treeframe.java

关于数据结构的JAVA源代码

package filetree;

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

public class TreeFrame extends JFrame {
  private JPanel contentPane;
  private BorderLayout borderLayout1 = new BorderLayout();
  private JScrollPane jScrollPane1 = new JScrollPane();
  private JButton jButton2 = new JButton();
  private JTree jTree1 ;

  //Construct the frame
  public TreeFrame() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception  {
    //setIconImage(Toolkit.getDefaultToolkit().createImage(TreeFrame.class.getResource("[Your Icon]")));
    contentPane = (JPanel) this.getContentPane();
    jButton2.setText("jButton2");
    contentPane.setLayout(borderLayout1);
    this.setSize(new Dimension(525, 469));
    this.setTitle("Frame Title");
    initTree("C:\\");
    contentPane.add(jScrollPane1, BorderLayout.CENTER);
    jScrollPane1.getViewport().add(jTree1, null);
    this.setVisible(true) ;
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
  }
  //Overridden so we can exit when window is closed
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }
  void initTree(String dir){
    FileTreeNode root=(FileTreeNode)buildTree(dir);
    DefaultTreeModel treemodel=new DefaultTreeModel(root);
    jTree1=new JTree(treemodel);
    MyTreeExpansionListener listener=new MyTreeExpansionListener(jTree1,root,treemodel,this);
    jTree1.addTreeExpansionListener(listener);
  }
  public TreeNode buildTree(String dir){
    FileTreeNode root=new FileTreeNode(new File(dir));
    root.readTree(false);
    return (TreeNode)root;
  }
  class FileTreeNode extends DefaultMutableTreeNode{
    boolean isAdded;
    public  FileTreeNode(File file){
      super(file);
      isAdded=false;
    }
    public boolean readTree(){
      return readTree(false);
    }
    public boolean readTree(boolean b){
      if (isAdded) return false;
      String list[]=getFileObject().list();
      if(list!=null){
        for(int i=0;i<list.length;i++){
          FileTreeNode subnode=new FileTreeNode(new File(getFileObject(),list[i]));
          add(subnode);
          if(b){
            subnode.readTree(b);

          }
        }
    }
    isAdded=true;
    return true;
    }
    public File getFileObject(){
      return (File)getUserObject();
    }
    public String toString(){
      File file=getFileObject();
      return file.getName().length()>0?file.getName():file.getPath();
    }
    public boolean isLeaf(){
      return ((File)userObject).isFile();
    }

  }
  class MyTreeExpansionListener implements TreeExpansionListener {
    FileTreeNode root;
    JTree jtree;
    DefaultTreeModel treemodel;
    JFrame frame;
    public MyTreeExpansionListener(JTree tree,FileTreeNode node,DefaultTreeModel tmodel,JFrame theFrame){
      root=node;
      jtree=tree;
      treemodel=tmodel;
      frame=theFrame;
    }
    //Called whenever an item in the tree has been expanded
    public void treeExpanded(TreeExpansionEvent event){
      TreePath path=event.getPath();
      FileTreeNode node=(FileTreeNode)path.getLastPathComponent();
      frame.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR ));
      frame.setEnabled(false);
      if(node.readTree(false)){
        int childrenIdx[]=new int[node.getChildCount()];
        int i=0;
        for(Enumeration e=node.children();e.hasMoreElements();){
          Object obj=e.nextElement();
          childrenIdx[i]=node.getIndex((TreeNode)obj) ;
          i++;
        }
        treemodel.nodesWereInserted(node,childrenIdx);

      }
      frame.setEnabled(true);
      frame.setCursor(Cursor.getDefaultCursor());
    }
    //Called whenever ab item in the tree has been collapsed
    public void treeCollapsed(TreeExpansionEvent event){
    }
  }
}