added example with Service issue #5 and #8

audiovisualizer/src/main/java/com/chibde/BaseVisualizer.java

@@ -68,8 +68,17 @@ public void setColor(int color) {
         this.paint.setColor(this.color);
     }
 
+    /**
+     * @deprecated will be removed in next version use {@link BaseVisualizer#setPlayer(int)} instead
+     * @param mediaPlayer MediaPlayer
+     */
+    @Deprecated
     public void setPlayer(MediaPlayer mediaPlayer) {
-        visualizer = new Visualizer(mediaPlayer.getAudioSessionId());
+        setPlayer(mediaPlayer.getAudioSessionId());
+    }
+
+    public void setPlayer(int audioSessionId) {
+        visualizer = new Visualizer(audioSessionId);
         visualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
 
         visualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {

sample/src/main/AndroidManifest.xml

@@ -50,5 +50,15 @@
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value=".MainActivity"/>
         </activity>
+
+        <service
+            android:name=".MediaPlayerService"
+            android:exported="false" />
+
+        <activity android:name=".ServiceExampleActivity">
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value=".MainActivity" />
+        </activity>
     </application>
 </manifest>

sample/src/main/java/com/chibde/audiovisualizer/sample/BaseActivity.java

@@ -31,7 +31,7 @@
  * Created by gautam chibde on 18/11/17.
  */
 abstract public class BaseActivity extends AppCompatActivity {
-    private static final int AUDIO_PERMISSION_REQUEST_CODE = 102;
+    public static final int AUDIO_PERMISSION_REQUEST_CODE = 102;
 
     public static final String[] WRITE_EXTERNAL_STORAGE_PERMS = {
             Manifest.permission.RECORD_AUDIO

sample/src/main/java/com/chibde/audiovisualizer/sample/MainActivity.java

@@ -53,6 +53,10 @@ public void lineBar(View view) {
         startActivity(LineBarVisualizerActivity.class);
     }
 
+    public void service(View view) {
+        startActivity(ServiceExampleActivity.class);
+    }
+
     public void startActivity(Class clazz) {
         startActivity(new Intent(this, clazz));
     }

sample/src/main/java/com/chibde/audiovisualizer/sample/MediaPlayerService.java

@@ -0,0 +1,82 @@
+package com.chibde.audiovisualizer.sample;
+
+import android.app.Service;
+import android.content.Intent;
+import android.media.MediaPlayer;
+import android.os.Binder;
+import android.os.IBinder;
+import android.support.annotation.Nullable;
+import android.support.v4.content.LocalBroadcastManager;
+
+public class MediaPlayerService extends Service {
+
+    public static final String INTENT_FILTER = "MediaPlayerServiceIntentFilter";
+    public static final String INTENT_AUDIO_SESSION_ID = "intent_audio_session_id";
+
+    private IBinder mediaPlayerServiceBinder = new MediaPlayerServiceBinder();
+    private MediaPlayer mediaPlayer;
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mediaPlayer = MediaPlayer.create(this, R.raw.red_e);
+        mediaPlayer.setLooping(false);
+
+        Intent intent = new Intent(INTENT_FILTER); //put the same message as in the filter you used in the activity when registering the receiver
+        intent.putExtra(INTENT_AUDIO_SESSION_ID, mediaPlayer.getAudioSessionId());
+        // Send audio session id through
+        LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
+    }
+
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        return mediaPlayerServiceBinder;
+    }
+
+    public void replay() {
+        if (mediaPlayer != null) {
+            mediaPlayer.seekTo(0);
+        }
+    }
+
+    @Override
+    public void onRebind(Intent intent) {
+        super.onRebind(intent);
+    }
+
+    @Override
+    public boolean onUnbind(Intent intent) {
+        return true;
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        if (mediaPlayer != null) {
+            mediaPlayer.release();
+        }
+    }
+
+    public boolean isPlaying() {
+        return mediaPlayer != null && mediaPlayer.isPlaying();
+    }
+
+    public void pause() {
+        if (mediaPlayer != null) {
+            mediaPlayer.pause();
+        }
+    }
+
+    public void start() {
+        if (mediaPlayer != null) {
+            mediaPlayer.start();
+        }
+    }
+
+    public class MediaPlayerServiceBinder extends Binder {
+        MediaPlayerService getService() {
+            return MediaPlayerService.this;
+        }
+    }
+}

sample/src/main/java/com/chibde/audiovisualizer/sample/ServiceExampleActivity.java

