public class TextDelayWatcher implements TextWatcher {

    private OnActionListener onActionListener;
    private Handler handler;
    @Nullable
    private Timer timer;
    @Nullable
    private Runnable runnable;

    public TextDelayWatcher(OnActionListener onActionListener) {
        this.onActionListener = onActionListener;
        this.handler = new Handler();
    }

    @Override
    public void afterTextChanged(final Editable arg0) {
        // user typed: start the timer
        timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                runnable = new Runnable() {
                    @Override
                    public void run() {
                        onActionListener.onAction(arg0);
                    }
                };
                handler.post(runnable);
            }
        }, 400); // 600ms delay before the timer executes the „run“ method from TimerTask
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // nothing to do here
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        // user is typing: reset already started timer (if existing)
        clear();
    }

    public void onDestroy() {
        clear();
        onActionListener = null;
    }

    public void clear() {
        if (timer != null) {
            timer.cancel();
            timer = null;
        }
        if (runnable != null) {
            handler.removeCallbacks(runnable);
            runnable = null;
        }
    }

    public interface OnActionListener {
        void onAction(Editable editable);
    }
}