2009/05/20 - Apache Shale has been retired.

   /*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to you under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.shale.usecases.rolodex;
  
  import java.io.IOException;
  import java.net.URLEncoder;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIData;
  import javax.faces.context.FacesContext;
  import javax.faces.context.ResponseWriter;
  import javax.faces.render.Renderer;
  
  import org.apache.shale.util.Messages;
  
  public class HeaderSorterRenderer extends Renderer {
  
      
      /***
       * <p>Localized messages for this application.</p>
       */
      private static Messages messages =
        new Messages("org.apache.shale.usecases.view.Bundle");
      
  
      /***
       * <p>Constant used to create the query parameter that
       * identifies the sorted column.</p>
       */
      private static final String SORTED_COLUMN = "s";
  
      
      /***
       * <p>Constant used to create the query parameter that
       * identifies the sorted column's next sort direction.</p>
       */
      private static final String SORTED_SEQUENCE = "a";
  
      
      
      /***
       * <p>Finds the parent IUData component.</p>
       */
      protected UIData findDataComponent(UIComponent uicomponent) {
          return (UIData) findDataParent(uicomponent);
      }
  
      /***
       * <p>Recursive method that finds the first parent Idata component.</p>
       */
      private UIComponent findDataParent(UIComponent uicomponent) {
          if (uicomponent == null)
              return null;
          if (uicomponent instanceof UIData)
              return uicomponent;
          else
              return findDataParent(uicomponent.getParent());
      }
  
      /***
       * <p>Returns the base context root of the form using the
       * view handler.</p>
       */
      protected String getActionStr(FacesContext context) {
          String uri = context.getViewRoot().getViewId();
          String url =
              context.getApplication().getViewHandler().getActionURL(
                  context,
                  uri);
  
          return url;
      }
  
      /***
       * <p>The name of the query parameter used to control column sorting.</p>
       */
      protected String getSortedTag(FacesContext context, UIData data) {
          StringBuffer clientId = new StringBuffer(data.getClientId(context));
          clientId.append(SORTED_COLUMN);
          return clientId.toString();
      }
 
     /***
      * <p>Determines if the column was click to be sorted on.</p>
      */
     protected boolean wasSelected(
         FacesContext context,
         UIData data,
         HeaderSorter column) {
 
         boolean wasSelected = false;
         Map params = context.getExternalContext().getRequestParameterMap();
         String tag = getSortedTag(context, data);
         if (params.containsKey(tag)) {
             String value = (String) params.get(tag);
             wasSelected = value.equals(column.getId());
             column.getAttributes().put("defaultSort", value);
 
             
             String sortAcending = (String) params.get(SORTED_SEQUENCE);
             boolean isSortedAcending =  true;
             try {
                 isSortedAcending = Boolean.valueOf(sortAcending).booleanValue();
             } catch (Exception e) {
             }
             
             // toggle the sort order flag
             column.setSortAscending(isSortedAcending);
 
             value = null;
         } else if (column.wasSelected()) {
             wasSelected = true;
         }
 
         tag = null;
         params = null;
 
         return wasSelected;
     }
 
     /***
      * <p>Initiates the component rendering.</p>
      */
     public void encodeBegin(FacesContext context, UIComponent component)
         throws IOException {
 
         if (context == null || component == null)
             throw new NullPointerException();
 
         if (!component.isRendered())
             return;
 
         ResponseWriter writer = context.getResponseWriter();
 
         UIData data = findDataComponent(component);
         if (data == null)
             throw new NullPointerException(messages.getMessage("headerSorter.invalid"));
 
         boolean wasSelected =
             wasSelected(context, data, (HeaderSorter) component);
 
         if (wasSelected) {
             GenericComparator adapter =
                 new GenericComparator();
             adapter.setSortAscending(
                 ((HeaderSorter) component).isSortAscending());
             adapter.setSortBy(
                 ((HeaderSorter) component).getSortBy());
 
             Collections.sort((List) data.getValue(), adapter);
 
             adapter = null;
             
             writer.startElement("input", component);
             writer.writeAttribute("type", "hidden", "type");
             writer.writeAttribute("name", this.getSortedTag(context, data), "name");
             writer.writeAttribute("value", ((HeaderSorter) component).getId(), "value");
             writer.write(' ');
         }
 
 
         StringBuffer url = new StringBuffer(getActionStr(context));
         url.append('?').append(getSortedTag(context, data)).append("=").append(
             URLEncoder.encode(component.getId(), "UTF-8"))
             .append("&").append(SORTED_SEQUENCE).append("=")
             .append(!((HeaderSorter) component).isSortAscending());
         writer.startElement("a", component);
         writer.writeAttribute("href", context.getExternalContext().encodeActionURL(url.toString()), "href");
         writer.writeText((String) ((HeaderSorter) component).getValue(), "value");
 
         url = null;
         writer = null;
         data = null;
 
         super.encodeBegin(context, component);
     }
 
     /***
      * <p>Completes component rendering.</p>
      */
     public void encodeEnd(FacesContext context, UIComponent component)
         throws IOException {
 
         if (context == null || component == null)
             throw new NullPointerException();
 
         if (!component.isRendered())
             return;
 
         super.encodeEnd(context, component);
 
         boolean wasSelected = ((HeaderSorter) component).wasSelected();
         boolean wasSortedAscending =
             ((HeaderSorter) component).isSortAscending();
 
         ResponseWriter writer = context.getResponseWriter();
 
         if (wasSelected) {
 
             StringBuffer url =
                 new StringBuffer(
                     context.getExternalContext().getRequestContextPath());
 
             String title = null;
             if (wasSortedAscending) {
                 if (((HeaderSorter) component).getAscImage() != null) {
                     url.append(((HeaderSorter) component).getAscImage());
                 } else {
                     url.append(messages.getMessage("headerSorter.ascImage"));
                 }
                 title = messages.getMessage("headerSorter.ascTitle");
             } else {
                 if (((HeaderSorter) component).getDescImage() != null) {
                     url.append(((HeaderSorter) component).getDescImage());
                 } else {
                     url.append(messages.getMessage("headerSorter.descImage"));
                 }
                 title = messages.getMessage("headerSorter.descTitle");
             }
 
             writer.startElement("img", component);
             writer.writeAttribute("border", "0", "border");
             writer.writeAttribute("src", context.getExternalContext().encodeActionURL(url.toString()), "src");
             writer.writeAttribute("title", title, "title");
             writer.write(' ');
                         
             url = null;
             title = null;
 
         }
         writer.endElement("a");
         writer = null;
 
     }
     
 }