app/src/main/java/me/tatarka/support/job/sample/MainActivity.java
public void onReceivedStopJob() {
        mShowStopView.setBackgroundColor(stopJobColor);
        Message m = Message.obtain(mHandler, MSG_UNCOLOUR_STOP);
        mHandler.sendMessageDelayed(m, 2000L); // uncolour in 1 second.
        mParamsTextView.setText("");
    }
public void onReceivedStopJob() {
        mShowStopView.setBackgroundColor(stopJobColor);
        Message m = Message.obtain(mHandler, MSG_UNCOLOUR_STOP);
        mHandler.sendMessageDelayed(m, 2000L); // uncolour in 1 second.
        mParamsTextView.setText("");
    }
Receives callback from the service when a job that previously landed on the app must stop
executing. Colours the UI and post a message to uncolour it after a second.