treeexpantionlistener.java

一个可以存储和打印成绩单的系统

package org.minjey.cjsjk.view.tree;

import java.util.Enumeration;

import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeWillExpandListener;
import javax.swing.tree.ExpandVetoException;

import org.minjey.cjsjk.model.Major;
import org.minjey.cjsjk.view.tree.node.MyTreeNode;

public class TreeExpantionListener implements TreeWillExpandListener {

	public void treeWillCollapse(TreeExpansionEvent e) throws ExpandVetoException {
		
	}

	public void treeWillExpand(TreeExpansionEvent e) throws ExpandVetoException {
		MyTreeNode node = (MyTreeNode)e.getPath().getLastPathComponent();
		node.buildChildNodes();
		Enumeration ec = node.children();
		while(ec.hasMoreElements()) {
			MyTreeNode cn = (MyTreeNode)ec.nextElement();
			if(!(cn.getUserObject() instanceof Major)) {
				cn.buildChildNodes();
			} else {
				cn.setVirtualChild();
			}
		}
	}

}