Preview layout in a view based on forms

I’m writing a view consisting of a form and a preview panel displaying the input given in the form. When a field is changed, the panel will refresh to show the updated field. I will probably add a refresh button to the panel to be on the safe side, but that is not important right now.

I’m having trouble with is how to tie an event to the form to do this. Since the preview panel should update whenever the form is filled I think it’d be a terrible idea to tie the updating to the view’s change event.