--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in 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.db.layer0.request;\r
+\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.layer0.variable.Variable;\r
+import org.simantics.layer0.Layer0;\r
+\r
+public class PossibleVariableIndexRoot extends VariableRead<Resource> {\r
+\r
+ public PossibleVariableIndexRoot(Variable variable) {\r
+ super(variable);\r
+ }\r
+\r
+ @Override\r
+ public Resource perform(ReadGraph graph) throws DatabaseException {\r
+\r
+ Layer0 L0 = Layer0.getInstance(graph);\r
+ \r
+ Resource represents = variable.getPossibleRepresents(graph);\r
+ if(represents != null) {\r
+ if(graph.isInstanceOf(represents, L0.IndexRoot)) return represents;\r
+ if(graph.getRootLibrary().equals(represents)) return null;\r
+ }\r
+ \r
+ return graph.syncRequest(new PossibleVariableIndexRoot(variable.getParent(graph)));\r
+\r
+ }\r
+\r
+}\r