void ScrollBox::__Update(const Point2i & mousePosition,
const Point2i & /*lastMousePosition*/)
{
// update position of items because of dragging
if (HasScrollBar() && scroll_mode!=SCROLL_MODE_NONE) {
int max_offset = GetMaxOffset();
int new_offset = offset;
if (scroll_mode == SCROLL_MODE_THUMB) {
Point2i track_pos = GetScrollTrackPos();
int height = GetTrackHeight();
new_offset = start_drag_offset +
((mousePosition.y - start_drag_y) * (size.y+max_offset))/height;
} else if (scroll_mode == SCROLL_MODE_DRAG) {
// Act as if the scroll corresponds to bringing the starting point to the
// current point
new_offset = start_drag_offset + start_drag_y - mousePosition.y;
}
if (new_offset < 0)
new_offset = 0;
if (new_offset > max_offset)
new_offset = max_offset;
if (new_offset != offset) {
offset = new_offset;
Pack();
}
}
}
//
/// Responds to the specified horizontal scrollEvent by calling ScrollBy or ScrollTo.
/// The type of scroll event is identified by the corresponding SB_ constants.
/// The 16-bit thumbPos argument is ignored. The function retrieves the 32-bit value
/// directly from the scroll bar instead.
//
void
TScroller::HScroll(uint scrollEvent, int)
{
switch (scrollEvent) {
case SB_LINEDOWN:
ScrollBy(XLine, 0);
break;
case SB_LINEUP:
ScrollBy(-XLine, 0);
break;
case SB_PAGEDOWN:
ScrollBy(XPage, 0);
break;
case SB_PAGEUP:
ScrollBy(-XPage, 0);
break;
case SB_TOP:
ScrollTo(0, YPos);
break;
case SB_BOTTOM:
ScrollTo(XRange, YPos);
break;
case SB_THUMBPOSITION:
ScrollTo(GetScrollTrackPos(SB_HORZ), YPos);
break;
case SB_THUMBTRACK:
{
int thumbPos32 = GetScrollTrackPos(SB_HORZ);
if (TrackMode)
ScrollTo(thumbPos32, YPos);
if (Window && HasHScrollBar)
SetScrollPos(SB_HORZ, thumbPos32, true);
break;
}
}
}
//
/// Responds to the specified vertical scrollEvent by calling ScrollBy or ScrollTo.
/// The type of scroll event is identified by the corresponding SB_ constants.
/// The 16-bit thumbPos argument is ignored. The function retrieves the 32-bit value
/// directly from the scroll bar instead.
//
void
TScroller::VScroll(uint scrollEvent, int)
{
switch (scrollEvent) {
case SB_LINEDOWN:
ScrollBy(0, YLine);
break;
case SB_LINEUP:
ScrollBy(0, -YLine);
break;
case SB_PAGEDOWN:
ScrollBy(0, YPage);
break;
case SB_PAGEUP:
ScrollBy(0, -YPage);
break;
case SB_TOP:
ScrollTo(XPos, 0);
break;
case SB_BOTTOM:
ScrollTo(XPos, YRange);
break;
case SB_THUMBPOSITION:
ScrollTo(XPos, GetScrollTrackPos(SB_VERT));
break;
case SB_THUMBTRACK:
{
int thumbPos32 = GetScrollTrackPos(SB_VERT);
if (TrackMode)
ScrollTo(XPos, thumbPos32);
if (Window && HasVScrollBar)
SetScrollPos(SB_VERT, thumbPos32, true);
break;
}
}
}
