Overriding Tkinter "x" Button Control (the Button That Close The Window)

When the user presses a close Button that I created, some tasks are performed before exiting. However, if the user clicks on the [X] button in the top-right of the window to close

Solution 1:

It sounds as if your save window should be modal.

If this is a basic save window, why are you reinventing the wheel? Tk has a tkFileDialog for this purpose.

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If what you want is to override the default behaviour of destroying the window, you can simply do:

root.protocol('WM_DELETE_WINDOW', doSomething)  # root is your root windowdefdoSomething():
    # check if saving# if not:
    root.destroy()

This way, you can intercept the destroy() call when someone closes the window (by any means) and do what you like.

Solution 2:

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


classApp(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)

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

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

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


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

Solution 3:

The command you are looking for is wm_protocol, giving it "WM_DELETE_WINDOW" as the protocol to bind to. It lets you define a procedure to call when the window manager closes the window (which is what happens when you click the [x]).