Awhile back, I created a GroupStack as a quick and dirty Spark implementation of the ViewStack I needed at the time. I've recently needed a more complete implementation of a Spark ViewStack for a project, particularly with support for deferred content creation and some of the other features left out of the GroupStack.
This version of the ViewStack is very close to a direct port, containing most all of the features and API from the Halo ViewStack. It’s based on Group (more specifically, my DeferredContentGroup which extends Group) due to my desire to substitute the contentGroup skin part (of type Group), found in many skins, with a ViewStack. The three features I did not port over is the support for history management, resizeToContent, and the usage of effect overlays. And, as with the rest of my library, it’s not that well tested, so be sure to let me know if you’re using this and you find some problems.
Source code located at: https://www.assembla.com/code/shinynet/subversion/nodes