How to write panel like GNOME-panel

["Bin Chen" <binary chen gmail com>]

Hi,

I want to write a panel like gnome-panel, the main objective is
receive the application startup notification(including the app name,
and icon), then I can iconize it in the panel. This can enable user
maximize/minimize a window by clicking the icon on the panel.

My question is how can I get the GTK+ program startup/exit signal?
Besides this, can I get the open/close signal by per window?

Thanks.
Bin