]> gerrit.simantics Code Review - simantics/platform.git/blob - bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/request/VariableIndexRoot.java
New implementation NearestOwnerFinder of CommonDBUtils.getNearestOwner
[simantics/platform.git] / bundles / org.simantics.db.layer0 / src / org / simantics / db / layer0 / request / VariableIndexRoot.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.db.layer0.request;
13
14 import org.simantics.db.ReadGraph;
15 import org.simantics.db.Resource;
16 import org.simantics.db.common.request.UnaryRead;
17 import org.simantics.db.exception.DatabaseException;
18 import org.simantics.db.layer0.variable.Variable;
19 import org.simantics.layer0.Layer0;
20
21 public class VariableIndexRoot extends UnaryRead<Variable, Resource> {
22
23     public VariableIndexRoot(Variable variable) {
24         super(variable);
25     }
26
27     @Override
28     public Resource perform(ReadGraph graph) throws DatabaseException {
29
30         Layer0 L0 = Layer0.getInstance(graph);
31         Resource r = parameter.getPossibleRepresents(graph);
32         if(r != null) {
33                 if(graph.isInstanceOf(r, L0.IndexRoot)) return r;
34         }
35         
36         Variable parent = parameter.getParent(graph);
37         if(parent != null) return graph.sync(new VariableIndexRoot(parent));
38         else return null;
39
40     }
41
42 }