/* * Copyright (C) 2010 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.example.android.newalarm; import android.app.Notification; import android.app.NotificationManager; import android.app.PendingIntent; import android.app.Service; import android.content.Intent; import android.os.Binder; import android.os.IBinder; import android.os.Parcel; import android.os.RemoteException; import android.widget.Toast; /** *

* This class implements a service. The service is started by AlarmActivity, which contains a * repeating countdown timer that sends a PendingIntent. The user starts and stops the timer with * buttons in the UI. *

*

* When this service is started, it creates a Runnable and starts it in a new Thread. The * Runnable does a synchronized lock on the service's Binder object for 15 seconds, then issues * a stopSelf(). The net effect is a new worker thread that takes 15 seconds to run and then * shuts down the entire service. The activity restarts the service after 15 more seconds, when the * countdown timer triggers again. *

*

* This service is provided as the service under test for the sample test application * AlarmServiceTest. *

*

* Note: Since this sample is based on the Android 1.5 platform, it does not implement * onStartCommand. See the Javadoc for android.app.Service for more details. *

*/ public class AlarmService extends Service { // Defines a label for the thread that this service starts private static final String ALARM_SERVICE_THREAD = "AlarmService"; // Defines 15 seconds public static final long WAIT_TIME_SECONDS = 15; // Define the number of milliseconds in one second public static final long MILLISECS_PER_SEC = 1000; /* * For testing purposes, the following variables are defined as fields and set to * package visibility. */ // The NotificationManager used to send notifications to the status bar. NotificationManager mNotificationManager; // An Intent that displays the client if the user clicks the notification. PendingIntent mContentIntent; // A Notification to send to the Notification Manager when the service is started. Notification mNotification; // A Binder, used as the lock object for the worker thread. IBinder mBinder = new AlarmBinder(); // A Thread object that will run the background task Thread mWorkThread; // The Runnable that is the service's "task". This illustrates how a service is used to // offload work from a client. Runnable mWorkTask = new Runnable() { public void run() { // Sets the wait time to 15 seconds, simulating a 15-second background task. long waitTime = System.currentTimeMillis() + WAIT_TIME_SECONDS * MILLISECS_PER_SEC; // Puts the wait in a while loop to ensure that it actually waited 15 seconds. // This covers the situation where an interrupt might have overridden the wait. while (System.currentTimeMillis() < waitTime) { // Waits for 15 seconds or interruption synchronized (mBinder) { try { // Waits for 15 seconds or until an interrupt triggers an exception. // If an interrupt occurs, the wait is recalculated to ensure a net // wait of 15 seconds. mBinder.wait(waitTime - System.currentTimeMillis()); } catch (InterruptedException e) { } } } // Stops the current service. In response, Android calls onDestroy(). stopSelf(); } }; /** * Makes a full concrete subclass of Binder, rather than doing it in line, for readability. */ public class AlarmBinder extends Binder { // Constructor. Calls the super constructor to set up the instance. public AlarmBinder() { super(); } @Override protected boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException { // Call the parent method with the arguments passed in return super.onTransact(code, data, reply, flags); } } /** * Initializes the service when it is first started by a call to startService() or * bindService(). */ @Override public void onCreate() { // Gets a handle to the system mNotification service. mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); // Updates the status bar to indicate that this service is running. showNotification(); // Creates a new thread. A new thread is used so that the service's work doesn't block // anything on the calling client's thread. By default, a service runs in the same // process and thread as the client that starts it. mWorkThread = new Thread( null, // threadgroup (in this case, null) mWorkTask, // the Runnable that will run in this thread ALARM_SERVICE_THREAD ); // Starts the thread mWorkThread.start(); } /** * Stops the service in response to the stopSelf() issued when the wait is over. Other * clients that use this service could stop it by issuing a stopService() or a stopSelf() on * the service object. */ @Override public void onDestroy() { // Cancels the status bar mNotification based on its ID, which is set in showNotification(). mNotificationManager.cancel(R.string.alarm_service_started); // Sends a notification to the screen. Toast.makeText( this, // the current context R.string.alarm_service_finished, // the message to show Toast.LENGTH_LONG // how long to keep the message on the screen ).show(); // show the text } // Returns the service's binder object to clients that issue onBind(). @Override public IBinder onBind(Intent intent) { return mBinder; } /** * Displays a notification in the status bar that this service is running. This method * also creates an Intent for the AlarmActivity client and attaches it to the notification * line. If the user clicks the line in the expanded status window, the Intent triggers * AlarmActivity. */ private void showNotification() { // Sets the text to use for the status bar and status list views. CharSequence notificationText = getText(R.string.alarm_service_started); // Sets the icon, status bar text, and display time for the mNotification. mNotification = new Notification( R.drawable.stat_sample, // the status icon notificationText, // the status text System.currentTimeMillis() // the time stamp ); // Sets up the Intent that starts AlarmActivity mContentIntent = PendingIntent.getActivity( this, // Start the Activity in the current context 0, // not used new Intent(this, AlarmActivity.class), // A new Intent for AlarmActivity 0 // Use an existing activity instance if available ); // Creates a new content view for the mNotification. The view appears when the user // shows the expanded status window. mNotification.setLatestEventInfo( this, // Put the content view in the current context getText(R.string.alarm_service_label), // The text to use as the label of the entry notificationText, // The text to use as the contents of the entry mContentIntent // The intent to send when the entry is clicked ); // Sets a unique ID for the notification and sends it to NotificationManager to be // displayed. The ID is the integer marker for the notification string, which is // guaranteed to be unique within the entire application. mNotificationManager.notify( R.string.alarm_service_started, // unique id for the mNotification mNotification // the mNotification object ); } }