I don't understand the step size of the fast table scroll bar.
What does container bottom have to do with delta & pageDelta?
recalculateVerticalScrollBar
| interval delta pageDelta visibleRows numberOfRows |
self hasDataSource ifFalse: [ ^ self ].
self recalculateVerticalScrollBarVisibilityIfHidden: [ ^ self ].
visibleRows := self container calculateExactVisibleRows.
numberOfRows := self dataSource numberOfRows.
interval := (visibleRows / numberOfRows) asFloat.
delta := 1/(self container bottom).
pageDelta := (self innerBounds height - 10) / (self container bottom).
self verticalScrollBar
scrollDelta: delta pageDelta: pageDelta;
interval: interval
