/**

 * 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;

    }

}