application-preferences-handler in System Menus

When the current eventspace is the initial eventspace, this procedure retrieves or installs a thunk that is called when the user selects the application Preferences menu item in Mac OS X. The thunk is always called in the initial eventspace's handler thread (as a callback). If the handler is set to #f, the Preferences item is disabled.

The default handler is #f.

• (application-preferences-handler) -> procedure of no arguments or #f

  If the current eventspace is the initial eventspace, returns the current handler, otherwise returns #f.

  
  

• (application-preferences-handler handler-thunk) -> void
     handler-thunk : procedure of no arguments or #f

  If the current eventspace is the initial eventspace, sets the current handler or disables the Preferences item, otherwise does nothing.