Help on Simple Threading Example

[João Abrantes]

I have some functions that take a while to run, so if they are run on the mainthread the whole interface will freeze. I want to run those functions on a separate thread and on the main thread I would the image of a spinner rotating just to show the user that we're working on his request. I tried to create a wrapper for these functions that take a lot of time to complete:

def add_spinner(func):

    def inner(self,*args,**kwargs):

        root = self.get_root_window()

        spinner = Spinner()

        root.add_widget(spinner)

        trigger = Clock.schedule_once(partial(func,self,*args,**kwargs))

        trigger()

    return inner

@add_spinner
def slow_function(dt):
    #do some very intensive computations here

But it doesn't work the whole interface still freezes and the spinner only starts to rotate when the function is over. Thanks for the help.

[João Abrantes]

just tested this on an even simpler example, doing:

def func(dt):

    print 'start'

    sleep(10)

    print 'finnish'

Clock.schedule_once(func)

will freeze my entire interface. Should I use the threading python library instead? I've heard multiprocessing is not compatible with android or iOs.

[João Abrantes]

Already solved my own problem. Sorry for the spam. Threading is the way to go, it seems that kivy's UrlRequest already uses threading. If you want an example that solves the problem of slow functions freezing the interface here it is:

from threading import Thread

class Dispatcher(Thread):

    def __init__(self,func,on_terminate,*args,**kwargs):

        super(Dispatcher,self).__init__()

        self.func = func

        self.args = args

        self.kwargs = kwargs

        self.on_terminate = on_terminate

        self.start()

   

    def run(self):

        self.func(*self.args,**self.kwargs)

        if self.on_terminate:

            self.on_terminate()

def add_spinner(func):

    def inner(*args,**kwargs):

        root = args[0].get_root_window()

        spinner = Spinner()

        root.add_widget(spinner)

        on_terminate = lambda: root.remove_widget(spinner)

        Dispatcher(func,on_terminate,*args,**kwargs)

    return inner

class MyWidget(SomeWidget):
  @add_spinner
     def slow_function(self):