
		super.onCreate();
		loadSandman();
		}

		/**
		* Called when this Dream is started.
		*/
		public void onStart() {
		// hook for subclasses
		Slog.v(TAG, "called Dream.onStart()");
		}

		private void loadSandman() {
		mSandman = IDreamManager.Stub.asInterface(ServiceManager.getService("dreams"));
		}

		/**
		@@ -335,16 +353,21 @@ public class Dream extends Service implements Window.Callback {
		* @param windowToken Binder to attach to the window to allow access to the correct window type.
		* @hide
		*/
		final /package/ void attach(IBinder windowToken) {
		if (DEBUG) Slog.v(TAG, "Dream attached on thread " + Thread.currentThread().getId());
		private final void attach(IBinder windowToken) {
		if (DEBUG) Slog.v(TAG, "Attached on thread " + Thread.currentThread().getId());

		if (mSandman == null) {
		Slog.w(TAG, "No dream manager found, super.onCreate may not have been called");
		loadSandman();
		}
		mWindowToken = windowToken;
		mWindow = PolicyManager.makeNewWindow(this);
		mWindow.setCallback(this);
		mWindow.requestFeature(Window.FEATURE_NO_TITLE);
		mWindow.setBackgroundDrawable(new ColorDrawable(0xFF000000));

		if (DEBUG) Slog.v(TAG, "attaching window token: " + windowToken
		+ " to window of type " + WindowManager.LayoutParams.TYPE_DREAM);
		if (DEBUG) Slog.v(TAG, String.format("Attaching window token: %s to window of type %s",
		windowToken, WindowManager.LayoutParams.TYPE_DREAM));

		WindowManager.LayoutParams lp = mWindow.getAttributes();
		lp.type = WindowManager.LayoutParams.TYPE_DREAM;
		@@ -356,57 +379,104 @@ public class Dream extends Service implements Window.Callback {
		);
		mWindow.setAttributes(lp);

		//WindowManagerImpl.getDefault().addView(mWindow.getDecorView(), lp);

		if (DEBUG) Slog.v(TAG, "created and attached window: " + mWindow);
		if (DEBUG) Slog.v(TAG, "Created and attached window: " + mWindow);

		mWindow.setWindowManager(null, windowToken, "dream", true);
		mWindowManager = mWindow.getWindowManager();

		// now make it visible
		// now make it visible (on the ui thread)
		mHandler.post(new Runnable(){
		@Override
		public void run() {
		if (DEBUG) Slog.v(TAG, "Dream window added on thread " + Thread.currentThread().getId());
		if (DEBUG) Slog.v(TAG, "Window added on thread " + Thread.currentThread().getId());

		try {
		getWindowManager().addView(mWindow.getDecorView(), mWindow.getAttributes());
		} catch (Throwable t) {
		Slog.w("Crashed adding window view", t);
		safelyFinish();
		return;
		}

		// start it up
		try {
		onStart();
		} catch (Throwable t) {
		Slog.w("Crashed in onStart()", t);
		safelyFinish();
		}
		}});
		}

		private void safelyFinish() {
		if (DEBUG) Slog.v(TAG, "safelyFinish()");
		try {
		finish();
		} catch (Throwable t) {
		Slog.w(TAG, "Crashed in safelyFinish()", t);
		finishInternal();
		return;
		}

		if (!mFinished) {
		Slog.w(TAG, "Bad dream, did not call super.finish()");
		finishInternal();
		}
		}

