--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/model/BlackboardDataFacet.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,78 @@
+package org.dive4elements.river.artifacts.model;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+
+import org.dive4elements.artifactdatabase.state.Facet;
+import org.dive4elements.artifactdatabase.state.DefaultFacet;
+
+
+/**
+ * Facet that writes artifact-uui and facet index on the blackboard,
+ * delivers data if asked so.
+ */
+public class BlackboardDataFacet extends DefaultFacet {
+
+    public BlackboardDataFacet() {}
+
+    /** Do not instantiate a BlackboardDataFacet, subclass it instead. */
+    public BlackboardDataFacet(int idx, String name, String description) {
+        super(idx, name, description);
+    }
+
+
+    /** Do not instantiate a BlackboardDataFacet, subclass it instead. */
+    public BlackboardDataFacet(String name, String description) {
+        super(0, name, description);
+    }
+
+
+    /** Define key to which to respond when asked for 'blackboard'
+     * (DataProvider)- data. */
+    public String areaDataKey(Artifact art) {
+        return art.identifier() + ":" + getName() + ":" + getIndex();
+    }
+
+
+    /** Hey, We can ArtifactUUID+:+FacetName+:+FacetIndex (i.e. getData)! */
+    @Override
+    public List getStaticDataProviderKeys(Artifact art) {
+        List list = new ArrayList();
+        list.add(areaDataKey(art));
+        return list;
+    }
+
+
+    /**
+     * Can provide whatever getData returns.
+     * @param key      will respond on uuid+index
+     * @param param    ignored
+     * @param context  ignored
+     * @return whatever getData delivers.
+     */
+    @Override
+    public Object provideBlackboardData(Artifact artifact,
+        Object key,
+        Object param,
+        CallContext context
+    ) {
+        if (key.equals(areaDataKey(artifact))) {
+            return getData(artifact, context);
+        }
+        else {
+            return null;
+        }
+    }
+
+    /** Copy deeply. */
+    @Override
+    public Facet deepCopy() {
+        BlackboardDataFacet copy = new BlackboardDataFacet();
+        copy.set(this);
+        return copy;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :