/**

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

  *

  * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.

  *

  * Oracle and Java are registered trademarks of Oracle and/or its affiliates.

  * Other names may be trademarks of their respective owners.

  *

  * The contents of this file are subject to the terms of either the GNU

  * General Public License Version 2 only ("GPL") or the Common

  * Development and Distribution License("CDDL") (collectively, the

  * "License"). You may not use this file except in compliance with the

  * License. You can obtain a copy of the License at

  * http://www.netbeans.org/cddl-gplv2.html

  * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

  * specific language governing permissions and limitations under the

  * License.  When distributing the software, include this License Header

  * Notice in each file and include the License file at

  * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the GPL Version 2 section of the License file that

  * accompanied this code. If applicable, add the following below the

  * License Header, with the fields enclosed by brackets [] replaced by

  * your own identifying information:

  * "Portions Copyrighted [year] [name of copyright owner]"

  *

  * Contributor(s):

  *

  * The Original Software is NetBeans. The Initial Developer of the Original

  * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.

  *

  * If you wish your version of this file to be governed by only the CDDL

  * or only the GPL Version 2, indicate your decision by adding

  * "[Contributor] elects to include this software in this distribution

  * under the [CDDL or GPL Version 2] license." If you do not indicate a

  * single choice of license, a recipient has the option to distribute

  * your version of this file under either the CDDL, the GPL Version 2 or

  * to extend the choice of license to its licensees as provided above.

  * However, if you add GPL Version 2 code and therefore, elected the GPL

  * Version 2 license, then the option applies only if the new code is

  * made subject to such option by the copyright holder.

  */

 package org.netbeans.html.ko4j;

 import net.java.html.json.Model;

 import org.netbeans.html.boot.spi.Fn;

 import org.netbeans.html.context.spi.Contexts;

 import org.netbeans.html.context.spi.Contexts.Provider;

 import org.netbeans.html.json.spi.Technology;

 import org.netbeans.html.json.spi.Transfer;

 import org.netbeans.html.json.spi.WSTransfer;

 import org.openide.util.lookup.ServiceProvider;

 /** Support for <a href="http://knockoutjs.com">knockout.js</a>

  * and its Java binding via {@link Model model classes}.

  * Registers {@link Provider}, so {@link java.util.ServiceLoader} can find it.

  *

  * @author Jaroslav Tulach

  * @since 0.7

  */

 @ServiceProvider(service = Provider.class)

 public final class KO4J implements Provider {

     private final Fn.Presenter presenter;

     private FXContext c;

     public KO4J() {

         this(null);

     }

     public KO4J(Fn.Presenter presenter) {

         this.presenter = presenter;

     }

     private FXContext getKO() {

         if (c == null) {

             c = new FXContext(presenter == null ? Fn.activePresenter() : presenter);

         }

         return c;

     }

     /** Return instance of the knockout.js for Java technology.

      * @return non-null instance

      */

     public Technology knockout() {

         return getKO();

     }

     /** Browser based implementation of transfer interface. Uses

      * browser method to convert string to JSON.

      * 

      * @return non-null instance

      */

     public Transfer transfer() {

         return getKO();

     }

     /** Returns browser based implementation of websocket transfer.

      * If available (for example JavaFX WebView on JDK7 does not have

      * this implementation).

      * 

      * @return an instance or <code>null</code>, if there is no

      *   <code>WebSocket</code> object in the browser

      */

     public WSTransfer<?> websockets() {

         return getKO().areWebSocketsSupported() ? getKO() : null;

     }

     /** Registers technologies at position 100:

      * <ul>

      *   <li>{@link #knockout()}</li>

      *   <li>{@link #transfer()}</li>

      *   <li>{@link #websockets()()} - if browser supports web sockets</li>

      * </ul>

      * @param context the context to register to

      * @param requestor the class requesting the registration

      */

     @Override

     public void fillContext(Contexts.Builder context, Class<?> requestor) {

         context.register(Technology.class, knockout(), 100);

         context.register(Transfer.class, transfer(), 100);

         context.register(WSTransfer.class, websockets(), 100);

     }

 }