Should GraphLink.java be restored for managing ElementIds?

[Finterly]

@egonw

We previously removed this class to have direct references to PathwayElement objects instead.

For example, the pathway model holds:

Map<String elementId, PathwayElement> instead of Map<String elementId, GraphIdContainer> as it was in the old code. And in all the methods we currently reference PathwayElement directly. Would it be better practice to restore the GraphLink.java class which seems to be using the Mediator Pattern (not sure: to avoid coupling/direct references?).

/**
 * This class only contains static methods and should not be instantiated.
 */
public abstract class GraphLink
{

    /**
     * All classes that have a graphId must implement this interface.
     * Those are PathwayElement.MPoint (i.e. points)
     * and PathwayElement (i.e. DataNodes, Shapes, etc).
     * They are needed for being refered to.
     *
     * This interface exists so we can easily iterate through all
     * objects containing a graphId.
     */
    public interface GraphIdContainer
    {
        String getGraphId();
        void setGraphId(String id);
        /** generate a unique graph Id and use that. */
        String setGeneratedGraphId();
        Set<GraphRefContainer> getReferences();
        /**
         * return the parent Gmmldata Object,
         * needed for maintaining a consistent list of graphId's
         */
        Pathway getPathway();

        /**
         * Convert a point to shape coordinates (relative
         * to the bounds of the GraphIdContainer)
         */
        Point2D toRelativeCoordinate(Point2D p);

        /**
         * Convert a point to pathway coordinates (relative
         * to the pathway)
         */
        Point2D toAbsoluteCoordinate(Point2D p);
    }

    /**
     * All classes that want to refer *to* a GraphIdContainer must
     * implement this interface. At this time that only goes for
     * PathwayElement.MPoint.
     */
    public interface GraphRefContainer
    {
        String getGraphRef();
        void linkTo(GraphIdContainer idc, double relX, double relY);
        void unlink();

        double getRelX();
        double getRelY();

        /**
         * return the parent Pathway object,
         * needed for maintaining a consistent list of graphId's
         */
        Pathway getPathway();

        /**
         * Called whenever the object being referred to changes coordinates.
         */
        void refeeChanged();
    }

    /**
     * Give an object that implements the graphId interface
     * a graphId, thereby possibly linking it to new objects.
     *
     * This is a helper for classes that need to implement the GraphIdContainer interface,
     * to avoid duplication.
     *
     * @param v the graphId
     * @param c the object to is going to get the new graphId
     * @param gd the pathway model, which is maintaining a complete list of all graphId's in this pathway
     */
    protected static void setGraphId(String v, GraphIdContainer c, Pathway data)
    {
        String graphId = c.getGraphId();
        if (graphId == null || !graphId.equals(v))
        {
            if (data != null)
            {
                if (graphId != null)
                {
                    data.removeGraphId(graphId);
                }
                if (v != null)
                {
                    data.addGraphId(v, c);
                }
            }
        }
    }

    /**
     * Return a list of GraphRefContainers (i.e. points)
     * referring to a certain GraphId.
     *
     * @param gid
     * @param gd
     * @return
     */
    public static Set<GraphRefContainer> getReferences(GraphIdContainer gid, Pathway gd)
    {
        if (gd == null || Utils.isEmpty(gid.getGraphId())) 
            return Collections.emptySet();
        else
            return gd.getReferringObjects(gid.getGraphId());
    }
}

[Finterly]

will investigate further. closing question for now.