Add audio focus control.

Change-Id: I17697bd557f4f399ae4a557a369a8bd280313b3a

Author: nic0lette

README.md

@@ -58,6 +58,23 @@ Another example with UAMP is to perform a search with the term "jazz?" one would
 Verification
 ============
 
+Audio Focus
+-----------
+
+This app allows for testing how media apps respond to audio focus changes.
+
+The app allows requesting and abandoning the following types of audio focus:
+
+* AUDIOFOCUS_GAIN
+* AUDIOFOCUS_GAIN_TRANSIENT
+* AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK
+
+For more information on audio focus please see
+[Managing Audio Focus](https://developer.android.com/guide/topics/media-apps/audio-focus.html).
+
+Supported Actions
+-----------------
+
 This tool displays the supported actions as reported by the MediaSession in the call to
 [MediaSessionCompat.setPlaybackState()](https://developer.android.com/reference/android/support/v4/media/session/MediaSessionCompat.html#setPlaybackState(android.support.v4.media.session.PlaybackStateCompat))
 as a list of prepare and play actions on the main screen. For actions that are not declared as

mediacontroller/src/main/java/com/example/android/mediacontroller/MediaAppControllerActivity.java

@@ -25,6 +25,7 @@
 import android.graphics.Color;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
+import android.media.AudioManager;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.RemoteException;
@@ -49,12 +50,14 @@
 import android.util.SparseArray;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.AdapterView;
 import android.widget.EditText;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.Spinner;
 import android.widget.TextView;
 import android.widget.Toast;
+import android.widget.ToggleButton;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -112,6 +115,7 @@ public class MediaAppControllerActivity extends AppCompatActivity {
     private MediaAppDetails mMediaAppDetails;
     private MediaControllerCompat mController;
     private MediaBrowserCompat mBrowser;
+    private AudioFocusHelper mAudioFocusHelper;
 
     private View mRootView;
     private Spinner mInputTypeView;
@@ -332,6 +336,10 @@ private void setupButtons() {
         findViewById(R.id.action_prepare).setOnClickListener(preparePlayHandler);
         findViewById(R.id.action_play).setOnClickListener(preparePlayHandler);
 
+        mAudioFocusHelper = new AudioFocusHelper(this,
+                (ToggleButton) findViewById(R.id.audio_focus_button),
+                (Spinner) findViewById(R.id.audio_focus_type));
+
         mActionButtonMap.clear();
         final List<Action> mediaActions = Action.createActions(this);
         for (final Action action : mediaActions) {
@@ -638,6 +646,85 @@ private int getTint(@PlaybackStateCompat.Actions long actions,
         }
     }
 
+    /**
+     * Helper class to manage audio focus requests and the UI surrounding this feature.
+     */
+    private static class AudioFocusHelper
+            implements View.OnClickListener,
+            AudioManager.OnAudioFocusChangeListener,
+            AdapterView.OnItemSelectedListener {
+
+        /**
+         * This list MUST match the order of the string-array
+         * {@see R.array.audio_focus_types}.
+         */
+        private static final int[] FOCUS_TYPES = {
+                AudioManager.AUDIOFOCUS_GAIN,
+                AudioManager.AUDIOFOCUS_GAIN_TRANSIENT,
+                AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK
+        };
+
+        private final AudioManager mAudioManager;
+        private final ToggleButton mToggleButton;
+        private final Spinner mFocusTypeSpinner;
+
+        private AudioFocusHelper(@NonNull Context context,
+                                 @NonNull ToggleButton focusToggleButton,
+                                 @NonNull Spinner focusTypeSpinner) {
+
+            mAudioManager = (AudioManager) context.getSystemService(AUDIO_SERVICE);
+            mToggleButton = focusToggleButton;
+            mFocusTypeSpinner = focusTypeSpinner;
+
+            mToggleButton.setOnClickListener(this);
+            mFocusTypeSpinner.setOnItemSelectedListener(this);
+        }
+
+        @Override
+        public void onClick(View v) {
+            if (mToggleButton.isChecked()) {
+                requestAudioFocus(getSelectedFocusType());
+            } else {
+                mAudioManager.abandonAudioFocus(this);
+            }
+        }
+
+        @Override
+        public void onAudioFocusChange(int focusChange) {
+            switch (focusChange) {
+                case AudioManager.AUDIOFOCUS_GAIN:
+                case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT:
+                case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK:
+                    mToggleButton.setChecked(true);
+                    break;
+                default:
+                    mToggleButton.setChecked(false);
+            }
+        }
+
+        private int getSelectedFocusType() {
+            return FOCUS_TYPES[mFocusTypeSpinner.getSelectedItemPosition()];
+        }
+
+        private void requestAudioFocus(final int hint) {
+            mAudioManager.requestAudioFocus(this, AudioManager.STREAM_VOICE_CALL, hint);
+        }
+
+        @Override
+        public void onItemSelected(AdapterView parent, View view, int position, long id) {
+            // If we're holding audio focus and the type should change, automatically
+            // request the new type of focus.
+            if (mToggleButton.isChecked()) {
+                requestAudioFocus(getSelectedFocusType());
+            }
+        }
+
+        @Override
+        public void onNothingSelected(AdapterView parent) {
+            // Nothing to do.
+        }
+    }
+
     private static class KeyComparator implements Comparator<String> {
         private final Set<String> mCapKeys = new HashSet<>();
 

mediacontroller/src/main/res/layout/media_info.xml

@@ -80,7 +80,35 @@
 
     <TextView
         android:id="@+id/media_info"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:gravity="top|start"
+        android:text="@string/media_info_default" />
+
+    <TextView
+        style="@style/TextAppearance.AppCompat.Large"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="@string/media_info_default" />
+        android:text="@string/audio_focus_title" />
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="32dp">
+
+        <ToggleButton
+            android:id="@+id/audio_focus_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:textOff="@string/audio_focus_gain_focus"
+            android:textOn="@string/audio_focus_abandon_focus" />
+
+        <Spinner
+            android:id="@+id/audio_focus_type"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:entries="@array/audio_focus_types" />
+
+    LinearLayout>
 LinearLayout>

mediacontroller/src/main/res/values/strings.xml

@@ -74,4 +74,18 @@
 
     <string name="action_skip_30s_forward">Skip 30sstring>
     <string name="action_skip_30s_backward">Skip back 30sstring>
+
+    <string name="audio_focus_title">Audio Focusstring>
+    <string name="audio_focus_gain_focus">Gainstring>
+    <string name="audio_focus_abandon_focus">Abandonstring>
+
+    
+    <string-array name="audio_focus_types">
+        <item>GAINitem>
+        <item>GAIN_TRANSIENTitem>
+        <item>GAIN_TRANSIENT_MAY_DUCKitem>
+    string-array>
 resources>