/*
    * 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.tree2;
  
  import java.io.IOException;
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import javax.faces.FacesException;
  import javax.faces.application.FacesMessage;
  import javax.faces.component.ContextCallback;
  import javax.faces.component.EditableValueHolder;
  import javax.faces.component.NamingContainer;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIComponentBase;
  import javax.faces.component.UINamingContainer;
  import javax.faces.component.UIViewRoot;
  import javax.faces.component.UniqueIdVendor;
  import javax.faces.component.visit.VisitCallback;
  import javax.faces.component.visit.VisitContext;
  import javax.faces.component.visit.VisitResult;
  import javax.faces.context.ExternalContext;
  import javax.faces.context.FacesContext;
  import javax.faces.el.ValueBinding;
  import javax.faces.event.AbortProcessingException;
  import javax.faces.event.ActionEvent;
  import javax.faces.event.FacesEvent;
  import javax.faces.event.FacesListener;
  import javax.faces.event.PhaseId;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFComponent;
  import org.apache.myfaces.shared_tomahawk.util.MessageUtils;
  import org.apache.myfaces.tomahawk.util.Constants;
  
  /**
   * TreeData is a {@link UIComponent} that supports binding data stored in a tree represented
   * by a {@link TreeNode} instance.  During iterative processing over the tree nodes in the
   * data model, the object for the current node is exposed as a request attribute under the key
   * specified by the <code>var</code> property.  {@link javax.faces.render.Renderer}s of this
   * component should use the appropriate facet to assist in rendering.
   *
   * @author Sean Schofield
   * @author Hans Bergsten (Some code taken from an example in his O'Reilly JavaServer Faces book. Copied with permission)
   * @version $Revision: 703742 $ $Date: 2008-10-11 17:10:36 -0500 (sáb, 11 oct 2008) $
   */
  @JSFComponent
  public class UITreeData extends UIComponentBase implements NamingContainer, Tree, UniqueIdVendor {
      private Log log = LogFactory.getLog(UITreeData.class);
  
      public static final String COMPONENT_TYPE = "org.apache.myfaces.UITree2";
      public static final String COMPONENT_FAMILY = "org.apache.myfaces.HtmlTree2";
      //private static final String DEFAULT_RENDERER_TYPE = "org.apache.myfaces.Tree2";
      private static final String MISSING_NODE = "org.apache.myfaces.tree2.MISSING_NODE";
      private static final int PROCESS_DECODES = 1;
      private static final int PROCESS_VALIDATORS = 2;
      private static final int PROCESS_UPDATES = 3;
  
      private TreeModel _cachedModel;
      private String _nodeId;
      private TreeNode _node;
  
      private Object _value;
      private String _var;
      private Map _saved = new HashMap();
  
      private TreeState _restoredState = null;
  
      private transient FacesContext _facesContext;
      
      private static final String SKIP_ITERATION_HINT = "javax.faces.visit.SKIP_ITERATION";
  
      /**
       * Constructor
       */
      public UITreeData()
      {
          //setRendererType(DEFAULT_RENDERER_TYPE);
     }
 
 
     // see superclass for documentation
     public String getFamily()
     {
         return COMPONENT_FAMILY;
     }
 
     //  see superclass for documentation
     public Object saveState(FacesContext context)
     {
         Object values[] = new Object[3];
         values[0] = super.saveState(context);
         values[1] = _var;
         values[2] = _restoredState;
         return ((Object) (values));
     }
 
 
     // see superclass for documentation
     public void restoreState(FacesContext context, Object state)
     {
         Object values[] = (Object[]) state;
         super.restoreState(context, values[0]);
 
         _var = (String)values[1];
         _restoredState = (TreeState) values[2];
     }
 
     public void encodeEnd(FacesContext context) throws IOException {
         super.encodeEnd(context);
 
         // prepare to save the tree state -- fix for MYFACES-618
         // should be done in saveState() but Sun RI does not call saveState() and restoreState()
         // with javax.faces.STATE_SAVING_METHOD = server
         TreeState state = getDataModel().getTreeState();
         if ( state == null)
         {
             // the model supplier has forgotten to return a valid state manager, but we need one
             state = new TreeStateBase();
         }
         // save the state with the component, unless it should explicitly not saved eg. session-scoped model and state
         _restoredState = (state.isTransient()) ? null : state;
 
