WM behaviour on wheel, focus, and raise

[moo moo]

Hello,

I recently tried xfce 4.2.2 and found it fascinating. However, I
noticed a WM behaviour that is quite different from my experience on
other X window managers, and this is a function that I found pretty
handy on managing windows.

In IceWM (,gnome, and many others as I remember), when a wheel mouse
wheel up or down in a unfocused window, the scroll bar inside the
window responses accordingly but does not raise nor become focused.
Meanwhile, clicking inside a window does raise the window and become
focused.

The advantage of this is, for example, in Firefox one can scroll a
textbox without clicking on it first, but simply place the mouse over
the textbox. Another situation is one can scroll a background window
and view its contents without loosing focus on the window working on.
Which keeps the desktop clean, efficient, and "quiet". No extra
redraws need to be done.

In xfce window manager, I found it impossible to behave like this. In
the Window manager preference setting utility, neither check/uncheck
"Raise on click" helps, because "wheel" event is considered as
"Click". If I check the option, window would raise when I scroll
(which is undesired). If I unckeck, window would not raise when I
click inside it (which is undesired, too). If we can separate wheel
(Button 4 5) and Clicks (Button 1 2 3), the user can have more
controll on the WM behaviour and a cleaner desktop.

Regards,

moowei