"""A simple but flexible modal dialog box."""

from Tkinter import *

class SimpleDialog:

    def __init__(self, master,

                 text='', buttons=[], default=None, cancel=None,

                 title=None, class_=None):

        if class_:

            self.root = Toplevel(master, class_=class_)

        else:

            self.root = Toplevel(master)

        if title:

            self.root.title(title)

            self.root.iconname(title)

        self.message = Message(self.root, text=text, aspect=400)

        self.message.pack(expand=1, fill=BOTH)

        self.frame = Frame(self.root)

        self.frame.pack()

        self.num = default

        self.cancel = cancel

        self.default = default

        self.root.bind('<Return>', self.return_event)

        for num in range(len(buttons)):

            s = buttons[num]

            b = Button(self.frame, text=s,

                       command=(lambda self=self, num=num: self.done(num)))

            if num == default:

                b.config(relief=RIDGE, borderwidth=8)

            b.pack(side=LEFT, fill=BOTH, expand=1)

        self.root.protocol('WM_DELETE_WINDOW', self.wm_delete_window)

        self._set_transient(master)

    def _set_transient(self, master, relx=0.5, rely=0.3):

        widget = self.root

        widget.withdraw() # Remain invisible while we figure out the geometry

        widget.transient(master)

        widget.update_idletasks() # Actualize geometry information

        if master.winfo_ismapped():

            m_width = master.winfo_width()

            m_height = master.winfo_height()

            m_x = master.winfo_rootx()

            m_y = master.winfo_rooty()

        else:

            m_width = master.winfo_screenwidth()

            m_height = master.winfo_screenheight()

            m_x = m_y = 0

        w_width = widget.winfo_reqwidth()

        w_height = widget.winfo_reqheight()

        x = m_x + (m_width - w_width) * relx

        y = m_y + (m_height - w_height) * rely

        if x+w_width > master.winfo_screenwidth():

            x = master.winfo_screenwidth() - w_width

        elif x < 0:

            x = 0

        if y+w_height > master.winfo_screenheight():

            y = master.winfo_screenheight() - w_height

        elif y < 0:

            y = 0

        widget.geometry("+%d+%d" % (x, y))

        widget.deiconify() # Become visible at the desired location

    def go(self):

        self.root.wait_visibility()

        self.root.grab_set()

        self.root.mainloop()

        self.root.destroy()

        return self.num

    def return_event(self, event):

        if self.default is None:

            self.root.bell()

        else:

            self.done(self.default)

    def wm_delete_window(self):

        if self.cancel is None:

            self.root.bell()

        else:

            self.done(self.cancel)

    def done(self, num):

        self.num = num

        self.root.quit()

if __name__ == '__main__':

    def test():

        root = Tk()

        def doit(root=root):

            d = SimpleDialog(root,

                         text="This is a test dialog.  "

                              "Would this have been an actual dialog, "

                              "the buttons below would have been glowing "

                              "in soft pink light.\n"

                              "Do you believe this?",

                         buttons=["Yes", "No", "Cancel"],

                         default=0,

                         cancel=2,

                         title="Test Dialog")

            print d.go()

        t = Button(root, text='Test', command=doit)

        t.pack()

        q = Button(root, text='Quit', command=t.quit)

        q.pack()

        t.mainloop()

    test()