/*
    * 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.tree.taglib;
  
  import javax.el.ValueExpression;
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.servlet.jsp.JspException;
  
  import org.apache.myfaces.custom.tree.HtmlTree;
  import org.apache.myfaces.custom.tree.model.DefaultTreeModel;
  import org.apache.myfaces.custom.tree.model.TreeModel;
  import org.apache.myfaces.custom.tree.model.TreePath;
  import org.apache.myfaces.shared_tomahawk.taglib.html.HtmlPanelGroupTag;
  
  /**
   * <p>
   * HtmlTree tag.
   * </p>
   *
   * @author <a href="mailto:oliver@rossmueller.com">Oliver Rossmueller </a>
   * @version $Revision: 664402 $ $Date: 2004/10/13 11:50:58
   */
  public class AbstractTreeTag extends HtmlPanelGroupTag {
  
      private ValueExpression value;
  
      private boolean expandRoot;
  
      public String getComponentType() {
          return "org.apache.myfaces.HtmlTree";
      }
  
      public String getRendererType() {
          return "org.apache.myfaces.HtmlTree";
      }
  
      public ValueExpression getValue() {
          return value;
      }
  
      public void setValue(ValueExpression newValue) {
          value = newValue;
      }
  
      public boolean isExpandRoot() {
          return expandRoot;
      }
  
      public void setExpandRoot(boolean expandRoot) {
          this.expandRoot = expandRoot;
      }
  
      /**
       * Obtain tree model or create a default model.
       */
      public int doStartTag() throws JspException {
          FacesContext context = FacesContext.getCurrentInstance();
  
          if (value != null) {
              TreeModel treeModel = (TreeModel) (value.getValue(context.getELContext()));
  
              if (treeModel == null) {
                  // create default model
                  treeModel = new DefaultTreeModel();
                  value.setValue(context.getELContext(), treeModel);
              }
          }
          int answer = super.doStartTag();
          HtmlTree tree = (HtmlTree) getComponentInstance();
  
          if (getCreated() && expandRoot) {
              // component was created, so expand the root node
              TreeModel model = tree.getModel(context);
  
              if (model != null) {
                  tree.expandPath(new TreePath(new Object[] { model.getRoot() }),
                          context);
              }
          }
  
          tree.addToModelListeners();
          return answer;
     }
 
     public void release() {
         super.release();
         value = null;
         expandRoot = false;
     }
 
     /**
      * Applies attributes to the tree component
      */
     protected void setProperties(UIComponent component) {
         super.setProperties(component);
         FacesContext context = FacesContext.getCurrentInstance();
 
         
         if (value != null) {
             if (!value.isLiteralText()) {
                 component.setValueExpression("model", value);
             }
         } else {
             ValueExpression binding = component.getValueExpression("model");
             if (binding == null) {
                 binding = context.getApplication().
                     getExpressionFactory().createValueExpression(
                     context.getELContext(),"#{sessionScope.tree}", Object.class);
             }
             component.setValueExpression("model", binding);
         }
     }
 }