Type Definition lvgl::widgets::bar::lv_design_cb_t

type lv_design_cb_t = Option<unsafe extern "C" fn(obj: *mut _lv_obj_t, clip_area: *const lv_area_t, mode: lv_design_mode_t) -> lv_design_res_t>;

The design callback is used to draw the object on the screen. It accepts the object, a mask area, and the mode in which to draw the object.