question: public synchronized OMGraphicList prepare ( ) { if ( spatialIndexes == null || spatialIndexes . isEmpty ( ) ) { logger . fine ( getName ( ) + ": spatialIndexes is empty!" ) ; return new OMGraphicList ( ) ; } Projection projection = getProjection ( ) ; if ( projection == null ) { logger . fine ( getName ( ) + ": prepare called with null projection" ) ; return new OMGraphicList ( ) ; } Point2D ul = projection . getUpperLeft ( ) ; Point2D lr = projection . getLowerRight ( ) ; double ulLat = ul . getY ( ) ; double ulLon = ul . getX ( ) ; double lrLat = lr . getY ( ) ; double lrLon = lr . getX ( ) ; OMGraphicList masterList = new OMGraphicList ( ) ; OMGraphicList list = null ; if ( ProjMath . isCrossingDateline ( ulLon , lrLon , projection . getScale ( ) ) ) { if ( logger . isLoggable ( Level . FINE ) ) { logger . fine ( getName ( ) + ": Dateline is on screen" ) ; } double ymin = Math . min ( ulLat , lrLat ) ; double ymax = Math . max ( ulLat , lrLat ) ; Iterator < SpatialIndexHandler > sii = spatialIndexes . iterator ( ) ; while ( sii . hasNext ( ) ) { SpatialIndexHandler sih = ( SpatialIndexHandler ) sii . next ( ) ; if ( ! sih . enabled ) continue ; try { list = sih . getGraphics ( ulLon , ymin , 180.0d , ymax , list , projection ) ; list = sih . getGraphics ( - 180.0d , ymin , lrLon , ymax , list , projection ) ; } catch ( java . io . IOException ex ) { ex . printStackTrace ( ) ; } catch ( FormatException fe ) { fe . printStackTrace ( ) ; } masterList . add ( list ) ; } } else { double xmin = ( double ) Math . min ( ulLon , lrLon ) ; double xmax = ( double ) Math . max ( ulLon , lrLon ) ; double ymin = ( double ) Math . min ( ulLat , lrLat ) ; double ymax = ( double ) Math . max ( ulLat , lrLat ) ; Iterator < SpatialIndexHandler > sii = spatialIndexes . iterator ( ) ; while ( sii . hasNext ( ) ) { SpatialIndexHandler sih = ( SpatialIndexHandler ) sii . next ( ) ; if ( ! sih . enabled ) continue ; if ( logger . isLoggable ( Level . FINE ) ) { logger . fine ( getName ( ) + ": Getting graphics from " + sih . prettyName + " spatial index" ) ; } try { list = sih . getGraphics ( xmin , ymin , xmax , ymax , list , projection ) ; } catch ( java . io . IOException ex ) { ex . printStackTrace ( ) ; } catch ( FormatException fe ) { fe . printStackTrace ( ) ; } masterList . add ( list ) ; } } return masterList ; }
target:  Creates an OMGraphicList containing graphics from all SpatialIndex objects and shapefiles.