file-menu:open-callback in frame:standard-menus<%>

This method is called when the open menu-item of the file-menu menu is selected.

• (send a-frame:standard-menus file-menu:open-callback item evt) -> void
     item : (instance (derived-from menu-item%))
     evt : (instance control-event%)

  Defaultly bound to:

  (λ (item control) (handler:open-file) #t)