package org.simantics.district.route.ui.internal;

import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.BundleContext;
import org.osgi.util.tracker.ServiceTracker;
import org.simantics.district.route.RouteService;

/**
 * The activator class controls the plug-in life cycle
 */
public class Activator extends AbstractUIPlugin {

    // The plug-in ID
    public static final String PLUGIN_ID = "org.simantics.district.route.ui"; //$NON-NLS-1$

    // The shared instance
    private static Activator plugin;

    private ServiceTracker<RouteService, ?> routeServiceTracker;

    /*
     * (non-Javadoc)
     * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
     */
    public void start(BundleContext context) throws Exception {
        super.start(context);
        plugin = this;

        // create a tracker and track the service
        routeServiceTracker = new ServiceTracker<>(context, RouteService.class.getName(), null);
        routeServiceTracker.open();
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
     */
    public void stop(BundleContext context) throws Exception {
        // close the service tracker
        routeServiceTracker.close();
        routeServiceTracker = null;

        plugin = null;
        super.stop(context);
    }

    /**
     * Returns the shared instance
     *
     * @return the shared instance
     */
    public static Activator getDefault() {
        return plugin;
    }

    public RouteService getRouteService() {
        return (RouteService) routeServiceTracker.getService();
    }

}