Question

I’m trying to change the layering of Tkinter Canvas widgets. With most widgets you can force the widget above other widgets by using the lift method. However, if I try the same on a Canvas widget I get an error.

Error :

TypeError: tag_raise() got an unexpected keyword argument 'aboveThis'

An Example of my Problem :

import Tkinter as Tk


root = Tk.Tk()

w, h = 200, 200

a = Tk.Canvas(root, bg='red', width=w, height=h)
a.grid(column=0, row=0)

b = Tk.Canvas(root, bg='blue', width=w, height=h)
b.grid(column=0, row=0)

a.lift(aboveThis=None)

root.mainloop()

If I do the same thing with Frame widgets, it works.

Example:

import Tkinter as Tk


root = Tk.Tk()

w, h = 200, 200

a = Tk.Frame(root, bg='red', width=w, height=h)
a.grid(column=0, row=0)

b = Tk.Frame(root, bg='blue', width=w, height=h)
b.grid(column=0, row=0)

a.lift(aboveThis=None)

root.mainloop()

Answer 1

The canvas lift() method is an alias for tag_raise(), which is used to raise not the canvas itself but entities within the canvas.

I found this comment within the Tkinter.py source code:

# lower, tkraise/lift hide Misc.lower, Misc.tkraise/lift,
# so the preferred name for them is tag_lower, tag_raise
# (similar to tag_bind, and similar to the Text widget);
# unfortunately can't delete the old ones yet (maybe in 1.6)

If you replace a.lift(aboveThis=None) with Tk.Misc.lift(a, aboveThis=None) then the canvas widget is raised correctly.