     }
 
     public void queueEvent(FacesEvent event)
     {
         super.queueEvent(new FacesEventWrapper(event, getNodeId(), this));
     }
 
 
     public void broadcast(FacesEvent event) throws AbortProcessingException
     {
         if (event instanceof FacesEventWrapper)
         {
             FacesEventWrapper childEvent = (FacesEventWrapper) event;
             String currNodeId = getNodeId();
             setNodeId(childEvent.getNodeId());
             FacesEvent nodeEvent = childEvent.getFacesEvent();
             nodeEvent.getComponent().broadcast(nodeEvent);
             setNodeId(currNodeId);
             return;
         }
         else if(event instanceof ToggleExpandedEvent)
         {
             ToggleExpandedEvent toggleEvent = (ToggleExpandedEvent) event;
             String currentNodeId = getNodeId();
             setNodeId(toggleEvent.getNodeId());
             toggleExpanded();
             setNodeId(currentNodeId);
         }
         else
         {
             super.broadcast(event);
             return;
         }
     }
 
 
     // see superclass for documentation
     public void processDecodes(FacesContext context)
     {
         if (context == null) throw new NullPointerException("context");
         if (!isRendered()) return;
 
         _cachedModel = null;
         _saved = new HashMap();
 
         setNodeId(null);
         decode(context);
 
         processNodes(context, PROCESS_DECODES, getDataModel().getTreeWalker());
         // After processNodes is executed, the node active is the last one
         // we have to set it to null again to avoid inconsistency on outsider
         // code (just like UIData components does)
         setNodeId(null);
 
     }
 
     // see superclass for documentation
     public void processValidators(FacesContext context)
     {
         if (context == null) throw new NullPointerException("context");
         if (!isRendered()) return;
 
         processNodes(context, PROCESS_VALIDATORS, getDataModel().getTreeWalker());
 
         setNodeId(null);
     }
 
 
     // see superclass for documentation
     public void processUpdates(FacesContext context)
     {
         if (context == null) throw new NullPointerException("context");
         if (!isRendered()) return;
 
         processNodes(context, PROCESS_UPDATES, getDataModel().getTreeWalker());
 
         setNodeId(null);
     }
 
     // see superclass for documentation
     /*
     public String getClientId(FacesContext context)
     {
         String ownClientId = super.getClientId(context);
         if (_nodeId != null)
         {
             return ownClientId + NamingContainer.SEPARATOR_CHAR + _nodeId;
         } else
         {
             return ownClientId;
         }
     }*/
     
     @Override
     public String getContainerClientId(FacesContext context)
     {
         String ownClientId = super.getContainerClientId(context);
         if (_nodeId != null)
         {
             return ownClientId + UINamingContainer.getSeparatorChar(context) + _nodeId;
         } 
         else
         {
             return ownClientId;
         }
     }
 
     // see superclass for documentation
     public void setValueBinding(String name, ValueBinding binding)
     {
         if ("value".equals(name))
         {
             _cachedModel = null;
         } else if ("nodeVar".equals(name) || "nodeId".equals(name) || "treeVar".equals(name))
         {
             throw new IllegalArgumentException("name " + name);
         }
         super.setValueBinding(name, binding);
     }
 
     // see superclass for documentation
     public void encodeBegin(FacesContext context) throws IOException
     {
         /**
          * The renderer will handle most of the encoding, but if there are any
          * error messages queued for the components (validation errors), we
          * do want to keep the saved state so that we can render the node with
          * the invalid value.
          */
 
         if (!keepSaved(context))
         {
             _saved = new HashMap();
         }
 
         // FIX for MYFACES-404
         // do not use the cached model the render phase
         _cachedModel = null;
 
         super.encodeBegin(context);
     }
 
     /**
      * Sets the value of the TreeData.
      *
      * @param value The new value
      *
      * @deprecated
      */
     public void setValue(Object value)
     {
         _cachedModel = null;
         _value = value;
     }
 
