package net.sf.tacos.components.timeline;

 import java.util.Collection;

 import java.util.Iterator;

 import org.apache.tapestry.BaseComponent;

 import org.apache.tapestry.IAsset;

 import org.apache.tapestry.IRequestCycle;

 import org.apache.tapestry.html.Shell;

 import org.apache.tapestry.json.JSONObject;

 /**

  * Timeline component, based on http://simile.mit.edu/timeline/

  *

  * @author Andreas Andreou, amplafi.com

  */

 public abstract class Timeline extends BaseComponent {

     public abstract Collection getEvents();

     public abstract String getEventsUrl();

     public abstract IAsset getTimelineAsset();

     public abstract IAsset getSimileAjaxAsset();    

     protected void prepareForRender(IRequestCycle cycle)

     {

         super.prepareForRender(cycle);

         if (!cycle.isRewinding()) 

         {

             Shell shell = Shell.get(cycle);

             if (getSimileAjaxAsset()!=null)

             {

                 addScriptToShell(shell, getSimileAjaxAsset().buildURL());

             }

             addScriptToShell(shell, getTimelineAsset().buildURL());

         }

     }

     public String getEventsJson()

     {

         JSONObject json = new JSONObject();

         for (Iterator iterator = getEvents().iterator(); iterator.hasNext();)

         {

             TimelineEvent evt = (TimelineEvent) iterator.next();

             evt.appendTo(json);

         }

         return json.toString(2);

     }

     private void addScriptToShell(Shell shell, String url) {

         shell.includeAdditionalContent(

                 "<script src=\"" + url + "\" type=\"text/javascript\"></script>");

     }

 }