resized in editor<%>

Called (indirectly) by snips within the editor: it forces a recalculation of the display information in which the specified snip has changed its size.

• (send an-editor resized snip redraw-now?) -> void
     snip : snip% object
     redraw-now? : boolean

  If redraw-now? is #f, the editor will require another message to repaint itself. (See also needs-update.)