 
     /**
      * Gets the model of the TreeData -
      *  due to backwards-compatibility, this can also be retrieved by getValue.
      *
      * @return The value
      */
     public Object getModel()
     {
         return getValue();
     }
 
     /**
      * Sets the model of the TreeData -
      *  due to backwards-compatibility, this can also be set by calling setValue.
      *
      * @param model The new model
      */
     public void setModel(Object model)
     {
         setValue(model);
     }
 
 
     /**
      * Gets the value of the TreeData.
      *
      * @JSFProperty
      *   required="true"
      * @return The value
      *
      * @deprecated
      */
     public Object getValue()
     {
         if (_value != null) return _value;
         ValueBinding vb = getValueBinding("value");
         return vb != null ? vb.getValue(getFacesContext()) : null;
     }
 
     /**
      * Set the request-scope attribute under which the data object for the current node wil be exposed
      * when iterating.
      *
      * @param var The new request-scope attribute name
      */
     public void setVar(String var)
     {
         _var = var;
     }
 
 
     /**
      * Return the request-scope attribute under which the data object for the current node will be exposed
      * when iterating. This property is not enabled for value binding expressions.
      * 
      * @JSFProperty
      * @return The iterator attribute
      */
     public String getVar()
     {
         return _var;
     }
 
     /**
      * Calls through to the {@link TreeModel} and returns the current {@link TreeNode} or <code>null</code>.
      *
      * @return The current node
      */
     public TreeNode getNode()
     {
         return _node;
     }
 
 
     public String getNodeId()
     {
         return _nodeId;
     }
 
 
     public void setNodeId(String nodeId)
     {
         saveDescendantState();
 
         _nodeId = nodeId;
 
         TreeModel model = getDataModel();
         if (model == null)
         {
             return;
         }
 
         try
         {
             _node = model.getNodeById(nodeId);
         }
         //TODO: change to an own exception
         catch (IndexOutOfBoundsException aob)
         {
             /**
              * This might happen if we are trying to process a commandLink for a node that node that no longer
              * exists.  Instead of allowing a RuntimeException to crash the application, we will add a warning
              * message so the user can optionally display the warning.  Also, we will allow the user to provide
              * their own value binding method to be called so they can handle it how they see fit.
              */
             FacesMessage message = MessageUtils.getMessageFromBundle(Constants.TOMAHAWK_DEFAULT_BUNDLE, MISSING_NODE, new String[] {nodeId});
             message.setSeverity(FacesMessage.SEVERITY_WARN);
             FacesContext.getCurrentInstance().addMessage(getId(), message);
 
             /** @todo call hook */
             /** @todo figure out whether or not to abort this method gracefully */
         }
 
         restoreDescendantState();
 
         if (_var != null)
         {
             Map requestMap = getFacesContext().getExternalContext().getRequestMap();
 
             if (nodeId == null)
             {
                 requestMap.remove(_var);
             } else
             {
                 requestMap.put(_var, getNode());
             }
         }
     }
 
     @Override
     public boolean invokeOnComponent(FacesContext context, String clientId, ContextCallback callback)
         throws FacesException
     {
         if (context == null || clientId == null || callback == null)
         {
             throw new NullPointerException();
         }
         
         final String baseClientId = getClientId(context);
 
         // searching for this component?
         boolean returnValue = baseClientId.equals(clientId);
 
         boolean isTemporalFacesContext = isTemporalFacesContext();
         if (!isTemporalFacesContext)
         {
             setTemporalFacesContext(context);
         }
         
         pushComponentToEL(context, this);
         try
         {
             if (returnValue)
             {
                 try
                 {
                     callback.invokeContextCallback(context, this);
                     return true;
                 }
                 catch (Exception e)
                 {
                     throw new FacesException(e);
                 }
             }
     
             // Now Look throught facets on this UIComponent
             for (Iterator<UIComponent> it = this.getFacets().values().iterator(); !returnValue && it.hasNext();)
             {
                 returnValue = it.next().invokeOnComponent(context, clientId, callback);
             }
     
             if (returnValue)
             {
                 return returnValue;
             }
             
             // is the component an inner component?
             if (clientId.startsWith(baseClientId))
             {
                 TreeModel model = getDataModel();
                 
