Change a widget's theme when being focused ?

["Do Thu Thuy" <dtthuy gmail com>]

Hi,

Gtk+ provides several states for a widget including: ACTIVE, 
SELECTED,PRELIGHT, NORMAL, INSENSITIVE. We can use these states as the 
conditions to change widget's properties (background, border, stretch..) 
using the rc file.The "PRELIGHT" state has effect when the mouse moves over 
the widget (for e.g: a button) and we can change the widget's properties 
according to that state. In my case, I want to use keyboard only. Can we 
dynamically change the properties (for e.g: background) of the widget if it 
is focused by keyboard using the "rc" file ? Or can we map the grab-focus 
event of keyboard to the PRELIGHT state which just has effect on mouse 
moving ?

Thank you for your help,
Do Thuy