Re: issue with auto-enable of Menus

[Wolfgang Lux]

> Am 13.11.2017 um 19:13 schrieb David Chisnall <theraven@sucs.org>:
> 
>> On 13 Nov 2017, at 17:52, Wolfgang Lux <wolfgang.lux@gmail.com> wrote:
>> 
>>> Would it make sense to not have custom code to enable/disable menu items, 
>>> and just have appkit do it for you depending on the target?
>> 
>> In my experience, custom code is unavoidable in almost any non-trivial case 
>> because the AppKit is not able to determine exactly when a menu item is 
>> applicable and when not. Having support for the selectors is a necessary but 
>> not a sufficient condition.
> 
> IOKit improves this relative to AppKit by adding the delegates to the 
> responder chain.  For custom views, I’ve taken to doing this and forwarding 
> some of the responder chain queries to the delegate.  It would also be nice 
> if there were some convention such as {selector}IsEnabled, so if you 
> implement -paste: and -pasteIsEnabled then you can turn off paste by 
> returning NO to -pasteIsEnabled.

Well, that almost exists in the form of -validateMenuItem: and 
-validateUserInterfaceItem:. It’s just that you implement just a single method 
that receives a selector argument rather than an individual method for each 
selector.

Wolfgang