abstractconfigtreenode.java

来自「swing编写的库存管理程序。毕业设计类」· Java 代码 · 共 206 行

/**
 * ========================================
 * JFreeReport : a free Java report library
 * ========================================
 *
 * Project Info:  http://www.jfree.org/jfreereport/index.html
 * Project Lead:  Thomas Morgner ([e-mail]);
 *
 * (C) Copyright 2000-2003, by Simba Management Limited and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * ------------------------------
 * AbstractConfigTreeNode.java
 * ------------------------------
 * (C)opyright 2003, by Thomas Morgner and Contributors.
 *
 * Original Author:  Thomas Morgner;
 * Contributor(s):   David Gilbert (for Simba Management Limited);
 *
 * $Id: AbstractConfigTreeNode.java,v 1.6 2003/11/07 18:33:52 taqua Exp $
 *
 * Changes 
 * -------------------------
 * 28.08.2003 : Initial version
 *  
 */

package org.jfree.report.modules.gui.config.model;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import javax.swing.tree.TreeNode;

/**
 * An abstract base implementation of the config tree node interface.
 * The implementation provides all base services needed to have an
 * valid TreeNode.
 * 
 * @author Thomas Morgner
 */
public abstract class AbstractConfigTreeNode implements ConfigTreeNode
{
  /** The list of tree nodes that act as childs. */
  private final ArrayList childs;
  /** The name of this node. */
  private final String name;
  /** The parent of this node or null, if this is the root node. */
  private TreeNode parent;

  /**
   * Creates a new config tree node with the given name. The node will
   * be able to have child nodes.
   * 
   * @param name the name of the node.
   */
  public AbstractConfigTreeNode(final String name)
  {
    childs = new ArrayList();
    this.name = name;
  }

  /**
   * Adds the given node to the tree model.
   * 
   * @param node the new node that should be added.
   */
  public void add (final ConfigTreeNode node)
  {
    if (node == null)
    {
      throw new NullPointerException();
    }
    if (childs.contains(node) == false)
    {
      childs.add (node);
      node.setParent(this);
    }
  }

  /**
   * Removes all child nodes.
   *
   */
  protected void reset ()
  {
    for (int i = 0; i < childs.size(); i++)
    {
      final ConfigTreeNode node = (ConfigTreeNode) childs.get(i);
      node.setParent(null);
    }
    childs.clear();
  }
  
  /**
   * Returns the child <code>TreeNode</code> at index
   * <code>childIndex</code>.
   * 
   * @param childIndex the index of the child node within this parent node.
   * @return the child node.
   */
  public TreeNode getChildAt(final int childIndex)
  {
    return (TreeNode) childs.get(childIndex);
  }

  /**
   * Returns the number of children <code>TreeNode</code>s the receiver
   * contains.
   * 
   * @return the number of child nodes.
   */
  public int getChildCount()
  {
    return childs.size();
  }

  /**
   * Returns true if the receiver allows children.
   * 
   * @return true, if this node allows child nodes.
   */
  public boolean getAllowsChildren()
  {
    return true;
  }

  /**
   * Returns the index of <code>node</code> in the receivers children.
   * If the receiver does not contain <code>node</code>, -1 will be
   * returned.
   * 
   * @param node the suspected child node.
   * @return the index of the given node or -1 if the node is not
   * contained in this node.
   */
  public int getIndex(final TreeNode node)
  {
    return childs.indexOf(node);
  }

  /**
   * Returns true if the receiver is a leaf.
   * 
   * @return true, if this node is a leaf node, false otherwise.
   */
  public boolean isLeaf()
  {
    return false;
  }

  /**
   * Returns the children of the receiver as an <code>Enumeration</code>.
   * 
   * @return all childs as enumeration.
   */
  public Enumeration children()
  {
    return Collections.enumeration(childs);
  }

  /**
   * Return the name of the node. 
   * @see org.jfree.report.modules.gui.config.model.ConfigTreeNode#getName()
   * 
   * @return the name of the node.
   */
  public String getName()
  {
    return name;
  }

  /**
   * Return the parent of this node or null if there is no parent. 
   * @see javax.swing.tree.TreeNode#getParent()
   * 
   * @return the parent
   */
  public TreeNode getParent()
  {
    return parent;
  }

  /**
   * Defines the parent of this node, or null if the node should not have a 
   * parent. 
   *
   * @param parent the new parent or null.
   */
  public void setParent(final TreeNode parent)
  {
    this.parent = parent;
  }
}