import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.net.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
public class WebBrowser
{
     public static void main(String [] args)
     {
          JFrame frame = new EditorPaneFrame();
          frame.show();
     }
}
class EditorPaneFrame extends JFrame
{
     private JTextField url;
     private JCheckBox editable;
     private JButton Carica;
     private JButton Indietro;
     private JEditorPane editorPane;
     private Stack urlStack = new Stack();
     public EditorPaneFrame()
     {
          setTitle("Java Web Browser");
          setSize(600,400);
          setLocationRelativeTo(null);
          setVisible(true);
          // set up text field and load button for typing in URL
          String protocollo = new String ("http://");
          url = new JTextField(protocollo,30);
          Carica = new JButton("Load");
          Carica.addActionListener(new ActionListener()
          {
               public void actionPerformed(ActionEvent event)
               {
                    try
                    {
                         // remember URL for back button
                         urlStack.push(url.getText());
                         editorPane.setPage(url.getText());
                    }
                    catch(Exception e)
                    {
                         editorPane.setText("Error: " +e);
                    }
               }
          });
          // set up back button and button action
          Indietro = new JButton("Back");
          Indietro.addActionListener(new ActionListener()
          {
               public void actionPerformed(ActionEvent event)
               {
                    if(urlStack.size()<=1) return;
                    try
                    {
                         urlStack.pop();
                         String urlString = (String)urlStack.peek();
                         url.setText(urlString);
                         editorPane.setPage(urlString);
                    }
                    catch(IOException e)
                    {
                         editorPane.setText("Error : " +e);
                    }
               }
          });
          editorPane = new JEditorPane();
          editorPane.setEditable(false);
          editorPane.addHyperlinkListener(new HyperlinkListener()
          {
               public void hyperlinkUpdate(HyperlinkEvent event)
               {
                    if(event.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
                    {
                         try
                         {
                              urlStack.push(event.getURL().toString());
                              url.setText(event.getURL().toString());
                              editorPane.setPage(event.getURL());
                         }
                         catch(IOException e)
                         {
                              editorPane.setText("Error: " + e);
                         }
                    }
               }
          });
          editable = new JCheckBox();
          editable.addActionListener(new ActionListener()
          {
               public void actionPerformed(ActionEvent event)
               {
                    editorPane.setEditable(editable.isSelected());
               }
          });
          Container contentPane = getContentPane();
			contentPane.add(new JScrollPane(editorPane), "Center");
			JPanel panel = new JPanel();
			panel.add(Indietro);
			panel.add(new JLabel("URL"));
			panel.add(url);
			panel.add(Carica);
			contentPane.add(panel,"North");
     }
}