Workspaces: design windows and source-code editors
Designing an application using AppBuilder involves creating building blocks and then gluing them together with appropriate 4GL code. In 4GL applications that are event-driven rather than procedure-driven, many of the building blocks will be user-interface related, and involve visual layout. Other building blocks have an internal and supporting role, and do not require you to lay out a visible representation.
The workspace for laying out visible objects is a design window. Figure 2–6 shows a design window for a SmartWindow—it is the SmartWindow itself. SmartWindows are outer-level organizers and members of the class SmartContainer.
The workspace for non-visible objects is the built-in source-code Section Editor, together with a window that shows a tree view of the editable components. Figure 2–7 shows a tree-view window.
It is important that you use only the built-in Section Editor to maintain your AppBuilder objects.
All AppBuilder-generated procedure files conform to a specific format, which allows AppBuilder to read and update them. AppBuilder cannot reliably read and understand a file that does not conform to this format. Even apparently trivial changes—in some cases, adding a blank character—can render a file unopenable. For more information about editing AppBuilder-generated procedure files, see the "Editing source code safely: the Section Editor" section.
If you open in AppBuilder a procedure file that it did not generate, AppBuilder does not display a design window or tree view for it. You must maintain such files manually, so AppBuilder displays the file in a standard procedure window.