headerless window, undecoration

[Steven J Abner]

 Stumped after weeks of trying, I'm reaching for some kind of hint, 
algorithm, anything to accomplish an undecorated window that behaves 
like a window such that it focuses, stacks just as a normal window. 
Resize, move, etc will be drawn in by a user that wants to create a 
non-supplied wm 'header' bar.
 Under gdk, I've created such an animal. I've tried to figure how they 
did it, but closest I've figured is they create an artificial topmost 
window. This still leaves me with how to not draw, and set a correct 
size. Also they used Motif.
 I've tried all the _NET_WM_WINDOW_TYPE_xxx(s), found that 
_NET_WM_STATE doesn't get set on undecorated. All remain as top of the 
stack.
 Closest I've come was using grab_button() for focus, but only works 
100% on one window manager, and left me trying to figure how to stack, 
leading back to reparent to an artificial window, which supports the 
reasoning of leaving event's window when entering titlebar area. Near 
as I can tell there is no way to not map a topmost and just map a 
child? Hadn't tried, so unverified :(
 Any pointers?
Steve

PS thank you Peter Harris, was very helpful and really cool link of 
info :)
And gdk version:

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