How to change colors of multiple widgets after hovering in Tkinter

[Peter Otten]

mountdoom12 at gmail.com wrote:

> I´m trying to make a script, which will change the background and
> foreground color of widgets after hovering.

> but when I hover on any button, nothing happens, they stay white. I know I
> could use a function, but there would be two functions for every widget (1
> for , 1 for ). I'd like to create a single function, which will recolor
> that widget I hover on and explain why this script is not doing what I
> want it to do.
> 
> I hope I described my problem well. 

You did.

> from Tkinter import *
> 
> root=Tk()
> 
> Hover1=Button(root,text="Red color", bg="white")
> Hover1.pack()
> 
> Hover2=Button(root,text="Yellow color", bg="white")
> Hover2.pack()
> 
> Hover1.bind("<Enter>",Hover1.configure(bg="red"))

This calls Hover1.configure(bg="red") once and binds the result of that 
method call (which is None) to the event. So the above line is equivalent to

Hover1.configure(bg="red")
Hover1.bind("<Enter>", None)

You say you don't want to write a function, but that is really the correct 
aproach. Fortunately there is a way to create such a function on the fly:

def f(event):
    Hover1.configure(bg="red")

can be written as

f = lambda event: Hover1.configure(bg="red")

With that your code becomes

Hover1.bind("<Enter>", lambda event: Hover1.configure(bg="red"))
Hover1.bind("<Leave>", lambda event: Hover1.configure(bg="white"))

and so on. In this specific case this doesn't have the desired effect 
because when the mouse enters a Button widget its background color changes 
to 'activebackground'. So you don't really need to bind the enter/leave 
events. Specify an activebackground instead when you create the buttons. For 
example:

Hover1 = Button(root, text="Red color", bg="white", activebackground="red")
Hover1.pack()