Python - TypeError: Cannot create graphics instruction outside the main Kivy thread

Question

I'm trying to change the screen after running this function which is a thread. but it gives me the error

 TypeError: Cannot create graphics instruction outside the main Kivy thread

I researched online regarding this and they told me to use clock property but I don't know how I can use it here. I just want to be able to change graphic instructions from this command. but if I don't thread it the app goes into not responding.

This is my code:

class Notice(Screen):
    def thread_notice(self):
            t1 = Thread(target= Notice.sendNotice, args =(self,))
            t1.daemon = True
            t1.start()
        
    def sendNotice(self):
        my_big_chunk_of_code()
        kv.current = 'menu'

Answer 1

You cannot do any kivy instructions outside of the main thread, which means you cant run sendNotice on a diffrent thread becuase it has kivy code in it... if my_big_chunk_of_code() takes time then remove the kv.current = 'menu' line and move it to, for example the thread_notice function.

By the way in the thread I suggest making the target: self.sendNotice instead of Notice.sendNotice which i think creates another instance of that class (not sure tho), it should work the same