extendsdefaulttreecellrenderer.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.*;

/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class ExtendsDefaultTreeCellRenderer  
{
	JFrame jf = new JFrame("根据节点类型定义图标");

	JTree tree;
	//定义几个初始节点
	DefaultMutableTreeNode root = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.ROOT , "数据库导航")); 
	DefaultMutableTreeNode salaryDb = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.DATABASE , "公司工资数据库"));
	DefaultMutableTreeNode customerDb = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.DATABASE , "公司客户数据库"));
	//定义salaryDb的两个子节点
	DefaultMutableTreeNode employee = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.TABLE , "员工表"));
	DefaultMutableTreeNode attend = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.TABLE , "考勤表"));
	//定义customerDb的一个子节点
	DefaultMutableTreeNode contact = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.TABLE , "联系方式表"));

	//定义employee的三个子节点
	DefaultMutableTreeNode id = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.INDEX , "员工ID"));
	DefaultMutableTreeNode name = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.COLUMN , "姓名"));
	DefaultMutableTreeNode gender = new DefaultMutableTreeNode(
		new NodeData(DBObjectType.COLUMN , "性别"));

	public void init()throws Exception
	{
		//通过add方法建立树节点之间的父子关系
		root.add(salaryDb);
		root.add(customerDb);
		salaryDb.add(employee);
		salaryDb.add(attend);
		customerDb.add(contact);
		employee.add(id);
		employee.add(name);
		employee.add(gender);
		//以根节点创建树
		tree = new JTree(root);
		
		//设置该JTree使用自定义的节点绘制器
		tree.setCellRenderer(new MyRenderer());
	
		//设置是否显示根节点的“展开/折叠”图标,默认是false
		tree.setShowsRootHandles(true);
		//设置节点是否可见,默认是true
		tree.setRootVisible(true);

		//设置使用Windows风格外观
		UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
		//更新JTree的UI外观
		SwingUtilities.updateComponentTreeUI(tree);

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

    public static void main(String[] args) throws Exception
    {
		new ExtendsDefaultTreeCellRenderer().init();
    }
}
//定义一个NodeData类，用于封装节点数据
class NodeData
{
	public int nodeType;
	public String nodeData;
	public NodeData(int nodeType , String nodeData)
	{
		this.nodeType = nodeType;
		this.nodeData = nodeData;
	}
	public String toString()
	{
		return nodeData;
	}
}
//定义一个接口，该接口里包含数据库对象类型的常量
interface DBObjectType
{
	int ROOT = 0;
	int DATABASE = 1;
	int TABLE = 2;
	int COLUMN = 3;
	int INDEX = 4;
}
class MyRenderer extends DefaultTreeCellRenderer
{
	//初始化5个图标
	ImageIcon rootIcon = new ImageIcon("icon/root.gif");
	ImageIcon databaseIcon = new ImageIcon("icon/database.gif");
	ImageIcon tableIcon = new ImageIcon("icon/table.gif");
	ImageIcon columnIcon = new ImageIcon("icon/column.gif");
	ImageIcon indexIcon = new ImageIcon("icon/index.gif");

	public Component getTreeCellRendererComponent(JTree tree, Object value,
		boolean sel, boolean expanded,  boolean leaf, int row, boolean hasFocus)
	{
		//执行父类默认的节点绘制操作
		super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);

		DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
		NodeData data = (NodeData)node.getUserObject();
		//根据数据节点里的nodeType数据决定节点图标
		ImageIcon icon = null;
		switch(data.nodeType)
		{
			case DBObjectType.ROOT:
				icon = rootIcon;
				break;
			case DBObjectType.DATABASE:
				icon = databaseIcon;
				break;
			case DBObjectType.TABLE:
				icon = tableIcon;
				break;
			case DBObjectType.COLUMN:
				icon = columnIcon;
				break;
			case DBObjectType.INDEX:
				icon = indexIcon;
				break;
		}
		//改变图标
		this.setIcon(icon);
		return this;
	}
}