From 9089689ce3fa706e95dff7e606fa17ae2c75d9f6 Mon Sep 17 00:00:00 2001
From: jannis <jannis@tadris.de>
Date: Wed, 8 Jan 2020 13:19:20 +0100
Subject: [PATCH] Request audio focus for announcements to duck other media

---
 .../announcement/VoiceAnnouncements.java      | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/app/src/main/java/de/tadris/fitness/announcement/VoiceAnnouncements.java b/app/src/main/java/de/tadris/fitness/announcement/VoiceAnnouncements.java
index 93fea5e..dce822f 100644
--- a/app/src/main/java/de/tadris/fitness/announcement/VoiceAnnouncements.java
+++ b/app/src/main/java/de/tadris/fitness/announcement/VoiceAnnouncements.java
@@ -20,7 +20,9 @@
 package de.tadris.fitness.announcement;
 
 import android.content.Context;
+import android.media.AudioManager;
 import android.speech.tts.TextToSpeech;
+import android.speech.tts.UtteranceProgressListener;
 import android.util.Log;
 
 import java.util.Locale;
@@ -43,6 +45,8 @@ public class VoiceAnnouncements {
     private final long intervalTime;
     private final int intervalInMeters;
 
+    private final AudioManager audioManager;
+
     public VoiceAnnouncements(Context context, VoiceAnnouncementCallback callback) {
         this.callback = callback;
         UserPreferences prefs = Instance.getInstance(context).userPreferences;
@@ -52,10 +56,14 @@ public class VoiceAnnouncements {
         this.intervalInMeters = (int) (1000.0 / UnitUtils.CHOSEN_SYSTEM.getDistanceFromKilometers(1) * prefs.getSpokenUpdateDistancePeriod());
 
         this.manager = new AnnouncementManager(context);
+        this.audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
     }
 
     private void ttsReady(int status) {
         ttsAvailable = status == TextToSpeech.SUCCESS && textToSpeech.setLanguage(Locale.getDefault()) >= 0;
+        if (ttsAvailable) {
+            textToSpeech.setOnUtteranceProgressListener(new TextToSpeechListener());
+        }
         callback.onVoiceAnnouncementIsReady(ttsAvailable);
     }
 
@@ -111,6 +119,23 @@ public class VoiceAnnouncements {
         textToSpeech.shutdown();
     }
 
+    private class TextToSpeechListener extends UtteranceProgressListener {
+
+        @Override
+        public void onStart(String utteranceId) {
+            audioManager.requestAudioFocus(null, AudioManager.STREAM_SYSTEM, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK);
+        }
+
+        @Override
+        public void onDone(String utteranceId) {
+            audioManager.abandonAudioFocus(null);
+        }
+
+        @Override
+        public void onError(String utteranceId) {
+        }
+    }
+
     public interface VoiceAnnouncementCallback {
         void onVoiceAnnouncementIsReady(boolean available);
     }