on-size

Called when the window is resized. The new size is paseed to the method. (The size values are for the entire window, not just the client area.)

• (send a-mred:wide-snip-canvas on-size width height) -> void
      width : small integer
      height : small integer

  Widens or narrows the marked snips (see add-wide-snip) so that their right-hand edges match the canvases edge