The free woodworking plans at the link will show you how to build a porch swing. You can adjust the length to suit your needs. All you need to build it is construction lumber and basic tools.
Here is a peace promoter and a queller of disturbances wherever there are very little kiddies around. It is an indoor swing that can be hung from the top of a doorcase. Further, though it may look a little complicated in the drawing, it is simplicity itself.