bundles/org.simantics.layer0.utils/src/org/simantics/layer0/utils/binaryPredicates/OrderedSetElementsPredicate.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.ArrayList;
  15 import java.util.Collection;
  16 import java.util.Collections;
  17
  18 import org.simantics.db.ReadGraph;
  19 import org.simantics.db.Resource;
  20 import org.simantics.db.Statement;
  21 import org.simantics.db.WriteGraph;
  22 import org.simantics.db.common.utils.OrderedSetUtils;
  23 import org.simantics.db.exception.DatabaseException;
  24 import org.simantics.layer0.Layer0;
  25 import org.simantics.utils.datastructures.Pair;
  26
  27 public class OrderedSetElementsPredicate extends BinaryPredicate {
  28
  29         public static final OrderedSetElementsPredicate INSTANCE =
  30                 new OrderedSetElementsPredicate();
  31
  32         @Override
  33         public Collection<Resource> getObjects(ReadGraph g, Resource subject) throws DatabaseException {
  34                 Layer0 l0 = Layer0.getInstance(g);
  35                 if(g.isInstanceOf(subject, l0.OrderedSet))
  36                         return OrderedSetUtils.toList(g, subject);
  37                 else
  38                         return Collections.emptyList();
  39         }
  40
  41         @Override
  42         public Collection<Pair<Resource, Resource>> getStatements(ReadGraph g) {
  43                 throw new UnsupportedOperationException();
  44         }
  45
  46         @Override
  47         public Collection<Resource> getSubjects(ReadGraph g, Resource object) throws DatabaseException {
  48                 Collection<Resource> result = new ArrayList<Resource>(1);
  49                 Layer0 l0 = Layer0.getInstance(g);
  50                 for(Statement stat : g.getStatements(object, l0.IsWeaklyRelatedTo)) {
  51                         Resource pred = stat.getPredicate();
  52                         if(g.isInstanceOf(pred, l0.OrderedSet) && !pred.equals(object))
  53                                 result.add(pred);
  54                 }
  55                 return result;
  56         }
  57
  58         @Override
  59         public boolean has(ReadGraph g, Resource subject, Resource object) throws DatabaseException {
  60                 return OrderedSetUtils.contains(g, subject, object) &&
  61                         g.isInstanceOf(subject, Layer0.getInstance(g).OrderedSet);
  62         }
  63
  64         @Override
  65         public boolean supportsGetObjects() {
  66                 return true;
  67         }
  68
  69         @Override
  70         public boolean supportsGetStatements() {
  71                 return false;
  72         }
  73
  74         @Override
  75         public boolean supportsGetSubjects() {
  76                 return true;
  77         }
  78
  79         @Override
  80         public void add(WriteGraph g, Resource subject, Resource object) throws DatabaseException {
  81                 OrderedSetUtils.add(g, subject, object);
  82         }
  83
  84         @Override
  85         public void remove(WriteGraph g, Resource subject, Resource object) throws DatabaseException {
  86                 OrderedSetUtils.remove(g, subject, object);
  87         }
  88
  89         @Override
  90         public boolean supportsAdditions() {
  91                 return true;
  92         }
  93
  94         @Override
  95         public boolean supportsRemovals() {
  96                 return true;
  97         }
  98
  99 }