question: public void renderDataForProjection ( Projection proj , Graphics g ) { if ( isProjectionOK ( proj ) ) { paint ( g ) ; } }
target:  This method is here to provide a default action for Layers as they act as a ProjectionPainter. Normally, ProjectionPainters are expected to receive the projection, gather/create OMGraphics that apply to the projection, and render them into the Graphics provided. This is supposed to be done in the same thread that calls this function, so the caller knows that when this method returns, everything that the ProjectionPainter needed to do is complete. <P> If the layer doesn't override this method, then the paint(Graphics) method will be called.