/**

 * 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.impl;

import java.io.Closeable;

import java.io.IOException;

import java.util.logging.Logger;

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

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

public final class FnContext implements Closeable {

    private static final Logger LOG = Logger.getLogger(FnContext.class.getName());

    private Object prev;

    private FnContext(Fn.Presenter p) {

        this.prev = p;

    }

    @Override

    public void close() throws IOException {

        if (prev != this) {

            currentPresenter((Fn.Presenter)prev);

            prev = this;

        }

    }

/*

    @Override

    protected void finalize() throws Throwable {

        if (prev != null) {

            LOG.warning("Unclosed context!");

        }

    }

*/

    public static Closeable activate(Fn.Presenter newP) {

        return new FnContext(currentPresenter(newP));

    }

    private static final ThreadLocal<Fn.Presenter> CURRENT = new ThreadLocal<Fn.Presenter>();

    public static Fn.Presenter currentPresenter(Fn.Presenter p) {

        Fn.Presenter prev = CURRENT.get();

        CURRENT.set(p);

        return prev;

    }

    public static Fn.Presenter currentPresenter() {

        Fn.Presenter p = CURRENT.get();

        if (p == null) {

            throw new IllegalStateException("No current WebView context around!");

        }

        return p;

    }

}