public void onMouseDown ( MouseDownEvent event ) { if ( event . getNativeButton ( ) != NativeEvent . BUTTON_RIGHT ) { dragging = true ; center = getScreenPosition ( event ) ; LineString radiusLine = mapWidget . getMapModel ( ) . getGeometryFactory ( ) . createLineString ( new Coordinate [ ] { center , center } ) ; mapWidget . getVectorContext ( ) . drawGroup ( mapWidget . getGroup ( RenderGroup . SCREEN ) , circleGroup ) ; mapWidget . getVectorContext ( ) . drawCircle ( circleGroup , "outer" , center , 1.0f , circleStyle ) ; mapWidget . getVectorContext ( ) . drawCircle ( circleGroup , "center" , center , 2.0f , circleStyle ) ; mapWidget . getVectorContext ( ) . drawLine ( circleGroup , "radius" , radiusLine , circleStyle ) ; } }
Register center point for the circle and start dragging and rendering .