/**

  * HTML via Java(tm) Language Bindings

  * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details. apidesign.org

  * designates this particular file as subject to the

  * "Classpath" exception as provided by apidesign.org

  * in the License file that accompanied this code.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://wiki.apidesign.org/wiki/GPLwithClassPathException

  */

 package org.apidesign.html.boot.spi;

 import java.io.Reader;

 import java.net.URL;

 import org.apidesign.html.boot.impl.FnUtils;

 /**

  *

  * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  */

 public abstract class Fn {

     private final Presenter presenter;

     protected Fn(Presenter presenter) {

         this.presenter = presenter;

     }

     public final boolean isValid() {

         return FnUtils.currentPresenter() == presenter;

     }

     public final Object invoke(Object thiz, Object... args) throws Exception {

         return handleInvoke(thiz, args);

     }

     protected abstract Object handleInvoke(Object thiz, Object... args) throws Exception;

     public interface Presenter {

         public Fn defineFn(String code, String... names);

         public void displayPage(URL page, Runnable onPageLoad);

         public void loadScript(Reader code) throws Exception;

     }

 }