on-insert (augmentable only) in pasteboard%

Called before a snip is inserted from the editor, after can-insert? is called to verify that the insertion is allowed. The after-insert method is guaranteed to be called after the insert has completed.

The editor is internally locked for writing when this method is called (see also Locks). Use after-insert to modify the editor, if necessary.

• (send a-pasteboard on-insert snip before x y) -> void
     snip : snip% object
     before : snip% object or #f
   x : real number
     y : real number