bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/request/NextOrderedSetElement.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.AsyncReadGraph;
  15 import org.simantics.db.Resource;
  16 import org.simantics.db.common.request.ResourceAsyncRead2;
  17 import org.simantics.db.procedure.AsyncProcedure;
  18
  19 public class NextOrderedSetElement extends ResourceAsyncRead2<Resource> {
  20
  21     public NextOrderedSetElement(Resource list, Resource element) {
  22         super(list, element);
  23     }
  24
  25     @Override
  26     public void perform(AsyncReadGraph graph, final AsyncProcedure<Resource> procedure) {
  27
  28         // resource = the list
  29         // resource2 = the element
  30
  31         graph.forPossibleObject(resource2, resource, new AsyncProcedure<Resource>() {
  32
  33             @Override
  34             public void exception(AsyncReadGraph graph, Throwable t) {
  35                 procedure.exception(graph, t);
  36             }
  37
  38             @Override
  39             public void execute(AsyncReadGraph graph, Resource next) {
  40                 if(resource.equals(next)) procedure.execute(graph, null);
  41                 else procedure.execute(graph, next);
  42             }
  43         });
  44
  45     }
  46
  47 }