thumbnail when the cursor is on the fvwmbutton

just like the image:
the my cursor cover the button ,it shows the thumbnail of the window.
how to make it ?
Thank you !
the fullsize of image

You could use FvwmButtons with the ActiveIcon condition.

– Thomas Adam

Thank you Adam!
I made a config for it ,it worked,but not the way I want .
Is that any examples about this?
Can you offer some examples or KEY words?I want some references
Than kyou again!

My name is Thomas.

Search these forums for “thumbnails” as there’s several versions of them – find one which works for you as the first step. Then I’ll talk you through the next one.

– Thomas Adam