How to use HSlider?

I'm thinking of using HSlider (HScroll) for mouse sensitivity adjustment in my game. I'm not sure exactly how to use it though, I added it in the layout, and when I test it, there's no knob to move around. 'getScrollPosition' always returns 0, I've tried 'setTrackSize' etc., but I'm not sure exactly what it means. I thought of checking out the EditBox source to see how it uses it, but I'm tired.

So how do I use the HScroll for this purpose?

example

scroll->setScrollRange(10);
scroll->setScrollPosition(5);
size_t pos = scroll->getScrollPosition();