[Tkinter-discuss] Re: [TkinterHow to change font sizes in a Tkinter app?

[stewart at midtoad.homelinux.org]

I'd like to be able to change font size in my Tkinter app.   I've attached a
sample app below that allow for this. Problem is, the method is run when the
menus are drawn, but doesn't run afterward.  How do I stop the font sizes from
changing when the app is started up?  One way might be a lambda function, but is
there any other cleaner solution? Thanks!

cheers
Stewart


---
title = 'FontSize demonstration'

# Import Pmw from this directory tree.
import sys
sys.path[:0] = ['../../..']

import Tkinter
import Pmw

class Demo:
    def __init__(self, parent):

        #Define a base font for use in all widgets
        #this can be changed later in the Options menu
        self.font=('Helvetica', 10, 'normal')


	# Create and pack the MenuBar.
	menuBar = Pmw.MenuBar(parent,
		hull_relief = 'raised',
		hull_borderwidth = 1)
	menuBar.pack(fill = 'x')
	self.menuBar = menuBar

	# Add some buttons to the MenuBar.
	menuBar.addmenu('File', 'Close this window or exit', font=self.font)
	menuBar.addmenuitem('File', 'command', 'Close this window',
		command = PrintOne('Action: close'),
        font=self.font,
		label = 'Close')
	menuBar.addmenuitem('File', 'separator')
	menuBar.addmenuitem('File', 'command', 'Exit the application',
		command = lambda: sys.exit("Bye"),
        font=self.font,
		label = 'Exit')

#		command = PrintOne('Action: exit'),

	menuBar.addmenu('Options', 'Set user preferences', font=self.font)
	menuBar.addcascademenu('Options', 'Size',
		'Set some other preferences', traverseSpec = 'z', tearoff = 1, font=self.font)
	for size in ('tiny', 'small', 'average', 'big', 'huge', 'monstrous'):
	    menuBar.addmenuitem('Size', 'command', 'Set size to ' + size,
                    command = self.setFont(size),
                    font=self.font,
                    label = size)

	# Create and pack the main part of the window.
	self.mainPart = Tkinter.Label(parent,
		text = 'This is the\nmain part of\nthe window',
        font=self.font,
		background = 'white',
		foreground = 'black',
		padx = 30,
		pady = 30)
	self.mainPart.pack(fill = 'both', expand = 1)

    def setFont(self, size):
        print 'current font size: ',self.font[1]
        #('tiny', 'small', 'average', 'big', 'huge')
        newFont = {'tiny': ('Helvetica', 6, 'normal'), 
                    'small': ('Helvetica', 8, 'normal'), 
                    'average': ('Helvetica', 10, 'normal'), 
                    'big': ('Helvetica', 12, 'normal'),
                    'huge': ('Helvetica', 14, 'normal'),
                    'monstrous': ('Helvetica', 18, 'normal')}
        self.font = newFont[size]
        print 'new font size: ', size
        root.update()

class PrintOne:
    def __init__(self, text):
        self.text = text

    def __call__(self):
        print self.text

######################################################################

# Create demo in root window for testing.
if __name__ == '__main__':
    root = Tkinter.Tk()
    Pmw.initialise(root)
    root.title(title)

    exitButton = Tkinter.Button(root, text = 'Exit', command = root.destroy)
    exitButton.pack(side = 'bottom')
    widget = Demo(root)
    root.mainloop()