1 /* 2 /* 3 * Copyright (C) 2011 The Android Open Source Project 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package com.android.emailcommon.service; 19 20 import android.content.ComponentName; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.content.ServiceConnection; 24 import android.os.AsyncTask; 25 import android.os.Debug; 26 import android.os.IBinder; 27 import android.os.Looper; 28 import android.os.RemoteException; 29 30 import com.android.mail.utils.LogUtils; 31 32 /** 33 * ServiceProxy is a superclass for proxy objects which make a single call to a service. It handles 34 * connecting to the service, running a task supplied by the subclass when the connection is ready, 35 * and disconnecting from the service afterwards. ServiceProxy objects cannot be reused (trying to 36 * do so generates an {@link IllegalStateException}). 37 * 38 * Subclasses must override {@link #onConnected} to store the binder. Then, when the subclass wants 39 * to make a service call, it should call {@link #setTask}, supplying the {@link ProxyTask} that 40 * should run when the connection is ready. {@link ProxyTask#run} should implement the necessary 41 * logic to make the call on the service. 42 */ 43 44 public abstract class ServiceProxy { 45 public static final String EXTRA_FORCE_SHUTDOWN = "ServiceProxy.FORCE_SHUTDOWN"; 46 47 private static final boolean DEBUG_PROXY = false; // DO NOT CHECK THIS IN SET TO TRUE 48 private final String mTag; 49 50 private final Context mContext; 51 protected final Intent mIntent; 52 private ProxyTask mTask; 53 private String mName = " unnamed"; 54 private final ServiceConnection mConnection = new ProxyConnection(); 55 // Service call timeout (in seconds) 56 private int mTimeout = 45; 57 private long mStartTime; 58 private boolean mTaskSet = false; 59 private boolean mTaskCompleted = false; 60 getIntentForEmailPackage(Context context, String actionName)61 public static Intent getIntentForEmailPackage(Context context, String actionName) { 62 return new Intent(getIntentStringForEmailPackage(context, actionName)); 63 } 64 65 /** 66 * Create Intent action based on the Email package name 67 * Package com.android.email + ACTION -> com.android.email.ACTION 68 * Package com.google.android.email + ACTION -> com.google.android.email.ACTION 69 * Package com.android.exchange + ACTION -> com.android.email.ACTION 70 * Package com.google.exchange + ACTION -> com.google.android.email.ACTION 71 * 72 * @param context the caller's context 73 * @param actionName the Intent action 74 * @return an Intent action based on the package name 75 */ getIntentStringForEmailPackage(Context context, String actionName)76 public static String getIntentStringForEmailPackage(Context context, String actionName) { 77 String packageName = context.getPackageName(); 78 int lastDot = packageName.lastIndexOf('.'); 79 return packageName.substring(0, lastDot + 1) + "email." + actionName; 80 } 81 82 /** 83 * This function is called after the proxy connects to the service but before it runs its task. 84 * Subclasses must override this to store the binder correctly. 85 * @param binder The service IBinder. 86 */ onConnected(IBinder binder)87 public abstract void onConnected(IBinder binder); 88 ServiceProxy(Context _context, Intent _intent)89 public ServiceProxy(Context _context, Intent _intent) { 90 mContext = _context; 91 mIntent = _intent; 92 mTag = getClass().getSimpleName(); 93 if (Debug.isDebuggerConnected()) { 94 mTimeout <<= 2; 95 } 96 } 97 98 private class ProxyConnection implements ServiceConnection { 99 @Override onServiceConnected(ComponentName name, IBinder binder)100 public void onServiceConnected(ComponentName name, IBinder binder) { 101 if (DEBUG_PROXY) { 102 LogUtils.v(mTag, "Connected: " + name.getShortClassName() + " at " + 103 (System.currentTimeMillis() - mStartTime) + "ms"); 104 } 105 106 // Let subclasses handle the binder. 