Graphics Programs Reference
In-Depth Information
Object Diagrams
iOS applications can get very large and use many classes and methods. One way to keep
your head wrapped around a project is to draw an
object diagram
. Object diagrams show
the major objects in an application and any objects they have as instance variables. (At Big
Nerd Ranch, we use a program called
OmniGraffle
to draw our object diagrams.) Most ex-
ercises in this topic will show you an object diagram to give you the big picture of the ap-
plication you are developing.
Figure 5.2
shows the object diagram for the complete
Where-
ami
application.
Figure 5.2 Whereami object diagram
Let's go through this diagram. At the top are the view objects:
• Several instances of
MKAnnotationView
appear as icons on the
MKMapView
.
• An
MKMapView
displays the map and the labels for the recorded locations.
