User's Guide
When you set prerequisites, you need to consider:
- Visibility
- What application contains the class that you want to subclass from? Though
the class you want to subclass from is loaded in your image, your application
(or, as the case may be, its subapplication) must have the application
containing that class in its prerequisite chain in order to see
it.
- Dependencies
- What application does your application (and its subapplications) need to
run? For example, suppose you have the applications AbcApplication
and XyzApplication. XyzApplication provides the
platform connections that AbcApplication needs to run.
Therefore, XyzApplication must be named a prerequisite of
AbcApplication.
When you created DevelopChooser, you selected Kernel
as the prerequisite. As Kernel is one of the base
applications in Smalltalk, naming it the prerequisite enables you to subclass
from about 100 classes.
To find out what classes are visible to your application when
Kernel is the prerequisite, do the following:
- From an Application Manager with DevelopChooser highlighted in
the list of applications, select Browse Application from the
Applications menu. This opens an Application Browser on your
application.
- From the Classes menu, select Visibility
> Add Prerequisite Classes. The names of
all classes contained in Kernel, its subapplications, and your
application are shown in the list of classes. With Kernel as
the prerequisite, your application can subclass from any one of these
classes.
When you define classes for DevelopChooser, you will subclass
from Object, which is visible (or contained in the list of classes
displayed).
[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]