bundles/org.simantics.db.common/src/org/simantics/db/common/request/PossibleIndexRoot.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.common.request;\r
  13 \r
  14 import java.util.Collection;\r
  15 import java.util.HashSet;\r
  16 \r
  17 import org.simantics.db.ReadGraph;\r
  18 import org.simantics.db.Resource;\r
  19 import org.simantics.db.exception.DatabaseException;\r
  20 import org.simantics.layer0.Layer0;\r
  21 \r
  22 public class PossibleIndexRoot extends ResourceRead<Resource> {\r
  23 \r
  24     public PossibleIndexRoot(Resource resource) {\r
  25         super(resource);\r
  26     }\r
  27 \r
  28     @Override\r
  29     public Resource perform(ReadGraph graph) throws DatabaseException {\r
  30 \r
  31         Layer0 L0 = Layer0.getInstance(graph);\r
  32         \r
  33         if (graph.isInstanceOf(resource, L0.IndexRoot))\r
  34             return resource;\r
  35         \r
  36         Collection<Resource> parents = new HashSet<Resource>(graph.getObjects(resource, L0.IsOwnedBy));\r
  37         Resource parent = parents.size() == 1 ? parents.iterator().next() : null;\r
  38 \r
  39         // What is this?\r
  40         if(resource.equals(parent))\r
  41                 parent = null;\r
  42 \r
  43         if (parent == null) {\r
  44                 \r
  45                 if(parents.size() > 1) {\r
  46                         // Maybe we have a case where there is ConsistsOf and HasProperty that is incorrectly classified as IsComposedOf\r
  47                         parent = graph.getPossibleObject(resource, L0.PartOf);\r
  48                 } \r
  49 \r
  50                 // Assertion object?\r
  51                 if(parent == null)\r
  52                         parent = graph.getPossibleObject(resource, L0.HasObjectInverse);\r
  53                 \r
  54                 if(parent == null) return null;\r
  55                 \r
  56         }\r
  57         \r
  58         return graph.syncRequest(new PossibleIndexRoot(parent));\r
  59 \r
  60     }\r
  61 \r
  62 }\r