Re: validateMenuItem: called too often?

[Fred Kiefer]

Dirk Lattermann wrote:
> I just realized that validateMenuItem: (here for the Save... menu item 
> with the saveDocument: action) is called every time the mouse enters or 
> exits a TextField, a TableView, a Browser and several other UI items. 
> This is an awful lot! Is it really needed? In which cases does it make 
> sense to change the enabled-status of a menu item or pop up cell based 
> on the mouse entering or exiting an UI item?

Looks like your question did get drowned in all that look and feel stuff :-)

The validation of menu items is triggered by [NSApplication run]. For 
each event, that isn't periodic or a mouse move, the main menu is 
validated. This is done to find out if a menu item should now be 
activate or deactivated based on the state of the application. Now what 
could be the cause of switching a menu item on (or off)? Almost 
anything! The mouse being over a different GUI item, as in your case, is 
just one possible example. With context sensitive menus, just think of 
menu items sending their action to the first responder, this flexibility 
is really needed. For text fields totally different menu items apply 
than for a button, and so on.

That said, it is questionable, if we should also validate all the sub 
menus of the main menu or just the visible ones. Another point is that 
there are new menu update protocolls for MacOSX 10.3, but this is 
unrelated to your problem.

Cheers
Fred