Patterns

Toplevel menus are displayed just under the title bar of the root or any other toplevel windows (or on Macintosh, along the upper edge of the screen). To create a toplevel menu, create a new Menu instance, and use add methods to add commands and other menu entries to it.

Example 32-1. Creating a toplevel menu

# menu-example-2.py

from Tkinter import *

root = Tk()

def hello():
    print "hello!"

# create a toplevel menu
menubar = Menu(root)
menubar.add_command(label="Hello!", command=hello)
menubar.add_command(label="Quit!", command=root.quit)

# display the menu
root.config(menu=menubar)

mainloop()

Pulldown menus (and other submenus) are created in a similar fashion. The main difference is that they are attached to a parent menu (using add_cascade), instead of a toplevel window.

Example 32-2. Creating toplevel and pulldown menus

# menu-example-3.py

from Tkinter import *

root = Tk()

def hello():
    print "hello!"

menubar = Menu(root)

# create a pulldown menu, and add it to the menu bar
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label="Open", command=hello)
filemenu.add_command(label="Save", command=hello)
filemenu.add_separator()
filemenu.add_command(label="Exit", command=root.quit)
menubar.add_cascade(label="File", menu=filemenu)

# create more pulldown menus
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label="Cut", command=hello)
editmenu.add_command(label="Copy", command=hello)
editmenu.add_command(label="Paste", command=hello)
menubar.add_cascade(label="Edit", menu=editmenu)

helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label="About", command=hello)
menubar.add_cascade(label="Help", menu=helpmenu)

# display the menu
root.config(menu=menubar)

mainloop()

Finally, a popup menu is created in the same way, but is explicitly displayed, using the post method:

Example 32-3. Creating and displaying a popup menu

# menu-example-4.py

from Tkinter import *

root = Tk()

def hello():
    print "hello!"

# create a popup menu
menu = Menu(root, tearoff=0)
menu.add_command(label="Undo", command=hello)
menu.add_command(label="Redo", command=hello)

# create a canvas
frame = Frame(root, width=512, height=512)
frame.pack()

def popup(event):
    menu.post(event.x_root, event.y_root)

# attach popup to canvas
frame.bind("<Button-3>", popup)

mainloop()

You can use the postcommand callback to update (or even create) the menu everytime it is displayed.

Example 32-4. Updating a menu on the fly

# menu-example-5.py

from Tkinter import *

counter = 0

def update():
    global counter
    counter = counter + 1
    menu.entryconfig(0, label=str(counter))

root = Tk()

menubar = Menu(root)

menu = Menu(menubar, tearoff=0, postcommand=update)
menu.add_command(label=str(counter))
menu.add_command(label="Exit", command=root.quit)

menubar.add_cascade(label="Test", menu=menu)

root.config(menu=menubar)

mainloop()

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