                 //We only use the tree walker to get the RootNodeId()
                 TreeWalker walker = model.getTreeWalker();
                 UIComponent facet = null;
                 walker.reset();
                 walker.setTree(this);
                 
                 String oldNodeId = getNodeId();
                 
                 try
                 {
                     while(!returnValue && walker.next())
                     {
                         TreeNode node = getNode();
                         facet = getFacet(node.getType());
     
                         if (facet == null)
                         {
                             log.warn("Unable to locate facet with the name: " + node.getType());
                             continue;
                         }
                         
                         returnValue = facet.invokeOnComponent(context, baseClientId, callback);
                     }
                 }
                 finally
                 {
                     setNodeId(oldNodeId);
                 }
             }
         }
         finally
         {
             //all components must call popComponentFromEl after visiting is finished
             popComponentFromEL(context);
             if (!isTemporalFacesContext)
             {
                 setTemporalFacesContext(null);
             }
         }
 
         return returnValue;
     }
     
     @Override
     public boolean visitTree(VisitContext context, VisitCallback callback)
     {
         if (!isVisitable(context))
         {
             return false;
         }
 
         boolean isTemporalFacesContext = isTemporalFacesContext();
         if (!isTemporalFacesContext)
         {
             setTemporalFacesContext(context.getFacesContext());
         }
         // save the current row index
         String oldNodeId = getNodeId();
         // set row index to -1 to process the facets and to get the rowless clientId
         setNodeId(null);
         // push the Component to EL
         pushComponentToEL(context.getFacesContext(), this);
         try
         {
             VisitResult visitResult = context.invokeVisitCallback(this,
                     callback);
             switch (visitResult)
             {
             //we are done nothing has to be processed anymore
             case COMPLETE:
                 return true;
 
             case REJECT:
                 return false;
 
                 //accept
             default:
                 // determine if we need to visit our children 
                 Collection<String> subtreeIdsToVisit = context
                         .getSubtreeIdsToVisit(this);
                 boolean doVisitChildren = subtreeIdsToVisit != null
                         && !subtreeIdsToVisit.isEmpty();
                 if (doVisitChildren)
                 {
                     Boolean skipIterationHint = (Boolean) context.getFacesContext().getAttributes().get(SKIP_ITERATION_HINT);
                     if (skipIterationHint != null && skipIterationHint.booleanValue())
                     {
                         // If SKIP_ITERATION is enabled, do not take into account rows.
                         if (getChildCount() > 0) {
                             for (UIComponent child : getChildren()) {
                                 if (child.visitTree(context, callback)) {
                                     return true;
                                 }
                             }
                         }
                     }
                     else
                     {
                         TreeWalker walker = getDataModel().getTreeWalker();
                         UIComponent facet = null;
                         walker.reset();
                         walker.setTree(this);
     
                         while(walker.next())
                         {
                             TreeNode node = getNode();
                             facet = getFacet(node.getType());
     
                             if (facet == null)
                             {
                                 log.warn("Unable to locate facet with the name: " + node.getType());
                                 continue;
                                 //throw new IllegalArgumentException("Unable to locate facet with the name: " + node.getType());
                             }
     
                             if (facet.visitTree(context, callback))
                             {
                                 return true;
                             }
                         }
                     }
                 }
             }
         }
         finally
         {
             // pop the component from EL and restore the old row index
             popComponentFromEL(context.getFacesContext());
             setNodeId(oldNodeId);
             if (!isTemporalFacesContext)
             {
                 setTemporalFacesContext(null);
             }
         }
 
         // Return false to allow the visiting to continue
         return false;
     }
     
     @Override
     protected FacesContext getFacesContext()
     {
         if (_facesContext == null)
         {
             return super.getFacesContext();
         }
         else
         {
             return _facesContext;
         }
     }
     
     private boolean isTemporalFacesContext()
     {
         return _facesContext != null;
     }
     
     private void setTemporalFacesContext(FacesContext facesContext)
     {
         _facesContext = facesContext;
     }
     
