background window and main window tkinter-CodePudding

I'm learning Tkinter and just had a doubt.

Is there any method that prevents me from working with the window in the background until I close the main window? I saw that there is an argument about this here, but I ended up losing it and decided to ask.

CodePudding user response：

Yes, it is possible (IIUC) and if I do understand correctly you simply want to block user for accessing other windows while your window is open. It has a slight flaw in that if user does a lot of alt-tabbing they may get keyboard focus on some other window but only the keyboard, as soon as they do anything with mouse they should get back to the main window. This can be handled using some module like keyboard to listen for global keyboard input but also perhaps it could be done using Windows API but for a tkinter only solution that is/should be effective enough you can use this:

import tkinter as tk


def check_focus():
    if root.focus_get() is None:
        root.focus_force()
    root.after(100, check_focus)


def create_shield():
    shield = tk.Toplevel(root)
    shield.attributes('-topmost', True)
    shield.attributes('-fullscreen', True)
    shield.attributes('-alpha', 0.01)
    shield.overrideredirect(True)
    shield.bind('<FocusIn>', lambda _: root.focus_force())


root = tk.Tk()
root.attributes('-topmost', True)

create_shield()
check_focus()

root.mainloop()

First there is the after "loop" that checks for focus to see if the window has any, this prevents some attempts of trying to alt-tab away but enough attempts may cause some kind of timeout and the window will get out of focus.

The other part is a "shield" that simply is another fullscreen window that is almost completely invisible (on other OS the attribute name may be -splash instead of -alpha) and just keeps it in top to assist in focusing on the main window.

Or just make the window fullscreen and topmost (again the issues with keyboard focus on other windows but now user has no issues whatsoever with accessing the other windows except they wouldn't see what they are typing) and this requires to implement some button to close the window (currently doable by alt f4 or shutting down the computer or killing the process via run without looking at what you are typing and perhaps some other way I haven't thought about, but for user convenience probably a button should be made that would simply destroy the window):

import tkinter as tk


root = tk.Tk()
root.attributes('-topmost', True)
root.attributes('-fullscreen', True)

root.mainloop()