Greg on Mobile

If you are interested in Slider but don’t know what to do until it is out, let me let you in on some tips that will give you a head start. See my first post to make sure you are up to date on the latest information regarding Slider.

Slider is branched from Flex 4.


Starting learning Flex 4. By getting started on Flex 4 you will be able to understand (and question) why we make the decisions we make in regards to Slider. Flex 4 is to the point (Beta 2) where it should not change much. So if you start learning it now, don’t worry, it won’t be a waste of time down the road. Ted Patrick is documenting his learning’s with starting flex 4 from scratch. That is a great place to start. Also since the Flex 4 SDK is open source there is no reason you can’t start contributing to it.




Start thinking about mobile application design now – it will save you time later.



We haven’t yet finalized what will and will not be shareable in terms of application logic but it will only make it easier if you make sure to not couple heavy UI’s with your application logic. Start taking into consideration how you could create lighter-weight views on top of your data. In a future post I will be sharing an overview of the screens feature which will help you started thinking ahead about how to build your app for mobile. (Also see Targets below) For now start making your views look like big Item Renderers by binding them to a separate, well defined data model.




Performance – the same but different.



You knew this one was going to be on here. While a framework aims to make development easier we can’t always protect developers from themselves. More, now than ever, you should understand the real effects of your code at runtime. Memory for the time being is less of an issue for the phones we are targeting. But there are two areas you should concentrate on in terms of runtime performance; code execution time and rendering speed. On the desktop you probably have not had to worry about rendering speed but for mobile you will have to. Hopefully you are already used to or at least understand how to measure code execution time. Rendering speed, however, is a bit more tricky. To better understand the rendering pipeline in Flash you should read this article by Sean Christmann which explains the “Elastic Racetrack” of Flash. As far as code execution check out the opensource FlexPMD project which scans your Flex code for best practices and common pitfalls. It already has several performance violations but hopefully in time we can get even more that are catered to mobile. It is extensible so you can create your own violations using regular expressions or Java. Just remember in the end – you have to run less code to run faster.




Release vs. Debug, and other targets.

CONFIG::DEBUG {
	// assuming that instantiation of the transition is occurring
	// right when a transition has been requested/started
	fpsTimerToken = perf.startFPSTimer(FPSTIMER_SLIDETRANSITION);
}

Even if your application is simple start thinking about different targets for your application. Even in a simple application you should be creating release/debug versions. One of the modifications we are making to Flex 4 SDK is the number of exceptions that are thrown that are simply not needed in release builds (but are valuable while debugging). By including less exception code, running less checks, and throwing less errors our apps can load and run faster. There are several ways you can create targets in Flex but I recommend checking out Conditional Compilation (I will have a more in-depth post on this soon). Beyond this start thinking about if there is other code that is very specific, say to the desktop, that you could refactor or conditional-ize.




Read the Apple iPhone HIG.

If you have never built a mobile application and struggle to visualize how it should be structured and what considerations come into play Apple’s iPhone HIG is a great resource to start with. Adobe is doing a lot of work on understanding what makes sense on the mobile platforms we are targeting and hope to give guidance to developers in the future by documenting ways to develop cross platform UIs as well as looking into automatically doing it for you with something called Adaptable UIs. (post on this coming soon)




You can create Mobile Flash Apps now.



Slider is not required to start building Mobile Apps, although it will make it a heck of a lot easier. Today you can already create and monetize applications on many devices. With more being announced every day.  You can even apply for funding from the Open Screen Project Fund if you have a great idea. Also read about the Ovi store from Nokia. Check out their overview for Flash developers. Here is an independent site that lists all the Flash apps on the store.




Watch this blog.

I plan to be fairly active here (as well as on twitter) posting information on Slider. The entire team agrees it is important to be very open and engage the community early and often in order to make sure we are building the right thing. This blog will be one of several outlets for that. Also feel free to send me any wild ideas or suggestions you may have. For a preview upcoming posts watch the Coming Soon section on the right-hand side of the site.

You can continue to hear more on Slider at:

RIA Radio – Recording Dec. 4th. (Live the week after)
RIAdventure Dec. 6th – 13th
More coming soon… (There is an event section on the right hand side that will be kept up-to-date)