FloatingViewService.java

//The root element of the collapsed view layout
final View collapsedView = mFloatingView.findViewById(R.id.collapse_view);
//The root element of the expanded view layout
final View expandedView = mFloatingView.findViewById(R.id.expanded_container);

//Set the close button
ImageView closeButtonCollapsed = (ImageView) mFloatingView.findViewById(R.id.close_btn);
closeButtonCollapsed.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        //close the service and remove the from from the window
        stopSelf();
    }
});

//Set the view while floating view is expanded.
//Set the play button.
ImageView playButton = (ImageView) mFloatingView.findViewById(R.id.play_btn);
playButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Toast.makeText(FloatingViewService.this, "Playing the song.", Toast.LENGTH_LONG).show();
    }
});

//Set the next button.
ImageView nextButton = (ImageView) mFloatingView.findViewById(R.id.next_btn);
nextButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Toast.makeText(FloatingViewService.this, "Playing next song.", Toast.LENGTH_LONG).show();
    }
});

//Set the pause button.
ImageView prevButton = (ImageView) mFloatingView.findViewById(R.id.prev_btn);
prevButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Toast.makeText(FloatingViewService.this, "Playing previous song.", Toast.LENGTH_LONG).show();
    }
});

//Set the close button
ImageView closeButton = (ImageView) mFloatingView.findViewById(R.id.close_button);
closeButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        collapsedView.setVisibility(View.VISIBLE);
        expandedView.setVisibility(View.GONE);
    }
});

//Open the application on thi button click
ImageView openButton = (ImageView) mFloatingView.findViewById(R.id.open_button);
openButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        //Open the application  click.
        Intent intent = new Intent(FloatingViewService.this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);

        //close the service and remove view from the view hierarchy
        stopSelf();
    }
});