packages/SystemUI/src/com/android/systemui/statusbar/ServiceMonitor.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2013 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.systemui.statusbar;

 import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.ServiceConnection;
 import android.content.pm.PackageManager;
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Message;
 import android.os.RemoteException;
 import android.os.UserHandle;
 import android.provider.Settings;
 import android.util.Log;

 import java.util.Arrays;

 /**
  * Manages a persistent connection to a service component defined in a secure setting.
  *
  * <p>If a valid service component is specified in the secure setting, starts it up and keeps it
  * running; handling setting changes, package updates, component disabling, and unexpected
  * process termination.
  *
  * <p>Clients can listen for important events using the supplied {@link Callbacks}.
  */
 public class ServiceMonitor {
     private static final int RECHECK_DELAY = 2000;
     private static final int WAIT_FOR_STOP = 500;

     public interface Callbacks {
         /** The service does not exist or failed to bind */
         void onNoService();
         /** The service is about to start, this is a chance to perform cleanup and
          * delay the start if necessary */
         long onServiceStartAttempt();
     }

     // internal handler + messages used to serialize access to internal state
     public static final int MSG_START_SERVICE = 1;
     public static final int MSG_CONTINUE_START_SERVICE = 2;
     public static final int MSG_STOP_SERVICE = 3;
     public static final int MSG_PACKAGE_INTENT = 4;
     public static final int MSG_CHECK_BOUND = 5;
     public static final int MSG_SERVICE_DISCONNECTED = 6;

     private final Handler mHandler = new Handler() {
         public void handleMessage(Message msg) {
             switch(msg.what) {
                 case MSG_START_SERVICE:
                     startService();
                     break;
                 case MSG_CONTINUE_START_SERVICE:
                     continueStartService();
                     break;
                 case MSG_STOP_SERVICE:
                     stopService();
                     break;
                 case MSG_PACKAGE_INTENT:
                     packageIntent((Intent)msg.obj);
                     break;
                 case MSG_CHECK_BOUND:
                     checkBound();
                     break;
                 case MSG_SERVICE_DISCONNECTED:
                     serviceDisconnected((ComponentName)msg.obj);
                     break;
             }
         }
     };

     private final ContentObserver mSettingObserver = new ContentObserver(mHandler) {
         public void onChange(boolean selfChange) {
             onChange(selfChange, null);
         }

         public void onChange(boolean selfChange, Uri uri) {
             if (mDebug) Log.d(mTag, "onChange selfChange=" + selfChange + " uri=" + uri);
             ComponentName cn = getComponentNameFromSetting();
             if (cn == null && mServiceName == null || cn != null && cn.equals(mServiceName)) {
                 if (mDebug) Log.d(mTag, "skipping no-op restart");
                 return;
             }
             if (mBound) {
                 mHandler.sendEmptyMessage(MSG_STOP_SERVICE);
             }
             mHandler.sendEmptyMessageDelayed(MSG_START_SERVICE, WAIT_FOR_STOP);
         }
     };

     private final class SC implements ServiceConnection, IBinder.DeathRecipient {
         private ComponentName mName;
         private IBinder mService;

         public void onServiceConnected(ComponentName name, IBinder service) {
             if (mDebug) Log.d(mTag, "onServiceConnected name=" + name + " service=" + service);
             mName = name;
             mService = service;
             try {
                 service.linkToDeath(this, 0);
             } catch (RemoteException e) {
                 Log.w(mTag, "Error linking to death", e);
             }
         }

         public void onServiceDisconnected(ComponentName name) {
             if (mDebug) Log.d(mTag, "onServiceDisconnected name=" + name);
             boolean unlinked = mService.unlinkToDeath(this, 0);
             if (mDebug) Log.d(mTag, "  unlinked=" + unlinked);
             mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName));
         }

         public void binderDied() {
             if (mDebug) Log.d(mTag, "binderDied");
             mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName));
         }
     }

     private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
         public void onReceive(Context context, Intent intent) {
             String pkg = intent.getData().getSchemeSpecificPart();
             if (mServiceName != null && mServiceName.getPackageName().equals(pkg)) {
                 mHandler.sendMessage(mHandler.obtainMessage(MSG_PACKAGE_INTENT, intent));
             }
         }
     };

     private final String mTag;
     private final boolean mDebug;

     private final Context mContext;
     private final String mSettingKey;
     private final Callbacks mCallbacks;

     private ComponentName mServiceName;
     private SC mServiceConnection;
     private boolean mBound;

     public ServiceMonitor(String ownerTag, boolean debug,
             Context context, String settingKey, Callbacks callbacks) {
         mTag = ownerTag + ".ServiceMonitor";
         mDebug = debug;
         mContext = context;
         mSettingKey = settingKey;
         mCallbacks = callbacks;
     }

     public void start() {
         // listen for setting changes
         ContentResolver cr = mContext.getContentResolver();
         cr.registerContentObserver(Settings.Secure.getUriFor(mSettingKey),
                 false /*notifyForDescendents*/, mSettingObserver, UserHandle.USER_ALL);

