A bit harder part was handling events. Air for Mobile supports touch and multi-touch events but generally you have to choose whether to use multi-touch, gesture or none. If you use gesture mode you can use defined gestures and all other simple events are interpeted like mouse events.  Choosing touch mode will enable you to have more control over events e.g synthetise you own gestures. When you decide not to use touch events, all will be interpreted as mouse events, and is advised to use when app is intended to run on touch and non-touch devices. My choice was to use touch and I was able to enable horizontal swipes between app screen as well as scrolling and taping for selected items. Of course mouse over events do not work on mobile devices.
After spending couple of days I was converted from Android ignorant to Android developer, and here are big thanks to Adobe. Being able to use the same, well known and adapted technology is a great thing which brings down entry-barrier into Android development world. Every Air/Flex developer will be able to create mobile versions of application using technology that is well known to him, using the same controls, effects and back-end communication. Only thing that changes is visual – but it is something you cannot avoid, and events, but it is nothing much different from ordinary mouse events.

Release date is said to be second half of 2010 so I expect to have final version of Air this autumn, but already there are plenty of apps in web. The only problem for me was unable to test it on real device – I don’t have Nexus One.

• new set of skinnable Spark components and skinning architecture which leads to better separation between data and view
• introducing FXG declarative syntax for defining graphics
• two way data binding

But if you want to explore full list of changes and improvements to framework, there is a “Flex 4 features and migration guide”, which could give you more information about it.

New set of Spark component architecture defines entirely new way of building application view. Now view and data are separated, and each of functional component can be skinned to look completly different than “default” one. For example you can skin radiobutton to look like button, but still have radiobutton functionality – single select or grouping. This feature is extremely useful, and makes life of developer much easier.

Spark components also adds some new features e.g better handling of text by RichText and RichEditableText controls which enables developer to handle text more efficiently and easily. My personal foe – Repeater could be replaced by Spark DataGroup component which behaves far more intuitive  and of course is suited to new skining architecture

Flex 4 introduces also FXG declarative syntax, it is similar to Degrafa, and in simple words enable programmer to create vector graphics by writing piece of MXML code. This alone is not a big deal, but please remember that there is a data binding mechanism – and having those two together implementing a custom bar progress indicator or some fancy buttons is much, much easier.

Finally we have databinding that works both ways, so when connected to e.g. RichEditableText you will got property synchronized with it’s text. The only thing to remember is to have property that need to be bound declared as public.

Flex 4 is a big step ahead, it resolves a lot of problems that was a pain in Flex 3. I will encourage everyone to use it since it is far better than Flex 3, in my opinion, and could save some development  time especially in skinning of application. Together with Catalyst and Flash Builder it will create a powerful platform for building RIA applications.

Flash Builder (which is a succesor to Flex Builder) is currently avialable in beta 2 version for some time now. Since Adobe is still postponing release date of final versions I decide not to wait any longer and try to grasp it’s new features in some application more complicated than samples provided in tutorials that could be found around the webAfter dowloading and installing application we get 60 days of evaluation period, but it can be prolonged using valid Flex 3 license number.

Flash Builder looks much the same as it’s older brother, but even on the first glance there are small changes that could make developer’s life easier – “Flex Naviagtor” which showed file structure of project in Flex Builder is now changed to “Package Explorer” which basically serves the same purpose but it doesn’t stop on the file level – you could expand each as or mxml file to see its attributes. properties and methods. Of course click on method take you dirrectly to it’s implementation – in fact from file level it looks and acts exactly the same as “Outline” view (which is still there).

When looking into code one could notice slighltly different ways of colouring code. Also Code assits works much better and more up to date with current standards when it comes to development environments. For example you could filter to only show events of certain component without need to scroll through numerous entities on hint list. The feature I found very useful durring some day-to-day work is connecting Code assits with Adobe livedocs with could save a lot of time when looking for explanation of some rarely used feature. Finally the code generation got feature of generating getters and setters with makes any excuses for not creating them futile. One of the most irritating feature of FlexBuilder 3 is also gone: when importing project into environment there is only one path to set. It was such a annoyance to have to copy path to second input each time because otherwise my project got copied to some “workdir” under “My documents”.

My general immpression is very good, Flash Builder is stable (at least with comparison to Flex Builder), there are some very nice features that was absent in Flex Builder 3 , and for those who don’t want to use Flex 4 SDK  (which is still beta) you can use  3.4 SDK as well. If you are got used to Flex Builder switching into new environment will be no problem because after all the core is still Eclipse.