How to check if Toplevel window is opened?-CodePudding

I would like to know if Toplevel window is opened or closed by the user manualy, with only one open button for opening the window. I tried to do it with winfo, but for some reason it doesn't work properly.

from tkinter import *
from tkinter import messagebox

global top
top= None
global counter
counter = 1
global root
root = None

def window1():
    root = Tk()
    root.geometry("300x200")
    root.title('Window1')
    my_button = Button(root, text="Open Window", command=openWindow2)
    my_button.pack(pady=50, padx=50)

    root.mainloop()

def openWindow2():
    global counter
    if (counter < 2):
        top = Toplevel()
        top.geometry("300x200")
        top.title('Window 2')
        my_label = Label(top, text="New Window!", font=("Helvetica, 24"))
        my_label.pack(pady=50, padx=50)
        counter  =1
    else:
        checkwind2()

def checkwind2():
    if (top is not None) and Toplevel.winfo_exists(top) == 1:
        #this situation never happens
        print("Window is opened")
    else:
        print("Window is closed")

window1()

CodePudding user response：

It appears you put globals in the wrong place and so the top variable always appears to be None. If you want to edit a variable outside a function, you need to add global inside the function.

Try this:

from tkinter import *
from tkinter import messagebox

top= None
counter = 1
root = None

def window1():
    root = Tk()
    root.geometry("300x200")
    root.title('Window1')
    my_button = Button(root, text="Open Window", command=openWindow2)
    my_button.pack(pady=50, padx=50)

    root.mainloop()

def openWindow2():
    global top
    global counter
    print(counter)
    if (counter < 2):
        top = Toplevel()
        top.geometry("300x200")
        top.title('Window 2')
        my_label = Label(top, text="New Window!", font=("Helvetica, 24"))
        my_label.pack(pady=50, padx=50)
        counter  =1
    else:
        checkwind2()

def checkwind2():
    if (top is not None) and Toplevel.winfo_exists(top) == 1:
        print("Window is opened")
    else:
        print("Window is closed")

window1()