TK binding mouse wheel scroll to scrolled list

[ilikepython]

I have a class that I use for a scrolled list. The problem is I want to be able to scroll the list using the mouse wheel. I am using bind and it's not working:

class ScrolledList(Frame):
    def __init__(self, parent = None):
        Frame.__init__(self, parent)
        self.box = Listbox(self)
        ... more code ...
 
        self.box.bind("<MouseWheel>", self.wheelscroll)
 
    def wheelscroll(self, event):
        if event.delta > 0:
            self.box.yview_scroll(-2, 'units')
        else:
            self.box.yview_scroll(2, 'units')
 

I also tried binding to the Frame but that doesn't work. I think the problem is the box isn't getting the messages, but then what should I bind to? Also, If I don't bind to the box, what happens if I have more than one scrolled list in one frame?

[bartonc]

Hi John,

here is a code snippet I have successfully used:

self.canvas.bind('<4>', lambda event : self.canvas.xview('scroll', -1, 'units'))
self.canvas.bind('<5>', lambda event : self.canvas.xview('scroll', 1, 'units'))

or if you do not like the lambda, you can use a callback like this:

def rollWheel(event):
if event.num == 4:
self.canvas.xview('scroll', -1, 'units')
elif event.num == 5:
self.canvas.xview('scroll', 1, 'units')

I hope this helps

From mail.python.org/pipemail, June of '06.

Hope that helps.

[ilikepython]

From mail.python.org/pipemail, June of '06.

Hope that helps.

Well I found that same page too, but it turns out that button 4 and 5 work only on linux, and on windows you have to use the mousewheel event.

[ilikepython]

I figured it out. The problem was that the list box never got focus. I added this line and it worked:

self.box.bind("<Button-1>", lambda x: self.box.focus())