title: Gain PanningMode behavior of ScrollViewer with mouse events
body: <p>I'm attempting to pan around the contents of a ScrollViewer in the same way you would pan around in a PDF document (scroll to zoom in/out, click + drag to pan) ScrollViewer has this functionality built in for Touch events (PanningMode), however this doesn't seem to translate to Click+Drag events. Is there a way to tell it to/emulate this functionality?</p>