Stop all playbacks from own application when activity starts

I am aware that when I want to stop other application from playing audio, I use audiofocus: http://ift.tt/1py0w48

However, I want to stop the audio that has been started by my own application.

I have few activities, one is the main screen, then the list of songs, each with own play/pause button. That works fine, when I hit play:

1. I check if I am already playing something and if so, I stop the player.


2. I start the song and set playing = songTitle so I will know that I'm already playing something.

However, when I change the activity or even go back from application to desktop, the music still plays - that's fine. But when I go back to my application it does not know that I am already playing a song and now when I click the song, two songs are playing at the same time.

What I want to do:

To make it work I would like to stop all the music I started to play (if any) on the very start of the onCreate for my SongsActivity. The problem is, I cannot just craete a new MediaPlayer and use stop() method because it's not attached with the songs that was previously started by another instance of MediaPlayer.

I use the WebView to display the interface:

public class SongsActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final String path = getExternalFilesDir(null).toString() + "/";
    final WebView webView = (WebView) findViewById(R.id.webview);
    webView.getSettings().setJavaScriptEnabled(true);
    final MediaPlayer mediaPlayer = MediaPlayer.create(getApplicationContext(), R.raw._first_song);

    WebViewClient webViewClient= new WebViewClient(){
        String playing = ""; //what we have started lately
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url)
        {
            if(url.contains("mp3")){
                String songTitle = url.replace("file:///android_asset/mp3-", "");
                if(mediaPlayer.isPlaying()){
                    mediaPlayer.stop();
                }

                if(!playing.equals(songTitle)) {

                    mediaPlayer.reset();
                    int resID = getApplicationContext().getResources().getIdentifier("_" + songTitle, "raw", getApplicationContext().getPackageName());

                    try {
                        AssetFileDescriptor afd = getApplicationContext().getResources().openRawResourceFd(resID);
                        if (afd != null) {
                            mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
                        }
                        afd.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    try {
                        mediaPlayer.prepare();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    playing = songTitle;
                    mediaPlayer.start();
                    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){

                        @Override
                        public void onCompletion(MediaPlayer mp) {
                            webView.reload(); //so the pause button will restart to play state
                        }
                    });
                }
            }
            return true;
        }

        @Override
        public void onLoadResource(WebView  view, String  url){}
    };
    webView.setWebViewClient(webViewClient);
    webView.loadUrl("file:///android_asset/songs.html");
}
...

}