At the beginning of the project after some research on control elements
I categorized all different types of control elements. Firstly by their amount of options. For the ones with just two options (for example on/off) the subcategories are switch, rotate, push/press, pull and slide. For the multi-optional elements the first separation is between selection and regulation. The regulation elements are separated again by continuous and in steps. The last layer for alle the mulit-optional element consists of switch, rotate and slide. Except one: the continuous rotating element is finally again separated in one-directional or multi-directional.