Java Reference
In-Depth Information
4
Handling Diversity
Walking into a mobile phone retail shop and looking around is a good
way to appreciate the enormous diversity of devices and what different
people want to do with them. There are devices that are used with one
hand and devices that have touch screens; screens can be large or small;
some devices have more than one screen; some have built-in GPS; and
the list could go on. Symbian OS provides a common platform for many
devices and families of devices, which ensures consistency of behavior
and functionality for users and gives developers a common and consistent
development platform across many models. For example, devices using
S60 5th Edition, S60 3rd Edition, UIQ 3.1, and UIQ 3.3 all have a large
common base.
The prevalence of Java ME on mobile phones has resulted in many
Java ME implementations, which in turn have resulted in fragmentation.
A common problem in Java ME on feature phones is that there are many
implementations, each with its own set of supported JSRs, implementation
defects, specification interpretations, optional features, implementation
gaps, and so on. The story of Java ME on Symbian OS is fundamentally
different. Having a single common Java ME platform for S60 5th Edition,
S60 3rd Edition, UIQ, and other Symbian OS UI platforms considerably
reduces the problems that plague other platforms, resulting in diversity
differences rather than fragmentation.
Realistically, it is hard to find two families of Symbian smartphones that
are completely identical. The diversity is due to native UI appearance,
branding, behavior, or functionality. This chapter discusses some general
guidelines that help developers to handle this diversity. We evaluate some
of the main cases of diversity and suggest a way of handling them. Even
though you need to take some measures to handle diversity, your Java
application, which will be deployed on many Symbian smartphones, runs
in a highly consistent Java ME environment with greater commonality
than almost any other Java ME platform.
