void
ScrollBar::SetSlider(unsigned size, unsigned view_size,
unsigned origin)
{
const int netto_height = GetNettoHeight();
// If (no size) slider fills the whole area (no scrolling)
int height = size > 0
? (int)(netto_height * view_size / size)
: netto_height;
// Prevent the slider from getting to small
if (height < GetWidth())
height = GetWidth();
if (height > netto_height)
height = netto_height;
// Calculate highest origin (counted in ListItems)
unsigned max_origin = size - view_size;
// Move the slider to the appropriate position
int top = (max_origin > 0) ?
((netto_height - height) * origin / max_origin) : 0;
// Prevent the slider from getting to big
// TODO: not needed?!
if (top + height > netto_height)
height = netto_height - top;
// Update slider coordinates
rc_slider.left = rc.left;
rc_slider.top = rc.top + GetWidth() + top;
rc_slider.right = rc.right;
rc_slider.bottom = rc_slider.top + height;
}
/**
* Returns the height of the visible scroll area of the ScrollBar
* (the area thats not covered with the slider)
*/
PixelScalar GetScrollHeight() const {
return GetNettoHeight() - GetSliderHeight();
}