     /**
      * Gets an array of String containing the ID's of all of the {@link TreeNode}s in the path to
      * the specified node.  The path information will be an array of <code>String</code> objects
      * representing node ID's. The array will starting with the ID of the root node and end with
      * the ID of the specified node.
      *
      * @param nodeId The id of the node for whom the path information is needed.
      * @return String[]
      */
     public String[] getPathInformation(String nodeId)
     {
         return getDataModel().getPathInformation(nodeId);
     }
 
     /**
      * Indicates whether or not the specified {@link TreeNode} is the last child in the <code>List</code>
      * of children.  If the node id provided corresponds to the root node, this returns <code>true</code>.
      *
      * @param nodeId The ID of the node to check
      * @return boolean
      */
     public boolean isLastChild(String nodeId)
     {
         return getDataModel().isLastChild(nodeId);
     }
 
     /**
      * Returns a previously cached {@link TreeModel}, if any, or sets the cache variable to either the
      * current value (if its a {@link TreeModel}) or to a new instance of {@link TreeModel} (if it's a
      * {@link TreeNode}) with the provided value object as the root node.
      *
      * @return TreeModel
      */
     public TreeModel getDataModel()
     {
         if (_cachedModel != null)
         {
             return _cachedModel;
         }
 
         Object value = getValue();
         if (value != null)
         {
             if (value instanceof TreeModel)
             {
                 _cachedModel = (TreeModel) value;
             }
             else if (value instanceof TreeNode)
             {
                 _cachedModel = new TreeModelBase((TreeNode) value);
             } else
             {
                 throw new IllegalArgumentException("Value must be a TreeModel or TreeNode");
             }
         }
 
         if (_restoredState != null)
             _cachedModel.setTreeState(_restoredState); // set the restored state (if there is one) on the model
 
         return _cachedModel;
     }
 
     /**
      * Epands all nodes by default.
      */
     public void expandAll()
     {
         toggleAll(true);
     }
 
     /**
      * Collapse all nodes by default.
      */
     public void collapseAll()
     {
         toggleAll(false);
     }
 
     /**
      * Toggles all of the nodes to either expanded or collapsed depending on the
      * parameter supplied.
      *
      * @param expanded Expand all of the nodes (a value of false indicates collapse
      * all nodes)
      */
     private void toggleAll(boolean expanded)
     {
         TreeWalker walker = getDataModel().getTreeWalker();
         walker.reset();
 
         TreeState state =  getDataModel().getTreeState();
         walker.setCheckState(false);
         walker.setTree(this);
 
         while(walker.next())
         {
             String id = getNodeId();
             if ((expanded && !state.isNodeExpanded(id)) || (!expanded && state.isNodeExpanded(id)))
             {
                 state.toggleExpanded(id);
             }
         }
     }
 
     /**
      * Expands all of the nodes in the specfied path.
      * @param nodePath The path to expand.
      */
     public void expandPath(String[] nodePath)
     {
         getDataModel().getTreeState().expandPath(nodePath);
     }
 
     /**
      * Expands all of the nodes in the specfied path.
      * @param nodePath The path to expand.
      */
     public void collapsePath(String[] nodePath)
     {
         getDataModel().getTreeState().collapsePath(nodePath);
     }
 
 
     protected void processNodes(FacesContext context, int processAction, TreeWalker walker)
     {
         UIComponent facet = null;
         walker.reset();
         walker.setTree(this);
 
         while(walker.next())
         {
             TreeNode node = getNode();
             facet = getFacet(node.getType());
 
             if (facet == null)
             {
                 log.warn("Unable to locate facet with the name: " + node.getType());
                 continue;
                 //throw new IllegalArgumentException("Unable to locate facet with the name: " + node.getType());
             }
 
             switch (processAction)
             {
                 case PROCESS_DECODES:
 
                     facet.processDecodes(context);
                     break;
 
                 case PROCESS_VALIDATORS:
 
                     facet.processValidators(context);
                     break;
 
                 case PROCESS_UPDATES:
 
                     facet.processUpdates(context);
                     break;
             }
         }
 
