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      1 /*
      2  * Copyright (C) 2011 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.supportv4.content;
     18 
     19 import com.example.android.supportv4.R;
     20 
     21 import android.app.Activity;
     22 import android.app.Service;
     23 import android.content.BroadcastReceiver;
     24 import android.content.Context;
     25 import android.content.Intent;
     26 import android.content.IntentFilter;
     27 import android.os.Bundle;
     28 import android.os.Handler;
     29 import android.os.IBinder;
     30 import android.os.Message;
     31 import android.support.v4.app.ServiceCompat;
     32 import android.support.v4.content.LocalBroadcastManager;
     33 import android.view.View;
     34 import android.view.View.OnClickListener;
     35 import android.widget.Button;
     36 import android.widget.TextView;
     37 
     38 /**
     39  * Demonstrates the use of a LocalBroadcastManager to easily communicate
     40  * data from a service to any other interested code.
     41  */
     42 public class LocalServiceBroadcaster extends Activity {
     43     static final String ACTION_STARTED = "com.example.android.supportv4.STARTED";
     44     static final String ACTION_UPDATE = "com.example.android.supportv4.UPDATE";
     45     static final String ACTION_STOPPED = "com.example.android.supportv4.STOPPED";
     46 
     47     LocalBroadcastManager mLocalBroadcastManager;
     48     BroadcastReceiver mReceiver;
     49 
     50     @Override
     51     protected void onCreate(Bundle savedInstanceState) {
     52         super.onCreate(savedInstanceState);
     53 
     54         setContentView(R.layout.local_service_broadcaster);
     55 
     56         // This is where we print the data we get back.
     57         final TextView callbackData = (TextView)findViewById(R.id.callback);
     58 
     59         // Put in some initial text.
     60         callbackData.setText("No broadcast received yet");
     61 
     62         // We use this to send broadcasts within our local process.
     63         mLocalBroadcastManager = LocalBroadcastManager.getInstance(this);
     64 
     65         // We are going to watch for interesting local broadcasts.
     66         IntentFilter filter = new IntentFilter();
     67         filter.addAction(ACTION_STARTED);
     68         filter.addAction(ACTION_UPDATE);
     69         filter.addAction(ACTION_STOPPED);
     70         mReceiver = new BroadcastReceiver() {
     71             @Override
     72             public void onReceive(Context context, Intent intent) {
     73                 if (intent.getAction().equals(ACTION_STARTED)) {
     74                     callbackData.setText("STARTED");
     75                 } else if (intent.getAction().equals(ACTION_UPDATE)) {
     76                     callbackData.setText("Got update: " + intent.getIntExtra("value", 0));
     77                 } else if (intent.getAction().equals(ACTION_STOPPED)) {
     78                     callbackData.setText("STOPPED");
     79                 }
     80             }
     81         };
     82         mLocalBroadcastManager.registerReceiver(mReceiver, filter);
     83 
     84         // Watch for button clicks.
     85         Button button = (Button)findViewById(R.id.start);
     86         button.setOnClickListener(mStartListener);
     87         button = (Button)findViewById(R.id.stop);
     88         button.setOnClickListener(mStopListener);
     89     }
     90 
     91     @Override
     92     protected void onDestroy() {
     93         super.onDestroy();
     94         mLocalBroadcastManager.unregisterReceiver(mReceiver);
     95     }
     96 
     97     private OnClickListener mStartListener = new OnClickListener() {
     98         public void onClick(View v) {
     99             startService(new Intent(LocalServiceBroadcaster.this, LocalService.class));
    100         }
    101     };
    102 
    103     private OnClickListener mStopListener = new OnClickListener() {
    104         public void onClick(View v) {
    105             stopService(new Intent(LocalServiceBroadcaster.this, LocalService.class));
    106         }
    107     };
    108 
    109     public static class LocalService extends Service {
    110         LocalBroadcastManager mLocalBroadcastManager;
    111         int mCurUpdate;
    112 
    113         static final int MSG_UPDATE = 1;
    114 
    115         Handler mHandler = new Handler() {
    116             @Override
    117             public void handleMessage(Message msg) {
    118                 switch (msg.what) {
    119                     case MSG_UPDATE: {
    120                         mCurUpdate++;
    121                         Intent intent = new Intent(ACTION_UPDATE);
    122                         intent.putExtra("value", mCurUpdate);
    123                         mLocalBroadcastManager.sendBroadcast(intent);
    124                         Message nmsg = mHandler.obtainMessage(MSG_UPDATE);
    125                         mHandler.sendMessageDelayed(nmsg, 1000);
    126                     } break;
    127                     default:
    128                         super.handleMessage(msg);
    129                 }
    130             }
    131         };
    132 
    133         @Override
    134         public void onCreate() {
    135             super.onCreate();
    136             mLocalBroadcastManager = LocalBroadcastManager.getInstance(this);
    137         }
    138 
    139         public int onStartCommand(Intent intent, int flags, int startId) {
    140             // Tell any local interested parties about the start.
    141             mLocalBroadcastManager.sendBroadcast(new Intent(ACTION_STARTED));
    142 
    143             // Prepare to do update reports.
    144             mHandler.removeMessages(MSG_UPDATE);
    145             Message msg = mHandler.obtainMessage(MSG_UPDATE);
    146             mHandler.sendMessageDelayed(msg, 1000);
    147             return ServiceCompat.START_STICKY;
    148         }
    149 
    150         @Override
    151         public void onDestroy() {
    152             super.onDestroy();
    153 
    154             // Tell any local interested parties about the stop.
    155             mLocalBroadcastManager.sendBroadcast(new Intent(ACTION_STOPPED));
    156 
    157             // Stop doing updates.
    158             mHandler.removeMessages(MSG_UPDATE);
    159         }
    160 
    161         @Override
    162         public IBinder onBind(Intent intent) {
    163             return null;
    164         }
    165     }
    166 }
    167