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How to destroy a window after opening a new one?

Time:11-04

I am working on a game called 'Flag Quiz' using tkinter. I have a script called mainmenu where I can choose between an easy mode and a hard mode. If I click on one of the buttons the recent mainmenu window disappears and a new tkinter window opens.

Here is my mainmenu script:

from tkinter import *
import tkinter as tk
from hardmode import HardApp
from easymode import EasyApp

class TitleScreen(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title('Flag Quiz')
        self.geometry('600x600')
        self.resizable(0,0)
        self.make_widgets()



    def make_widgets(self):
        self.background = PhotoImage(file = './background.png')
        self.label = Label(self, image=self.background)
        self.label.place(x=0, y=0, relwidth=1, relheight=1)
        self.easy = Button(self, text="Easy Mode", height=2, width=6, font=('default', 20), command=self.play_easy)
        self.hard = Button(self, text="Hard Mode", height=2, width=6, font=('default', 20), command=self.play_hard)
        self.easy.place(relx=0.5, rely=0.45, anchor=CENTER)
        self.hard.place(relx=0.5, rely=0.55, anchor=CENTER)

    def play_easy(self):
        self.withdraw()
        self.app = EasyApp()
        #self.app.start()

    def play_hard(self):
        self.withdraw()
        self.app = HardApp()
        #self.app.start()




    def start(self):
        self.mainloop()

TitleScreen().start()

And here is my easy mode script:

import tkinter as tk
from tkinter import *
import random
import os
import json

class EasyApp(tk.Toplevel):
    def __init__(self):
        super().__init__()
        self.title('Flag Quiz')
        self.geometry('')
        self.resizable(0,0)
        self.score = 0
        self.create_widgets()

    def create_widgets(self):
        # variables
        self.user_guess = StringVar(self)
        self.text = StringVar(self)
        self.text.set(" ")

        # initial image
        self.scoretext = Label(self, text="Score: ").pack(side='top', fill='x')
        self.scorevalue = Label(self, text=self.score).pack(side='top', fill='x')
        self.file = random.choice(os.listdir('pngs'))
        self.randimg = PhotoImage(file='pngs/{}'.format(self.file))
        self.randimg = self.randimg.subsample(2, 2)
        self.panel = Label(self, image=self.randimg)
        self.panel.pack()

        self.country, self.ext = self.file.split('.')
        self.countries = self.load_lookup()
        self.countryname = [country for country in self.countries if country['alpha2'] == self.country]

        self.s = []
        for i in range(0,3):
            country = random.choice(self.countries)
            self.s.append(country['de'])

        self.s.append(self.countryname[0]['de'])
        random.shuffle(self.s)

        self.btndict = {}
        for i in range(4):
            self.btndict[self.s[i]] = Button(self, text=self.s[i], height=2, width=35, font=('default', 20), command=lambda j=self.s[i]: self.check_input(j))
            self.btndict[self.s[i]].pack()


    def check_input(self, d):
        if d != self.countryname[0]['de']:
            print("Falsch")
        else:
            self.score  = 5
            for widget in self.winfo_children():
                widget.destroy()
            self.create_widgets()



    def load_lookup(self):
        with open('lookup.json') as file:
            self.obj = file.read()

        self.countryobj = json.loads(self.obj)
        return self.countryobj

    # def start(self):
    #     self.mainloop()

After clicking the close button (the default button on windows/osx to close a window) the window from my easy mode app disappears but PyCharm says that my program is still running.

I made some investigations and removed the self.withdraw() function in the function play_easy(self) in my mainmenu script. So now the mainmenu is still open after I click on the easy mode button. If I'm closing both windows now, the program fully ends. Replacing self.withdraw() with self.destroy() is not working. The main menu is closed, but a new empty window opens instead.

Any suggestions on how to handle this problem so that my program fully ends if I click the close button within the easy/hard mode window?

CodePudding user response:

You have two windows - main window created with Tk and subwindow created with Toplevel. When you use close button to close main window then it should also close all subwindows but when you close subwindow then it doesn't close main window (parent window) but only own subwindows - because usually it can be useful to display again main window to select other options and open again subwindow.


One of the methods is to destroy first window and use Tk to create new window.

But in this method you can't use some button in second window to go back to first window - and sometimes it can be problem. Even if you create again first window then it will not remeber previous values (if you have some Entry or other widgets to set values)

# from tkinter import *  # PEP8: `import *` is not preferred`
import tkinter as tk

class EasyApp(tk.Tk):  # use `Tk` instead of `Toplevel`

    def __init__(self):
        super().__init__()
        self.scoretext = tk.Label(self, text="EasyApp")
        self.scoretext.pack()

    #def start(self):
    #    self.mainloop()

class TitleScreen(tk.Tk):
    
    def __init__(self):
        super().__init__()
        self.button = tk.Button(self, text="Easy Mode", command=self.play_easy)
        self.button.pack()

    def play_easy(self):
        self.destroy()  # destroy current window
        self.app = EasyApp()

    def start(self):
        self.mainloop()

TitleScreen().start()

Other method is to use self.wm_protocol("WM_DELETE_WINDOW", self.on_close) to execute function on_close when you use close button and in this function destroy main window (master).