     }
 
     /**
      * To support using input components for the nodes (e.g., input fields, checkboxes, and selection
      * lists) while still only using one set of components for all nodes, the state held by the components
      * for the current node must be saved for a new node is selected.
      */
     private void saveDescendantState()
     {
         FacesContext context = getFacesContext();
         Iterator i = getFacets().values().iterator();
         while (i.hasNext())
         {
             UIComponent facet = (UIComponent) i.next();
             saveDescendantState(facet, context);
         }
     }
 
     /**
      * Overloaded helper method for the no argument version of this method.
      *
      * @param component The component whose state needs to be saved
      * @param context   FacesContext
      */
     private void saveDescendantState(UIComponent component, FacesContext context)
     {
         if (component instanceof EditableValueHolder)
         {
             EditableValueHolder input = (EditableValueHolder) component;
             String clientId = component.getClientId(context);
             SavedState state = (SavedState) _saved.get(clientId);
             if (state == null)
             {
                 state = new SavedState();
                 _saved.put(clientId, state);
             }
             state.setValue(input.getLocalValue());
             state.setValid(input.isValid());
             state.setSubmittedValue(input.getSubmittedValue());
             state.setLocalValueSet(input.isLocalValueSet());
         }
 
         List kids = component.getChildren();
         for (int i = 0; i < kids.size(); i++)
         {
             saveDescendantState((UIComponent) kids.get(i), context);
         }
     }
 
 
     /**
      * Used to configure a new node with the state stored previously.
      */
     private void restoreDescendantState()
     {
         FacesContext context = getFacesContext();
         Iterator i = getFacets().values().iterator();
         while (i.hasNext())
         {
             UIComponent facet = (UIComponent) i.next();
             restoreDescendantState(facet, context);
         }
     }
 
     /**
      * Overloaded helper method for the no argument version of this method.
      *
      * @param component The component whose state needs to be restored
      * @param context   FacesContext
      */
     private void restoreDescendantState(UIComponent component, FacesContext context)
     {
         String id = component.getId();
         component.setId(id); // forces the cilent id to be reset
 
         if (component instanceof EditableValueHolder)
         {
             EditableValueHolder input = (EditableValueHolder) component;
             String clientId = component.getClientId(context);
             SavedState state = (SavedState) _saved.get(clientId);
             if (state == null)
             {
                 state = new SavedState();
             }
             input.setValue(state.getValue());
             input.setValid(state.isValid());
             input.setSubmittedValue(state.getSubmittedValue());
             input.setLocalValueSet(state.isLocalValueSet());
         }
 
         List kids = component.getChildren();
         for (int i = 0; i < kids.size(); i++)
         {
             restoreDescendantState((UIComponent)kids.get(i), context);
         }
         Map facets = component.getFacets();
         for(Iterator i = facets.values().iterator(); i.hasNext();)
         {
             restoreDescendantState((UIComponent)i.next(), context);
         }
     }
 
     /**
      * A regular bean with accessor methods for all state variables.
      *
      * @author Sean Schofield
      * @author Hans Bergsten (Some code taken from an example in his O'Reilly JavaServer Faces book. Copied with permission)
      * @version $Revision: 703742 $ $Date: 2008-10-11 17:10:36 -0500 (sáb, 11 oct 2008) $
      */
     private static class SavedState implements Serializable
     {
         private static final long serialVersionUID = 273343276957070557L;
         private Object submittedValue;
         private boolean valid = true;
         private Object value;
         private boolean localValueSet;
 
         Object getSubmittedValue()
         {
             return submittedValue;
         }
 
         void setSubmittedValue(Object submittedValue)
         {
             this.submittedValue = submittedValue;
         }
 
         boolean isValid()
         {
             return valid;
         }
 
         void setValid(boolean valid)
         {
             this.valid = valid;
         }
 
         Object getValue()
         {
             return value;
         }
 
         void setValue(Object value)
         {
             this.value = value;
         }
 
         boolean isLocalValueSet()
         {
             return localValueSet;
         }
 
         void setLocalValueSet(boolean localValueSet)
         {
             this.localValueSet = localValueSet;
         }
     }
 
