I think it's only doable with nwjs. If you add the nw.js object you can access the x,y position of the window.
Then to check if it changed you could do
global number winx=0
global number winy=0
start of layout
--- set winx to nwjs.windowx
--- set winy to nwjs.windowy
winx != nwjs.windowx
or
winy != nwjs.windowy
--- set text to "user moved window"