Comparing the Python code to the Tcl version, the most blatant
difference is the many Pack.config() calls needed to emulate a single
'pack configure' call. I think a streamlined interface for this is
needed, e.g.
w.pack({'side': 'left', 'expand': 1})
Likewise for 'wm', 'raise' and possibly other Tcl procedures that have
widget arguments. But Tkinter.py is a good start already!
(Two more remarks on Tkinter: (1) The defaulting of screenName to
$DISPLAY or ':0' is unnecessary, the Tk library does this (except
':0', which isn't standard X11 policy anyway). (2) I would like
w.cmd(...) to return the return value of tk.call(...) -- this is
sometimes useful.
Here's my dialog.py file:
======================================================================
# A Python function that generates dialog boxes with a text message,
# optional bitmap, and any number of buttons.
# Cf. Ousterhout, Tcl and the Tk Toolkit, Figs. 27.2-3, pp. 269-270.
from Tkinter import *
# (This is missing in the distributed Tkinter)
class Message(Widget):
def __init__(self, master=None, cnf={}):
Widget.__init__(self, master, 'message', cnf)
def dialog(master, title, text, bitmap, default, *args):
# 1. Create the top-level window and divide it into top
# and bottom parts.
w = Toplevel(master, {'class': 'Dialog'})
w.tk.call('global', 'button')
top = Frame(w, {'relief': 'raised', 'bd': 1})
Pack.config(top, 'side', 'top')
Pack.config(top, 'fill', 'both')
bot = Frame(w, {'relief': 'raised', 'bd': 1})
Pack.config(bot, 'side', 'bottom')
Pack.config(bot, 'fill', 'both')
# 2. Fill the top part with the bitmap and message.
msg = Message(top,
{'width': '3i',
'text': text,
'font':
'-Adobe-Times-Medium-R-Normal-*-180-*'})
Pack.config(msg, 'side', 'right')
Pack.config(msg, 'expand', 1)
Pack.config(msg, 'fill', 'both')
Pack.config(msg, 'padx', '3m')
Pack.config(msg, 'pady', '3m')
if bitmap:
bm = Label(top, {'bitmap': bitmap})
Pack.config(bm, 'side', 'left')
Pack.config(bm, 'padx', '3m')
Pack.config(bm, 'pady', '3m')
# 3. Create a row of buttons at the bottom of the dialog.
buttons = []
i = 0
for but in args:
b = Button(bot, {'text': but,
'command': ('set', 'button', i)})
buttons.append(b)
if i == default:
bd = Frame(bot, {'relief': 'sunken', 'bd': 1})
w.tk.call('raise', b)
Pack.config(bd, 'side', 'left')
Pack.config(bd, 'expand', 1)
Pack.config(bd, 'padx', '3m')
Pack.config(bd, 'pady', '2m')
Pack.config(b, 'in', bd)
Pack.config(b, 'side', 'left')
Pack.config(b, 'padx', '2m')
Pack.config(b, 'pady', '2m')
Pack.config(b, 'ipadx', '2m')
Pack.config(b, 'ipady', '1m')
else:
Pack.config(b, 'side', 'left')
Pack.config(b, 'expand', 1)
Pack.config(b, 'padx', '3m')
Pack.config(b, 'pady', '3m')
Pack.config(b, 'ipady', '2m')
Pack.config(b, 'ipady', '1m')
i = i+1
# 4. Set up a binding for <Return>, if there's a default,
# set a grab, and claim the focus too.
if default >= 0:
w.bind('<Return>',
lambda b=buttons[default], i=default:
(b.cmd('flash'),
b.tk.call('set', 'button', i)))
oldFocus = w.tk.call('focus')
w.tk.call('grab', 'set', w)
w.tk.call('focus', w)
# 5. Wait for the user to respond, then restore the focus
# and return the index of the selected button.
w.tk.call('tkwait', 'variable', 'button')
w.tk.call('destroy', w)
w.tk.call('focus', oldFocus)
return w.tk.call('set', 'button')
# The rest is the test program.
def go():
i = dialog(mainWidget,
'Not Responding',
"The file server isn't responding right now; "
"I'll keep trying.",
'',
-1,
'OK')
print 'pressed button', i
i = dialog(mainWidget,
'File Modified',
'File "tcl.h" has been modified since '
'the last time it was saved. '
'Do you want to save it before exiting the application?',
'warning',
0,
'Save File',
'Discard Changes',
'Return To Editor')
print 'pressed button', i
def test():
global mainWidget
mainWidget = Frame()
Pack.config(mainWidget)
start = Button(mainWidget, {'text': 'Press Here To Start'})
Pack.config(start)
start['command'] = go
mainWidget.tk.mainloop()
if __name__ == '__main__':
test()
======================================================================
--Guido van Rossum, CWI, Amsterdam <Guido.van.Rossum@cwi.nl>
URL: <http://www.cwi.nl/cwi/people/Guido.van.Rossum.html>