workcraft/workcraft

package org.workcraft.observation;

import org.workcraft.dom.Node;

public abstract class StateSupervisor extends HierarchySupervisor implements StateObserver {

    private void nodeAdded(Node node) {
        if (node instanceof ObservableState) {
            ((ObservableState) node).addObserver(this);
        }
        for (Node n : node.getChildren()) {
            nodeAdded(n);
        }
    }

    private void nodeRemoved(Node node) {
        if (node instanceof ObservableState) {
            ((ObservableState) node).removeObserver(this);
        }
        for (Node n : node.getChildren()) {
            nodeRemoved(n);
        }
    }

    @Override
    public final void handleEvent(HierarchyEvent e) {
        if (e instanceof NodesAddedEvent) {
            for (Node n : e.getAffectedNodes()) {
                nodeAdded(n);
            }
        } else if (e instanceof NodesDeletedEvent) {
            for (Node n : e.getAffectedNodes()) {
                nodeRemoved(n);
            }
        }
        handleHierarchyEvent(e);
    }

    public void handleHierarchyEvent(HierarchyEvent e) {

    }

    @Override
    public final void notify(StateEvent e) {
        handleEvent(e);
    }

    public abstract void handleEvent(StateEvent e);

}