John Spurlock | 5c45412 | 2013-06-17 07:35:46 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 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.android.systemui.statusbar; |
| 18 | |
| 19 | import android.content.BroadcastReceiver; |
| 20 | import android.content.ComponentName; |
| 21 | import android.content.ContentResolver; |
| 22 | import android.content.Context; |
| 23 | import android.content.Intent; |
| 24 | import android.content.IntentFilter; |
| 25 | import android.content.ServiceConnection; |
| 26 | import android.content.pm.PackageManager; |
| 27 | import android.database.ContentObserver; |
| 28 | import android.net.Uri; |
| 29 | import android.os.Bundle; |
| 30 | import android.os.Handler; |
| 31 | import android.os.IBinder; |
| 32 | import android.os.Message; |
| 33 | import android.os.RemoteException; |
| 34 | import android.os.UserHandle; |
| 35 | import android.provider.Settings; |
| 36 | import android.util.Log; |
| 37 | |
| 38 | import java.util.Arrays; |
| 39 | |
| 40 | /** |
| 41 | * Manages a persistent connection to a service component defined in a secure setting. |
| 42 | * |
| 43 | * <p>If a valid service component is specified in the secure setting, starts it up and keeps it |
| 44 | * running; handling setting changes, package updates, component disabling, and unexpected |
| 45 | * process termination. |
| 46 | * |
| 47 | * <p>Clients can listen for important events using the supplied {@link Callbacks}. |
| 48 | */ |
| 49 | public class ServiceMonitor { |
| 50 | private static final int RECHECK_DELAY = 2000; |
| 51 | private static final int WAIT_FOR_STOP = 500; |
| 52 | |
| 53 | public interface Callbacks { |
| 54 | /** The service does not exist or failed to bind */ |
| 55 | void onNoService(); |
| 56 | /** The service is about to start, this is a chance to perform cleanup and |
| 57 | * delay the start if necessary */ |
| 58 | long onServiceStartAttempt(); |
| 59 | } |
| 60 | |
| 61 | // internal handler + messages used to serialize access to internal state |
| 62 | public static final int MSG_START_SERVICE = 1; |
| 63 | public static final int MSG_CONTINUE_START_SERVICE = 2; |
| 64 | public static final int MSG_STOP_SERVICE = 3; |
| 65 | public static final int MSG_PACKAGE_INTENT = 4; |
| 66 | public static final int MSG_CHECK_BOUND = 5; |
| 67 | public static final int MSG_SERVICE_DISCONNECTED = 6; |
| 68 | |
| 69 | private final Handler mHandler = new Handler() { |
| 70 | public void handleMessage(Message msg) { |
| 71 | switch(msg.what) { |
| 72 | case MSG_START_SERVICE: |
| 73 | startService(); |
| 74 | break; |
| 75 | case MSG_CONTINUE_START_SERVICE: |
| 76 | continueStartService(); |
| 77 | break; |
| 78 | case MSG_STOP_SERVICE: |
| 79 | stopService(); |
| 80 | break; |
| 81 | case MSG_PACKAGE_INTENT: |
| 82 | packageIntent((Intent)msg.obj); |
| 83 | break; |
| 84 | case MSG_CHECK_BOUND: |
| 85 | checkBound(); |
| 86 | break; |
| 87 | case MSG_SERVICE_DISCONNECTED: |
| 88 | serviceDisconnected((ComponentName)msg.obj); |
| 89 | break; |
| 90 | } |
| 91 | } |
| 92 | }; |
| 93 | |
| 94 | private final ContentObserver mSettingObserver = new ContentObserver(mHandler) { |
| 95 | public void onChange(boolean selfChange) { |
| 96 | onChange(selfChange, null); |
| 97 | } |
| 98 | |
| 99 | public void onChange(boolean selfChange, Uri uri) { |
| 100 | if (mDebug) Log.d(mTag, "onChange selfChange=" + selfChange + " uri=" + uri); |
John Spurlock | 4db614d | 2013-06-27 10:15:19 -0400 | [diff] [blame] | 101 | ComponentName cn = getComponentNameFromSetting(); |
| 102 | if (cn == null && mServiceName == null || cn != null && cn.equals(mServiceName)) { |
| 103 | if (mDebug) Log.d(mTag, "skipping no-op restart"); |
| 104 | return; |
| 105 | } |
