Request audio focus.

MyTracks/src/com/google/android/apps/mytracks/services/FroyoStatusAnnouncerTask.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.android.apps.mytracks.services;
+
+import static com.google.android.apps.mytracks.MyTracksConstants.TAG;
+
+import android.content.Context;
+import android.media.AudioManager;
+import android.media.AudioManager.OnAudioFocusChangeListener;
+import android.speech.tts.TextToSpeech;
+import android.speech.tts.TextToSpeech.OnUtteranceCompletedListener;
+import android.util.Log;
+
+import java.util.HashMap;
+
+/**
+ * This class will periodically announce the user's trip statistics for Froyo and future handsets.
+ * This class will request and release audio focus.
+ *
+ * @author Sandor Dornbush
+ */
+public class FroyoStatusAnnouncerTask
+    extends StatusAnnouncerTask
+    implements OnUtteranceCompletedListener, OnAudioFocusChangeListener {
+  
+  private AudioManager audioManager;
+
+  public FroyoStatusAnnouncerTask(Context context) {
+    super(context);
+    audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+  }
+
+  protected void onTtsInit(int status) {
+    super.onTtsInit(status);
+    if (status == TextToSpeech.SUCCESS) {
+      tts.setOnUtteranceCompletedListener(this);
+    }
+  }
+
+  protected void speakAnnouncment(String announcement) {
+    audioManager.requestAudioFocus(this,
+          TextToSpeech.Engine.DEFAULT_STREAM, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK);
+    // We don't care about the id.
+    // It is supplied here to force onUtteranceCompleted to be called.
+    HashMap<String, String> params = new HashMap<String, String>();
+    params.put(TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID, "not_used");
+    tts.speak(announcement, TextToSpeech.QUEUE_FLUSH, params);
+  }
+
+  @Override
+  public void onUtteranceCompleted(String utteranceId) {
+    Log.d(TAG, "FroyoStatusAnnouncerTask: Abandoning audio focus.");
+    audioManager.abandonAudioFocus(this);
+  }
+
+  @Override
+  public void onAudioFocusChange(int focusChange) {
+    // We don't care.
+  }
+}

MyTracks/src/com/google/android/apps/mytracks/services/StatusAnnouncerFactory.java

@@ -41,7 +41,11 @@ public class StatusAnnouncerFactory {
    */
   public PeriodicTask create(Context context) {
     if (hasTts) {
-      return new StatusAnnouncerTask(context);
+      if (ApiFeatures.getInstance().supportsAudioFocus()) {
+        return new FroyoStatusAnnouncerTask(context);
+      } else {
+        return new StatusAnnouncerTask(context);
+      }
     } else {
       return null;
     }

MyTracks/src/com/google/android/apps/mytracks/services/StatusAnnouncerTask.java

@@ -59,7 +59,7 @@ public class StatusAnnouncerTask implements PeriodicTask {
   /**
    * The interface to the text to speech engine.
    */
-  private TextToSpeech tts;
+  protected TextToSpeech tts;
 
   /**
    * The response received from the TTS engine after initialization.
@@ -98,7 +98,7 @@ public class StatusAnnouncerTask implements PeriodicTask {
   /**
    * Called when the TTS engine is initialized.
    */
-  private void onTtsInit(int status) {
+  protected void onTtsInit(int status) {
     Log.i(MyTracksConstants.TAG, "TrackRecordingService.TTS init: " + status);
     this.ready = status == TextToSpeech.SUCCESS;
 
@@ -146,6 +146,10 @@ public class StatusAnnouncerTask implements PeriodicTask {
 
     String announcement = getAnnouncement(service.getTripStatistics());
     Log.d(MyTracksConstants.TAG, "Announcement: " + announcement);
+    speakAnnouncment(announcement);
+  }
+
+  protected void speakAnnouncment(String announcement) {
     tts.speak(announcement, TextToSpeech.QUEUE_FLUSH, null);
   }
 

MyTracks/src/com/google/android/apps/mytracks/util/ApiFeatures.java

@@ -107,6 +107,10 @@ public class ApiFeatures {
     return getApiLevel() >= 9;
   }
   
+  public boolean supportsAudioFocus() {
+    return getApiLevel() >= 8;
+  }
+  
   /**
    * There's a bug (#1587) in Cupcake and Donut which prevents you from
    * using a SQLiteQueryBuilder twice.  That is, if you call buildQuery