Add my own event to "Sent Events" in Interface Builder menu for my own custom UIView

Question

I have created a subclass of UIView and I would like to have it publish custom events that show up in Interface Builder (actually Xcode4) the same way that controls like UIButton have a bunch of events in the "Sent Events" area when you right click on a control in the Xcode 4 designer. I know I can use Delegation (via Protocols) or Notification (via the UINotificationCenter) to let the objects using my custom view know when certain things happen, but I would like to know if the "The Target-Action Mechanism" (described in the Cocoa Fundamentals Guide) is appropriate/desirable/possible to use and be integrated with the Xcode designer. Coming from a mostly .NET background, this approach seems to be closely related to the .NET event model and makes the most sense to me.

Answer 1

There's UIControlEventApplicationReserved, which gives you a range of event identifiers that your app can use. However, I don't think there's any way to tell Interface Builder about application-defined events, so you won't get the same support for your events in IB as you find for UIControl's standard events. Instead, you'll have to specify the target and action for each app-defined event in code. (Please, someone correct me if I'm mistaken on this point.) That's not at all difficult, but it is a little different.

Answer 2

A simple way to do this is to extend UIControl instead of UIView this will allow you to add a target to all the default events (same as UIButton etc).

Note: in order for my custom UIControl to handle the events as opposed to the controls I layered on top of it I had to ensure that userInteractionEnabled = NO was set on all the layered controls.