org.ops4j.pax.wicket.internal.PaxWicketPageTracker Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.ops4j.pax.wicket.service Show documentation
Pax Wicket Service is an OSGi extension of the Wicket framework, allowing for dynamic loading and unloading of Wicket components and pageSources.
There is a newer version: 5.0.0
Show newest version
/**
 * Copyright OPS4J
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License. You may obtain
 * a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.ops4j.pax.wicket.internal;

import static org.ops4j.pax.wicket.api.Constants.APPLICATION_NAME;
import static org.ops4j.pax.wicket.internal.TrackingUtil.createAllPageFactoryFilter;

import org.ops4j.pax.wicket.api.PageFactory;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.util.tracker.ServiceTracker;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

final class PaxWicketPageTracker extends ServiceTracker {

    private static final Logger LOGGER = LoggerFactory.getLogger(PaxWicketPageTracker.class);

    private final String applicationName;
    private final PaxWicketPageFactory paxWicketPageFactory;

    PaxWicketPageTracker(BundleContext context, String applicationName, PaxWicketPageFactory paxWicketPageFactory) {
        super(context, createAllPageFactoryFilter(context, applicationName), null);

        this.applicationName = applicationName;
        this.paxWicketPageFactory = paxWicketPageFactory;
    }

    /**
     * Default implementation of the {@code ServiceTrackerCustomizer.addingService} method.
     * 
     * 
     * This method is only called when this ServiceTracker object has been constructed with a
     * null ServiceTrackerCustomizer argument.
     * 
     * The default implementation returns the result of calling getService, on the
     * BundleContext object with which this ServiceTracker object was created, passing the
     * specified ServiceReference object.
     * 

     * This method can be overridden in a subclass to customize the service object to be tracked for the service being
     * added. In that case, take care not to rely on the default implementation of removedService that will unget the
     * service.
     * 
     * @param reference Reference to service being added to this ServiceTracker object.
     * 
     * @return The service object to be tracked for the service added to this ServiceTracker object.
     * 
     * @see org.osgi.util.tracker.ServiceTrackerCustomizer
     */
    @Override
    public final Object addingService(ServiceReference reference) {
        PageFactory pageSource = (PageFactory) super.addingService(reference);
        Class pageClass = pageSource.getPageClass();
        paxWicketPageFactory.add(pageClass, pageSource);
        return pageSource;
    }

    /**
     * Default implementation of the ServiceTrackerCustomizer.modifiedService method.
     * 
     * 

     * This method is only called when this ServiceTracker object has been constructed with a
     * null ServiceTrackerCustomizer argument.
     * 
     * The default implementation does nothing.
     * 
     * @param reference Reference to modified service.
     * @param service The service object for the modified service.
     * 
     * @see org.osgi.util.tracker.ServiceTrackerCustomizer
     */
    @Override
    public final void modifiedService(ServiceReference reference, Object service) {
        PageFactory pageSource = (PageFactory) service;
        String appName = (String) reference.getProperty(APPLICATION_NAME);
        if (!applicationName.equals(appName)) {
            Class pageClass = pageSource.getPageClass();
            paxWicketPageFactory.remove(pageClass);
        }
    }

    /**
     * Default implementation of the ServiceTrackerCustomizer.removedService method.
     * 
     * 

     * This method is only called when this ServiceTracker object has been constructed with a
     * null ServiceTrackerCustomizer argument.
     * 
     * The default implementation calls ungetService, on the BundleContext object with which
     * this ServiceTracker object was created, passing the specified ServiceReference object.
     * 
     * This method can be overridden in a subclass. If the default implementation of addingService method
     * was used, this method must unget the service.
     * 
     * @param reference Reference to removed service.
     * @param service The service object for the removed service.
     * 
     * @see org.osgi.util.tracker.ServiceTrackerCustomizer
     */
    @Override
    public final void removedService(ServiceReference reference, Object service) {
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("removedService( " + reference + ", " + service + ");");
        }
        PageFactory pageSource = (PageFactory) service;
        Class pageclass = pageSource.getPageClass();
        paxWicketPageFactory.remove(pageclass);

        super.removedService(reference, service);
    }
}