		/**
		* Stop the dream and wake up.
		* Stops the dream, detaches from the window, and wakes up.
		*
		* After this method is called, the service will be stopped.
		* Subclasses must call through to the superclass implementation.
		*
		* <p>After this method is called, the service will be stopped.</p>
		*/
		public void finish() {
		if (DEBUG) Slog.v(TAG, "finish()");
		finishInternal();
		}

		private void finishInternal() {
		if (DEBUG) Slog.v(TAG, "finishInternal() mFinished = " + mFinished);
		if (mFinished) return;
		try {
		mSandman.awaken(); // assuming we were started by the DreamManager
		stopSelf(); // if launched via any other means
		mFinished = true;
		} catch (RemoteException ex) {
		// sigh
		}

		if (mSandman != null) {
		mSandman.awakenSelf(mWindowToken);
		} else {
		Slog.w(TAG, "No dream manager found");
		}
		stopSelf(); // if launched via any other means

		class IDreamServiceWrapper extends IDreamService.Stub {
		public IDreamServiceWrapper() {
		} catch (Throwable t) {
		Slog.w(TAG, "Crashed in finishInternal()", t);
		}
		}

		public void attach(IBinder windowToken) {
		Dream.this.attach(windowToken);
		@Override
		public void onDestroy() {
		if (DEBUG) Slog.v(TAG, "onDestroy()");
		super.onDestroy();

		if (DEBUG) Slog.v(TAG, "Removing window");
		try {
		mWindowManager.removeView(mWindow.getDecorView());
		} catch (Throwable t) {
		Slog.w(TAG, "Crashed removing window view", t);
		}
		}

		/**
		* Implement to return the implementation of the internal accessibility
		* service interface. Subclasses should not override.
		*/
		@Override
		public final IBinder onBind(Intent intent) {
		return new IDreamServiceWrapper();
		if (DEBUG) Slog.v(TAG, "onBind() intent = " + intent);
		return new DreamServiceWrapper();
		}

		private class DreamServiceWrapper extends IDreamService.Stub {
		public void attach(IBinder windowToken) {
		Dream.this.attach(windowToken);
		}
		}

		}

core/java/android/service/dreams/DreamManagerService.java

deleted100644 → 0

+0 −247

Original line number	Diff line number	Diff line
		package android.service.dreams;

		import static android.provider.Settings.Secure.SCREENSAVER_COMPONENTS;
		import static android.provider.Settings.Secure.SCREENSAVER_DEFAULT_COMPONENT;
		import java.io.FileDescriptor;
		import java.io.PrintWriter;

		import android.app.ActivityManagerNative;
		import android.content.BroadcastReceiver;
		import android.content.ComponentName;
		import android.content.Context;
		import android.content.Intent;
		import android.content.IntentFilter;
		import android.content.ServiceConnection;
		import android.content.pm.PackageManager;
		import android.os.Binder;
		import android.os.IBinder;
		import android.os.RemoteException;
		import android.os.UserHandle;
		import android.provider.Settings;
		import android.util.Slog;
		import android.view.IWindowManager;
		import android.view.WindowManager;
		import android.view.WindowManagerGlobal;

		/**
		*
		* @hide
		*
		*/

		public class DreamManagerService
		extends IDreamManager.Stub
		implements ServiceConnection
		{
		private static final boolean DEBUG = true;
		private static final String TAG = "DreamManagerService";

		final Object mLock = new Object[0];

		private Context mContext;
		private IWindowManager mIWindowManager;

		private ComponentName mCurrentDreamComponent;
		private IDreamService mCurrentDream;
		private Binder mCurrentDreamToken;
		private int mCurrentUserId;

		public DreamManagerService(Context context) {
		if (DEBUG) Slog.v(TAG, "DreamManagerService startup");
		mContext = context;
		mIWindowManager = WindowManagerGlobal.getWindowManagerService();
		}

		private void checkPermission(String permission) {
		if (PackageManager.PERMISSION_GRANTED != mContext.checkCallingOrSelfPermission(permission)) {
		throw new SecurityException("Access denied to process: " + Binder.getCallingPid()
		+ ", must have permission " + permission);
		}
		}

		// IDreamManager method
		@Override
		public void dream() {
		ComponentName[] dreams = getDreamComponentsForUser(mCurrentUserId);
		ComponentName name = dreams != null && dreams.length > 0 ? dreams[0] : null;
		if (name != null) {
		synchronized (mLock) {
		final long ident = Binder.clearCallingIdentity();
		try {
		bindDreamComponentL(name, false);
		} finally {
		Binder.restoreCallingIdentity(ident);
		}
		}
		}
		}

