/*
    * 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.model;
  
  import org.apache.myfaces.custom.tree.DefaultMutableTreeNode;
  import org.apache.myfaces.custom.tree.MutableTreeNode;
  import org.apache.myfaces.custom.tree.TreeNode;
  
  import java.io.Serializable;
  import java.util.Iterator;
  import java.util.Collection;
  import java.util.LinkedList;
  
  
  /**
   * @author <a href="mailto:oliver@rossmueller.com">Oliver Rossmueller</a>
   * @version $Revision: 472638 $ $Date: 2006-11-08 15:54:13 -0500 (Wed, 08 Nov 2006) $
   */
  public class DefaultTreeModel
          implements TreeModel, Serializable
  {
  
      private TreeNode root;
      private LinkedList listeners = new LinkedList();
  
  
      public DefaultTreeModel()
      {
          this(new DefaultMutableTreeNode("Root"));
      }
  
  
      public DefaultTreeModel(TreeNode root)
      {
          this.root = root;
      }
  
  
      public Object getRoot()
      {
          return root;
      }
  
  
      public Object getChild(Object parent, int index)
      {
          return ((TreeNode)parent).getChildAt(index);
      }
  
  
      public int getChildCount(Object parent)
      {
          return ((TreeNode)parent).getChildCount();
      }
  
  
      public boolean isLeaf(Object node)
      {
          return ((TreeNode)node).isLeaf();
      }
  
  
      public void valueForPathChanged(TreePath path, Object newValue)
      {
          MutableTreeNode node = (MutableTreeNode)path.getLastPathComponent();
  
          node.setUserObject(newValue);
      }
  
  
      public int getIndexOfChild(Object parent, Object child)
      {
          return ((TreeNode)parent).getIndex((TreeNode)child);
      }
  
  
      public Collection getTreeModelListeners()
      {
          return listeners;
      }
  
  
      /**
      * Invoke this method after you've changed how node is to be
      * represented in the tree.
      */
     public void nodeChanged(TreeNode node)
     {
         if (listeners.isEmpty())
         {
             // nobody cares
             return;
         }
 
         if (node != null)
         {
             TreeNode parent = node.getParent();
 
             if (parent != null)
             {
                 int index = parent.getIndex(node);
                 if (index != -1)
                 {
                     int[] childIndices = new int[1];
 
                     childIndices[0] = index;
                     nodesChanged(parent, childIndices);
                 }
             }
             else if (node == getRoot())
             {
                 nodesChanged(node, null);
             }
         }
     }
 
 
     /**
      * Invoke this method after you've changed how the children identified by
      * childIndicies are to be represented in the tree.
      */
     public void nodesChanged(TreeNode node, int[] childIndices)
     {
         if (listeners.isEmpty())
         {
             // nobody cares
             return;
         }
 
         if (node != null)
         {
             if (childIndices != null)
             {
                 int count = childIndices.length;
 
                 if (count > 0)
                 {
                     Object[] children = new Object[count];
 
                     for (int i = 0; i < count; i++)
                     {
                         children[i] = node.getChildAt(childIndices[i]);
                     }
                     fireTreeNodesChanged(this, getPathToRoot(node), childIndices, children);
                 }
             }
             else if (node == root)
             {
                 fireTreeNodesChanged(this, getPathToRoot(node), null, null);
             }
         }
     }
 
 
     /**
      * Invoke this method if you've totally changed the children of
      * node and its childrens children...  This will post a
      * treeStructureChanged event.
      */
     public void nodeStructureChanged(TreeNode node)
     {
         if (listeners.isEmpty())
         {
             // nobody cares
             return;
         }
 
         if (node != null)
         {
             fireTreeStructureChanged(this, getPathToRoot(node), null, null);
         }
     }
 
 
     /**
      * Invoke this method after you've inserted some TreeNodes into
      * node.  childIndices should be the index of the new elements and
      * must be sorted in ascending order.
      */
     public void nodesWereInserted(TreeNode node, int[] childIndices)
     {
         if (listeners.isEmpty())
         {
             // nobody cares
             return;
         }
         if (node != null && childIndices != null && childIndices.length > 0)
         {
             int cCount = childIndices.length;
             Object[] newChildren = new Object[cCount];
 
             for (int counter = 0; counter < cCount; counter++)
             {
                 newChildren[counter] = node.getChildAt(childIndices[counter]);
             }
             fireTreeNodesInserted(this, getPathToRoot(node), childIndices,
                                   newChildren);
         }
     }
 
