/*
    * 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.myfaces.custom.autoscroll;
  
  import java.io.IOException;
  
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIForm;
  import javax.faces.context.FacesContext;
  import javax.faces.context.ResponseWriter;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFRenderer;
  import org.apache.myfaces.shared_tomahawk.config.MyfacesConfig;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlFormRendererBase;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlRenderer;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlRendererUtils;
  
  /**
   * 
   * @since 1.1.10
   * @author Leonardo Uribe (latest modification by $Author: lu4242 $)
   * @version $Revision: 691856 $ $Date: 2008-09-03 21:40:30 -0500 (mié, 03 sep 2008) $
   */
  @JSFRenderer(renderKitId = "HTML_BASIC",
      family = "org.apache.myfaces.custom.autoscroll.AutoscrollHiddenField",
      type = "org.apache.myfaces.custom.autoscroll.AutoscrollHiddenField")
  public class AutoscrollHiddenFieldRenderer extends HtmlRenderer
  {
      private static final String SCROLL_HIDDEN_INPUT = "org.apache.myfaces.SCROLL_HIDDEN_INPUT";
      
      @Override
      public void encodeEnd(FacesContext context, UIComponent component)
              throws IOException
      {
          //Check npe
          super.encodeEnd(context, component);
          
          //It is necessary a small to obtain the renderer parent of this field.
          //In theory the current component is called from a form renderer,
          //because this component is only added by
          //facesContext.getViewRoot().addComponentResource()
          //with target="form".
          component.popComponentFromEL(context);
          try
          {
              UIComponent form = UIComponent.getCurrentComponent(context);
  
              if (form instanceof UIForm)
              {
                  ResponseWriter writer = context.getResponseWriter();
                  if (MyfacesConfig.getCurrentInstance(context.getExternalContext()).isAutoScroll())
                  {
                      //Render as original, to prevent duplicate hidden input rendering
                      HtmlFormRendererBase.renderScrollHiddenInputIfNecessary(form, context, writer);
                  }
                  else
                  {
                      // No automatic scroll, but use of t:autoscroll, so force the rendering of the hidden field.
                      // It is not necessary to check if the hidden input has been rendered, because there is no
                      // other component that renders it.
                      HtmlRendererUtils.renderAutoScrollHiddenInput(context, writer);
                      context.getExternalContext().getRequestMap().put(getScrollHiddenInputName(context, form), Boolean.TRUE);
                  }
              }
          }
          finally
          {
              //Restore the stack
              component.pushComponentToEL(context, component);
          }
      }
      
      private static String getScrollHiddenInputName(FacesContext facesContext, UIComponent form) {
          StringBuffer buf = new StringBuffer();
          buf.append(SCROLL_HIDDEN_INPUT);
          buf.append("_");
          buf.append(form.getClientId(facesContext));
          return buf.toString();
      }
  }