org.simantics.district.route/src/org/simantics/district/route/internal/Activator.java

   1 package org.simantics.district.route.internal;
   2
   3 import java.util.Hashtable;
   4
   5 import org.osgi.framework.BundleActivator;
   6 import org.osgi.framework.BundleContext;
   7 import org.osgi.framework.Constants;
   8 import org.osgi.framework.ServiceEvent;
   9 import org.osgi.framework.ServiceListener;
  10 import org.osgi.framework.ServiceReference;
  11 import org.osgi.framework.ServiceRegistration;
  12 import org.osgi.util.tracker.ServiceTracker;
  13 import org.simantics.district.route.RouteService;
  14 import org.simantics.district.route.Router;
  15
  16 /**
  17  * @author Tuukka Lehtonen
  18  * @since 6.09
  19  */
  20 public class Activator implements BundleActivator, ServiceListener {
  21
  22     private static BundleContext context;
  23     private static Activator instance;
  24
  25     static BundleContext getContext() {
  26         return context;
  27     }
  28
  29     public static Activator getInstance() {
  30         return instance;
  31     }
  32
  33     private RouteServiceImpl                routeService;
  34     private ServiceRegistration<?>          routeServiceRegistration;
  35     private ServiceTracker<RouteService, ?> routeServiceTracker;
  36     private ServiceTracker<Router, ?>       routerTracker;
  37
  38     @Override
  39     public void start(BundleContext context) throws Exception {
  40         Activator.instance = this;
  41         Activator.context = context;
  42         routeService = new RouteServiceImpl();
  43
  44         // register the service
  45         routeServiceRegistration = context.registerService(RouteService.class.getName(), routeService, new Hashtable<>());
  46
  47         // create a tracker and track the service
  48         routeServiceTracker = new ServiceTracker<>(context, RouteService.class.getName(), null);
  49         routeServiceTracker.open();
  50
  51         // Register initially availble routers
  52         routerTracker = new ServiceTracker<>(context, Router.class.getName(), null);
  53         routerTracker.open();
  54         for (Object router : routerTracker.getServices()) {
  55             routeService.registerRouter((Router) router);
  56         }
  57
  58         // have a service listener to implement the whiteboard pattern
  59         context.addServiceListener(this, "(" + Constants.OBJECTCLASS + "=" + Router.class.getName() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
  60
  61         // grab the service
  62         routeService = (RouteServiceImpl) routeServiceTracker.getService();
  63     }
  64
  65     @Override
  66     public void stop(BundleContext context) throws Exception {
  67         // close the service tracker
  68         routeServiceTracker.close();
  69         routeServiceTracker = null;
  70
  71         routeServiceRegistration.unregister();
  72
  73         routeService.close();
  74         routeService = null;
  75         context = null;
  76         instance = null;
  77     }
  78
  79     public void serviceChanged(ServiceEvent ev) {
  80         ServiceReference<?> sr = ev.getServiceReference();
  81         switch (ev.getType()) {
  82             case ServiceEvent.REGISTERED:
  83                 routeService.registerRouter((Router) context.getService(sr));
  84                 break;
  85             case ServiceEvent.UNREGISTERING:
  86                 routeService.unregisterRouter((Router) context.getService(sr));
  87                 break;
  88         }
  89     }
  90
  91     public RouteService getRouteService() {
  92         return routeService;
  93     }
  94
  95 }