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      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.res.Configuration;
     20 import android.provider.Settings;
     21 import android.util.Log;
     22 
     23 import com.android.systemui.R;
     24 import com.android.systemui.SystemUI;
     25 
     26 import java.io.FileDescriptor;
     27 import java.io.PrintWriter;
     28 
     29 /**
     30  * Ensure a single status bar service implementation is running at all times.
     31  *
     32  * <p>The implementation either comes from a service component running in a remote process (defined
     33  * using a secure setting), else falls back to using the in-process implementation according
     34  * to the product config.
     35  */
     36 public class SystemBars extends SystemUI implements ServiceMonitor.Callbacks {
     37     private static final String TAG = "SystemBars";
     38     private static final boolean DEBUG = false;
     39     private static final int WAIT_FOR_BARS_TO_DIE = 500;
     40 
     41     // manages the implementation coming from the remote process
     42     private ServiceMonitor mServiceMonitor;
     43 
     44     // in-process fallback implementation, per the product config
     45     private BaseStatusBar mStatusBar;
     46 
     47     @Override
     48     public void start() {
     49         if (DEBUG) Log.d(TAG, "start");
     50         mServiceMonitor = new ServiceMonitor(TAG, DEBUG,
     51                 mContext, Settings.Secure.BAR_SERVICE_COMPONENT, this);
     52         mServiceMonitor.start();  // will call onNoService if no remote service is found
     53     }
     54 
     55     @Override
     56     public void onNoService() {
     57         if (DEBUG) Log.d(TAG, "onNoService");
     58         createStatusBarFromConfig();  // fallback to using an in-process implementation
     59     }
     60 
     61     @Override
     62     public long onServiceStartAttempt() {
     63         if (DEBUG) Log.d(TAG, "onServiceStartAttempt mStatusBar="+mStatusBar);
     64         if (mStatusBar != null) {
     65             // tear down the in-process version, we'll recreate it again if needed
     66             mStatusBar.destroy();
     67             mStatusBar = null;
     68             return WAIT_FOR_BARS_TO_DIE;
     69         }
     70         return 0;
     71     }
     72 
     73     @Override
     74     protected void onConfigurationChanged(Configuration newConfig) {
     75         if (mStatusBar != null) {
     76             mStatusBar.onConfigurationChanged(newConfig);
     77         }
     78     }
     79 
     80     @Override
     81     public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
     82         if (mStatusBar != null) {
     83             mStatusBar.dump(fd, pw, args);
     84         }
     85     }
     86 
     87     private void createStatusBarFromConfig() {
     88         if (DEBUG) Log.d(TAG, "createStatusBarFromConfig");
     89         final String clsName = mContext.getString(R.string.config_statusBarComponent);
     90         if (clsName == null || clsName.length() == 0) {
     91             throw andLog("No status bar component configured", null);
     92         }
     93         Class<?> cls = null;
     94         try {
     95             cls = mContext.getClassLoader().loadClass(clsName);
     96         } catch (Throwable t) {
     97             throw andLog("Error loading status bar component: " + clsName, t);
     98         }
     99         try {
    100             mStatusBar = (BaseStatusBar) cls.newInstance();
    101         } catch (Throwable t) {
    102             throw andLog("Error creating status bar component: " + clsName, t);
    103         }
    104         mStatusBar.mContext = mContext;
    105         mStatusBar.mComponents = mComponents;
    106         mStatusBar.start();
    107         if (DEBUG) Log.d(TAG, "started " + mStatusBar.getClass().getSimpleName());
    108     }
    109 
    110     private RuntimeException andLog(String msg, Throwable t) {
    111         Log.w(TAG, msg, t);
    112         throw new RuntimeException(msg, t);
    113     }
    114 }
    115