Tk MouseWheel Support

[Greg Couch]

On Mar 10, 1:37 pm, Corey Richardson <kb1... at aim.com> wrote:
> On 03/10/2011 03:35 PM, Corey Richardson wrote:
>
> > Middle button is Button-3 IIRC, and I think it'd be MouseUp and
> > MouseDown. I'm really not sure though.
>
> It's Button-2 rather.
>
> --
> Corey Richardson

Middle button is button-3 on Mac OS X, and button-2 on Linux and
Windows.  Very annoying, to say the least.

For X11, here's a better way to inject MouseWheel events so all
widgets that understand MouseWheel events will work without additional
code:

def mousewheel(e, delta):
    try:
        w = e.widget.focus_displayof()
    except AttributeError:
        # e.widget might be string
        # if not created by Tkinter (eg., menu tearoff)
        return
    if w: w.event_generate('<MouseWheel>', delta=delta,
            state=e.state, rootx=e.x_root, rooty=e.y_root,
            x=e.x, y=e.y, time=e.time)
root.bind_all('<Button-4>', lambda e, mw=mousewheel: mw(e, 120))
root.bind_all('<Button-5>', lambda e, mw=mousewheel: mw(e, -120))