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     // The plug-in ID
  23     public static final String PLUGIN_ID = "org.simantics.district.route"; //$NON-NLS-1$
  24
  25     private static BundleContext context;
  26     private static Activator instance;
  27
  28     static BundleContext getContext() {
  29         return context;
  30     }
  31
  32     public static Activator getInstance() {
  33         return instance;
  34     }
  35
  36     private RouteServiceImpl                routeService;
  37     private ServiceRegistration<?>          routeServiceRegistration;
  38     private ServiceTracker<RouteService, ?> routeServiceTracker;
  39     private ServiceTracker<Router, ?>       routerTracker;
  40
  41     @Override
  42     public void start(BundleContext context) throws Exception {
  43         Activator.instance = this;
  44         Activator.context = context;
  45         routeService = new RouteServiceImpl();
  46
  47         // register the service
  48         routeServiceRegistration = context.registerService(RouteService.class.getName(), routeService, new Hashtable<>());
  49
  50         // create a tracker and track the service
  51         routeServiceTracker = new ServiceTracker<>(context, RouteService.class.getName(), null);
  52         routeServiceTracker.open();
  53
  54         // Register initially availble routers
  55         routerTracker = new ServiceTracker<>(context, Router.class.getName(), null);
  56         routerTracker.open();
  57         Object[] routers = routerTracker.getServices();
  58         if (routers != null) {
  59             for (Object router : routers)
  60                 routeService.registerRouter((Router) router);
  61         }
  62
  63         // have a service listener to implement the whiteboard pattern
  64         context.addServiceListener(this, "(" + Constants.OBJECTCLASS + "=" + Router.class.getName() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
  65
  66         // grab the service
  67         routeService = (RouteServiceImpl) routeServiceTracker.getService();
  68     }
  69
  70     @Override
  71     public void stop(BundleContext context) throws Exception {
  72         // close the service tracker
  73         routeServiceTracker.close();
  74         routeServiceTracker = null;
  75
  76         routeServiceRegistration.unregister();
  77
  78         routeService.close();
  79         routeService = null;
  80         context = null;
  81         instance = null;
  82     }
  83
  84     public void serviceChanged(ServiceEvent ev) {
  85         ServiceReference<?> sr = ev.getServiceReference();
  86         switch (ev.getType()) {
  87             case ServiceEvent.REGISTERED:
  88                 routeService.registerRouter((Router) context.getService(sr));
  89                 break;
  90             case ServiceEvent.UNREGISTERING:
  91                 routeService.unregisterRouter((Router) context.getService(sr));
  92                 break;
  93         }
  94     }
  95
  96     public RouteService getRouteService() {
  97         return routeService;
  98     }
  99
 100 }