         // listen for package/component changes
         IntentFilter filter = new IntentFilter();
         filter.addAction(Intent.ACTION_PACKAGE_ADDED);
         filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
         filter.addDataScheme("package");
         mContext.registerReceiver(mBroadcastReceiver, filter);

         mHandler.sendEmptyMessage(MSG_START_SERVICE);
     }

     private ComponentName getComponentNameFromSetting() {
         String cn = Settings.Secure.getStringForUser(mContext.getContentResolver(),
                 mSettingKey, UserHandle.USER_CURRENT);
         return cn == null ? null : ComponentName.unflattenFromString(cn);
     }

     // everything below is called on the handler

     private void packageIntent(Intent intent) {
         if (mDebug) Log.d(mTag, "packageIntent intent=" + intent
                 + " extras=" + bundleToString(intent.getExtras()));
         if (Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())) {
             mHandler.sendEmptyMessage(MSG_START_SERVICE);
         } else if (Intent.ACTION_PACKAGE_CHANGED.equals(intent.getAction())) {
             PackageManager pm = mContext.getPackageManager();
             boolean serviceEnabled =
                     pm.getApplicationEnabledSetting(mServiceName.getPackageName())
                         != PackageManager.COMPONENT_ENABLED_STATE_DISABLED
                     && pm.getComponentEnabledSetting(mServiceName)
                         != PackageManager.COMPONENT_ENABLED_STATE_DISABLED;
             if (mBound && !serviceEnabled) {
                 stopService();
                 scheduleCheckBound();
             } else if (!mBound && serviceEnabled) {
                 startService();
             }
         }
     }

     private void stopService() {
         if (mDebug) Log.d(mTag, "stopService");
         boolean stopped = mContext.stopService(new Intent().setComponent(mServiceName));
         if (mDebug) Log.d(mTag, "  stopped=" + stopped);
         mContext.unbindService(mServiceConnection);
         mBound = false;
     }

     private void startService() {
         mServiceName = getComponentNameFromSetting();
         if (mDebug) Log.d(mTag, "startService mServiceName=" + mServiceName);
         if (mServiceName == null) {
             mBound = false;
             mCallbacks.onNoService();
         } else {
             long delay = mCallbacks.onServiceStartAttempt();
             mHandler.sendEmptyMessageDelayed(MSG_CONTINUE_START_SERVICE, delay);
         }
     }

     private void continueStartService() {
         if (mDebug) Log.d(mTag, "continueStartService");
         Intent intent = new Intent().setComponent(mServiceName);
         try {
             mServiceConnection = new SC();
             mBound = mContext.bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE);
             if (mDebug) Log.d(mTag, "mBound: " + mBound);
         } catch (Throwable t) {
             Log.w(mTag, "Error binding to service: " + mServiceName, t);
         }
         if (!mBound) {
             mCallbacks.onNoService();
         }
     }

     private void serviceDisconnected(ComponentName serviceName) {
         if (mDebug) Log.d(mTag, "serviceDisconnected serviceName=" + serviceName
                 + " mServiceName=" + mServiceName);
         if (serviceName.equals(mServiceName)) {
             mBound = false;
             scheduleCheckBound();
         }
     }

     private void checkBound() {
         if (mDebug) Log.d(mTag, "checkBound mBound=" + mBound);
         if (!mBound) {
             startService();
         }
     }

     private void scheduleCheckBound() {
         mHandler.removeMessages(MSG_CHECK_BOUND);
         mHandler.sendEmptyMessageDelayed(MSG_CHECK_BOUND, RECHECK_DELAY);
     }

     private static String bundleToString(Bundle bundle) {
         if (bundle == null) return null;
         StringBuilder sb = new StringBuilder('{');
         for (String key : bundle.keySet()) {
             if (sb.length() > 1) sb.append(',');
             Object v = bundle.get(key);
             v = (v instanceof String[]) ? Arrays.asList((String[]) v) : v;
             sb.append(key).append('=').append(v);
         }
         return sb.append('}').toString();
     }
 }
	/*
	* Copyright (C) 2013 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.systemui.statusbar;

	import android.content.BroadcastReceiver;
	import android.content.ComponentName;
	import android.content.ContentResolver;
	import android.content.Context;
	import android.content.Intent;
	import android.content.IntentFilter;
	import android.content.ServiceConnection;
	import android.content.pm.PackageManager;
	import android.database.ContentObserver;
	import android.net.Uri;
	import android.os.Bundle;
	import android.os.Handler;
	import android.os.IBinder;
	import android.os.Message;
	import android.os.RemoteException;
	import android.os.UserHandle;
	import android.provider.Settings;
	import android.util.Log;

	import java.util.Arrays;

