Center Toplevel() windows to main CTk() windows

[HyperNylium]

I recently made an app where you could click on an "update" button and a window (Toplevel window) would pop out. But the problem was that I wanted it to be centered on the CTk() window. So, I made this function. Hope you enjoy!

Before we begin, let me showcase what this would even look like:

This is the function by itself:

def CenterWindowToMain(Screen: CTk, width: int, height: int):
    """Centers the window to the main tkinter window"""
    main_screen_width = Screen.winfo_width()
    main_screen_height = Screen.winfo_height()
    main_screen_X = Screen.winfo_x()
    main_screen_Y = Screen.winfo_y()
    x = main_screen_X + (main_screen_width - width) // 2
    y = main_screen_Y + (main_screen_height - height) // 2
    return f"{width}x{height}+{int(x)}+{int(y)}"

This is the code I used to make the screenshot above:

from customtkinter import CTk, CTkToplevel

def CenterWindowToDisplay(Screen: CTk, width: int, height: int, scale_factor: float = 1.0):
    """Centers the window to the main display/monitor"""
    screen_width = Screen.winfo_screenwidth()
    screen_height = Screen.winfo_screenheight()
    x = int(((screen_width/2) - (width/2)) * scale_factor)
    y = int(((screen_height/2) - (height/1.5)) * scale_factor)
    return f"{width}x{height}+{x}+{y}"

def CenterWindowToMain(Screen: CTk, width: int, height: int):
    """Centers the window to the main tkinter window"""
    main_screen_width = Screen.winfo_width()
    main_screen_height = Screen.winfo_height()
    main_screen_X = Screen.winfo_x()
    main_screen_Y = Screen.winfo_y()
    x = main_screen_X + (main_screen_width - width) // 2
    y = main_screen_Y + (main_screen_height - height) // 2
    return f"{width}x{height}+{int(x)}+{int(y)}"

def launch_toplevel_window():
    toplevel_window = CTkToplevel()
    toplevel_window.title("toplevel window")
    toplevel_window.attributes('-topmost', True)
    toplevel_window.geometry(CenterWindowToMain(window, 500, 250))

window = CTk()

# Will launch a 900x400 window in the center of the main screen (CTk is the main window)
window.geometry(CenterWindowToDisplay(window, 900, 400, window._get_window_scaling()))

# Ensure the main window is fully drawn to get the correct values from winfo_width() and winfo_height().
window.update()

launch_toplevel_window()

window.mainloop()

If you want more info on the CenterWindowToDisplay() function, I'd suggest you look here

You may use this code however you like :)