java - How do I make the AlertDialog box appear outside the app?

Question

@Override
public void run() {
    //Create thread that can alter the UI
    AlarmPage.this.runOnUiThread(new Runnable() {
        public void run() {
            cal = Calendar.getInstance();
            //See if current time matches set alarm time
            if((cal.get(Calendar.HOUR_OF_DAY) == alarmTime.getCurrentHour()) 
                    && (cal.get(Calendar.MINUTE) == alarmTime.getCurrentMinute())){
                //If the sound is playing, stop it and rewind
                if(sound.isPlaying()){
                    ShowDialog();
                    alarmTimer.cancel();
                    alarmTask.cancel();
                    alarmTask = new PlaySoundTask();
                    alarmTimer = new Timer();
                    alarmTimer.schedule(alarmTask, sound.getDuration(), sound.getDuration());
                }
                sound.start();
            }       
        }
    });
}

public void ShowDialog() {
    final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);

    alertDialog.setTitle("REMINDER!");
    alertDialog.setMessage("Turn off alarm by pressing off");

    alertDialog.setNegativeButton("Off", new DialogInterface.OnClickListener(){
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(getApplicationContext(), "OFF", Toast.LENGTH_SHORT);
        }
    });

    alertDialog.show();
}

I am making a simple alarm clock app that notifies the user. I want to make a alert box that gives the user the option to turn off the alarm when it goes off. I was able to make the alert box, but it only appears in the app not outside of the app. I understand the app has to be in the background running. If I need to show more code or be more specific, just ask please.

Answer 1

Add a line as:

public void ShowDialog() {
    final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);

    alertDialog.setTitle("REMINDER!");
    alertDialog.setMessage("Turn off alarm by pressing off");

    alertDialog.setNegativeButton("Off", new DialogInterface.OnClickListener(){
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(getApplicationContext(), "OFF", Toast.LENGTH_SHORT).show();
        }
    });

    alertDialog.show();
    // line you have to add
    alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_TOAST);
}

check now.