+ (let ((active mouse-wheel-mode))
+ ;; Deactivate before changing the setting.
+ (when active (mouse-wheel-mode -1))
+ (set-default var button)
+ (when active (mouse-wheel-mode 1))))
+
+(defvar mouse-wheel-down-button 4)
+(make-obsolete-variable 'mouse-wheel-down-button
+ 'mouse-wheel-down-event)
+(defcustom mouse-wheel-down-event
+ ;; In the latest versions of XEmacs, we could just use mouse-%s as well.
+ (if (memq window-system '(w32 mac))
+ 'wheel-up
+ (intern (format (if (featurep 'xemacs) "button%s" "mouse-%s")
+ mouse-wheel-down-button)))
+ "Event used for scrolling down."
+ :group 'mouse
+ :type 'symbol
+ :set 'mouse-wheel-change-button)