--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2010, 2011 Association for Decentralized Information Management in\r
+ * Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.browsing.ui.model.children;\r
+\r
+import java.util.ArrayList;\r
+import java.util.Collection;\r
+import java.util.Collections;\r
+\r
+import org.simantics.browsing.ui.model.tests.Test;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.Statement;\r
+import org.simantics.db.exception.DatabaseException;\r
+\r
+/**\r
+ * A child rule that says that there is exactly one child node whose content \r
+ * is equal to the content of the parent.\r
+ * @author Hannu Niemistö\r
+ */\r
+public class RelationStatementRule implements ChildRule {\r
+\r
+ Resource relation;\r
+ \r
+ public RelationStatementRule(Resource relation, Test test) {\r
+ this.relation = relation;\r
+ }\r
+ \r
+ @Override\r
+ public Collection<?> getChildren(ReadGraph graph, Object parent) throws DatabaseException {\r
+ ArrayList<Statement> result = new ArrayList<Statement>();\r
+ for(Resource property : graph.getPredicates((Resource)parent)) {\r
+ if(graph.isSubrelationOf(property, relation)) {\r
+ result.addAll(graph.getStatements((Resource)parent, property));\r
+ }\r
+ }\r
+ return result;\r
+ }\r
+\r
+ @Override\r
+ public Collection<?> getParents(ReadGraph graph, Object child)\r
+ throws DatabaseException {\r
+ return Collections.emptyList();\r
+ }\r
+ \r
+ @Override\r
+ public boolean isCompatible(Class<?> contentType) {\r
+ return contentType.equals(Resource.class);\r
+ }\r
+}\r