on-size

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

• (send an-editor-canvas on-size width height) -> void
      width : exact integer in [0, 10000]
      height : exact integer in [0, 10000]

  If the canvas is dispalying an editor, its on-display-size method is called.