android/src/org/rockbox/Helper/MediaButtonReceiver.java

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Thomas Martitz
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 package org.rockbox.Helper;
  23
  24 import org.rockbox.RockboxFramebuffer;
  25 import org.rockbox.RockboxService;
  26 import android.content.BroadcastReceiver;
  27 import android.content.ComponentName;
  28 import android.content.Context;
  29 import android.content.Intent;
  30 import android.content.IntentFilter;
  31 import android.media.AudioManager;
  32 import android.view.KeyEvent;
  33
  34 public class MediaButtonReceiver
  35 {
  36     /* A note on the API being used. 2.2 introduces a new and sane API
  37      * for handling multimedia button presses
  38      * http://android-developers.blogspot.com/2010/06/allowing-applications-to-play-nicer.html
  39      *
  40      * the old API is flawed. It doesn't have management for
  41      * concurrent media apps
  42      *
  43      * if multiple media apps are running
  44      * probably all of them want to respond to media keys
  45      *
  46      * it's not clear which app wins, it depends on the
  47      * priority set for the IntentFilter (see below)
  48      *
  49      * so this all might or might not work on < 2.2 */
  50
  51     IMultiMediaReceiver api;
  52
  53     public MediaButtonReceiver(Context c)
  54     {
  55         try {
  56             api = new NewApi(c);
  57         } catch (Throwable t) {
  58             /* Throwable includes Exception and the expected
  59              * NoClassDefFoundError */
  60             api = new OldApi(c);
  61         }
  62     }
  63
  64     public void register()
  65     {
  66         api.register();
  67     }
  68
  69     public void unregister()
  70     {
  71         api.unregister();
  72     }
  73
  74     /* helper class for the manifest */
  75     public static class MediaReceiver extends BroadcastReceiver
  76     {
  77         private void startService(Context c, Intent baseIntent)
  78         {
  79             baseIntent.setClass(c, RockboxService.class);
  80             c.startService(baseIntent);
  81         }
  82         @Override
  83         public void onReceive(Context context, Intent intent)
  84         {
  85             if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction()))
  86             {
  87                 KeyEvent key = (KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
  88                 if (key.getAction() == KeyEvent.ACTION_UP)
  89                 {   /* pass the pressed key to Rockbox, starting it if needed */
  90                     RockboxService s = RockboxService.get_instance();
  91                     if (s == null || !s.isRockboxRunning())
  92                         startService(context, intent);
  93                     else if (RockboxFramebuffer.buttonHandler(key.getKeyCode(), false))
  94                         abortBroadcast();
  95                 }
  96             }
  97         }
  98     }
  99
 100     private interface IMultiMediaReceiver
 101     {
 102         void register();
 103         void unregister();
 104     }
 105
 106     private static class NewApi
 107                     implements IMultiMediaReceiver, AudioManager.OnAudioFocusChangeListener
 108     {
 109         private AudioManager audio_manager;
 110         private ComponentName receiver_name;
 111         private boolean running = false;
 112
 113         NewApi(Context c)
 114         {
 115             audio_manager = (AudioManager)c.getSystemService(Context.AUDIO_SERVICE);
 116             receiver_name = new ComponentName(c, MediaReceiver.class);
 117         }
 118
 119         public void register()
 120         {
 121             try {
 122                 audio_manager.registerMediaButtonEventReceiver(receiver_name);
 123                 audio_manager.requestAudioFocus(this, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
 124                 running = true;
 125             } catch (Exception e) {
 126                 // Nothing
 127                 e.printStackTrace();
 128             }
 129         }
 130
 131         public void unregister()
 132         {
 133             try
 134             {
 135                 audio_manager.unregisterMediaButtonEventReceiver(receiver_name);
 136                 audio_manager.abandonAudioFocus(this);
 137                 running = false;
 138             } catch (Exception e) {
 139                 // Nothing
 140                 e.printStackTrace();
 141             }
 142         }
 143
 144         public void onAudioFocusChange(int focusChange)
 145         {
 146             Logger.d("Audio focus" + ((focusChange>0)?"gained":"lost")+
 147                                          ": "+ focusChange);
 148             if (running)
 149             {   /* Play nice and stop for the the other app */
 150                 if (focusChange == AudioManager.AUDIOFOCUS_LOSS)
 151                     RockboxFramebuffer.buttonHandler(KeyEvent.KEYCODE_MEDIA_STOP, false);
 152             }
 153         }
 154
 155     }
 156
 157     private static class OldApi implements IMultiMediaReceiver
 158     {
 159         private static final IntentFilter filter = new IntentFilter(Intent.ACTION_MEDIA_BUTTON);
 160         private MediaReceiver receiver;
 161         private Context context;
 162         OldApi(Context c)
 163         {
 164             filter.setPriority(1); /* 1 higher than the built-in media player */
 165             receiver = new MediaReceiver();
 166             context = c;
 167         }
 168
 169         public void register()
 170         {
 171             context.registerReceiver(receiver, filter);
 172         }
 173
 174         public void unregister()
 175         {
 176             context.unregisterReceiver(receiver);
 177         }
 178
 179     }
 180 }