The FXScrollbar class has been renamed to FXScrollBar.

When the new SCROLLBAR_WHEELJUMP option is passed for an FXScrollBar widget, moving the mouse wheel inside the scroll bar will "jump scroll" instead of performing smooth scrolling. This jump scrolling mode is useful when you're scrolling complicated contents which are difficult to redraw quickly. In a related change, the FXScrollArea widget will automatically activate this option for its scroll bars when you pass the SCROLLERS_DONT_TRACK option to the FXScrollArea.