How can I get the height of Firefox addon-bar with javascript?

It can be fatter or thinner depending on whether if includes text,
and whether it is enabled or not.
So I need to know what is the height of addon-bar -I’m struggling to find a working answer all day long.

Do you specifically need to know the height of the toolbar? Or do you just need the overall height of the viewable area?


I need to know the height of the addon-bar only (at the bottom of Firefox window).

I don’t think you can as it is part of the browser chrome (although I would be happy to be proved wrong).
Out of interest, why do you need to do this?

AFAIK you can work with the browser chrome via a plugin or extension, but as Pullo stated you can’t get information about it.

Thanks for the responses -it can’t be done with Js.
Not interested in extensions, plugins.