NSToolbarItem子类不调用事件

Question

I've created a subclass for NSToolbarItem and am trying to catch the -(void)mouseDown:(NSEvent *)theEvent in order to change its state (that's what I added in my subclass as NSToolbarItem doesn't support states out of the box).

Problem is that the event mouseDown: is never called, even though I set my toolbar items' class identities in Interface Builder to the one of my new class.

Why is this? NSToolbarItem is related to NSView , so it should be capable of events no?

Answer 1

NSToolbarItem is a subclass of NSObject, not of NSResponder. The event is never called because it is never supposed to handle any. An NSToolbarItem is like a NSDictionary for an NSToolbar, it stores what it needs to draw.