from tkinter import *

class WindowList:

def __init__(self):
self.dict = {}
self.callbacks = []

def add(self, window):
window.after_idle(self.call_callbacks)
self.dict[str(window)] = window

def delete(self, window):
try:
del self.dict[str(window)]
except KeyError:
# Sometimes, destroy() is called twice
pass
self.call_callbacks()

def add_windows_to_menu(self, menu):
list = []
for key in self.dict:
window = self.dict[key]
try:
title = window.get_title()
except TclError:
continue
list.append((title, key, window))
list.sort()
for title, key, window in list:
menu.add_command(label=title, command=window.wakeup)

def register_callback(self, callback):
self.callbacks.append(callback)

def unregister_callback(self, callback):
try:
self.callbacks.remove(callback)
except ValueError:
pass

def call_callbacks(self):
for callback in self.callbacks:
try:
callback()
except:
t, v, tb = sys.exc_info()
print("warning: callback failed in WindowList", t, ":", v)

registry = WindowList()

add_windows_to_menu = registry.add_windows_to_menu
register_callback = registry.register_callback
unregister_callback = registry.unregister_callback


class ListedToplevel(Toplevel):

def __init__(self, master, **kw):
Toplevel.__init__(self, master, kw)
registry.add(self)
self.focused_widget = self

def destroy(self):
registry.delete(self)
Toplevel.destroy(self)
# If this is Idle's last window then quit the mainloop
# (Needed for clean exit on Windows 98)
if not registry.dict:
self.quit()

def update_windowlist_registry(self, window):
registry.call_callbacks()

def get_title(self):
# Subclass can override
return self.wm_title()

def wakeup(self):
try:
if self.wm_state() == "iconic":
self.wm_withdraw()
self.wm_deiconify()
self.tkraise()
self.focused_widget.focus_set()
except TclError:
# This can happen when the window menu was torn off.
# Simply ignore it.
pass