How can I switch to the Halo theme in Flash Builder 4?

Question

As you know, Adobe added a new theme called Spark in Flash Builder 4, but it looks really ugly to me. The problem is that I can't switch the current theme to Halo!

What I've tried:

1. Change theme settings in project properties. No effect - all new buttons and other controls had this theme
2. Use compiler settings: -theme=${flexlib}/themes/Halo/halo.swc - no effect also, the same story as above

Then I noticed that there are 2 namespaces in my MXML file:

xmlns:s="library://ns.adobe.com/flex/spark" 
xmlns:mx="library://ns.adobe.com/flex/mx"

When I switched button declaration from <s:Button> to <mx:Button> then my button began to look much better. But I can't switch all such declarations manually, and I don't imagine making the same change to the Application tag would apply the style at an application level.

So, my big question: How can I make Flash Builder 4 use the same theme as in Flash Builder 3? How can I apply it to all new controls? Are there any tricks that I missed?

Answer 1

Within the provided themes for Flex 4, there are no skins with the older "mx" styling for the new spark controls (s:Button and so on.) If you want to make your spark controls look like the old mx controls you'll need to create your own skins. The other option, as you mentioned, would be to switch all instances of the spark controls to their older mx counterparts. The downside is that you won't gain any of the efficiencies introduced with the new spark components. Sorry I don't have better news for you.

Answer 2

Switching the components "manually" might not actually be that hard. Some find and replaces switching <s: to <mx: and </s: to </mx: would easily catch all the dropin replacements, and hopefully you don't have too many that actually differ in the component name.

Since that's the accepted way to set the style of components, it seems like what you're ultimately going to have to do, one way or another.