Overriding Tkinter “X” button control (the button that close the window) [duplicate]

Answer 1

Using the method procotol, we can redefine the WM_DELETE_WINDOW protocol by associating with it the call to a function, in this case the function is called on_exit:

import tkinter as tk
from tkinter import messagebox


class App(tk.Tk):

    def __init__(self):
        tk.Tk.__init__(self)
        self.title("Handling WM_DELETE_WINDOW protocol")
        self.geometry("500x300+500+200")
        self.make_topmost()
        self.protocol("WM_DELETE_WINDOW", self.on_exit)

    def on_exit(self):
        """When you click to exit, this function is called"""
        if messagebox.askyesno("Exit", "Do you want to quit the application?"):
            self.destroy()

    def center(self):
        """Centers this Tk window"""
        self.eval('tk::PlaceWindow %s center' % app.winfo_pathname(app.winfo_id()))

    def make_topmost(self):
        """Makes this window the topmost window"""
        self.lift()
        self.attributes("-topmost", 1)
        self.attributes("-topmost", 0)


if __name__ == '__main__':
    App().mainloop()