Invalidate programmatically piano keys on android

Question

I have class Key that extends View and put objects of this class on layout. Key is key of piano and when it's pressed, it should change image to presses key. For this aim it has methods press() that change state, play note and calls invalidate() method and release() that change state and also calls invalidate() method. I want to play programatically sounds and create object of class Recorder where I put in ArrayList references to keys that will be presses. Meanwhile I create ArrayList durations with time delay before the next note. It plays well my melody, but it does not redraw keys and locks method onDraw() that I overrode. I want to show how keys play sequentially. How to fix it? I tried to run any threads like runOnUiThread for playing this melody and nothing is going.

Answer 1

OK. I solved this problem. For every key I create an instance of class that extends AsyncTask and override doInBackground() method.