		// IDreamManager method
		@Override
		public void setDreamComponents(ComponentName[] componentNames) {
		Settings.Secure.putStringForUser(mContext.getContentResolver(),
		SCREENSAVER_COMPONENTS,
		componentsToString(componentNames),
		UserHandle.getCallingUserId());
		}

		private static String componentsToString(ComponentName[] componentNames) {
		StringBuilder names = new StringBuilder();
		if (componentNames != null) {
		for (ComponentName componentName : componentNames) {
		if (names.length() > 0)
		names.append(',');
		names.append(componentName.flattenToString());
		}
		}
		return names.toString();
		}

		private static ComponentName[] componentsFromString(String names) {
		String[] namesArray = names.split(",");
		ComponentName[] componentNames = new ComponentName[namesArray.length];
		for (int i = 0; i < namesArray.length; i++)
		componentNames[i] = ComponentName.unflattenFromString(namesArray[i]);
		return componentNames;
		}

		// IDreamManager method
		@Override
		public ComponentName[] getDreamComponents() {
		return getDreamComponentsForUser(UserHandle.getCallingUserId());
		}

		private ComponentName[] getDreamComponentsForUser(int userId) {
		String names = Settings.Secure.getStringForUser(mContext.getContentResolver(),
		SCREENSAVER_COMPONENTS,
		userId);
		return names == null ? null : componentsFromString(names);
		}

		// IDreamManager method
		@Override
		public ComponentName getDefaultDreamComponent() {
		String name = Settings.Secure.getStringForUser(mContext.getContentResolver(),
		SCREENSAVER_DEFAULT_COMPONENT,
		UserHandle.getCallingUserId());
		return name == null ? null : ComponentName.unflattenFromString(name);
		}

		// IDreamManager method
		@Override
		public void testDream(ComponentName name) {
		if (DEBUG) Slog.v(TAG, "startDream name=" + name
		+ " pid=" + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid());
		// checkPermission(android.Manifest.permission.SET_WALLPAPER_COMPONENT);
		synchronized (mLock) {
		final long ident = Binder.clearCallingIdentity();
		try {
		bindDreamComponentL(name, true);
		} finally {
		Binder.restoreCallingIdentity(ident);
		}
		}
		}

		// IDreamManager method
		@Override
		public void awaken() {
		if (DEBUG) Slog.v(TAG, "awaken()");
		synchronized (mLock) {
		if (mCurrentDream != null) {
		if (DEBUG) Slog.v(TAG, "disconnecting: " + mCurrentDreamComponent + " service: " + mCurrentDream);
		mContext.unbindService(this);
		mCurrentDream = null;
		mCurrentDreamToken = null;
		}
		}
		}

		// IDreamManager method
		@Override
		public boolean isDreaming() {
		synchronized (mLock) {
		return mCurrentDreamToken != null;
		}
		}

		public void bindDreamComponentL(ComponentName componentName, boolean test) {
		if (DEBUG) Slog.v(TAG, "bindDreamComponent: componentName=" + componentName
		+ " pid=" + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid());

		Intent intent = new Intent(Intent.ACTION_MAIN)
		.setComponent(componentName)
		.addFlags(
		Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
		)
		.putExtra("android.dreams.TEST", test);

		mCurrentDreamComponent = componentName;
		mCurrentDreamToken = new Binder();
		try {
		if (DEBUG) Slog.v(TAG, "Adding window token: " + mCurrentDreamToken
		+ " for window type: " + WindowManager.LayoutParams.TYPE_DREAM);
		mIWindowManager.addWindowToken(mCurrentDreamToken,
		WindowManager.LayoutParams.TYPE_DREAM);
		} catch (RemoteException e) {
		Slog.w(TAG, "Unable to add window token. Proceed at your own risk.");
		}

		if (!mContext.bindService(intent, this, Context.BIND_AUTO_CREATE)) {
		Slog.w(TAG, "unable to bind service: " + componentName);
		}
		}

