Called on window updates to validate the visible items.
- macOS 10.0+
You typically use this method by overriding it in a subclass. The default implementation of this method iterates through the list of visible items, sending each a
validate message. Override it and call
super if you want to know when this method is called.
In macOS 10.6 and later toolbars no longer automatically validate for some events, including:
NSKey. In addition, validation for
NSFlags events is deferred with the timer restarting for every new deferrable event. So a sequence of key events will not trigger any validation at all, until either a pause of .85 seconds, or an event other than
NSFlags is processed. This change was made as an optimization.