While NSTabView, and thus NSTabViewController, offers several visual styles, none of them resemble the style of Xcode’s tab views. Emulating that appearance will make a fine goal. The completed application is shown in Figure 31.1.
Figure 31.1 The completed
NerdTabViewController in action
As with NSTabViewController, NerdTabViewController will display a button for each child view controller. The contents of the selected child view controller will appear below the buttons. To react to view controllers being added and removed from the controller you will override insertChildViewController(_:atIndex:) and ...