Design Issue 2?Constrained Screen Size

Designing for simplicity and ease of use is a consistently important aspect of design, regardless of the technology or the medium. A screen with a large number of controls or displayed information takes more time for the user to absorb what is being displayed. Such applications are more "fiddly" than those in which controls and displayed information is displayed sparingly on a screen. Increasing the number of buttons on a screen increases the time it takes to learn an application.[1]

[1] For more guidelines for how to design a Palm application that is easy to use and consistent with other Palm applications, refer to "Palm OS Programmer's Companion," Document Number 3004-003. This document is part of the Palm OS Software Development Kit.

In MIDP on the Palm, the Form is not limited to a particular size when appending Items. For example, if you wanted to add 20 StringItems to a Form, there is nothing to stop you from doing it. In Figure 4.1, the MIDlet has 20 StringItems on the Form, but only 11 are visible without scrolling down. Tapping on the down arrow shows the remainder.

Figure 4.1. There are too many items on the screen to see without scrolling


Even though it is possible to add more Items than can be seen on the Form, it is not recommended. An application is made a bit more approachable if scrolling screens are avoided. To avoid the screen in our example, use a list to display the information.