Calculate the scrollbar range and page_step size for scrolling in pixels.
void CL_ScrollBar::calculate_ranges( int view_size, int total_size);
Detailed description:
This is equal to calling set_min(0), set_max(total_size-view_size) and set_page_step((total_size-scroll_max)*scroll_max)/(total_size)). The range of the scrollbar will be the amount of pixels the view needs to be moved to show all the data.