CODEWITHSUNDEEP
pythontkintertext
Not My Name
Not My Name

Reputation: 63

Tkinter window not displaying until after program is run

global window
window = Tk()
window.geometry('300x200')
window.minsize(300,200)
window.maxsize(300,200)
window.configure(bg='black')
window.title("testupdate")

global outputtext
outputtext = tk.StringVar()
outputtext.set("starting window...")

my_label = tk.Label(window, textvariable = outputtext, bg = 'black', fg = 'white', font = 'terminal')
my_label.pack()

class ChangeLabel():
    def __init__(self, text):
        outputtext = tk.StringVar()
        outputtext.set(text)
        my_label.config(textvariable = outputtext)

Here's the main code: https://replit.com/@YourPetFinch/textadventure#main.py

I've been trying to make a text adventure game with Tkinter so I can package it all nicely as an app. I created a function that I can call from another file to update a label as the game output so I can keep the GUI setup simple, but I've been having a problem where the window won't show up until the code has finished running. I'm new to tkinter (and honestly not very good at Python in general) so this is probably a stupid question.

Upvotes: 0

Views: 697

Answers (1)

Tim Roberts
Tim Roberts

Reputation: 54620

That's not how global is used. The global statement is only used inside a function, to state that you're going to modify a global. You can't actually make a global that crosses files, but your from gui import * will handle that.

The issue here is understanding event-driven programming. When you create a window, nothing gets drawn. All that does is send a number of messages to signal the core. The messages will not get fetched and dispatched until it gets into the .mainloop(). The main loop processes all the messages and does the drawing, which might queue up more messages.

So, you cannot use time.sleep(2) like that. As you saw, that will interrupt the process and prevent any drawing from being done. Instead, you will have to use window.after to request a callback after some number of seconds. The .mainloop monitors the timers, and will give you a call when time runs out. You cannot use time.sleep inside an event handler either, for the same reason; your GUI will freeze until your event handler returns.

Upvotes: 1

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