Hot from the recent SVCC 2007 here is one of the demos I presented.



As you have guessed it is a Google maps viewer (thanks to SwingX-ws's JXMapKit) that display a custom waypoint, which is rendered by a GraphicsOperation. The code for setting the map with Groovy is very similar to the one described here so the real deal is how to setup a GraphicsBuilder enabled WaypointRenderer, look no further:
class GroovyWaypointRenderer implements WaypointRenderer { private go = null Color outline Color fill public boolean paintWaypoint(Graphics2D g, JXMapViewer map, Waypoint waypoint) { if( !go ) initGo() go.execute( g, map ) return false } private void initGo(){ def gb = new GraphicsBuilder() Jdk6GraphicsBuilderHelper.registerOperations(gb) go = gb.build { transformations { translate( x: 0, y: -20 ) } renderingHint( key: 'antialiasing', value: 'antialias on' ) add( color: outline, fill: fill, strokeWidth: 2 ){ circle( cx: 8, cy: 0, radius: 8 ) path { moveTo( x: 0, y: 0 ) hline( x: 16 ) lineTo( x: 8, y: 30 ) close() } } font( face: "Helvetica", style: Font.BOLD, size: 24 ) text( text: 'SVCC', x: -22, y: -30, color: 'black', fill: 'green' ) } } }
It is not the fanciest version because JXMapKit will eventually call paintWaypoint() every time you move around the map, that means the GraphicsOperation is executed every time as well. An optimized version would save the first execution into an off-screen image and use that image in subsequent calls.

Keep on Groovying!