John Spurlock | 5c45412 | 2013-06-17 07:35:46 -0400 | [diff] [blame] | 106 | if (mBound) { |
| 107 | mHandler.sendEmptyMessage(MSG_STOP_SERVICE); |
| 108 | } |
| 109 | mHandler.sendEmptyMessageDelayed(MSG_START_SERVICE, WAIT_FOR_STOP); |
| 110 | } |
| 111 | }; |
| 112 | |
| 113 | private final class SC implements ServiceConnection, IBinder.DeathRecipient { |
| 114 | private ComponentName mName; |
| 115 | private IBinder mService; |
| 116 | |
| 117 | public void onServiceConnected(ComponentName name, IBinder service) { |
| 118 | if (mDebug) Log.d(mTag, "onServiceConnected name=" + name + " service=" + service); |
| 119 | mName = name; |
| 120 | mService = service; |
| 121 | try { |
| 122 | service.linkToDeath(this, 0); |
| 123 | } catch (RemoteException e) { |
| 124 | Log.w(mTag, "Error linking to death", e); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | public void onServiceDisconnected(ComponentName name) { |
| 129 | if (mDebug) Log.d(mTag, "onServiceDisconnected name=" + name); |
| 130 | boolean unlinked = mService.unlinkToDeath(this, 0); |
| 131 | if (mDebug) Log.d(mTag, " unlinked=" + unlinked); |
| 132 | mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName)); |
| 133 | } |
| 134 | |
| 135 | public void binderDied() { |
| 136 | if (mDebug) Log.d(mTag, "binderDied"); |
| 137 | mHandler.sendMessage(mHandler.obtainMessage(MSG_SERVICE_DISCONNECTED, mName)); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() { |
| 142 | public void onReceive(Context context, Intent intent) { |
| 143 | String pkg = intent.getData().getSchemeSpecificPart(); |
| 144 | if (mServiceName != null && mServiceName.getPackageName().equals(pkg)) { |
| 145 | mHandler.sendMessage(mHandler.obtainMessage(MSG_PACKAGE_INTENT, intent)); |
| 146 | } |
| 147 | } |
| 148 | }; |
| 149 | |
| 150 | private final String mTag; |
| 151 | private final boolean mDebug; |
| 152 | |
| 153 | private final Context mContext; |
| 154 | private final String mSettingKey; |
| 155 | private final Callbacks mCallbacks; |
| 156 | |
| 157 | private ComponentName mServiceName; |
| 158 | private SC mServiceConnection; |
| 159 | private boolean mBound; |
| 160 | |
| 161 | public ServiceMonitor(String ownerTag, boolean debug, |
| 162 | Context context, String settingKey, Callbacks callbacks) { |
| 163 | mTag = ownerTag + ".ServiceMonitor"; |
| 164 | mDebug = debug; |
| 165 | mContext = context; |
| 166 | mSettingKey = settingKey; |
| 167 | mCallbacks = callbacks; |
| 168 | } |
| 169 | |
| 170 | public void start() { |
| 171 | // listen for setting changes |
| 172 | ContentResolver cr = mContext.getContentResolver(); |
| 173 | cr.registerContentObserver(Settings.Secure.getUriFor(mSettingKey), |
| 174 | false /*notifyForDescendents*/, mSettingObserver, UserHandle.USER_ALL); |
| 175 | |
| 176 | // listen for package/component changes |
| 177 | IntentFilter filter = new IntentFilter(); |
| 178 | filter.addAction(Intent.ACTION_PACKAGE_ADDED); |
| 179 | filter.addAction(Intent.ACTION_PACKAGE_CHANGED); |
| 180 | filter.addDataScheme("package"); |
| 181 | mContext.registerReceiver(mBroadcastReceiver, filter); |
| 182 | |
| 183 | mHandler.sendEmptyMessage(MSG_START_SERVICE); |
| 184 | } |
| 185 | |
John Spurlock | 4db614d | 2013-06-27 10:15:19 -0400 | [diff] [blame] | 186 | private ComponentName getComponentNameFromSetting() { |
| 187 | String cn = Settings.Secure.getStringForUser(mContext.getContentResolver(), |
| 188 | mSettingKey, UserHandle.USER_CURRENT); |
| 189 | return cn == null ? null : ComponentName.unflattenFromString(cn); |
| 190 | } |
| 191 | |
John Spurlock | 5c45412 | 2013-06-17 07:35:46 -0400 | [diff] [blame] | 192 | // everything below is called on the handler |
| 193 | |
| 194 | private void packageIntent(Intent intent) { |
