bundles/org.simantics.layer0.utils/src/org/simantics/layer0/utils/binaryPredicates/Relation.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.layer0.utils.binaryPredicates;
  13
  14 import java.util.Collection;
  15
  16 import org.simantics.db.ReadGraph;
  17 import org.simantics.db.Resource;
  18 import org.simantics.db.WriteGraph;
  19 import org.simantics.db.common.utils.NameUtils;
  20 import org.simantics.db.exception.DatabaseException;
  21 import org.simantics.utils.datastructures.Pair;
  22
  23 public class Relation extends BinaryPredicate {
  24
  25         Resource relation;
  26
  27         public Relation(Resource relation) {
  28                 this.relation = relation;
  29         }
  30
  31         @Override
  32         public Collection<Resource> getObjects(ReadGraph g, Resource subject) throws DatabaseException {
  33                 return g.getObjects(subject, relation);
  34         }
  35
  36         @Override
  37         public Collection<Pair<Resource, Resource>> getStatements(ReadGraph g) {
  38                 throw new UnsupportedOperationException();
  39         }
  40
  41         @Override
  42         public Collection<Resource> getSubjects(ReadGraph g, Resource object) throws DatabaseException {
  43                 return g.getObjects(object, g.getInverse(relation));
  44         }
  45
  46         @Override
  47         public boolean has(ReadGraph g, Resource subject, Resource object) throws DatabaseException {
  48                 return g.hasStatement(subject, relation, object);
  49         }
  50
  51         @Override
  52         public boolean supportsGetObjects() {
  53                 return true;
  54         }
  55
  56         @Override
  57         public boolean supportsGetStatements() {
  58                 return false;
  59         }
  60
  61         @Override
  62         public boolean supportsGetSubjects() {
  63                 return true;
  64         }
  65
  66         @Override
  67         public void add(WriteGraph g, Resource subject, Resource object) throws DatabaseException {
  68                 g.claim(subject, relation, object);
  69         }
  70
  71         @Override
  72         public void remove(WriteGraph g, Resource subject, Resource object) throws DatabaseException {
  73                 g.denyStatement(subject, relation, object);
  74         }
  75
  76         @Override
  77         public boolean supportsAdditions() {
  78                 return true;
  79         }
  80
  81         @Override
  82         public boolean supportsRemovals() {
  83                 return false;
  84         }
  85
  86         @Override
  87         public int hashCode() {
  88                 final int prime = 31;
  89                 int result = 1;
  90                 result = prime * result
  91                                 + ((relation == null) ? 0 : relation.hashCode());
  92                 return result;
  93         }
  94
  95         @Override
  96         public boolean equals(Object obj) {
  97                 if (this == obj)
  98                         return true;
  99                 if (obj == null)
 100                         return false;
 101                 if (getClass() != obj.getClass())
 102                         return false;
 103                 Relation other = (Relation) obj;
 104                 if (relation == null) {
 105                         if (other.relation != null)
 106                                 return false;
 107                 } else if (!relation.equals(other.relation))
 108                         return false;
 109                 return true;
 110         }
 111
 112         @Override
 113         public IBinaryPredicate inverse(ReadGraph g) throws DatabaseException {
 114                 return new Relation(g.getInverse(relation));
 115         }
 116
 117         @Override
 118         public String toString(ReadGraph g) throws DatabaseException {
 119                 return NameUtils.getSafeName(g, relation);
 120         }
 121
 122 }