These events are generated by wWindow when the window is scrolling. Notice that these events are very similar to wScrollEvent but not derive from wCommandEvent. It means, these events won't propagate upwards by default.

wEvent_ScrollWinSent to window before all of following event. Use getKind() to know what kind of type it is.
wEvent_ScrollWinTopScroll to top or leftmost.
wEvent_ScrollWinBottomScroll to bottom or rightmost.
wEvent_ScrollWinLineUpScroll line up or left
wEvent_ScrollWinLineDownScroll line down or right.
wEvent_ScrollWinPageUpScroll page up or left.
wEvent_ScrollWinPageDownScroll page down or right.
wEvent_ScrollWinThumbTrackFrequent events sent as the user drags the thumbtrack.
wEvent_ScrollWinThumbReleaseThumb release events.
wEvent_ScrollWinChangedEnd of scrolling events


wEvent_ScrollWinFirst = 32770
wEvent_ScrollWin = 32771
wEvent_ScrollWinTop = 32772
wEvent_ScrollWinBottom = 32773
wEvent_ScrollWinLineUp = 32774
wEvent_ScrollWinLineDown = 32775
wEvent_ScrollWinPageUp = 32776
wEvent_ScrollWinPageDown = 32777
wEvent_ScrollWinThumbTrack = 32778
wEvent_ScrollWinThumbRelease = 32779
wEvent_ScrollWinChanged = 32780
wEvent_ScrollWinLast = 32781


method getKind(self: wScrollWinEvent): int {...}{.inline, raises: [], tags: [].}
Returns what kind of event type this is. Basically used in wEvent_ScrollWin.
method getOrientation(self: wScrollWinEvent): int {...}{.inline, raises: [], tags: [].}
Returns wHorizontal or wVertical
method getScrollPos(self: wScrollWinEvent): int {...}{.raises: [], tags: [].}
Returns the position of the scrollbar.