bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/request/VariableIndexRoot.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.db.layer0.request;\r
  13 \r
  14 import org.simantics.db.ReadGraph;\r
  15 import org.simantics.db.Resource;\r
  16 import org.simantics.db.common.request.UnaryRead;\r
  17 import org.simantics.db.exception.DatabaseException;\r
  18 import org.simantics.db.layer0.variable.Variable;\r
  19 import org.simantics.layer0.Layer0;\r
  20 \r
  21 public class VariableIndexRoot extends UnaryRead<Variable, Resource> {\r
  22 \r
  23     public VariableIndexRoot(Variable variable) {\r
  24         super(variable);\r
  25     }\r
  26 \r
  27     @Override\r
  28     public Resource perform(ReadGraph graph) throws DatabaseException {\r
  29 \r
  30         Layer0 L0 = Layer0.getInstance(graph);\r
  31         Resource r = parameter.getPossibleRepresents(graph);\r
  32         if(r != null) {\r
  33                 if(graph.isInstanceOf(r, L0.IndexRoot)) return r;\r
  34         }\r
  35         \r
  36         Variable parent = parameter.getParent(graph);\r
  37         if(parent != null) return graph.sync(new VariableIndexRoot(parent));\r
  38         else return null;\r
  39 \r
  40     }\r
  41 \r
  42 }\r