		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
		if (DEBUG) Slog.v(TAG, "connected to dream: " + name + " binder=" + service + " thread=" + Thread.currentThread().getId());

		mCurrentDream = IDreamService.Stub.asInterface(service);
		try {
		if (DEBUG) Slog.v(TAG, "attaching with token:" + mCurrentDreamToken);
		mCurrentDream.attach(mCurrentDreamToken);
		} catch (RemoteException ex) {
		Slog.w(TAG, "Unable to send window token to dream:" + ex);
		}
		}

		@Override
		public void onServiceDisconnected(ComponentName name) {
		if (DEBUG) Slog.v(TAG, "disconnected: " + name + " service: " + mCurrentDream);
		// Only happens in exceptional circumstances
		}

		@Override
		protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
		mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DUMP, TAG);

		pw.println("Dreamland:");
		pw.print(" component="); pw.println(mCurrentDreamComponent);
		pw.print(" token="); pw.println(mCurrentDreamToken);
		pw.print(" dream="); pw.println(mCurrentDream);
		}

		public void systemReady() {

		// dream settings are kept per user, so keep track of current user
		try {
		mCurrentUserId = ActivityManagerNative.getDefault().getCurrentUser().id;
		} catch (RemoteException e) {
		Slog.w(TAG, "Couldn't get current user ID; guessing it's 0", e);
		}
		IntentFilter filter = new IntentFilter();
		filter.addAction(Intent.ACTION_USER_SWITCHED);
		mContext.registerReceiver(new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
		String action = intent.getAction();
		if (Intent.ACTION_USER_SWITCHED.equals(action)) {
		mCurrentUserId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
		if (DEBUG) Slog.v(TAG, "userId " + mCurrentUserId + " is in the house");
		}
		}}, filter);

		if (DEBUG) Slog.v(TAG, "ready to dream!");
		}

		}

core/java/android/service/dreams/IDreamManager.aidl

+2 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ package android.service.dreams;
		import android.os.Bundle;
		import android.os.ParcelFileDescriptor;
		import android.content.ComponentName;
		import android.os.IBinder;

		/** @hide */
		interface IDreamManager {
		@@ -29,4 +30,5 @@ interface IDreamManager {
		ComponentName getDefaultDreamComponent();
		void testDream(in ComponentName componentName);
		boolean isDreaming();
		void awakenSelf(in IBinder token);
		}
		No newline at end of file

core/res/AndroidManifest.xml

+15 −0

Original line number	Diff line number	Diff line
		@@ -140,6 +140,9 @@

		<protected-broadcast android:name="android.os.UpdateLock.UPDATE_LOCK_CHANGED" />

		<protected-broadcast android:name="android.intent.action.DREAMING_STARTED" />
		<protected-broadcast android:name="android.intent.action.DREAMING_STOPPED" />

		<!-- ====================================== -->
		<!-- Permissions for things that cost money -->
		<!-- ====================================== -->
		@@ -1929,6 +1932,18 @@
		android:permissionGroup="android.permission-group.SYSTEM_TOOLS"
		android:protectionLevel="signature\|system" />

		<!-- Allows applications to read dream settings and dream state.
		@hide -->
		<permission android:name="android.permission.READ_DREAM_STATE"
		android:permissionGroup="android.permission-group.SYSTEM_TOOLS"
		android:protectionLevel="signature" />

		<!-- Allows applications to write dream settings, and start or stop dreaming.
		@hide -->
		<permission android:name="android.permission.WRITE_DREAM_STATE"
		android:permissionGroup="android.permission-group.SYSTEM_TOOLS"
		android:protectionLevel="signature" />

		<!-- Allow an application to read and write the cache partition.
		@hide -->
		<permission android:name="android.permission.ACCESS_CACHE_FILESYSTEM"