CODEWITHSUNDEEP
pythontkinter
Yoddlenod
Yoddlenod

Reputation: 51

Pausing from within a tkinter function

I'm trying to create a couple of functions which do things in a sequential order. First they need to open a new window and display a label, then they need to wait for some seconds, then they need to call another function. However, I'm struggling to get the functions to wait, all the methods I've tried (.after, .sleep, .wait_visibility) seem to be ignored and it just skips to the next function call without pausing.

Here's what I have (sorry if it's messy, I'm new to python):

from tkinter import *
import time

root =Tk()
root.geometry('600x600')

def scale_screen(event = None):
    global s_screen
    s_screen = Toplevel(root)
    s_screen.title('Residual Inhibition Tester')
    s_screen.geometry('600x600')
    s_screen.transient(root) 
    s_screen.bind('<Return>', sel)
    global var 
    var = IntVar()
    scale = Scale(s_screen, variable = var, orient = HORIZONTAL, length = 1000)
    scale.focus_set()
    scale.pack(anchor=CENTER) 
    button = Button(s_screen, text="Select", command=sel)
    button.pack(anchor=CENTER)

def sel(event = None):
    label = Label(s_screen)
    selection = "Value = " + str(var.get())
    label.config(text = selection)   
    interval_screen()

def interval_screen():
    global i_screen
    i_screen = Toplevel(root)
    i_screen.geometry('600x600')
    i_screen.transient(root)
    i_label = Label(i_screen, text = "Please Wait")
    i_label.pack(anchor = CENTER)
    s_screen.destroy()
    i_screen.after(3000, masker_screen) 
    #time.sleep(3)
    #i_screen.after(300,i_label.configure(text="Playing New Masker Noise")) 
    #root.wait_visibility(window = i_screen) 




def masker_screen():
    global m_screen
    m_screen = Toplevel(root)
    m_screen.geometry('600x600')
    m_screen.transient(root) 
    m_label = Label(m_screen, text = "Playing New Masker Noise").pack(anchor = CENTER)
    m_screen.after(3000, lambda: scale_screen(event = None))
    i_screen.destroy()

b1 = Button(root, command = scale_screen).pack(anchor=CENTER)
root.bind('<Return>', scale_screen)
root.mainloop()

In this example, the program will run but just skip the interval_screen entirely and just do the masker_screen. I'm also not averse to just using one screen and using the .configure methods to change the label text if that's easier.

Thanks!

Upvotes: 0

Views: 644

Answers (1)

Bryan Oakley
Bryan Oakley

Reputation: 386342

Without seeing all the ways you tried it, it's impossible to know what you did wrong. In general you should never call time.sleep and you should never call after with just a single argument. Also, when you use after with two arguments, the second argument must be a reference to a function.

The proper way to do this is to have your first function call your second function via after:

def interval_screen():
    ...
    i_screen.after(3000, maker_screen)

def masker_screen():
    ...
    m_screen.after(3000, lambda: scale_screen(event = None))

Note that in your updated question you're using after incorrectly: 

m_screen.after(3000, scale_screen(event = None))

You're calling the function scale_screen(...) immediately, and giving the result of that to the after function. If you need to pass arguments to your function you must create another function that does not require arguments. The simplest way to do this is with lambda, though you can also use functools.partial or you can create your own function.

Upvotes: 2

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