/* ================================================================

 * Cewolf : Chart enabling Web Objects Framework

 * ================================================================

 *

 * Project Info:  http://cewolf.sourceforge.net

 * Project Lead:  Guido Laures (guido@laures.de);

 *

 * (C) Copyright 2002, by Guido Laures

 *

 * This library is free software; you can redistribute it and/or modify it under the terms

 * of the GNU Lesser General Public License as published by the Free Software Foundation;

 * either version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License along with this

 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 */

package de.laures.cewolf.taglib.util;

import javax.servlet.jsp.PageContext;

import javax.servlet.jsp.tagext.Tag;

import org.jfree.data.general.Dataset;

import de.laures.cewolf.ChartHolder;

import de.laures.cewolf.DatasetProduceException;

import de.laures.cewolf.taglib.tags.CewolfRootTag;

/**

 * Helper class to easily retrieve some objects of page context.

 * @author  glaures

 */

public class PageUtils {

    private final static String TOOLTIPS_ENABLED_ATTR = PageUtils.class.getName() + ".ttenabled";

    /** Creates a new instance of ChartDefinitionFactory */

    private PageUtils() {}

    public static ChartHolder getChartHolder(String chartId, PageContext ctx){

        return (ChartHolder)ctx.getAttribute(chartId, PageContext.PAGE_SCOPE);

    }

    public static final ChartHolder getChartHolder(Tag tag, PageContext ctx){

        CewolfRootTag root = findRoot(tag, ctx);

        if(root instanceof ChartHolder){

            return (ChartHolder)root;

        } else {

            return getChartHolder(root.getChartId(), ctx);

        }

    }

    public static final Dataset getDataset(String chartId, PageContext ctx) throws DatasetProduceException {

        return (Dataset) getChartHolder(chartId, ctx).getDataset();

    }

    public static final CewolfRootTag findRoot(Tag t, PageContext ctx){

        Tag res = t;

        while(!(res instanceof CewolfRootTag)){

            res = res.getParent();

        }

        return (CewolfRootTag)res;

    }

    public static final void setToolTipsEnabled(PageContext ctx){

        if(!isToolTipsEnabled(ctx)){

            ctx.setAttribute(TOOLTIPS_ENABLED_ATTR, "true", PageContext.PAGE_SCOPE);

        }

    }

    public static final boolean isToolTipsEnabled(PageContext ctx){

        return ctx.getAttribute(TOOLTIPS_ENABLED_ATTR, PageContext.PAGE_SCOPE) != null;

    }

}