Information Technology Reference
In-Depth Information
Chapter 8:Creating More Ad-
vanced Effects with Interface
Builder
In This Chapter
Using File's Owner and First Responder
Subclassing views and other objects
Creating custom IB objects
Creating views with static images
Supporting non-English languages
Creating outlets and actions is a key step in application design with Interface Builder (IB). More complex applica-
tions require more advanced skills, which are discussed in this chapter.
Using File's Owner and First Responder
The top two objects in the list at the left of the IB interface are
placeholders.
They make it possible to link to ob-
jects that are outside the nib file.
Using File's Owner
File's Owner is a placeholder for the object that loaded the nib. It represents a different object in every nib. For
example, in
MainWindow.xib
in the sample project in Chapter 7, File's Owner is a placeholder for the
UIApplication
object. In
IBViewController.xib
, File's Owner stands in for the
IBViewControl-
ler
object.
This may seem complex the first time you encounter this feature, and it's certainly not an intuitive feature, be-
cause the true class/object name isn't displayed next to the icon.
However, if you select the File's Owner icon, you can check the class name in the Identity Inspector. It appears in
the Class field at the top of the Utility Area.
Caution
These placeholders can seem confusing, but it's critical that you take time to experiment with them until you under-
stand them. It's very difficult to use IB correctly if you don't.
