have a look at http://v-play.net/doc/vplay1-multitoucharea.html
In the MultiTouchArea you have signals like onSwipeUp() and so on…
Then you could create a Numberanimation (http://qt-project.org/doc/qt-4.8/qml-numberanimation.html) in the given direction.
This would be the first approach that comes to my mind. Let me know if this works for you!