#

# An Introduction to Tkinter

# tkSimpleDialog.py

#

# Copyright (c) 1997 by Fredrik Lundh

#

# fredrik@pythonware.com

# http://www.pythonware.com

#

# --------------------------------------------------------------------

# dialog base class

'''Dialog boxes

This module handles dialog boxes. It contains the following

public symbols:

Dialog -- a base class for dialogs

askinteger -- get an integer from the user

askfloat -- get a float from the user

askstring -- get a string from the user

'''

from Tkinter import *

class Dialog(Toplevel):

    '''Class to open dialogs.

    This class is intended as a base class for custom dialogs

    '''

    def __init__(self, parent, title = None):

        '''Initialize a dialog.

        Arguments:

            parent -- a parent window (the application window)

            title -- the dialog title

        '''

        Toplevel.__init__(self, parent)

        # If the master is not viewable, don't

        # make the child transient, or else it

        # would be opened withdrawn

        if parent.winfo_viewable():

            self.transient(parent)

        if title:

            self.title(title)

        self.parent = parent

        self.result = None

        body = Frame(self)

        self.initial_focus = self.body(body)

        body.pack(padx=5, pady=5)

        self.buttonbox()

        self.wait_visibility() # window needs to be visible for the grab

        self.grab_set()

        if not self.initial_focus:

            self.initial_focus = self

        self.protocol("WM_DELETE_WINDOW", self.cancel)

        if self.parent is not None:

            self.geometry("+%d+%d" % (parent.winfo_rootx()+50,

                                      parent.winfo_rooty()+50))

        self.initial_focus.focus_set()

        self.wait_window(self)

    def destroy(self):

        '''Destroy the window'''

        self.initial_focus = None

        Toplevel.destroy(self)

    #

    # construction hooks

    def body(self, master):

        '''create dialog body.

        return widget that should have initial focus.

        This method should be overridden, and is called

        by the __init__ method.

        '''

        pass

    def buttonbox(self):

        '''add standard button box.

        override if you do not want the standard buttons

        '''

        box = Frame(self)

        w = Button(box, text="OK", width=10, command=self.ok, default=ACTIVE)

        w.pack(side=LEFT, padx=5, pady=5)

        w = Button(box, text="Cancel", width=10, command=self.cancel)

        w.pack(side=LEFT, padx=5, pady=5)

        self.bind("<Return>", self.ok)

        self.bind("<Escape>", self.cancel)

        box.pack()

    #

    # standard button semantics

    def ok(self, event=None):

        if not self.validate():

            self.initial_focus.focus_set() # put focus back

            return

        self.withdraw()

        self.update_idletasks()

        try:

            self.apply()

        finally:

            self.cancel()

    def cancel(self, event=None):

        # put focus back to the parent window

        if self.parent is not None:

            self.parent.focus_set()

        self.destroy()

    #

    # command hooks

    def validate(self):

        '''validate the data

        This method is called automatically to validate the data before the

        dialog is destroyed. By default, it always validates OK.

        '''

        return 1 # override

    def apply(self):

        '''process the data

        This method is called automatically to process the data, *after*

        the dialog is destroyed. By default, it does nothing.

        '''

        pass # override

# --------------------------------------------------------------------

# convenience dialogues

class _QueryDialog(Dialog):

    def __init__(self, title, prompt,

                 initialvalue=None,

                 minvalue = None, maxvalue = None,

                 parent = None):

        if not parent:

            import Tkinter

            parent = Tkinter._default_root

        self.prompt   = prompt

        self.minvalue = minvalue

        self.maxvalue = maxvalue

        self.initialvalue = initialvalue

        Dialog.__init__(self, parent, title)

    def destroy(self):

        self.entry = None

        Dialog.destroy(self)

    def body(self, master):

        w = Label(master, text=self.prompt, justify=LEFT)

        w.grid(row=0, padx=5, sticky=W)

        self.entry = Entry(master, name="entry")

        self.entry.grid(row=1, padx=5, sticky=W+E)

        if self.initialvalue:

            self.entry.insert(0, self.initialvalue)

            self.entry.select_range(0, END)

        return self.entry

    def validate(self):

        import tkMessageBox

        try:

            result = self.getresult()

        except ValueError:

            tkMessageBox.showwarning(

                "Illegal value",

                self.errormessage + "\nPlease try again",

                parent = self

            )

            return 0

        if self.minvalue is not None and result < self.minvalue:

            tkMessageBox.showwarning(

                "Too small",

                "The allowed minimum value is %s. "

                "Please try again." % self.minvalue,

                parent = self

            )

            return 0

        if self.maxvalue is not None and result > self.maxvalue:

            tkMessageBox.showwarning(

                "Too large",

                "The allowed maximum value is %s. "

                "Please try again." % self.maxvalue,

                parent = self

            )

            return 0

        self.result = result

        return 1

class _QueryInteger(_QueryDialog):

    errormessage = "Not an integer."

    def getresult(self):

        return int(self.entry.get())

def askinteger(title, prompt, **kw):

    '''get an integer from the user

    Arguments:

        title -- the dialog title

        prompt -- the label text

        **kw -- see SimpleDialog class

    Return value is an integer

    '''

    d = _QueryInteger(title, prompt, **kw)

    return d.result

class _QueryFloat(_QueryDialog):

    errormessage = "Not a floating point value."

    def getresult(self):

        return float(self.entry.get())

def askfloat(title, prompt, **kw):

    '''get a float from the user

    Arguments:

        title -- the dialog title

        prompt -- the label text

        **kw -- see SimpleDialog class

    Return value is a float

    '''

    d = _QueryFloat(title, prompt, **kw)

    return d.result

class _QueryString(_QueryDialog):

    def __init__(self, *args, **kw):

        if kw.has_key("show"):

            self.__show = kw["show"]

            del kw["show"]

        else:

            self.__show = None

        _QueryDialog.__init__(self, *args, **kw)

    def body(self, master):

        entry = _QueryDialog.body(self, master)

        if self.__show is not None:

            entry.configure(show=self.__show)

        return entry

    def getresult(self):

        return self.entry.get()

def askstring(title, prompt, **kw):

    '''get a string from the user

    Arguments:

        title -- the dialog title

        prompt -- the label text

        **kw -- see SimpleDialog class

    Return value is a string

    '''

    d = _QueryString(title, prompt, **kw)

    return d.result

if __name__ == "__main__":

    root = Tk()

    root.update()

    print askinteger("Spam", "Egg count", initialvalue=12*12)

    print askfloat("Spam", "Egg weight\n(in tons)", minvalue=1, maxvalue=100)

    print askstring("Spam", "Egg label")