void EZ_UpdateScrollbar(EZ_Widget *scr, int tsize,
int dsize, int start)
This function update the state of a scrollbar.
void EZ_GetScrollbarState(EZ_Widget *scr, int *tsize,
int *dsize, int *start)
This function returns the state of a scrollbar.
int EZ_SetScrollbarDiscreteSpeed(EZ_Widget *scr, int speed)
This function returns the current discrete scrolling speed.
This function sets the discrete scrolling speed of a scrollbar. The discrete scrolling speed is used when the arrow button is pressed or the arrow key is pressed when a scrollbar is in focus.