Updating display during the running of a method

[Tim Woodhams]

Hi, I am trying to teach myself Kivy (and python) and have come to a problem. I have a method (see below) based around music and dance that I want to change the display based on time. Currently the display doesn't update during the running of the method but does when it is finished. I've search the net but I am very confused about how to update the display whenever I would like to.

Thanks for your help

Method:

    def playRoutine(self,routine):

        moves = routine[0] # reads in list of moves

        total = 0

        moveBeats = []

        for b in routine[1]: # constructs a list of beat to switch move

            total += b

            moveBeats.append(total)

        beats = 0

        move = 0

        secPerBeat = 60/routine[2] #convert bpm to seconds per beat

        startTime = time.time()

        while beats < moveBeats[-1]:

            try: #deals with end of list

                self.ids.current.text = moves[move] #changes display

                self.ids.next.text = moves[move+1]

            except:

                self.ids.current.text = moves[move]

                self.ids.next.text = ""

            while beats < moveBeats[move]:

                beats += 1

                #sleep for the correct time for next beat

                time.sleep(startTime+beats*secPerBeat-time.time())

                self.flash()

            move += 1

               

    def flash(self):

        '''Temp: displays word flash every beat.

        to do: switch to flash background and

        add optional tick'''

        self.ids.flasher.text = "flash"

        time.sleep (0.05)

        self.ids.flasher.text = ""

[Robert]

More general that Kivy.

UI apps are event driven, so UI changes are scheduled on an event loop.

Events are scheduled based on the current event, input events, clock events, or thread events.

NEVER use sleep() in the main thread, this will block the event loop and stall the app UI (similarly never join() a thread).

Perhaps this will get you started https://kivy.org/doc/stable/api-kivy.clock.html

[Tim Woodhams]

Thanks Robert

Yes Clock.schedule_once does exactly what I need. Thank you for the general advice too.

Cheers

Tim