From: "Tam Hanna" <[EMAIL PROTECTED]> > I don't beleive that artificially restricting to OS5 is a good idea. > Just think about all the Zires and the existing user base. > I always try to target OS3.5, as that is a pretty good common > denominator(first 8meg devices,...)! > The difficulties with pre-OS4.1 are you get into times when the base APIs were still in a state of flux. This affects things such as form painting (the event sequences and the way background painting was done changed), the serial libraries changed, sound management changed (I think?). Not that I want to imply that this has stopped happening. :-)
Our code for 3.1 to 4.1 support effectively has an abstraction layer that works out what routines are appropriate for the OS version and adjusts. It's a pain to support and debug. While I agree that you can often support a wider variety of devices by coding carefully, it's easy to forget how much has been added to Palm OS. Image buttons, for instance, are pre-4.1 from memory and handling those yourself is just a pain. They're also an example of something that influences the look of the app and can only be worked around by having two sets of resources. The other approach is to make an assessment as to how much of the coding work is interface-driven. For an app that has a lot of code related to storing data, performing calculations and communicating with a server it can be a relatively small task to define a function interface between the core modules (which will change very little over OS versions) and the interface (which will look completely different under a colour 320x320 OS5 device than on a mono 160x160 OS 3.5 device) and then build two interfaces. For your friend build the OS 3.5 interface but tinker with a prettier colour interface that you can flesh out if the app becomes viable as a commercial product. It sounds more complicated to have two interfaces but it's often less work to have two simple, tightly targeted code modules than one complex, multi-version, multi-format code module. If you plan for this from day one you can save some pain downstream. Chris Tutty -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
