In Chapters 3 and 4, we covered some of the basics involved in creating a user interface in Interface Builder and using a target/action to connect it to application code written in Xcode. We’ve really only scratched the surface so far, but you should be happy to know that the target/action system you learned to use in the last two chapters is used by almost all of the user interface objects in Cocoa. If you’re not quite sure what’s so great about that, you might want to review Chapter 3 just one more time to be sure you’ve grasped the target/action concept.
By now, you’ve surely noticed the wide variety of user interface objects listed in Interface Builder’s Object Library pane. Now it’s time to dig deeper into Cocoa’s ...