@@ -0,0 +1,138 @@
+package com.chibde.audiovisualizer.sample;
+
+import android.Manifest;
+import android.content.BroadcastReceiver;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.ServiceConnection;
+import android.content.pm.PackageManager;
+import android.os.IBinder;
+import android.support.annotation.NonNull;
+import android.support.v4.content.ContextCompat;
+import android.support.v4.content.LocalBroadcastManager;
+import android.support.v7.app.AppCompatActivity;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.ImageButton;
+
+import com.chibde.visualizer.BarVisualizer;
+
+public class ServiceExampleActivity extends AppCompatActivity {
+    private MediaPlayerService mBoundService;
+    private BarVisualizer barVisualizer;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        if (getActionBar() != null) {
+            getActionBar().setDisplayHomeAsUpEnabled(true);
+        }
+        setContentView(R.layout.activity_service_example);
+        barVisualizer = findViewById(R.id.visualizer);
+
+        // set custom color to the line.
+        barVisualizer.setColor(ContextCompat.getColor(this, R.color.custom));
+
+        // define custom number of bars you want in the visualizer between (10 - 256).
+        barVisualizer.setDensity(70);
+        initialize();
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        // register LocalBroadcastManager
+        LocalBroadcastManager.getInstance(this).registerReceiver(bReceiver, new IntentFilter(MediaPlayerService.INTENT_FILTER));
+        Intent intent = new Intent(this, MediaPlayerService.class);
+        startService(intent);
+        bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
+    }
+
+    private void initialize() {
+        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M
+                && checkSelfPermission(Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
+            requestPermissions(BaseActivity.WRITE_EXTERNAL_STORAGE_PERMS, BaseActivity.AUDIO_PERMISSION_REQUEST_CODE);
+        }
+    }
+
+    @Override
+    public void onRequestPermissionsResult(
+            int requestCode,
+            @NonNull String[] permissions,
+            @NonNull int[] grantResults) {
+        switch (requestCode) {
+            case BaseActivity.AUDIO_PERMISSION_REQUEST_CODE:
+                if (grantResults.length > 0
+                        && grantResults[0] != PackageManager.PERMISSION_GRANTED) {
+                    finish();
+                }
+        }
+    }
+
+
+    public void replay(View view) {
+        mBoundService.replay();
+    }
+
+    public void playPause(View view) {
+        playPauseBtnClicked((ImageButton) view);
+    }
+
+    /**
+     * receive audio session id required for visualizer through
+     * broadcast receiver from service
+     * ref https://stackoverflow.com/a/27652660/5164673
+     */
+    private BroadcastReceiver bReceiver = new BroadcastReceiver() {
+
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            int audioSessionId = intent.getIntExtra(MediaPlayerService.INTENT_AUDIO_SESSION_ID, -1);
+            if (audioSessionId != -1) {
+                barVisualizer.setPlayer(audioSessionId);
+            }
+        }
+    };
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        stopService(new Intent(this, MediaPlayerService.class));
+        unbindService(serviceConnection);
+    }
+
+    protected void onPause() {
+        super.onPause();
+        // unregister LocalBroadcastManager
+        LocalBroadcastManager.getInstance(this).unregisterReceiver(bReceiver);
+    }
+
+    public void playPauseBtnClicked(ImageButton btnPlayPause) {
+        if (mBoundService.isPlaying()) {
+            mBoundService.pause();
+            btnPlayPause.setImageDrawable(ContextCompat.getDrawable(
+                    this,
+                    R.drawable.ic_play_red_48dp));
+        } else {
+            mBoundService.start();
+            btnPlayPause.setImageDrawable(ContextCompat.getDrawable(
+                    this,
+                    R.drawable.ic_pause_red_48dp));
+        }
+    }
+
+    private ServiceConnection serviceConnection = new ServiceConnection() {
+
+        @Override
+        public void onServiceDisconnected(ComponentName name) {
+        }
+
+        @Override
+        public void onServiceConnected(ComponentName name, IBinder service) {
+            MediaPlayerService.MediaPlayerServiceBinder myBinder = (MediaPlayerService.MediaPlayerServiceBinder) service;
+            mBoundService = myBinder.getService();
+        }
+    };
+}

sample/src/main/java/com/chibde/audiovisualizer/sample/visualizer/BarVisualizerActivity.java

