[Galago-devel] DBus Signal for Volume?

[Arigead]

Hello all,
    new to this list, and have joined as I have a quick question. I
maybe in the wrong place for this question but if so please re-direct me
and accept my apologies.

I'm working on a project which is working on learning user input to a
system and trying to pre-empt the user's inputs over time. I'm currently
getting sources of User Input from various DBus Signals. I'd like to
have a Signal which would inform me of "Volume" changes by the user.

I've been using a Dbus-monitor app to have a quick look at what signals
are sent when the user (me) changes the volume on my Ubuntu 9.10 system.
On the System bus I've got nothing that looks too useful:

signal sender=:1.2 -> dest=(null destination) serial=1488
path=/org/freedesktop/Hal/devices/computer_logicaldev_input_4;
interface=org.freedesktop.Hal.Device; member=Condition
   string "ButtonPressed"
   string "volume-up"

That signal doesn't give me anything too useful as I can only see that
the volume has gone up not what it's been set to. On the Session Bus
I've got a much more useful looking method call:

method call sender=:1.7 -> dest=org.freedesktop.Notifications serial=35
path=/org/freedesktop/Notifications;
interface=org.freedesktop.Notifications; member=Notify
   string "gnome-settings-daemon"
   uint32 0
   string "notification-audio-volume-medium"
   string " "
   string ""
   array [
   ]
   array [
      dict entry(
         string "value"
         variant             int32 46
      )
      dict entry(
         string "x-canonical-private-synchronous"
         variant             string "volume"
      )
   ]
   int32 -1

Embedded in this method call is a value "int32 46". This looks more
useful and I was considering looking at the code for this method call
and in it adding a signal. So when the DBus method
org.freedesktop.Notifications; member=Notify gets called part of it's
processing fires off a signal with the int value for volume.

I've no problem adding code to libnotify to perform this functionality
on a local copy but I'm just wondering if this is the right piece of
code to be hacking. It's just for a demo and not something I'd plan to
release, unless it was deemed useful by somebody.

Anyhow if anybody has the knowledge, and time to let me know if I'm in
the correct place I'd be most grateful

Thanks a million in advance and like I say please redirect, to a better
place.