Re: Tkinter update

Bill Janssen (janssen@parc.xerox.com)
Fri, 3 Jun 1994 15:25:07 PDT

I've played around a bit with it, too.

> 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!

Indeed, a great start! I tried your suggestion, seems much nicer. But
then I actually added another `special' configuration parameter called
`packing' to the create config list, so that I could either write

top = Frame(w, {'relief': 'raised', 'bd': 1,
'packing': {'side': 'top', 'fill': 'both'}})

(which is probably the preferred form around here) or

top = Frame(w, {'relief': 'raised', 'bd': 1 })
top.pack ({'side': 'top', 'fill': 'both'})

Here are the three changed methods in Widget():

class Widget(Pack, Place, Tk):
def __init__(self, master, widgetName, cnf={}, extra=()):
if not master:
master = self.master = Tk()
self.tk = master.tk
if master.pathName=='.':
self.pathName = '.' + `id(self)`
else:
self.pathName = master.pathName + '.' + `id(self)`
self.widgetName = widgetName
apply(self.tk.call, (widgetName, self.pathName) + extra)
if (cnf.has_key('packing')):
packing = cnf['packing']
del cnf['packing']
else: packing = None
configure(self, cnf)
if (packing):
self.pack(packing)
def pack(self, dict={}):
for i in dict.items():
Pack.__setitem__(self, i[0], i[1])
Pack.config(self)
def endmainloop(self):
self.tk.call ('destroy', '.')

This allows me to write Guido's dialog box as:

=====================================
# 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,
'packing': {'side': 'top', 'fill': 'both'}})
bot = Frame(w, {'relief': 'raised', 'bd': 1,
'packing': {'side': 'bottom', '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-*',
'packing': { 'side': 'right', 'expand': 1, 'fill': 'both',
'padx': '3m', 'pady': '3m'}})
if bitmap:
bm = Label(top, {'bitmap': bitmap,
'packing': { 'side': 'left',
'padx': '3m', '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,
'packing': { 'side': 'left', 'expand': 1,
'padx': '3m', 'pady': '2m'}})
w.tk.call('raise', b)
b.pack ({'in': bd, 'side': 'left', 'padx': '2m', 'pady': '2m',
'ipadx': '2m', 'ipady': '1m'})
else:
b.pack ({'side': 'left', 'expand': 1, 'padx': '3m', 'pady': '3m',
'ipady': '2m', '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', 'command': go})
start.pack()
endit = Button(mainWidget, {'text': 'Exit', 'command': lambda: mainWidget.endmainloop(),
'packing': {'fill' : 'both'}})
mainWidget.tk.mainloop()

if __name__ == '__main__':
test()
==================================

Bill