View Javadoc

1   /* This file is part of COPAL (COntext Provisioning for All).
2    *
3    * COPAL is a part of SM4All (Smart hoMes for All) project.
4    *
5    * COPAL is free software: you can redistribute it and/or modify
6    * it under the terms of the GNU Lesser General Public License as published by
7    * the Free Software Foundation, either version 3 of the License, or
8    * (at your option) any later version.
9    *
10   * COPAL is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   * GNU Lesser General Public License for more details.
14   *
15   * You should have received a copy of the GNU Lesser General Public License
16   * along with COPAL. If not, see <http://www.gnu.org/licenses/>.
17   */
18  package at.ac.tuwien.infosys.sm4all.copal.rest.internal;
19  
20  import at.ac.tuwien.infosys.sm4all.copal.api.osgi.GenericActivator;
21  import at.ac.tuwien.infosys.sm4all.copal.api.service.ContextQueryFactory;
22  import at.ac.tuwien.infosys.sm4all.copal.rest.provider.XMLProcessedEventQueryReader;
23  
24  /**
25   * This tracker set and unsets the {@link ContextQueryFactory} service with
26   * {@link ServiceImpl} as it changes its availability.
27   * 
28   * @author sanjin
29   */
30  public class ContextQueryFactoryTracker extends GenericActivator {
31  
32      private final ServiceImpl service;
33  
34      /**
35       * Creates instance of {@link ContextQueryFactory} OSGi Tracker for
36       * specified {@link ServiceImpl}.
37       * 
38       * @param service the {@link ServiceImpl}.
39       */
40      public ContextQueryFactoryTracker(final ServiceImpl service) {
41          super(ContextQueryFactory.class.getName());
42  
43          this.service = service;
44      }
45  
46      @Override
47      protected void start() {
48          final ContextQueryFactory queryFactory = getDependency(ContextQueryFactory.class.getName());
49  
50          this.service.setQueryFactory(queryFactory);
51          XMLProcessedEventQueryReader.setFactory(queryFactory);
52      }
53  
54      @Override
55      protected void stop() {
56          XMLProcessedEventQueryReader.setFactory(null);
57          this.service.setQueryFactory(null);
58      }
59  }