Radiobuttons in Tk [QUESTION]

mjc4y@uvacs.cs.virginia.edu
Thu, 2 Feb 1995 10:56:35 -0500

Good Question.

To break this connection, you need to specify a different "variable"
option for each of the two radio button menus. Here's some sample code
of a program with two radio menus and a button to print out the state
of each menu. I make no claims that this is the best software
engineering solution (there are global variable, and I initialize them
in what might seem to be strange places), but I think the intent is
pretty clear.

Hope this helps!

cheers,
Matt
------------- snip %< ------------------

from Tkinter import *

# The way to think about this is that each radio button menu
# controls a different variable -- clicking on one of the
# mutually exclusive choices in a radiobutton assigns some value
# to an application variable you provide. When you define a
# radiobutton menu choice, you have the option of specifying the
# name of a varaible and value to assign to that variable when
# that choice is selected. This clever mechanism relieves you,
# the programmer, from having to write a dumb callback that
# probably wouldn't have done anything more than an assignment
# anyway. The Tkinter options for this follow their Tk
# counterparts:
# {"variable" : my_flavor_variable, "value" : "strawberry"}
# where my_flavor_variable is an instance of one of the
# subclasses of Variable, provided in Tkinter.py (there is
# StringVar(), IntVar(), DoubleVar() and BooleanVar() to choose
# from)

def makePoliticalParties():
# make menu button
Radiobutton_button = Menubutton(mBar, {'text': 'Political Party',
'underline': 0,
Pack: {'side': 'left',
'padx': '2m'}})

# the primary pulldown
Radiobutton_button.menu = Menu(Radiobutton_button)

Radiobutton_button.menu.add('radiobutton', {'label': 'Republican',
'variable' : party,
'value' : 1})

Radiobutton_button.menu.add('radiobutton', {'label': 'Democrat',
'variable' : party,
'value' : 2})

Radiobutton_button.menu.add('radiobutton', {'label': 'Libertarian',
'variable' : party,
'value' : 3})

party.set(2)

# set up a pointer from the file menubutton back to the file menu
Radiobutton_button['menu'] = Radiobutton_button.menu

return Radiobutton_button

def makeFlavors():
# make menu button
Radiobutton_button = Menubutton(mBar, {'text': 'Flavors',
'underline': 0,
Pack: {'side': 'left',
'padx': '2m'}})
# the primary pulldown
Radiobutton_button.menu = Menu(Radiobutton_button)

Radiobutton_button.menu.add('radiobutton', {'label': 'Strawberry',
'variable' : flavor,
'value' : 'Strawberry'})

Radiobutton_button.menu.add('radiobutton', {'label': 'Chocolate',
'variable' : flavor,
'value' : 'Chocolate'})

Radiobutton_button.menu.add('radiobutton', {'label': 'Rocky Road',
'variable' : flavor,
'value' : 'Rocky Road'})

# choose a default
flavor.set("Chocolate")

# set up a pointer from the file menubutton back to the file menu
Radiobutton_button['menu'] = Radiobutton_button.menu

return Radiobutton_button

def printStuff():
print "party is", party.get()
print "flavor is", flavor.get()
print ""

#################################################
#### Main starts here ...
root = Tk()

# make a menu bar
mBar = Frame(root, {'relief': 'raised',
'bd': 2,
Pack: {'side': 'top',
'fill': 'x'}})

# make two application variables,
# one to control each radio button set
party = IntVar()
flavor = StringVar()

Radiobutton_button = makePoliticalParties()
Radiobutton_button2 = makeFlavors()

# finally, install the buttons in the menu bar.
# This allows for scanning from one menubutton to the next.
mBar.tk_menuBar(Radiobutton_button, Radiobutton_button2)

b = Button(root, {"text": "print party and flavor",
"command" : printStuff,
"fg": "red"})
b.pack({"side" : "top"})

root.title('menu demo')
root.iconname('menu demo')

root.mainloop()

------------- snip %< ------------------

Tom Jones writes:
| Using python, with the tkinter include,
| I have found that if I have two menus of
| radio-buttons, they work "together", so that I
| can only have one item on in both menus, when
| I would (obviously) want one item on in
| each menu.
|
| I don't believe this to be the result of
| erroneous usage, and can supply an example
| if anybody wants one.
|
| I would really appreciate it if anybody who
| has successfully used two distinct menus
| of radio buttons could point me to some
| code or brief explanation,
|
|
| thanks,
|
|
| tom
|
| ---------------------------------------------------------------
| Thomas J. Jones | PHONE : +61 2 351-3503 | FAX: +61 2 351-3838
| Basser Department of Computer Science, Sydney University
| We have tamed lightning and used it to teach sand to think.
| ---------------------------------------------------------------