@@ -36,7 +36,7 @@ protected void init() {
         barVisualizer.setDensity(70);
 
         // Set your media player to the visualizer.
-        barVisualizer.setPlayer(mediaPlayer);
+        barVisualizer.setPlayer(mediaPlayer.getAudioSessionId());
     }
 
     public void replay(View view) {

sample/src/main/java/com/chibde/audiovisualizer/sample/visualizer/CircleBarVisualizerActivity.java

@@ -29,7 +29,7 @@ public class CircleBarVisualizerActivity extends BaseActivity {
     protected void init() {
         CircleBarVisualizer circleBarVisualizer = findViewById(R.id.visualizer);
         circleBarVisualizer.setColor(ContextCompat.getColor(this, R.color.custom));
-        circleBarVisualizer.setPlayer(mediaPlayer);
+        circleBarVisualizer.setPlayer(mediaPlayer.getAudioSessionId());
     }
 
     public void replay(View view) {

sample/src/main/java/com/chibde/audiovisualizer/sample/visualizer/CircleVisualizerActivity.java

@@ -38,7 +38,7 @@ protected void init() {
         circleVisualizer.setStrokeWidth(1);
 
         // Set your media player to the visualizer.
-        circleVisualizer.setPlayer(mediaPlayer);
+        circleVisualizer.setPlayer(mediaPlayer.getAudioSessionId());
     }
 
     public void replay(View view) {

sample/src/main/java/com/chibde/audiovisualizer/sample/visualizer/LineBarVisualizerActivity.java

@@ -36,7 +36,7 @@ protected void init() {
         lineBarVisualizer.setDensity(90f);
 
         // Set your media player to the visualizer.
-        lineBarVisualizer.setPlayer(mediaPlayer);
+        lineBarVisualizer.setPlayer(mediaPlayer.getAudioSessionId());
     }
 
     public void replay(View view) {

sample/src/main/java/com/chibde/audiovisualizer/sample/visualizer/LineVisualizerActivity.java

@@ -35,7 +35,7 @@ protected void init() {
         lineVisualizer.setStrokeWidth(1);
 
         // Set you media player to the visualizer.
-        lineVisualizer.setPlayer(mediaPlayer);
+        lineVisualizer.setPlayer(mediaPlayer.getAudioSessionId());
     }
 
     public void replay(View view) {

sample/src/main/res/layout/activity_main.xml

@@ -54,9 +54,22 @@
     <Button
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_margin="8dp"
         android:background="@color/custom"
         android:onClick="lineBar"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginLeft="8dp"
+        android:layout_marginRight="8dp"
+        android:layout_marginStart="8dp"
         android:text="@string/line_bar_visualizer"
         android:textColor="@color/white"/>
+
+    <Button
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_margin="8dp"
+        android:background="@color/custom"
+        android:onClick="service"
+        android:text="@string/activity_with_service"
+        android:textColor="@color/white"/>
 </LinearLayout>

sample/src/main/res/layout/activity_service_example.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.chibde.visualizer.BarVisualizer
+        android:id="@+id/visualizer"
+        android:layout_width="match_parent"
+        android:layout_height="250dp"/>
+
+    <include layout="@layout/layout_audio_buttons"/>
+</RelativeLayout>

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

@@ -7,4 +7,5 @@
     <string name="circle_visualizer">Circle Visualizer</string>
     <string name="circle_bar_visualizer">Circle Bar Visualizer</string>
     <string name="line_bar_visualizer">Line Bar Visualizer</string>
+    <string name="activity_with_service">Activity With Service</string>
 </resources>