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.keys():

            window = self.dict[key]

            try:

                title = window.get_title()

            except TclError:

                continue

            list.append((title, window))

        list.sort()

        for title, 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:

                print "warning: callback failed in WindowList", \

                      sys.exc_type, ":", sys.exc_value

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