android - getting java.lang.IllegalStateException: The current thread must have a looper

I am getting this error, and my application crashes:

java.lang.IllegalStateException: The current thread must have a looper!

I didn't get much about how to use looper on Google, I am using threads(mainly for sleep function), handler(for downloading the image while Async task is running) and Async task(for getting the JSON data from the URL). I have no idea how to resolve this issue, so any suggestions will be vey helpful.

This is the code for the thread which is executed on click of the button:

View view = flingContainer.getSelectedView();
          view.findViewById(R.id.item_swipe_right_indicator).setAlpha((float) 1.0);

        Thread timer = new Thread() {
            public void run() {

                try {
                    sleep(320);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    flingContainer.getTopCardListener().selectLeft();
                }
            }
        };
        timer.start();

I am using this libray and log-cat is:

where: at com.enormous.quotesgram.MainActivity$3.run(MainActivity.java:479) in last in log-cat corresponds to the line: flingContainer.getTopCardListener().selectLeft(); in above piece of code.