Building Cocoa Applications: A Step by Step Guide

Window Types and Behavior

On-screen windows fall into four principal categories, which vary in appearance and function:

• Document windows

• Utility windows

• Dialogs (includes sheets)

• Alerts

We’ll describe each of these window types in the following sections. After that we’ll discuss how and when these four types of windows become the main or key window in an application. For many of our examples we’ll use the TextEdit application, the basic word-processor application bundled with Mac OS X and located in the /Applications folder.

Document Windows

A document window is file-based and is the main working area of an application. A window containing a text document being edited in a word processor is a document window, as is a window containing a spreadsheet in a spreadsheet application or an image being manipulated in a graphics editor application. Most document windows, like some of the windows in Figure 1-1 and the window in Figure 1-3, have resize controls and close, minimize, and zoom buttons. The resize control is at the lower-right corner of a document window, while the three window-control buttons are on the left side of the window’s title bar.

Figure 1-3. A document window in TextEdit editing a file called “Document Window”

The small proxy (file) icon to the left of the title in a document window can be manipulated with drag-and-drop, as can a file icon in the Finder. Command-pressing ...