How can I register a callback for when a Kivy gui is loaded?
In my Kivy app, as soon as the GUI is loaded (aka the window pops up with the initial view), I need to kick off a function that loads expensive data and updates the UI. 
So far i've been using the on_start method in App but this runs before the GUI is loaded. 
essentially, i want something like $( document ).ready() (from jquery) but for ivy
You could Clock.schedule(some_function, 0) in your build method, I think that would run after everything is initialised but before the next frame.
kivy -- event for when guis is loaded