	/**
	* Manages a persistent connection to a service component defined in a secure setting.
	*
	* <p>If a valid service component is specified in the secure setting, starts it up and keeps it
	* running; handling setting changes, package updates, component disabling, and unexpected
	* process termination.
	*
	* <p>Clients can listen for important events using the supplied {@link Callbacks}.
	*/
	public class ServiceMonitor {
	private static final int RECHECK_DELAY = 2000;
	private static final int WAIT_FOR_STOP = 500;

	public interface Callbacks {
	/** The service does not exist or failed to bind */
	void onNoService();
	/** The service is about to start, this is a chance to perform cleanup and
	* delay the start if necessary */
	long onServiceStartAttempt();
	}

	// internal handler + messages used to serialize access to internal state
	public static final int MSG_START_SERVICE = 1;
	public static final int MSG_CONTINUE_START_SERVICE = 2;
	public static final int MSG_STOP_SERVICE = 3;
	public static final int MSG_PACKAGE_INTENT = 4;
	public static final int MSG_CHECK_BOUND = 5;
	public static final int MSG_SERVICE_DISCONNECTED = 6;

	private final Handler mHandler = new Handler() {
	public void handleMessage(Message msg) {
	switch(msg.what) {
	case MSG_START_SERVICE:
	startService();
	break;
	case MSG_CONTINUE_START_SERVICE:
	continueStartService();
	break;
	case MSG_STOP_SERVICE:
	stopService();
	break;
	case MSG_PACKAGE_INTENT:
	packageIntent((Intent)msg.obj);
	break;
	case MSG_CHECK_BOUND:
	checkBound();
	break;
	case MSG_SERVICE_DISCONNECTED:
	serviceDisconnected((ComponentName)msg.obj);
	break;
	}
	}
	};

	private final ContentObserver mSettingObserver = new ContentObserver(mHandler) {
	public void onChange(boolean selfChange) {
	onChange(selfChange, null);
	}

	public void onChange(boolean selfChange, Uri uri) {
	if (mDebug) Log.d(mTag, "onChange selfChange=" + selfChange + " uri=" + uri);
	ComponentName cn = getComponentNameFromSetting();
	if (cn == null && mServiceName == null \|\| cn != null && cn.equals(mServiceName)) {
	if (mDebug) Log.d(mTag, "skipping no-op restart");
	return;
	}
	if (mBound) {
	mHandler.sendEmptyMessage(MSG_STOP_SERVICE);
	}
	mHandler.sendEmptyMessageDelayed(MSG_START_SERVICE, WAIT_FOR_STOP);
	}
	};

	private final class SC implements ServiceConnection, IBinder.DeathRecipient {
	private ComponentName mName;
	private IBinder mService;

	public void onServiceConnected(ComponentName name, IBinder service) {
	if (mDebug) Log.d(mTag, "onServiceConnected name=" + name + " service=" + service);
	mName = name;
	mService = service;
	try {
	service.linkToDeath(this, 0);
	} catch (RemoteException e) {
	Log.w(mTag, "Error linking to death", e);
	}
	}

	public void onServiceDisconnected(ComponentName name) {
	if (mDebug) Log.d(mTag, "onServiceDisconnected name=" + name);
	boolean unlinked = mService.unlinkToDeath(this, 0);
	if (mDebug) Log.d(mTag, " unlinked=" + unlinked);
	mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName));
	}

	public void binderDied() {
	if (mDebug) Log.d(mTag, "binderDied");
	mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName));
	}
	}

	private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
	public void onReceive(Context context, Intent intent) {
	String pkg = intent.getData().getSchemeSpecificPart();
	if (mServiceName != null && mServiceName.getPackageName().equals(pkg)) {
	mHandler.sendMessage(mHandler.obtainMessage(MSG_PACKAGE_INTENT, intent));
	}
	}
	};

	private final String mTag;
	private final boolean mDebug;

	private final Context mContext;
	private final String mSettingKey;
	private final Callbacks mCallbacks;

	private ComponentName mServiceName;
	private SC mServiceConnection;
	private boolean mBound;

	public ServiceMonitor(String ownerTag, boolean debug,
	Context context, String settingKey, Callbacks callbacks) {
	mTag = ownerTag + ".ServiceMonitor";
	mDebug = debug;
	mContext = context;
	mSettingKey = settingKey;
	mCallbacks = callbacks;
	}

	public void start() {
	// listen for setting changes
	ContentResolver cr = mContext.getContentResolver();
	cr.registerContentObserver(Settings.Secure.getUriFor(mSettingKey),
	false /notifyForDescendents/, mSettingObserver, UserHandle.USER_ALL);

