on-scroll

   

Called when the value of one of the canvas's scrollbars changes.

• (send a-wx:canvas on-scroll event) -> void
      event :  wx:command-event% object

  The get-command-int method of event returns the position of the scrollbar.

  The get-extra-long method od of event returns either  wx:const-horizontal or  wx:const-vertical.

  The get-event-type method of event returns one of:

  •  wx:const-event-type-scroll-linedown -- called when the scrollbar is incremented by a line, by clicking on the bottom arrow of a vertical scrollbar or right-hand arrow of a horizontal scrollbar
  •  wx:const-event-type-scroll-lineup -- called when the scrollbar is decremented by a line, by clicking on the top arrow of a vertical scrollbar or left-hand arrow of a horizontal scrollbar
  •  wx:const-event-type-scroll-pagedown -- called when the scrollbar is incremented by a page
  •  wx:const-event-type-scroll-pageup -- called when the scrollbar is decremented by a page
  •  wx:const-event-type-scroll-top -- called when the scrollbar is set to the top
  •  wx:const-event-type-scroll-bottom -- called when the scrollbar is set to the bottom
  •  wx:const-event-type-scroll-thumbtrack -- called when the the scrollbar is being dragged