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I find this an extremely useful way to organize my code projects. You will see a worked example of this shortly.

When you create a new project or class file in Xcode, notice that there is a brief author and copyright statement in a comment at the top of each file; however, you will look in vain for an Xcode Preferences item that sets the values you see here. In fact, these settings are managed completely outside Xcode, in the Mac OS X Address Book! Xcode will pick up your record (often called the Me record) from Address Book to provide the name (only the first and last names are picked up from this record by Xcode). If your record has a Company Name entry, that will go into the copyright statement. If you don t have a Company Name in your Me record, the copyright statement will read Copyright __MyCompanyName__ 2009.

The toolbar in the Project Workspace provides expected shortcuts to many common functions. The shortcuts available depend on the layout you choose (see Figure 2 6 for the standard options), but as usual with Apple software you can customize the toolbar to have exactly the features you want (right-click on the toolbar and choose Customize Toolbar...).

Note the toolbar in the All-In-One layout in particular. I like this layout because it keeps everything within the range of a single click, and this is illustrated nicely with the Page button group on the left. This allows you to switch between coding and debugging page views when you are running your application. Another very useful button is the Breakpoints button. This allows you to turn all of your breakpoints on and off in one click. Note that the Build and Run button changes to Build and Debug when breakpoints are set; if you disable breakpoints, the appearance changes back to Build and Run. This is all probably best illustrated with a quick example. Let s add some code, put in a breakpoint, and run the application. If you are not in All-In-One layout, close your project (as I mentioned a while back, Xcode does not allow you to change layouts while a project is open), go to Xcode Preferences... or use the keyboard shortcut , (that s Command and a comma), find the General Preferences panel, and choose All-In-One from the popup named Layout:. Now open your project again and select the file My_First_ProjectAppDelegate.m (click on the filename in the Detail view). Listing 2 1 shows how the code looks in the Editor view.

Listing 2 1. My_First_ProjectAppDelegate.m // // // // // // My_First_ProjectAppDelegate.m My First Project Created by Ian Piper on 23/08/2009 Copyright 2009 Tellura Information Services. All rights reserved.

#import "My_First_ProjectAppDelegate.h" @synthesize window; - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { // Insert code here to initialize your application }

Don t worry too much about following the code for now. All you are going to do is to add a line of code to log a message in the Console. Add the line indicated in bold in Listing 2 2.

Listing 2 2. Adding a logging statement [ ] - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { // Insert code here to initialize your application NSLog(@"Application has initialized"); } [ ]

TIP: The NSLog command is a convenient way to add debugging messages to your applications; the message is displayed in the console. You can use this to display variable values too, which can be useful when bug tracking. Now you need to set a breakpoint. Click once in the gray border to the left of the line of code you just added. You will see a blue arrow in the border (see Figure 2 7). This is a breakpoint an instruction to the compiler to halt execution when it reaches this point.