Name: skT88420 Date: 08/31/99


Two versions of an applet are included; one for AppletViewer and one for Netscape (requires the 1.2.2 plugin).

The applet creates a split pane, scrollable on the left with a JTree, and JEditorPane on the right.

Clicking on a leaf loads an HTML document in the JEditorPane window.

The applet works until the page is reloaded. Then the JEditor pane displays TEXT instead of interpreting the HTML.

***BEGIN CODE (refernced files not included)***

import javax.swing.*;
import javax.swing.JApplet;
import javax.swing.text.EditorKit;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.event.TreeSelectionListener;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.tree.TreeSelectionModel;
import java.net.URL;
import java.net.MalformedURLException;
import java.net.*;
import java.io.*;
import java.io.IOException;
import javax.swing.JEditorPane;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.*;

public class NetscapeOption extends JApplet {

  private JFrame frame;
  private JEditorPane htmlPane;
  private DefaultMutableTreeNode top;
  
  
  

public void init() {

// Force SwingApplet to come up in the System L&F
String laf = UIManager.getSystemLookAndFeelClassName();

try {
UIManager.setLookAndFeel(laf);
//If you want the Cross Platform L&F instead, comment out the above line and
//uncomment the following:
// UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
} catch (UnsupportedLookAndFeelException exc) {
System.err.println("Warning: UnsupportedLookAndFeel: " + laf);
} catch (Exception exc) {
System.err.println("Error loading " + laf + ": " + exc);
};
  
    frame = new JFrame("Netscape Options");
  
    //Create Nodes.
    top = new DefaultMutableTreeNode("Netscape Navigator");
  
  
    //Create a tree allowing one selection at a time
    final JTree tree = new JTree(top);
  
    //Create a scrollpane and add the tree to it
    JScrollPane optionView = new JScrollPane(tree);
    
    //Create the pane to view the HTML
    
    htmlPane = new JEditorPane();
    
    //htmlPane.setContentType("text/html");
    
    //setContentPane didn't work. Trying the hard way.
    EditorKit kit1 = htmlPane.getEditorKitForContentType("text/html");
    htmlPane.setEditorKit(kit1);
    
    
    
    
    htmlPane.setEditable(false);
  
    JScrollPane htmlView = new JScrollPane(htmlPane);
  
    //Add panes to a split pane
    JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
    splitPane.setTopComponent(optionView);
    splitPane.setBottomComponent(htmlPane);
    
    splitPane.setDividerLocation(150);
    splitPane.setPreferredSize(new Dimension(795, 475));
    
    //Add split pane to the frame
    getContentPane().add(splitPane, BorderLayout.CENTER);
    
    tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
  
  //Listen for when selection changes.
  tree.addTreeSelectionListener(new TreeSelectionListener() {
      
    public void valueChanged(TreeSelectionEvent e) {
      
      DefaultMutableTreeNode node = (DefaultMutableTreeNode)tree.getLastSelectedPathComponent();
        
      if (node == null) return;
        
      Object nodeInfo = node.getUserObject();
      
      System.out.println(nodeInfo);
        
      if (node.isLeaf()) {
      
        //System.out.println("You Clicked on a leaf!!!");
        BookInfo book = (BookInfo)nodeInfo;
        displayURL(book.bookURL);
          
        
          
      }
        
    }
  
  
  
  
  });
  
    frame.pack();
    frame.setVisible(true);
   }
   
   public void start() {
    
    createNodes(top);
    
    
  
        
}




  
  private class BookInfo {
  
  public String bookName;
  public URL bookURL;
  //public String prefix = "file:" + System.getProperty("user.dir") + System.getProperty("file.separator");
    
  public BookInfo(String book, String filename) {
    
    //System.out.println(getCodeBase());
    
    bookName = book;
    try {
      
      bookURL = new URL(getCodeBase() + filename);
    } catch (java.net.MalformedURLException exc) {
      
      System.err.println("Attempted to create a record with a bad URL: " + bookURL);
      bookURL = null;
    }
  }
    
  public String toString() {
      
   return bookName;
  }
      
}

  private void displayURL(URL url) {
  
    try {
      
      //Attempts to explicitly set editor
      htmlPane.setContentType("text/html");
      
      //Checks editor type ***NOTICE*** on reload, switches from
      //HTML to TEXT
      System.out.println(htmlPane.getContentType());
      
      htmlPane.setPage(url);
      
    } catch (IOException e) {
    
      System.err.println("Attempted to read a bad URL: " + url);
    }
  }
  
  private void createNodes(DefaultMutableTreeNode top) {
  
    DefaultMutableTreeNode category = null;
    DefaultMutableTreeNode subcategory = null;
    DefaultMutableTreeNode book = null;
    
    category = new DefaultMutableTreeNode("Navigator");
    top.add(category);
    
    subcategory = new DefaultMutableTreeNode("APPEARANCE");
    category.add(subcategory);
    
    book = new DefaultMutableTreeNode(new BookInfo("General", "1navappgen.html"));
    subcategory.add(book);
    
    book = new DefaultMutableTreeNode(new BookInfo("Fonts", "2navappfonts.html"));
    subcategory.add(book);
    
    book = new DefaultMutableTreeNode(new BookInfo("Colors", "3navappcolors.html"));
    subcategory.add(book);
    
    subcategory = new DefaultMutableTreeNode("NAVIGATOR");
    category.add(subcategory);
    
    book = new DefaultMutableTreeNode(new BookInfo("General", "4navnavgen.html"));
    subcategory.add(book);
    
  }
  

}

***END CODE***

java version "1.2.2"
Classic VM (build JDK-1.2.2-W, native threads, symcjit)

java full version "JDK-1.2.2-W"
(Review ID: 94670)
======================================================================