September 2002
Intermediate to advanced
1272 pages
31h 12m
English
Content preview from Cocoa® Programming
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Menu Validation
The Application Kit implements menus with the NSMenu class. After each user event, visible menu items are automatically validated. By default, a menu item is valid, and therefore enabled, if its target can respond to its action. If no object that responds to the menu item’s action is found, the menu item is invalid and disabled.
When the target for a menu item is a specific object, default validation is simple. The target either responds to the action or it does not. When the target of a menu item is nil the expanded responder chain is searched to validate the menu item. If any object in the expanded responder chain responds to the action the menu item is valid. Otherwise, it is invalid.
The default validation can be enhanced ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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