Carousel slide distance binding

[Lomelgande]

Is there a way to get the information on how far a slide has moved inside the Carousel widget? I have a carousel inside a popup and want the popup to change size as I move the carousel. I can kind of do this with an index bind but the problem is it doesn't resize until after the slide has changed and does it all at once. I want it to grow as the slide is moved to the right and shrink as the slide is moved to the left. Is there an easy way to do this?