Hi there.
Is there a way to be noticed when an application is launching or bringing to the top. (With DBUS or by another way)

When an application is closing?

I would be able de listening dbus in the background and doing somethig when worldclock is launched (brought to the top) or closed for exemple...

Thank you.

PS: Doe's a Dbus messages documentation exist? with ALL signals and method calls available sorted by app path?

No idea, but you can use dbus-monitor to see the messages flying around.
In general, the top_application method is called on the application D-Bus object (in this case com.nokia.worldclock, path=/com/nokia/worldclock, interface=com.nokia.worldclock). You can listen for that on the session bus.
For the shutdown, you can listen to the NameOwnerChanged calls as worldclock detaches from the bus.

thank you for the answer. i didn't checked it so i waste a lot of time to find all that by myself.

I used nameOwnerChanged signal to know when an app starts or stops.
The problem is that hildon-desktop pre starts some apps and effectively call the top_application method to popup the app

I think i can catch method_calls with low level dbus lib
but im using glib bindings is it possible match whatever we want with glib binding?

An other solution is to disable (temporarily...) prestarting...

The NameOwnerChanged signals are broadcast, so you can just connect to them on the D-Bus object (org.freedesktop.DBus, path="/org/freedesktop/DBus", interface="org.freedesktop.DBus") with dbus-glib.