Learning the iOS 4 SDK for JavaScript Programmers

Building the User Interface

At this point you have the working Objective-C code for Workbench, but you haven’t done anything yet to generate the button that appears in the app or to connect that button to the runMyCode: method. You’ll use the separate Xcode tool called Interface Builder (or IB) to do that.

Xcode not only generates the basic source code files for you, but it also generates the Interface Builder files you’ll use. Expand the Resources folder in the Groups & Files panel, as shown in Figure 3-8. Two of the files have names ending in the .xib extension. Although pronounced “zib,” you will more commonly hear these files referred to as “nib” files. Previous generations of Interface Builder for Mac OS development created files with the .nib extension, but for the current version of Xcode, Interface Builder generates files with the .xib extension.

About .nib and .xib Files

The name “nib” originated eons ago at NeXT Computer, the company that Steve Jobs founded in 1985. The company created a new operating system, called NeXTSTEP, and a development environment for that OS. Eventually acquired by Apple, the operating system technology found its way into Mac OS X, and the development environment, which included the NeXT Interface Builder component, grew into today’s SDKs for Mac OS X and iOS programming. You can find plenty of NeXTSTEP heritage in today’s Cocoa programming, even in the naming of various pieces. For example, the “NS” part of the NSLog() function described in this ...