HelenOS sources

ui_slider_btn_h   250 uspace/lib/ui/src/slider.c 		rect->p1.y = pos.y + ui_slider_btn_h;
ui_slider_btn_h   290 uspace/lib/ui/src/slider.c 	rect.p0.y = pos.y + ui_slider_btn_h / 2 - ui_slider_groove_width / 2;
ui_slider_btn_h   293 uspace/lib/ui/src/slider.c 	rect.p1.y = pos.y + ui_slider_btn_h / 2 + ui_slider_groove_width / 2;
HelenOS homepage, sources at GitHub