What’s different about developing a
mobile application versus a web or
desktop application? While many
existing Flex concepts and patterns
carry over directly to mobile
development, developers will need to
take into account the differences in
interaction patterns, screen real
estate, and performance
characteristics of mobile devices
compared to desktop computers. As a
result, we recommend using the new
mobile features in Flex to craft UIs
specific to mobile devices, while
sharing underlying model and data
access code with your desktop or web
application. Additionally, we
recommend certain best practices when
developing mobile applications with
Flex, such as using ActionScript and
FXG rather than MXML for creating item
renderers and skins.
Taken from http://labs.adobe.com/technologies/flex/mobile/faq.html#differences
As per my usual qualifying statement: I haven't tried this. Since this is of some interest to me and I've got a bit of free time I'll give making a hero app and running it as a desktop app versus as a mobile app a shot and post back here once I have it working or find a wall.
The runtime: Adobe AIR 2.5 on mobile
devices The initial versions of the
mobile development features in "Hero"
and "Burrito" are targeted at creating
standalone installed applications
using the Adobe AIR runtime for mobile
devices. By focusing on AIR, Flex can
take full advantage of the integration
AIR provides with each mobile
platform, such as the ability to
handle hardware back and menu buttons
and to access local storage.
Running on AIR Finally, it's important
to realize that in addition to all the
mobile Flex components listed above,
you can also directly take advantage
of all the APIs that are available in
AIR on mobile devices—geolocation,
accelerometer, camera integration, and
so forth. While some of these features
are not exposed as Flex components,
they are easy to access directly using
ActionScript. For more information on
developing using the APIs provided by
AIR on mobile devices, see AIR mobile
docs.
http://www.adobe.com/devnet/flex/articles/mobile_development_hero_burrito.html
Basically it's looking like the answer to all the questions is positive.
Yes and likely yes. (as they re-iterate throughout anything I've found on the topic the controls in Hero were made specifically for touch, taking into consideration the fat finger vs the mouse pointer, my guess is it will render slightly differently on the desktop and it's best to actually develop the UIs separately, although the web-services/model can be combined into a shared library/project)
You should have access to everything provided to the desktop (plus info from GPS/accelerometer etc., but obviously wouldn't get those on desktop), but don't have nearly as good a processor so what will work on the desktop may not on a lower performance computing device, but for low resource consumption tasks this shouldn't be a worry.
Yes this is a core feature of Flex, I don't see how it would be possible to make a (useful) RIA without web services. For confirmation on this one look no further than Adobe TV: http://tv.adobe.com/watch/adc-presents/flex-mobile-part-1-beginning-a-mobile-application/ <-- that app is using a web service (doesn't really matter to Flex what the underlying server technology is so long as it can make HTTP requests against it, RemoteObject/AMFService should serve your purpose)