 
     /**
      * Invoke this method after you've removed some TreeNodes from
      * node.  childIndices should be the index of the removed elements and
      * must be sorted in ascending order. And removedChildren should be
      * the array of the children objects that were removed.
      */
     public void nodesWereRemoved(TreeNode node, int[] childIndices, Object[] removedChildren)
     {
         if (listeners.isEmpty())
         {
             // nobody cares
             return;
         }
         if (node != null && childIndices != null)
         {
             fireTreeNodesRemoved(this, getPathToRoot(node), childIndices, removedChildren);
         }
     }
 
 
     /**
      * Collect all parent nodes up to the root node.
      *
      * @param node the TreeNode to get the path for
      */
     public TreeNode[] getPathToRoot(TreeNode node)
     {
         return getPathToRoot(node, 0);
     }
 
 
     /**
      * Recursivly collect parent nodes up the the root node.
      *
      * @param node  the TreeNode to get the path for
      * @param depth number of steps already taken towards the root (on recursive calls)
      * @return an array giving the path from the root to the specified node
      */
     protected TreeNode[] getPathToRoot(TreeNode node, int depth)
     {
         TreeNode[] answer;
 
         if (node == null)
         {
             if (depth == 0)
             {
                 // nothing to do
                 return null;
             }
             else
             {
                 // end recursion
                 answer = new TreeNode[depth];
             }
         }
         else
         {
             // recurse
             depth++;
 
             if (node == root)
             {
                 // we found the root node
                 answer = new TreeNode[depth];
             }
             else
             {
                 answer = getPathToRoot(node.getParent(), depth);
             }
             answer[answer.length - depth] = node;
         }
         return answer;
     }
 
 
     /**
      * Notify all listeners of a node change.
      *
      * @param source       the node being changed
      * @param path         the path to the root node
      * @param childIndices the indices of the changed elements
      * @param children     the changed elements
      */
     protected void fireTreeNodesChanged(Object source, Object[] path, int[] childIndices, Object[] children)
     {
         TreeModelEvent event = null;
         for (Iterator iterator = listeners.iterator(); iterator.hasNext();)
         {
             TreeModelListener listener = (TreeModelListener)iterator.next();
             if (event == null)
             {
                 event = new TreeModelEvent(source, path, childIndices, children);
             }
             listener.treeNodesChanged(event);
         }
     }
 
 
     /**
      * Notify all listeners of structure change.
      *
      * @param source       the node where new elements are being inserted
      * @param path         the path to the root node
      * @param childIndices the indices of the new elements
      * @param children     the new elements
      */
     protected void fireTreeNodesInserted(Object source, Object[] path, int[] childIndices, Object[] children)
     {
         TreeModelEvent event = null;
         for (Iterator iterator = listeners.iterator(); iterator.hasNext();)
         {
             TreeModelListener listener = (TreeModelListener)iterator.next();
             if (event == null)
             {
                 event = new TreeModelEvent(source, path, childIndices, children);
             }
             listener.treeNodesInserted(event);
         }
     }
 
 
     /**
      * Notify all listeners of structure change.
      *
      * @param source       the node where elements are being removed
      * @param path         the path to the root node
      * @param childIndices the indices of the removed elements
      * @param children     the removed elements
      */
     protected void fireTreeNodesRemoved(Object source, Object[] path, int[] childIndices, Object[] children)
     {
         TreeModelEvent event = null;
         for (Iterator iterator = listeners.iterator(); iterator.hasNext();)
         {
             TreeModelListener listener = (TreeModelListener)iterator.next();
             if (event == null)
             {
                 event = new TreeModelEvent(source, path, childIndices, children);
             }
             listener.treeNodesRemoved(event);
         }
     }
 
 
     /**
      * Notify all listeners of structure change.
      *
      * @param source       the node where the tree model has changed
      * @param path         the path to the root node
      * @param childIndices the indices of the affected elements
      * @param children     the affected elements
      */
     protected void fireTreeStructureChanged(Object source, Object[] path, int[] childIndices, Object[] children)
     {
         TreeModelEvent event = null;
         for (Iterator iterator = listeners.iterator(); iterator.hasNext();)
         {
             TreeModelListener listener = (TreeModelListener)iterator.next();
             if (event == null)
             {
                 event = new TreeModelEvent(source, path, childIndices, children);
             }
             listener.treeStructureChanged(event);
         }
     }
 
 
     /**
      * Notify all listeners of structure change.
      *
      * @param source the node where the tree model has changed
      * @param path   the path to the root node
      */
     protected void fireTreeStructureChanged(Object source, TreePath path)
     {
         TreeModelEvent event = null;
         for (Iterator iterator = listeners.iterator(); iterator.hasNext();)
         {
             TreeModelListener listener = (TreeModelListener)iterator.next();
             if (event == null)
             {
                 event = new TreeModelEvent(source, path);
             }
             listener.treeStructureChanged(event);
         }
     }
 
 }