Cocoa Programming for OS X: The Big Nerd Ranch Guide

Controls and Outlets

So far, you have not needed outlets to the sliders. Everything has been done within the action methods, so you have been able to use sender to access these controls. But if you want to access a control outside of its action method, you need to create and connect an outlet.

One place you might want to access a control is the NSWindowController method windowDidLoad(). This method is called after the objects and their connections are loaded from the NIB but before the window is displayed to the user. It is where you can do extra initialization for your interface.

In this section, you are going to override windowDidLoad() to ensure that when the app starts, the sliders and the color well correspond to the default ...