     /**
      * Inner class used to wrap the original events produced by child components in the tree.
      * This will allow the tree to find the appropriate component later when its time to
      * broadcast the events to registered listeners.  Code is based on a similar private
      * class for UIData.
      */
     private static class FacesEventWrapper extends FacesEvent
     {
         private static final long serialVersionUID = -3056153249469828447L;
         private FacesEvent _wrappedFacesEvent;
         private String _nodeId;
 
 
         public FacesEventWrapper(FacesEvent facesEvent, String nodeId, UIComponent component)
         {
             super(component);
             _wrappedFacesEvent = facesEvent;
             _nodeId = nodeId;
         }
 
 
         public PhaseId getPhaseId()
         {
             return _wrappedFacesEvent.getPhaseId();
         }
 
 
         public void setPhaseId(PhaseId phaseId)
         {
             _wrappedFacesEvent.setPhaseId(phaseId);
         }
 
 
         public void queue()
         {
             _wrappedFacesEvent.queue();
         }
 
 
         public String toString()
         {
             return _wrappedFacesEvent.toString();
         }
 
 
         public boolean isAppropriateListener(FacesListener faceslistener)
         {
             // this event type is only intended for wrapping a real event
             return false;
         }
 
 
         public void processListener(FacesListener faceslistener)
         {
             throw new UnsupportedOperationException("This event type is only intended for wrapping a real event");
         }
 
 
         public FacesEvent getFacesEvent()
         {
             return _wrappedFacesEvent;
         }
 
 
         public String getNodeId()
         {
             return _nodeId;
         }
     }
 
     /**
      * Returns true if there is an error message queued for at least one of the nodes.
      *
      * @param context FacesContext
      * @return whether an error message is present
      */
     private boolean keepSaved(FacesContext context)
     {
         Iterator clientIds = _saved.keySet().iterator();
         while (clientIds.hasNext())
         {
             String clientId = (String) clientIds.next();
             Iterator messages = context.getMessages(clientId);
             while (messages.hasNext())
             {
                 FacesMessage message = (FacesMessage) messages.next();
                 if (message.getSeverity().compareTo(FacesMessage.SEVERITY_ERROR) >= 0)
                 {
                     return true;
                 }
             }
         }
 
         return false;
     }
 
     /**
      * Toggle the expanded state of the current node.
      */
     public void toggleExpanded()
     {
         getDataModel().getTreeState().toggleExpanded(getNodeId());
     }
 
     /**
      * Indicates whether or not the current {@link TreeNode} is expanded.
      * @return boolean
      */
     public boolean isNodeExpanded()
     {
         return getDataModel().getTreeState().isNodeExpanded(getNodeId());
     }
 
     /**
      * Implements the {@link javax.faces.event.ActionListener} interface.  Basically, this
      * method is used to listen for node selection events (when a user has clicked on a
      * leaf node.)
      *
      * @param event ActionEvent
      */
     public void setNodeSelected(ActionEvent event)
     {
         getDataModel().getTreeState().setSelected(getNodeId());
     }
 
     /**
      * Indicates whether or not the current {@link TreeNode} is selected.
      * @return boolean
      */
     public boolean isNodeSelected()
     {
         return (getNodeId() != null) ? getDataModel().getTreeState().isSelected(getNodeId()) : false;
     }
     
     /**
      * 
      * {@inheritDoc}
      * 
      * @since 2.0
      */
     public String createUniqueId(FacesContext context, String seed)
     {
         StringBuilder bld = new StringBuilder();
 
         // Generate an identifier for a component. The identifier will be prefixed with UNIQUE_ID_PREFIX, and will be unique within this UIViewRoot. 
         if(seed==null)
         {
             Long uniqueIdCounter = (Long) getStateHelper().get(PropertyKeys.uniqueIdCounter);
             uniqueIdCounter = (uniqueIdCounter == null) ? 0 : uniqueIdCounter;
             getStateHelper().put(PropertyKeys.uniqueIdCounter, (uniqueIdCounter+1L));
             return bld.append(UIViewRoot.UNIQUE_ID_PREFIX).append(uniqueIdCounter).toString();
         }
         // Optionally, a unique seed value can be supplied by component creators which should be included in the generated unique id.
         else
         {
             return bld.append(UIViewRoot.UNIQUE_ID_PREFIX).append(seed).toString();
         }
     }
     
     enum PropertyKeys
     {
         uniqueIdCounter
     }
 }