This is much more elegant than xxkb.
I use a Dvorak keymap for the US layout, and fbxkb brings up the zz.png image, I guess because it's unknown.
On my machine I've replaced the us.png and zz.png images with images (60x60) of the letters "US" and "Dv". I'd upload them for example, but am not sure how to do that on SF. I'm also not sure how frequently this project is visited.