I am having a problem in positioning the login window in center of my screen.

This is my code:

from customtkinter import *
from PIL import Image
from tkinter import messagebox
from views.registration import RegistrationWindow
from views.homepage import HomepageWindow
from views.admin import AdminWindow
from models.database import authenticate_user

class LoginApp(CTk):
    def __init__(self):
        super().__init__()
        self.title("Login")
        self.setup_window()
        self.create_widgets()

    def setup_window(self):
        height = 430
        width = 530

        x = (self.winfo_screenwidth() // 2) - (width // 2)
        y = (self.winfo_screenheight() // 2) - (height // 2)

        self.geometry(f"{width}x{height}+{x}+{y}")

    def create_widgets(self):
        image_path = "images/prdp_logo.png"
        image = CTkImage(dark_image=Image.open(image_path), size=(150, 150))
        image_label = CTkLabel(master=self, image=image, text="")
        image_label.place(relx=0.5, rely=0.3, anchor="center")
        
        self.username_entry = CTkEntry(master=self, placeholder_text="Username", font=("Arial", 12), text_color="white", width=300)
        self.username_entry.place(relx=0.5, rely=0.5, anchor="center")

        self.password_entry = CTkEntry(master=self, placeholder_text="Password", font=("Arial", 12), text_color="white", width=300, show="*")
        self.password_entry.place(relx=0.5, rely=0.6, anchor="center")

        CTkButton(master=self, text="LOGIN", font=("Arial", 12), text_color="white", width=200, command=self.login).place(relx=0.5, rely=0.7, anchor="center")
        CTkButton(master=self, text="REGISTER", font=("Arial", 12), text_color="white", width=200, command=self.open_registration_window).place(relx=0.5, rely=0.8, anchor="center")

    def open_registration_window(self):
        RegistrationWindow(self)

    def login(self):
        username = self.username_entry.get().strip()
        password = self.password_entry.get().strip()

        if not username or not password:
            messagebox.showerror("Error", "Please enter your username and password!")
            return

        result = authenticate_user(username, password)
        if result:
            fullname, role = result
            self.withdraw()
            if role == "ADMIN":
                admin_panel = AdminWindow(fullname, self)
                admin_panel.mainloop()
            else:
                homepage = HomepageWindow(fullname, self)
                homepage.mainloop()
        else:
            messagebox.showerror("Error", "Invalid username or password!")

I came up with the idea on changing the scale in display settings. My current scale is 125% which is the recommended. Then I tried changing it to 100% and it worked, the window is now positioned in the center of my screen. But if I change it back to 125% it goes back to the same problem not being centered again. I tried testing other applications in 125% scale and they are centered on my screen upon opening. I don't know why my application doesn't do the same.

I am having a problem in positioning the login window in center of my screen.

This is my code:

from customtkinter import *
from PIL import Image
from tkinter import messagebox
from views.registration import RegistrationWindow
from views.homepage import HomepageWindow
from views.admin import AdminWindow
from models.database import authenticate_user

class LoginApp(CTk):
    def __init__(self):
        super().__init__()
        self.title("Login")
        self.setup_window()
        self.create_widgets()

    def setup_window(self):
        height = 430
        width = 530

        x = (self.winfo_screenwidth() // 2) - (width // 2)
        y = (self.winfo_screenheight() // 2) - (height // 2)

        self.geometry(f"{width}x{height}+{x}+{y}")

    def create_widgets(self):
        image_path = "images/prdp_logo.png"
        image = CTkImage(dark_image=Image.open(image_path), size=(150, 150))
        image_label = CTkLabel(master=self, image=image, text="")
        image_label.place(relx=0.5, rely=0.3, anchor="center")
        
        self.username_entry = CTkEntry(master=self, placeholder_text="Username", font=("Arial", 12), text_color="white", width=300)
        self.username_entry.place(relx=0.5, rely=0.5, anchor="center")

        self.password_entry = CTkEntry(master=self, placeholder_text="Password", font=("Arial", 12), text_color="white", width=300, show="*")
        self.password_entry.place(relx=0.5, rely=0.6, anchor="center")

        CTkButton(master=self, text="LOGIN", font=("Arial", 12), text_color="white", width=200, command=self.login).place(relx=0.5, rely=0.7, anchor="center")
        CTkButton(master=self, text="REGISTER", font=("Arial", 12), text_color="white", width=200, command=self.open_registration_window).place(relx=0.5, rely=0.8, anchor="center")

    def open_registration_window(self):
        RegistrationWindow(self)

    def login(self):
        username = self.username_entry.get().strip()
        password = self.password_entry.get().strip()

        if not username or not password:
            messagebox.showerror("Error", "Please enter your username and password!")
            return

        result = authenticate_user(username, password)
        if result:
            fullname, role = result
            self.withdraw()
            if role == "ADMIN":
                admin_panel = AdminWindow(fullname, self)
                admin_panel.mainloop()
            else:
                homepage = HomepageWindow(fullname, self)
                homepage.mainloop()
        else:
            messagebox.showerror("Error", "Invalid username or password!")

I came up with the idea on changing the scale in display settings. My current scale is 125% which is the recommended. Then I tried changing it to 100% and it worked, the window is now positioned in the center of my screen. But if I change it back to 125% it goes back to the same problem not being centered again. I tried testing other applications in 125% scale and they are centered on my screen upon opening. I don't know why my application doesn't do the same.

• python
• tkinter
• customtkinter

• Try calling self.update_idletasks() before calling setup_window and after calling create_widgets. Creating widgets affects TK geometry. – Ze'ev Ben-Tsvi Commented Jan 30 at 13:43

1 Answer 1

Tkinter processes positions weird when you're not on 100% scaling.

Here's how to make tkinter "aware" of the current DPI:

from ctypes import windll
windll.shcore.SetProcessDpiAwareness(2)

Make sure this code is ran before creating the window. Bonus: it also makes the window not blurry anymore!

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