I want to do in Adobe AIR (e.g. in ActionScript 3.0) what Facebook Messenger does when it’s “maximized”:

So imagine that I would be making a clone of this Facebook Messenger.
Is this possible in Adobe AIR?
I’ve tried to search in the AIR Reference with no success. And I don’t even know what words to use in Google Search.
The general term I’ve heard used for this kind of feature is “Docking.” There seem to be a lot of front-end component libraries that offer this capability within a window (built in Flex or Java or C#, that I’ve seen). However the ability to dock a window with regard to the OS view, where all other windows occupy the remaining area after an application is docked appears to require OS specific code to indicate to the operating system that the usable window space should change. I’ve found no solution for this within AIR however did eventually find this link to some C# code, intuition tells me this wasn’t implemented in AIR because it was difficult to come up with a cross platform solution to the issue (not sure how easy this would be given the X windowing interface or other types of platforms they would have to deal with).
The options seem to be limited to working with C#, .NET, and/or windows forms (I believe this was formerly MFC, but I’ve been out of the Microsoft code world for quite a while). You could potentially use a NativeProcess in AIR to spin off a C# exe that could send the signal to the OS but I have in no way proven this to be actually achievable, it just seems plausible, but would require further investigation and would definitely eliminate any cross platform capability offered by AIR. If you’re simply more comfortable working with Flex layouts/component sets and other features, you could start with the C# code for creating a docking area, this could branch down one of two paths then, attempt to spin up that process using a NativeProcess in AIR if that fails continue using .NET to build the remainder of the application. If you were to go the AIR route packaging the C# exe with the AIR installation should be relatively trivial.