This tutorial shows you how to create your first Cocoa app. It assumes no previous experience with programming or Xcode.

The app you will create contains no code, yet still has some impressive functionality. It's a basic starting point only, but enough to get you going. You must be using Xcode on Mac OS X 10.4 Tiger (click here for Leopard version).

This tutorial is written and illustrated by Scott Stevenson

First, Launch Xcode. If you have not installed Xcode, you can find it on your Mac OS X installation CD or the disk that came with your Mac. The installer is called Xcode Tools.

Once Xcode is running, open Preferences and set your Layout to All-in-One.

All-in-One is the layout preferred by many pros, and is used in all of the visuals in this tutorial.

After you've changed the layout, close the Preferences window and choose File → New Project

Choose Cocoa Application. Some of the items in the project list have similar names, so choose carefully. Click the Next button, and you'll be asked to name the project:

Name the project "CocoaNotepad". You can choose any location you like. It's good to put all of your projects in one location, so ~/Development/CocoaNotepad might be a good choice.

Once you create the project, the main Xcode window appears. The Xcode window has several views you can switch between using the Pages toolbar item.

This is the Project View. It lists files, search results, build settings, and more. Clicking the Build and Go toolbar item will compile your application and run it.

There's a dropdown in the toolbar labeled Active Build Configuration, initially set to Debug.

This dropdown controls build settings. You'd set this to Release and re-build if you want to run your application outside of Xcode. Leave it set to Debug for now.

The Pages segmented control at the far left of the toolbar allows you to switch between the Project, Build, and Debugging views.

Switch to the Build View by clicking the middle icon in the Pages toolbar item. The rest of this tutorial will use this view exclusively.

In the Build View, unfold the CocoaNotepad group, then the Resources folder. Double-click the MainMenu.nib item to open it in Interface Builder.

Interface Builder is used by Cocoa programmers to lay out the user interface of an application.

The Application Window and is where you place controls that the user will see. The Menu displays the contents of your application's menu bar. You can double-click menu items to rename them or simply select them to move or delete them.

The Object Palette contains stock items in Cocoa that you can add to your application via drag-and-drop. Open the object palette now using Tools → Palettes → Show Palettes.

The Document Window displays the contents of the MainMenu.nib file itself. The user doesn't see this in the application — it's only used during development. (Keep in mind that anyone can open an application's NIB file, though.)

The items in the object palette can be dragged out and dropped onto the application window. The icons along the top of the palette represent groups of items. You can hover the mouse over the groups and items to see their names.

The third toolbar icon from the left displays the Cocoa Text group. Click on it to display the group contents, then drag NSTextView to the application canvas.

Place the text view near the top-left of the window, then resize it using the handles around the outside:

It should nearly fill the window, with a bit of space on the bottom. The exact size is not important.

Finally, we need to set the sizing attributes for the text view so that it keeps the same proportions as the window. Select the text view and choose Tools → Show Inspector, then select Size from the dropdown at the top of the inspector window.

The bottom half of the inspector window contains a section labeled Autosizing. These are called "spring and struts."

Click the horizontal and vertical lines in the internal box so that they change to springs. This will cause the text view's internal size to grow and shrink with the window.

Select the Cocoa Menus group in the object palette. In most cases, this is the first group in the toolbar.

Drag the Format menu item from the palette over to the application menu bar and drop it between Edit and Window.

Save MainMenu.nib by pressing ⌘-S. If you are asked to select a format, choose the 10.2 and later option.

Switch back to Xcode, then build and run the application by pressing ⌘-R, or by simply choose Build → Build and Run.

Even though this project doesn't have a single line of custom code, you can see that we already have a working application. Choose Format → Font → Show Fonts to choose a font and start typing.

It can't save files, but it uses Cocoa's built-in text view so you can use fonts, colors, international text, and spell checking. It also support drag-and-drop, text search, and many other features.

The application also supports printing and can create PDF files. To try this out, simply choose File → Print. Click Preview in the print dialog to convert the text to a PDF.

This document can be treated as any other PDF document, including text selection, searching and annotation.

The goal of this tutorial is just to give you a taste of what Cocoa has to offer. Even though we didn't write any code, we ended up with an application which has some very sophisticated text handling. The Xcode project is contained in the following zip file. If you'd like to see more tutorials like this, please make a donation. Please consider the download a thank you gift for your contribution.