Mac OS X Leopard - ARCAism

Layout Views: This category includes views that provide layout but don’t display data,
such as split views, scroll views, tab views, and boxes. There is also a custom view object
for adding your own NSView subclasses to the nib.
Special: In addition to the standard interface elements, there are many special views,
controllers, and other objects provided by various APIs. Special groups included by default
include Core Data, Web Kit, Address Book, Image Kit, PDF Kit, QuickTime Kit, and
Quartz Composer. There is also a special Interface Builder template to integrate custom
objects into the library.
The Nib
The main window represents the nib itself. While Interface Builder simply calls it Document, I’m
going to refer to it as the Nib window. It offers three views: icon, list, and column, as shown in
Figure 25-14. With the exception of Cover Flow, these are the same views used by the Finder.
Figure 25-14. Interface Builder’s three nib views
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Although you can navigate your view hierarchy by clicking around the interface itself, some
items can be difficult to select. The Nib window’s column view is especially convenient for selecting
objects buried deep within subviews, especially as your interface becomes more complicated.
Views are typically contained in other views, but every hierarchy is going to contain an
object that is not contained by anything else. The Nib window contains these top-level objects,
which are typically windows or panels. The Nib window also contains special components for
your convenience:
File’s Owner: Although a separate entity in its own right, the nib is not simply floating in
space. It’s actually owned by your document class, MyDocument. In order to communicate
with the document class, objects in the nib talk to the File’s Owner object.
Application: Even though your nib has a direct line to its owner, sometimes its objects
need to communicate with the application itself. The Application object facilitates that
communication.
First Responder: Sometimes an object needs to communicate with whoever is responsible
for performing a given action. For times like these, Mac OS X maintains a party line
known as the responder chain. To put an event on the responder chain, objects in the nib
can send them to First Responder.
Controllers: Controller objects are not views, so they can’t be contained as subviews. As
such, the Nib window contains any controllers in the nib. Indeed, while windows and
panels can simply be dragged anywhere on the screen, controller objects must be dragged
into the Nib window directly. The one exception is the user defaults controller, which will
automatically be added to the Nib window should you bind an object to it.