Can't make truly modal dialog box in tkinter

Question

I have created a custom dialog box as follows:

class DialogOkCancel(Toplevel):
    """DialogOk Displays a simple 'ok' dialog"""

    def __init__(
        self,
        text: str = "",
        width: int = 300,
        height: int = 200,
        *args,
        **kwargs,
    ):
        super().__init__(title=c.DEFAULT_TITLE)

        self.text = text
        self.width = width
        self.height = height

    def show(self) -> None:

        xpos = (self.winfo_screenwidth() / 2) - (self.width / 2)
        ypos = (self.winfo_screenheight() / 2) - (self.height / 2) - 300
        self.geometry(f"{int(self.width)}x{int(self.height)}+{int(xpos)}+{int(ypos)}")
        self.resizable(False, False)

        self.grid_rowconfigure(index=0, weight=0)
        self.grid_rowconfigure(index=1, weight=0)
        self.grid_columnconfigure(index=0, weight=1)
        self.grid_columnconfigure(index=1, weight=1)

        default_font = font.nametofont("TkDefaultFont")
        default_font.configure(family=c.DEFAULT_FONT_FAMILY)
        default_font.configure(size=c.DEFAULT_FONT_SIZE)

        self.choice = None

        self.text = Label(self, text=self.text, font=default_font, anchor="center")
        self.text.grid(
            row=0, column=0, columnspan=2, padx=(10, 0), pady=(10, 0), sticky="nswe"
        )

        button1 = Button(self, text="Ok", bootstyle="dark", command=self.ok)
        button1.grid(row=1, column=0, padx=(10, 0), pady=(10, 10), sticky="nswe")

        button2 = Button(self, text="Cancel", bootstyle="dark", command=self.cancel)
        button2.grid(row=1, column=1, padx=(10, 10), pady=(10, 10), sticky="nswe")

        self.protocol("WM_DELETE_WINDOW", self.cancel)
        self.wait_visibility()
        self.grab_set()

        self.master.wait_window(self)
        return self.choice

    def ok(self):
        self.choice = True
        self.grab_release()
        self.destroy()

    def cancel(self):
        self.choice = None
        self.grab_release()
        self.destroy()

I have bound the command-q,window close and quit menu option to it as follows:

root.createcommand("tk::mac::Quit", app_quit)
root.protocol("WM_DELETE_WINDOW", app_quit)
root.bind("<Command-q>", app_quit)

The handler is as follows:

def app_quit(*args, **kwargs) -> None:

    dialog = DialogOkCancel(
        f"Are you sure you want to quit?\nThe current game will be saved.",
        height=110,
        width=350,
    )
    ans = dialog.show()

    if ans is True:
        sys.exit()

When i press command-q, close the window or select the quit menu option, the dialog is shown correctly and no further input is allowed in the program.

My problem is that if I press command-q again, or try to close the window again, or select quit from the menu option, then i get multiple copies of the dialog.

Any suggests how to prevent this would be much appreciated. thanks

Answer 1

Thank you Bryan, I have done this:

 def app_quit(self, *args, **kwargs) -> None:

        if self.dialog is None:
            self.dialog = DialogOkCancel(
                f"Are you sure you want to quit?\nThe current game will be saved.",
                height=110,
                width=350,
            )
            ans = self.dialog.show()

            if ans is True:
                self.game.script.save_script(self.game.script.filename)
                sys.exit()

            self.dialog = None

And that works, thanks.

However, while the main interface is blocked, the app menus still work and allow user interaction. Not ideal.