You doubt when calling back the activity with a certain fragment from the notification bar

Good morning,

I have an application that uses a layout in barra de notificaciones . Within the layout, I have a botón with an icon which if I put it is abre la aplicación with the main activity. The problem arises, because what it opens is as if it were a new activity, in which everything I have done is lost. I would like it when the button was pressed, what I already had was opened and the notifications bar was retracted.

The code of the button is as follows:

private void openActivity(){
    Intent myIntent = new Intent(parent, MainActivity.class);
    myIntent.putExtra("key", "open"); //Optional parameters
    parent.startActivity(myIntent);
}

But as I said before, this only opens the application of 0, however if I am outside the app and I press the button of the square that shows the open applications and then I click on my app, it opens as I want.

So necesito que el botón abra la aplicación que ya está abierta en segundo plano .

This is my class for the notification bar:

public class NotificationPanel extends BroadcastReceiver {

private static Context parent;
private static NotificationManager nManager;
private static NotificationCompat.Builder nBuilder;
private static RemoteViews remoteView;
private static RadioOnline radio;
private static final String MyOnClick1 = "IconButton";
private static final String MyOnClick2 = "ButtonStop";
private static final String MyOnClick3 = "ButtonPlay";

public NotificationPanel() {
}

public NotificationPanel(Context parent, RadioOnline radio) {
    this.parent = parent;
    this.radio = radio;
    nBuilder = new NotificationCompat.Builder(parent)
            .setContentTitle("Radio ECCA")
            .setContentText("Radio Online activada")
            .setSmallIcon(R.mipmap.ic_launcher)
            .setPriority(Notification.PRIORITY_HIGH)
            .setOngoing(true);

    remoteView = new RemoteViews(parent.getPackageName(), R.layout.notification_layout);


    setListeners(remoteView);//Llama al método que genera los botones a la escucha.
    nBuilder.setContent(remoteView);

    nManager = (NotificationManager) parent.getSystemService(Context.NOTIFICATION_SERVICE);
    nManager.notify(2, nBuilder.build());

}

public void setListeners(RemoteViews view){
    view.setOnClickPendingIntent(R.id.imageButtonNbarLogo, getPendingSelfIntent(parent, MyOnClick1));
    view.setOnClickPendingIntent(R.id.btnStopNbar, getPendingSelfIntent(parent, MyOnClick2));
    view.setOnClickPendingIntent(R.id.btnPlayNbar, getPendingSelfIntent(parent, MyOnClick3));
}

protected PendingIntent getPendingSelfIntent(Context context, String action){
    Intent icon = new Intent(context, getClass());
    icon.setAction(action);
    return PendingIntent.getBroadcast(context, 0, icon, 0);
}

@Override
public void onReceive(Context context, Intent intent) {
    if (MyOnClick1.equals(intent.getAction())) {
        Toast.makeText(context, "Icono tocado", Toast.LENGTH_SHORT).show();
        Log.w("Widget", "Clicked Icon");
        openActivity();
    }else if (MyOnClick2.equals(intent.getAction())){
        //Toast.makeText(context, "Botón Stop tocado", Toast.LENGTH_SHORT).show();
        Log.w("Widget", "Clicked button stop");
        try {
            pararRadio();
            activarPlay();
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(context, e.getMessage(), Toast.LENGTH_LONG).show();
        }
    }else if (MyOnClick3.equals(intent.getAction())){
        //Toast.makeText(context, "Botón Play tocado", Toast.LENGTH_SHORT).show();
        Log.w("Widget", "Clicked button play");
        try {
            if (radio.isNetworkConnectedRemote(parent)){
                Toast.makeText(context, "Hay internet", Toast.LENGTH_LONG).show();
                activarStop();
            }
        } catch (Exception e) {
            Toast.makeText(context, e.getMessage(), Toast.LENGTH_LONG).show();
            e.printStackTrace();
        }
    }
}

public void notificationCancel() {
    nManager.cancel(2);
}

private void pararRadio() throws Exception {
    Log.w("Widget", "Dentro del método pararRadio");

    if (this.radio.getPlayer().isPlaying())
    {
        Log.w("Widget", "Se está reproduciendo");

        try
        {
            this.radio.stopPlaying();
        }
        catch (Exception e) {
            e.printStackTrace();
            throw new Exception("Se ha producido un error al parar el reproductor\n"+e);
        }
    }
}

private void iniciarRadio() throws Exception {
    Log.w("Widget", "Dentro del método pararRadio");

    if (this.radio.getPlayer().isPlaying())
    {
        Log.w("Widget", "Se está reproduciendo");
    }else{
        try
        {
            this.radio.startPlayingRemote();
        }
        catch (Exception e) {
            e.printStackTrace();
            throw new Exception("Se ha producido un error al inicializar el reproductor\n"+e);
        }
    }
}

private void activarPlay(){
    Resources res = parent.getResources();
    String mystring = res.getString(R.string.infoNbarStoped);
    this.remoteView.setViewVisibility(R.id.btnStopNbar, View.INVISIBLE);
    this.remoteView.setViewVisibility(R.id.btnPlayNbar, View.VISIBLE);
    //this.remoteView.setBoolean(R.id.btnPlayNbar, "setEnabled", true);
    this.remoteView.setTextViewText(R.id.messageNbar, mystring);
    nManager.notify(2, nBuilder.build());
}

private void activarStop(){
    Resources res = parent.getResources();
    String mystring = res.getString(R.string.infoNbar);
    this.remoteView.setViewVisibility(R.id.btnStopNbar, View.VISIBLE);
    this.remoteView.setViewVisibility(R.id.btnPlayNbar, View.INVISIBLE);
    //this.remoteView.setBoolean(R.id.btnPlayNbar, "setEnabled", true);
    this.remoteView.setTextViewText(R.id.messageNbar, mystring);
    nManager.notify(2, nBuilder.build());
}

private void openActivity(){
    Intent myIntent = new Intent(parent, MainActivity.class);
    myIntent.putExtra("key", "open"); //Optional parameters
    parent.startActivity(myIntent);
}
}

Greetings, I'm learning a lot with you.