Flex Mobile project scaling with Retina display iPad (3rd gen).

Question

Adobe et al,
With the new iPad 3 we now have a ton more pixels to utilize. I'm familiar with and have already successfully tested the AIR 3.1+ commandline compiler option (-platformsdk) to get Retina display on the new iPad. In ActionScript mobile projects the content is rendered beautifully on the new iPad. But with Flex Mobile projects, something is happening that causes it to render incorrectly. It's retina display alright, but the size is way too small.
Below is an image WITHOUT the -platformsdk build tag, that causes the app to be pixel doubled to fit on the new iPad:
Notice that it's scaled proportionally, even though the text and components are slightly pixelated. Not a big deal, but noticeable on the device.
This image is taken with the app rendering in Retina display (setting the -platformsdk pointing to iOS 5.1 SDK):
As you can see, the text/components are rendered really clear, but the scale is way off. Obviously it's getting the width of 2048x1536 from the device, but it's way too small.
How do I fix this? I've tried changing the applicationDPI, but it doesn't fix it. Setting a width/height of 1024x768 does nothing either. It seems we need to overrride a behavior that causes it to fit everything in so small.
A little help?
Thanks,
iBrent

Answer 1

Alright, kevinkorngut's answer was the right one. It appears that even though AIR 3.x can render high resolution apps, it still returns the incorrect DPI for the new iPad. In a Flex Mobile project you have to override the DPI using the method mentioned above.
Here are the results I got:
Using the runtimeDPIProvider property on the TabViewApplication tag (works for any of the three project types) I created a class that extends RuntimeDPIProvider. To detect which iPad I was on, I used the following code:
override public function get runtimeDPI():Number
     var os:String = Capabilities.os;
     if(os.indexOf("iPad") != -1)
          if(Capabilities.screenResolutionX > 2000 || Capabilities.screenResolutionY > 2000)
               return DPIClassification.DPI_320;
          } else {
               return DPIClassification.DPI_160;
     } else {
          return Capabilities.screenDPI;
I'm returning a DPI of 320 as this gives the best result that matches the proportions of the device. In other words, even though the iPad DPI is 264, setting the app to 320 gives the correct size at the new Retina display.
In order for this to work, you must compile the app with the -platformsdk flag pointing to iOS 5.1 SDK, and currently that means you need a Mac running Lion with Xcode 4.3.1. Here's the adt command I used:
adt -package -target ipa-test -storetype pkcs12 -keystore ~/Desktop/iOS_DevCert.p12 -provisioning-profile ~/Desktop/iOS_DevProfile.mobileprovision newiPadTest.ipa newiPadTest-app.xml newiPadTest.swf -platformsdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPh oneOS5.1.sdk
Also, the -app.xml descriptor file must have the <requestedDisplayResolution>high</requestedDisplayResolution> within the <iPhone> tags.
Thanks everyone for their replies!
iBrent