I will say this, getting SFML to work in qt creator is a pain in the butt. But lucky for you I made a tutorial on how to build and add SFML to qt creator (
) *Also I am not self promotioning, I know the video is very bad but sadly it isn't well documented how to do this*. And finally here is a tutorial on how to create an SFML Widget in qt creator (
http://becomingindiedev.blogspot.com/2013/10/qt-5-and-sfml-20-integration.html) *There is a bug associated with the code presented but he does post a fix in the bottom, however personally the code does work*. And finally as a sidenote if you want to put this editor in a .ui layout what you will want to do is create the widget and then promote a Widget to it in the designer.
Any Questions leave a comment.