+ return
+ end
+
+ if params[:node]
+ bbox = Node.find(params[:node]).bbox.to_unscaled
+ @lat = bbox.centre_lat
+ @lon = bbox.centre_lon
+ elsif params[:way]
+ bbox = Way.find(params[:way]).bbox.to_unscaled
+ @lat = bbox.centre_lat
+ @lon = bbox.centre_lon
+ elsif params[:gpx]
+ trace = Trace.visible_to(@user).find(params[:gpx])
+ @lat = trace.latitude
+ @lon = trace.longitude