Keeping in mind that mobile devices are harder to use than desktop
computers, due to factors such as the lack of a mouse, small screen
size, and slower network speeds, one can see that widgets gain vital
importance in making it easy for mobile users to access web services.
Mobile users no longer need to struggle with pages not designed for small
screens and containing technologies not supported by mobile device
browsers. With such a strong need to mobilize the web, a number of
widget platforms targeted at mobile devices has surfaced in the past few
Yahoo Go! ( mobile.yahoo.com/go ) brings Yahoo! Mobile widgets to
270+ mobile device models.
S60 WRT Widgets ( www.forum.nokia.com/main/resources/
technologies/browsing/widgets.html ) uses the browser based on S60
WebKit as a run-time environment
for mobile widgets on the
WidSets ( www.widsets.com ) provides mobile widgets to any device
based on Java ME MIDP 2.0.
Of these, Yahoo Go! and WidSets are the most popular, with the
latter being entirely Java ME-based, therefore supporting a bigger range
of devices and having the potential to reach the largest mobile run-time
platform, Java ME. In this appendix, we focus on WidSets and how a
developer with fair experience in Java and web technologies can use it
to bring the power of Internet services to devices enabled with Java ME,
ranging from mid- to low-end Nokia S40 models to high-end Symbian
A.1 Why Are WidSets Relevant to Java?
The reason why the WidSets platform is covered in this topic is that
developing widgets for it is very simple for Java ME developers. The
WidSets Scripting Language (WSL) has the same look-and-feel as the Java
programming language and should be very familiar to developers used
to Java or any C++-based languages. It was created to allow Java and
widgets for WidSets.
One may ask why Java is not used for programming, since the WidSets
Mobile Dashboard itself is written in this language. The main reason is that
MIDP devices do not allow loading of new class files after an application
is installed, therefore making it impossible to add new functionality to the
application by writing widgets in Java. Using a scripting alternative, such
as WSL, overcomes this challenge and allows developers to dynamically