	// listen for package/component changes
	IntentFilter filter = new IntentFilter();
	filter.addAction(Intent.ACTION_PACKAGE_ADDED);
	filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
	filter.addDataScheme("package");
	mContext.registerReceiver(mBroadcastReceiver, filter);

	mHandler.sendEmptyMessage(MSG_START_SERVICE);
	}

	private ComponentName getComponentNameFromSetting() {
	String cn = Settings.Secure.getStringForUser(mContext.getContentResolver(),
	mSettingKey, UserHandle.USER_CURRENT);
	return cn == null ? null : ComponentName.unflattenFromString(cn);
	}

	// everything below is called on the handler

	private void packageIntent(Intent intent) {
	if (mDebug) Log.d(mTag, "packageIntent intent=" + intent
	+ " extras=" + bundleToString(intent.getExtras()));
	if (Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())) {
	mHandler.sendEmptyMessage(MSG_START_SERVICE);
	} else if (Intent.ACTION_PACKAGE_CHANGED.equals(intent.getAction())) {
	PackageManager pm = mContext.getPackageManager();
	boolean serviceEnabled =
	pm.getApplicationEnabledSetting(mServiceName.getPackageName())
	!= PackageManager.COMPONENT_ENABLED_STATE_DISABLED
	&& pm.getComponentEnabledSetting(mServiceName)
	!= PackageManager.COMPONENT_ENABLED_STATE_DISABLED;
	if (mBound && !serviceEnabled) {
	stopService();
	scheduleCheckBound();
	} else if (!mBound && serviceEnabled) {
	startService();
	}
	}
	}

	private void stopService() {
	if (mDebug) Log.d(mTag, "stopService");
	boolean stopped = mContext.stopService(new Intent().setComponent(mServiceName));
	if (mDebug) Log.d(mTag, " stopped=" + stopped);
	mContext.unbindService(mServiceConnection);
	mBound = false;
	}

	private void startService() {
	mServiceName = getComponentNameFromSetting();
	if (mDebug) Log.d(mTag, "startService mServiceName=" + mServiceName);
	if (mServiceName == null) {
	mBound = false;
	mCallbacks.onNoService();
	} else {
	long delay = mCallbacks.onServiceStartAttempt();
	mHandler.sendEmptyMessageDelayed(MSG_CONTINUE_START_SERVICE, delay);
	}
	}

	private void continueStartService() {
	if (mDebug) Log.d(mTag, "continueStartService");
	Intent intent = new Intent().setComponent(mServiceName);
	try {
	mServiceConnection = new SC();
	mBound = mContext.bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE);
	if (mDebug) Log.d(mTag, "mBound: " + mBound);
	} catch (Throwable t) {
	Log.w(mTag, "Error binding to service: " + mServiceName, t);
	}
	if (!mBound) {
	mCallbacks.onNoService();
	}
	}

	private void serviceDisconnected(ComponentName serviceName) {
	if (mDebug) Log.d(mTag, "serviceDisconnected serviceName=" + serviceName
	+ " mServiceName=" + mServiceName);
	if (serviceName.equals(mServiceName)) {
	mBound = false;
	scheduleCheckBound();
	}
	}

	private void checkBound() {
	if (mDebug) Log.d(mTag, "checkBound mBound=" + mBound);
	if (!mBound) {
	startService();
	}
	}

	private void scheduleCheckBound() {
	mHandler.removeMessages(MSG_CHECK_BOUND);
	mHandler.sendEmptyMessageDelayed(MSG_CHECK_BOUND, RECHECK_DELAY);
	}

	private static String bundleToString(Bundle bundle) {
	if (bundle == null) return null;
	StringBuilder sb = new StringBuilder('{');
	for (String key : bundle.keySet()) {
	if (sb.length() > 1) sb.append(',');
	Object v = bundle.get(key);
	v = (v instanceof String[]) ? Arrays.asList((String[]) v) : v;
	sb.append(key).append('=').append(v);
	}
	return sb.append('}').toString();
	}
	}