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

  * 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;

     }

 }