on-local-char

Called by on-char when the event is not handled by a caret-owning snip.

Consider overriding on-default-char instead of this method.

• (send a-text:return-mixin on-local-char event) -> void
      event : key-event% object

  Either lets the keymap handle the event or calls on-default-char .

  If key is either return or newline, invoke the return thunk (initialization argument).