April 2004
Intermediate to advanced
480 pages
8h 29m
English
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Chapter 25. Updating Menus
In many applications, it is necessary to enable and disable menu items as the user interacts with the application. In particular, as the first responder changes, a menu item that is nil-targeted will need to be disabled if the responder chain does not respond to its action. By default, this activity is handled for you. When displaying itself, the menu item will automatically figure out if the current target has the appropriate action. If it does not, the menu item will be disabled.
When a menu item is deciding whether it should be enabled, it will ask its target if it implements validateMenuItem:. If so, the target is sent validateMenuItem:. If the target returns YES, the menu item is enabled.
To enable and disable menu ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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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