| 195 | if (mDebug) Log.d(mTag, "packageIntent intent=" + intent |
| 196 | + " extras=" + bundleToString(intent.getExtras())); |
| 197 | if (Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())) { |
| 198 | mHandler.sendEmptyMessage(MSG_START_SERVICE); |
| 199 | } else if (Intent.ACTION_PACKAGE_CHANGED.equals(intent.getAction())) { |
| 200 | PackageManager pm = mContext.getPackageManager(); |
| 201 | boolean serviceEnabled = |
| 202 | pm.getApplicationEnabledSetting(mServiceName.getPackageName()) |
| 203 | != PackageManager.COMPONENT_ENABLED_STATE_DISABLED |
| 204 | && pm.getComponentEnabledSetting(mServiceName) |
| 205 | != PackageManager.COMPONENT_ENABLED_STATE_DISABLED; |
| 206 | if (mBound && !serviceEnabled) { |
| 207 | stopService(); |
| 208 | scheduleCheckBound(); |
| 209 | } else if (!mBound && serviceEnabled) { |
| 210 | startService(); |
| 211 | } |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | private void stopService() { |
| 216 | if (mDebug) Log.d(mTag, "stopService"); |
| 217 | boolean stopped = mContext.stopService(new Intent().setComponent(mServiceName)); |
| 218 | if (mDebug) Log.d(mTag, " stopped=" + stopped); |
| 219 | mContext.unbindService(mServiceConnection); |
| 220 | mBound = false; |
| 221 | } |
| 222 | |
| 223 | private void startService() { |
John Spurlock | 4db614d | 2013-06-27 10:15:19 -0400 | [diff] [blame] | 224 | mServiceName = getComponentNameFromSetting(); |
John Spurlock | 5c45412 | 2013-06-17 07:35:46 -0400 | [diff] [blame] | 225 | if (mDebug) Log.d(mTag, "startService mServiceName=" + mServiceName); |
| 226 | if (mServiceName == null) { |
| 227 | mBound = false; |
| 228 | mCallbacks.onNoService(); |
| 229 | } else { |
| 230 | long delay = mCallbacks.onServiceStartAttempt(); |
| 231 | mHandler.sendEmptyMessageDelayed(MSG_CONTINUE_START_SERVICE, delay); |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | private void continueStartService() { |
| 236 | if (mDebug) Log.d(mTag, "continueStartService"); |
| 237 | Intent intent = new Intent().setComponent(mServiceName); |
| 238 | try { |
| 239 | mServiceConnection = new SC(); |
| 240 | mBound = mContext.bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE); |
| 241 | if (mDebug) Log.d(mTag, "mBound: " + mBound); |
| 242 | } catch (Throwable t) { |
| 243 | Log.w(mTag, "Error binding to service: " + mServiceName, t); |
| 244 | } |
| 245 | if (!mBound) { |
| 246 | mCallbacks.onNoService(); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | private void serviceDisconnected(ComponentName serviceName) { |
| 251 | if (mDebug) Log.d(mTag, "serviceDisconnected serviceName=" + serviceName |
| 252 | + " mServiceName=" + mServiceName); |
| 253 | if (serviceName.equals(mServiceName)) { |
| 254 | mBound = false; |
| 255 | scheduleCheckBound(); |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | private void checkBound() { |
| 260 | if (mDebug) Log.d(mTag, "checkBound mBound=" + mBound); |
| 261 | if (!mBound) { |
| 262 | startService(); |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | private void scheduleCheckBound() { |
| 267 | mHandler.removeMessages(MSG_CHECK_BOUND); |
| 268 | mHandler.sendEmptyMessageDelayed(MSG_CHECK_BOUND, RECHECK_DELAY); |
| 269 | } |
| 270 | |
| 271 | private static String bundleToString(Bundle bundle) { |
| 272 | if (bundle == null) return null; |
| 273 | StringBuilder sb = new StringBuilder('{'); |
| 274 | for (String key : bundle.keySet()) { |
| 275 | if (sb.length() > 1) sb.append(','); |
| 276 | Object v = bundle.get(key); |
| 277 | v = (v instanceof String[]) ? Arrays.asList((String[]) v) : v; |
| 278 | sb.append(key).append('=').append(v); |
| 279 | } |
| 280 | return sb.append('}').toString(); |
| 281 | } |
| 282 | } |