How to get the animation affect like Kpanel?

[Tian Feng]

I am writing an application using Qt in the Linux (RedHat) which intends
to implement a task bar like the kpanel on
the bottom of the KDE desktop.

Reading those codes in the kpanel (under kdebase package), I cannot get
the idea how to implment the animation to pop LEFT or RIGHT the taskbar,
or show / hide it, could anyone give me a brief introduction? ( I mean,
the taksbar on the bottom of K-desktop, can be shown or hidden into a
very small button with an arrow onto it).

Thanks in advance,