107 onConnected(binder); 108 109 // Do our work in another thread. 110 new AsyncTask<Void, Void, Void>() { 111 @Override 112 protected Void doInBackground(Void... params) { 113 try { 114 mTask.run(); 115 } catch (RemoteException e) { 116 } 117 try { 118 // Each ServiceProxy handles just one task, so we unbind after we're 119 // done with our work. 120 mContext.unbindService(mConnection); 121 } catch (IllegalArgumentException e) { 122 // This can happen if the user ended the activity that was using the 123 // service. This is harmless, but we've got to catch it. 124 } 125 mTaskCompleted = true; 126 synchronized(mConnection) { 127 if (DEBUG_PROXY) { 128 LogUtils.v(mTag, "Task " + mName + " completed; disconnecting"); 129 } 130 mConnection.notify(); 131 } 132 return null; 133 } 134 }.execute(); 135 } 136 137 @Override onServiceDisconnected(ComponentName name)138 public void onServiceDisconnected(ComponentName name) { 139 if (DEBUG_PROXY) { 140 LogUtils.v(mTag, "Disconnected: " + name.getShortClassName() + " at " + 141 (System.currentTimeMillis() - mStartTime) + "ms"); 142 } 143 } 144 } 145 146 protected interface ProxyTask { run()147 public void run() throws RemoteException; 148 } 149 setTimeout(int secs)150 public ServiceProxy setTimeout(int secs) { 151 mTimeout = secs; 152 return this; 153 } 154 getTimeout()155 public int getTimeout() { 156 return mTimeout; 157 } 158 setTask(ProxyTask task, String name)159 protected boolean setTask(ProxyTask task, String name) throws IllegalStateException { 160 if (mTaskSet) { 161 throw new IllegalStateException("Cannot call setTask twice on the same ServiceProxy."); 162 } 163 mTaskSet = true; 164 mName = name; 165 mTask = task; 166 mStartTime = System.currentTimeMillis(); 167 if (DEBUG_PROXY) { 168 LogUtils.v(mTag, "Bind requested for task " + mName); 169 } 170 return mContext.bindService(mIntent, mConnection, Context.BIND_AUTO_CREATE); 171 } 172 173 /** 174 * Callers that want to wait on the {@link ProxyTask} should call this immediately after calling 175 * {@link #setTask}. This will wait until the task completes, up to the timeout (which can be 176 * set with {@link #setTimeout}). 177 */ waitForCompletion()178 protected void waitForCompletion() { 179 /* 180 * onServiceConnected() is always called on the main thread, and we block the current thread 181 * for up to 10 seconds as a timeout. If we're currently on the main thread, 182 * onServiceConnected() is not called until our timeout elapses (and the UI is frozen for 183 * the duration). 184 */ 185 if (Looper.myLooper() == Looper.getMainLooper()) { 186 throw new IllegalStateException("This cannot be called on the main thread."); 187 } 188 189 synchronized (mConnection) { 190 long time = System.currentTimeMillis(); 191 try { 192 if (DEBUG_PROXY) { 193 LogUtils.v(mTag, "Waiting for task " + mName + " to complete..."); 194 } 195 mConnection.wait(mTimeout * 1000L); 196 } catch (InterruptedException e) { 197 // Can be ignored safely 198 } 199 if (DEBUG_PROXY) { 200 LogUtils.v(mTag, "Wait for " + mName + 201 (mTaskCompleted ? " finished in " : " timed out in ") + 202 (System.currentTimeMillis() - time) + "ms"); 203 } 204 } 205 } 206 207 /** 208 * Connection test; return indicates whether the remote service can be connected to 209 * @return the result of trying to connect to the remote service 210 */ test()211 public boolean test() { 212 try { 213 return setTask(new ProxyTask() { 214 @Override 215 public void run() throws RemoteException { 216 if (DEBUG_PROXY) { 217 LogUtils.v(mTag, "Connection test succeeded in " + 218 (System.currentTimeMillis() - mStartTime) + "ms"); 219 } 220 } 221 }, "test"); 222 } catch (Exception e) { 223 // For any failure, return false. 224 return false; 225 } 226 } 227 } 228