This way you can still use Button to go back to main window which will remember previous content.

# from tkinter import *  # PEP8: `import *` is not preferred`
import tkinter as tk

class EasyApp(tk.Toplevel):  # still use `Toplevel`

    def __init__(self, master):  # send main window as master/parent
        super().__init__(master)  # it will also set `self.master = master`
        
        self.scoretext = tk.Label(self, text="EasyApp")
        self.scoretext.pack()
        
        self.button = tk.Button(self, text="Go Back", command=self.go_back)
        self.button.pack()

        # run `on_close` when used `close button`
        #self.protocol("WM_DELETE_WINDOW", self.on_close)
        self.wm_protocol("WM_DELETE_WINDOW", self.on_close)
        
    def go_back(self):
        self.destroy()           # destroy only current window
        self.master.deiconify()  # show again main window

    def on_close(self):
        self.destroy()         # destroy current window
        self.master.destroy()  # destroy main window
        
class TitleScreen(tk.Tk):
    
    def __init__(self):
        super().__init__()

        self.entry = tk.Entry(self)
        self.entry.pack()
        self.entry.insert('end', "You can change text")
        
        self.button = tk.Button(self, text="Easy Mode", command=self.play_easy)
        self.button.pack()

    def play_easy(self):
        self.withdraw()  
        self.app = EasyApp(self)  # send main window as argument

    def start(self):
        self.mainloop()

TitleScreen().start()

CodePudding user response:

Here's a fairly simple architecture for doing what you want. An application class is derived from Tk() which hides the default "root" window it normally displays and all the windows it does display are subclasses of a custom Toplevel subclass I've named BaseWin.

This class is just a Toplevel with its protocol for being delete (closed) set to call an a method named on_close(). This additional method simply destroys the current window before quits the application's mainloop() causing it to terminate.

The first window—an instance of the TitleScreen class—is displayed automatically when an instance of the application class is created. This window has two Buttons one labelled Easy Mode and the other Hard Mode. When one of them is clicked, an instance of the appropriate Toplevel subclass is created after the current window is removed by it call its destroy() method.

mainmenu.py

import tkinter as tk
from tkinter.constants import *
from tkinter import font as tkfont
from basewin import BaseWin
from easymode import EasyApp
from hardmode import HardApp


class SampleApp(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title('Flag Quiz')
        self.geometry('600x600')
        self.resizable(FALSE, FALSE)
        self.title_font = tkfont.Font(family='Helvetica', size=18, weight="bold")
        self.withdraw()  # Hide default root Tk window.
        startpage = TitleScreen(self.master)
        self.mainloop()


class TitleScreen(BaseWin):
    def __init__(self, master):
        super().__init__(master)
        self.make_widgets()

    def make_widgets(self):
        label = tk.Label(self, text="This is the Start Page", font=self.master.title_font)
        label.pack(side="top", fill="x", pady=10)

        self.easy = tk.Button(self, text="Easy Mode", font=('default', 20),
                              command=self.play_easy)
        self.hard = tk.Button(self, text="Easy Mode", font=('default', 20),
                              command=self.play_hard)
        self.easy.pack()
        self.hard.pack()

    def play_easy(self):
        self.destroy()
        self.app = EasyApp(self.master)

    def play_hard(self):
        self.destroy()
        self.app = HardApp(self.master)


if __name__ == '__main__':
    SampleApp()

basewin.py

import tkinter as tk
from tkinter.constants import *


class BaseWin(tk.Toplevel):
    def __init__(self, master):
        super().__init__(master)
        self.protocol("WM_DELETE_WINDOW", self.on_close)

    def on_close(self):
        self.destroy()      # Destroy current window
        self.master.quit()  # Quit app.

easymode.py

import tkinter as tk
from tkinter.constants import *
from basewin import BaseWin


class EasyApp(BaseWin):
    def __init__(self, master):
        super().__init__(master)
        self.title('Flag Quiz')
        self.resizable(FALSE, FALSE)
        self.make_widgets()

    def make_widgets(self):
        label = tk.Label(self, text="This is the Easy App", font=self.master.title_font)
        label.pack(side="top", fill="x", pady=10)

hardmode.py

import tkinter as tk
from tkinter.constants import *
from basewin import BaseWin


class HardApp(BaseWin):
    def __init__(self, master):
        super().__init__(master)
        self.title('Flag Quiz')
        self.resizable(FALSE, FALSE)
        self.make_widgets()

    def make_widgets(self):
        label = tk.Label(self, text="This is the Hard App", font=self.master.title_font)
        label.pack(side="top", fill="x", pady=10)
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