Displaying a plugin editor in a custom Component

I already posted something like this in the Audio Plugins section, but it didn’t get much attention.
I wanted to put the editor of a plugin (I’m developing a host) inside a CalloutBox.
So I created a CustomCalloutBox and gave it the editor as the Component to be displayed.
It works fine when the parent Component isn’t null, but if the parent Component is null (in this way the CalloutBox is added directly to the Desktop), the editor just vanishes.
I’m guessing that’s because plugin editors require a heavy-weight window…
So I created a DocumentWIndow, set it’s titlebar height to 0, overrode paint() and resized() and recreated the look of a CalloutBox.
Now it works, but the window’s background is black.
Is there a way to make a window transparent?
I don’t think it’s possible (at least not on Windows, if I remember correctly you can’t have transparent windows).

Yeah, you’re going to have problems with that on windows, because transparent windows probably aren’t going to play nicely with plugins, which expect a normal solid window.

Alright, that’s what I thought.
Too bad, I was gonna create a super nice workflow for editing plugins…

You could probably rig up some kind of transparent window border around a normal window.