@Override
    public void updateProgress(final float progress, final int downloadingState) {

        runOnUiThread(new Runnable() {
            @Override
            public void run() {

             Toast.makeText(MainActivity.this, "Downloading... " + progress, Toast.LENGTH_SHORT).show();

                if (progress > 0 && progress < 100) {
                    progress_bar_download.setVisibility(View.VISIBLE);
                    progress_bar_download.setProgress((int) progress);
                }  else {
                    progress_bar_download.setVisibility(View.GONE);
                }
            }
        });
    }