editjtree.java

疯狂Java讲义_源码(含Java设计模式CHM

import javax.swing.*;
import javax.swing.tree.*;
import java.awt.event.*;
import java.awt.*;

/**
 * @author  yeeku.H.lee [e-mail]
 * @version  1.0
 * <br>Copyright (C), 2005-2008, yeeku.H.Lee
 * <br>This program is protected by copyright laws.
 * <br>Program Name:
 * <br>Date: 
 */
public class EditJTree
{
	JFrame jf;

	JTree tree;
	//上面JTree对象对应的model
	DefaultTreeModel model;
	
	//定义几个初始节点
	DefaultMutableTreeNode root = new DefaultMutableTreeNode("中国"); 
	DefaultMutableTreeNode guangdong = new DefaultMutableTreeNode("广东");
	DefaultMutableTreeNode guangxi = new DefaultMutableTreeNode("广西");
	DefaultMutableTreeNode foshan = new DefaultMutableTreeNode("佛山");
	DefaultMutableTreeNode shantou = new DefaultMutableTreeNode("汕头");
	DefaultMutableTreeNode guilin = new DefaultMutableTreeNode("桂林");
	DefaultMutableTreeNode nanning = new DefaultMutableTreeNode("南宁");

	//定义需要被拖动的TreePath
	TreePath movePath;

    JButton addSiblingButton = new JButton("添加兄弟节点");
    JButton addChildButton = new JButton("添加子节点");
    JButton deleteButton = new JButton("删除节点");
    JButton editButton = new JButton("编辑当前节点");

	public void init()
	{
		guangdong.add(foshan);
		guangdong.add(shantou);
		guangxi.add(guilin);
		guangxi.add(nanning);
		root.add(guangdong);
		root.add(guangxi);
		
		jf = new JFrame("树");
		tree = new JTree(root);
		//获取JTree对应的TreeModel对象
		model = (DefaultTreeModel)tree.getModel();
		//设置JTree可编辑
		tree.setEditable(true);
		MouseListener ml = new MouseAdapter() 
		{
			//按下鼠标时候获得被拖动的节点
			public void mousePressed(MouseEvent e)
			{
				//如果需要唯一确定某个节点，必须通过TreePath来获取。
				TreePath tp = tree.getPathForLocation(e.getX(), e.getY());
				if (tp != null)
				{
					movePath = tp;
				}
			}
			//鼠标松开时获得需要拖到哪个父节点
			public void mouseReleased(MouseEvent e)
			{
				//根据鼠标松开时的TreePath来获取TreePath
				TreePath tp = tree.getPathForLocation(e.getX(), e.getY());

				if (tp != null && movePath != null)
				{
					//阻止向子节点拖动
					if (movePath.isDescendant(tp) && movePath != tp)
					{
						JOptionPane.showMessageDialog(jf, "目标节点是被移动节点的子节点，无法移动！", 
							"非法操作", JOptionPane.ERROR_MESSAGE );
						return;
					}
					//既不是向子节点移动，而且鼠标按下、松开的不是同一个节点
					else if (movePath != tp)
					{
						System.out.println(tp.getLastPathComponent());
						//add方法可以先将原节点从原父节点删除，再添加到新父节点中
						((DefaultMutableTreeNode)tp.getLastPathComponent()).add(
							(DefaultMutableTreeNode)movePath.getLastPathComponent());
						movePath = null;
						tree.updateUI();
					}
				}
			}
		};
		tree.addMouseListener(ml);

		JPanel panel = new JPanel();

		addSiblingButton.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				//获取选中节点
				DefaultMutableTreeNode selectedNode
					= (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
				//如果节点为空，直接返回
				if (selectedNode == null) return;
				//获取该选中节点的父节点
				DefaultMutableTreeNode parent
					= (DefaultMutableTreeNode)selectedNode.getParent();
				//如果父节点为空，直接返回
				if (parent == null) return;
				//创建一个新节点
				DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("新节点");
				//获取选中节点的选中索引
				int selectedIndex = parent.getIndex(selectedNode);
				//在选中位置插入新节点
				model.insertNodeInto(newNode, parent, selectedIndex + 1);
				//--------下面代码实现显示新节点（自动展开父节点）-------
				//获取从根节点到新节点的所有节点
				TreeNode[] nodes = model.getPathToRoot(newNode);
				//使用指定的节点数组来创建TreePath
				TreePath path = new TreePath(nodes);
				//显示指定TreePath
				tree.scrollPathToVisible(path);
			}
		});
		panel.add(addSiblingButton);

		addChildButton.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				//获取选中节点
				DefaultMutableTreeNode selectedNode
					= (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
				//如果节点为空，直接返回
				if (selectedNode == null) return;
				//创建一个新节点
				DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("新节点");
				//直接通过model来添加新节点，则无需通过调用JTree的updateUI方法
				//model.insertNodeInto(newNode, selectedNode, selectedNode.getChildCount());
				//直接通过节点添加新节点，则需要调用tree的updateUI方法
				selectedNode.add(newNode);
				//--------下面代码实现显示新节点（自动展开父节点）-------
				TreeNode[] nodes = model.getPathToRoot(newNode);
				TreePath path = new TreePath(nodes);
				tree.scrollPathToVisible(path);
				tree.updateUI();
			}
		});
		panel.add(addChildButton);

		deleteButton.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				DefaultMutableTreeNode selectedNode
					= (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
				if (selectedNode != null && selectedNode.getParent() != null)
				{
					//删除指定节点
					model.removeNodeFromParent(selectedNode);
				}
			}
		});
		panel.add(deleteButton);

		editButton.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				TreePath selectedPath = tree.getSelectionPath();
				if (selectedPath != null)
				{
					//编辑选中节点
					tree.startEditingAtPath(selectedPath);
				}
			}
		});
		panel.add(editButton);

		jf.add(new JScrollPane(tree));
		jf.add(panel , BorderLayout.SOUTH);
		jf.pack();
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.setVisible(true);
	}

    public static void main(String[] args) 
    {
        new EditJTree().init();
    }
}