1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.apis.app; 18 19 import android.app.Activity; 20 import android.app.Notification; 21 import android.app.NotificationManager; 22 import android.app.PendingIntent; 23 import android.app.Service; 24 import android.content.Intent; 25 import android.os.Bundle; 26 import android.os.IBinder; 27 import android.util.Log; 28 import android.view.View; 29 import android.view.View.OnClickListener; 30 import android.widget.Button; 31 32 import java.lang.reflect.InvocationTargetException; 33 import java.lang.reflect.Method; 34 35 // Need the following import to get access to the app resources, since this 36 // class is in a sub-package. 37 import com.example.android.apis.R; 38 39 /** 40 * This is an example of implementing an application service that can 41 * run in the "foreground". It shows how to code this to work well by using 42 * the improved Android 2.0 APIs when available and otherwise falling back 43 * to the original APIs. Yes: you can take this exact code, compile it 44 * against the Android 2.0 SDK, and it will against everything down to 45 * Android 1.0. 46 */ 47 public class ForegroundService extends Service { 48 static final String ACTION_FOREGROUND = "com.example.android.apis.FOREGROUND"; 49 static final String ACTION_BACKGROUND = "com.example.android.apis.BACKGROUND"; 50 51 // BEGIN_INCLUDE(foreground_compatibility) 52 private static final Class[] mStartForegroundSignature = new Class[] { 53 int.class, Notification.class}; 54 private static final Class[] mStopForegroundSignature = new Class[] { 55 boolean.class}; 56 57 private NotificationManager mNM; 58 private Method mStartForeground; 59 private Method mStopForeground; 60 private Object[] mStartForegroundArgs = new Object[2]; 61 private Object[] mStopForegroundArgs = new Object[1]; 62 63 /** 64 * This is a wrapper around the new startForeground method, using the older 65 * APIs if it is not available. 66 */ 67 void startForegroundCompat(int id, Notification notification) { 68 // If we have the new startForeground API, then use it. 69 if (mStartForeground != null) { 70 mStartForegroundArgs[0] = Integer.valueOf(id); 71 mStartForegroundArgs[1] = notification; 72 try { 73 mStartForeground.invoke(this, mStartForegroundArgs); 74 } catch (InvocationTargetException e) { 75 // Should not happen. 76 Log.w("ApiDemos", "Unable to invoke startForeground", e); 77 } catch (IllegalAccessException e) { 78 // Should not happen. 79 Log.w("ApiDemos", "Unable to invoke startForeground", e); 80 } 81 return; 82 } 83 84 // Fall back on the old API. 85 setForeground(true); 86 mNM.notify(id, notification); 87 } 88 89 /** 90 * This is a wrapper around the new stopForeground method, using the older 91 * APIs if it is not available. 92 */ 93 void stopForegroundCompat(int id) { 94 // If we have the new stopForeground API, then use it. 95 if (mStopForeground != null) { 96 mStopForegroundArgs[0] = Boolean.TRUE; 97 try { 98 mStopForeground.invoke(this, mStopForegroundArgs); 99 } catch (InvocationTargetException e) { 100 // Should not happen. 101 Log.w("ApiDemos", "Unable to invoke stopForeground", e); 102 } catch (IllegalAccessException e) { 103 // Should not happen. 104 Log.w("ApiDemos", "Unable to invoke stopForeground", e); 105 } 106 return; 107 } 108 109 // Fall back on the old API. Note to cancel BEFORE changing the 110 // foreground state, since we could be killed at that point. 111 mNM.cancel(id); 112 setForeground(false); 113 } 114 115 @Override 116 public void onCreate() { 117 mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); 118 try { 119 mStartForeground = getClass().getMethod("startForeground", 120 mStartForegroundSignature); 121 mStopForeground = getClass().getMethod("stopForeground", 122 mStopForegroundSignature); 123 } catch (NoSuchMethodException e) { 124 // Running on an older platform. 125 mStartForeground = mStopForeground = null; 126 } 127 } 128 129 @Override 130 public void onDestroy() { 131 // Make sure our notification is gone. 132 stopForegroundCompat(R.string.foreground_service_started); 133 } 134 // END_INCLUDE(foreground_compatibility) 135 136 // BEGIN_INCLUDE(start_compatibility) 137 // This is the old onStart method that will be called on the pre-2.0 138 // platform. On 2.0 or later we override onStartCommand() so this 139 // method will not be called. 140 @Override 141 public void onStart(Intent intent, int startId) { 142 handleCommand(intent); 143 } 144 145 @Override 146 public int onStartCommand(Intent intent, int flags, int startId) { 147 handleCommand(intent); 148 // We want this service to continue running until it is explicitly 149 // stopped, so return sticky. 150 return START_STICKY; 151 } 152 // END_INCLUDE(start_compatibility) 153 154 void handleCommand(Intent intent) { 155 if (ACTION_FOREGROUND.equals(intent.getAction())) { 156 // In this sample, we'll use the same text for the ticker and the expanded notification 157 CharSequence text = getText(R.string.foreground_service_started); 158 159 // Set the icon, scrolling text and timestamp 160 Notification notification = new Notification(R.drawable.stat_sample, text, 161 System.currentTimeMillis()); 162 163 // The PendingIntent to launch our activity if the user selects this notification 164 PendingIntent contentIntent = PendingIntent.getActivity(this, 0, 165 new Intent(this, Controller.class), 0); 166 167 // Set the info for the views that show in the notification panel. 168 notification.setLatestEventInfo(this, getText(R.string.local_service_label), 169 text, contentIntent); 170 171 startForegroundCompat(R.string.foreground_service_started, notification); 172 173 } else if (ACTION_BACKGROUND.equals(intent.getAction())) { 174 stopForegroundCompat(R.string.foreground_service_started); 175 } 176 } 177 178 @Override 179 public IBinder onBind(Intent intent) { 180 return null; 181 } 182 183 // ---------------------------------------------------------------------- 184 185 /** 186 * <p>Example of explicitly starting and stopping the {@link ForegroundService}. 187 * 188 * <p>Note that this is implemented as an inner class only keep the sample 189 * all together; typically this code would appear in some separate class. 190 */ 191 public static class Controller extends Activity { 192 @Override 193 protected void onCreate(Bundle savedInstanceState) { 194 super.onCreate(savedInstanceState); 195 196 setContentView(R.layout.foreground_service_controller); 197 198 // Watch for button clicks. 199 Button button = (Button)findViewById(R.id.start_foreground); 200 button.setOnClickListener(mForegroundListener); 201 button = (Button)findViewById(R.id.start_background); 202 button.setOnClickListener(mBackgroundListener); 203 button = (Button)findViewById(R.id.stop); 204 button.setOnClickListener(mStopListener); 205 } 206 207 private OnClickListener mForegroundListener = new OnClickListener() { 208 public void onClick(View v) { 209 Intent intent = new Intent(ForegroundService.ACTION_FOREGROUND); 210 intent.setClass(Controller.this, ForegroundService.class); 211 startService(intent); 212 } 213 }; 214 215 private OnClickListener mBackgroundListener = new OnClickListener() { 216 public void onClick(View v) { 217 Intent intent = new Intent(ForegroundService.ACTION_BACKGROUND); 218 intent.setClass(Controller.this, ForegroundService.class); 219 startService(intent); 220 } 221 }; 222 223 private OnClickListener mStopListener = new OnClickListener() { 224 public void onClick(View v) { 225 stopService(new Intent(Controller.this, 226 ForegroundService.class)); 227 } 228 }; 229 } 230 } 231
