Sliding effect of widgets

[dolly vittal <dollyvittal yahoo com>]

Hi All,

I am developing a small GTK+ application on the lines of a media player.   When a widget replaces another 
widget, I need to have the sliding effect.   I have searched the GTK+ and came to know that the sliding 
effects are not implemented in it.  I would like to know if  GTK+ themes need to be used for the sliding 
effects.   If the themes are to be used, it would be very helpful if anybody could suggest a theme with that 
effect.   Also, if GTK+ source code needs to be changed,  it would be helpful if you could give me some 
pointers on where to start.

Thanks.

Regards,
Dolly