A careful study of your application's existing user interface implementation can make a huge difference in ensuring the success
of your project and holding down costs. When it comes to modernizing the user interface, some programs are better suited and
less costly to update than others. Here are some qualities to consider:
- The easiest applications to convert tend to be those that already use the Screen Section.
- The most difficult programs to convert tend to be those in which the user interface code is dispersed throughout the program,
that is, programs that do not use the Screen Section, or do not organize screen processing code into separate procedures.
If your application fits that description and you are going to undertake a large GUI upgrade project, it is nearly certain
that it will be more efficient to implement your new user interface with the Screen Section. Also consider that Screen Section
code is much easier to maintain over the life of the application than is distributed UI DISPLAY and ACCEPT code. A large enhancement
project presents a good opportunity to move to the Screen Section.
- However, if you're doing a small enhancement project that is confined to a small portion of your code, using individual DISPLAY
statements to create and process your screen elements might be reasonable.
- Programs that already include a menu bar, the old-style character-based pop-up windows (subwindows), and support for the mouse,
are well on their way to a modern user interface. These elements are easy to upgrade and enhance to take advantage of ACUCOBOL-GT
GUI support. Note, however, that just because an application already includes this functionality does not mean that there
won't be substantial work in adding floating windows and controls.
- Evaluate your existing, character-based user interface screens for translatability into the graphical model. Many text-mode screens make dense use of the screen. In contrast, graphical screens tend to be
more open, having more white space and fewer fields. Also, graphical objects tend to take up more space on the screen than their equivalent text-mode objects
(mostly due to the boxes used to frame controls). It may require a lot of work to reformulate your character screens into
attractive, functional graphical screens. This problem is just as challenging for applications that already make use of pop-up
windows and menu-bars as for those that don't.