import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.util.*;
public class Browser extends JApplet{
	public static String START_PAGE = "http://www.dn.se";
	public JTextField textField = null;
	public JEditorPane editorPane = null;
	public JButton prev = null;
	public JButton next = null;
	public String[] nav;
	public int pointer;
	public int size; 
	public void init(){
		try{
			nav = new String[100];
			pointer = 0;
			size = 1;
			editorPane = new JEditorPane(START_PAGE);
			editorPane.addHyperlinkListener(new LinkListener());
			nav[pointer] = editorPane.getPage().toString();
			textField = new JTextField(START_PAGE, 60);
			textField.addKeyListener(new ReturnListener());
			prev = new JButton("<");
			prev.setEnabled(false);
			prev.addActionListener(new PrevListener());
			next = new JButton(">");
			next.setEnabled(false);
			next.addActionListener(new NextListener());
			editorPane.setEditable(false);
			//FlowLayout Default
			JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEADING));
			panel.add(prev);
			panel.add(next);
			panel.add(textField);
			getContentPane().add(panel, BorderLayout.NORTH);
			getContentPane().add(new JScrollPane(editorPane), BorderLayout.CENTER);
		}catch(Exception e){
			editorPane.setText(e.toString());
		}
	}
	
	class PrevListener implements ActionListener{
		public void actionPerformed(ActionEvent e){
			if (pointer > 0){
				pointer--;
				try{
					editorPane.setPage(nav[pointer]);
					textField.setText(nav[pointer]);
				}catch(IOException ioe){
					editorPane.setText(ioe.toString());
				}
			}
			if (pointer == 0)
				prev.setEnabled(false);
			if (pointer + 2 == size)
				next.setEnabled(true);
		}
	}
	
	class NextListener implements ActionListener{
		public void actionPerformed(ActionEvent e){
			if (pointer + 2 == size)
				next.setEnabled(false);
			if (pointer == 0)
				prev.setEnabled(true);
			pointer++;
			try{
				editorPane.setPage(nav[pointer]);
				textField.setText(nav[pointer]);
			}catch(IOException ioe){
				editorPane.setText(ioe.toString());
			}			
		}
	}
	
	class ReturnListener implements KeyListener{
		public void keyPressed(KeyEvent e){
			if (e.getKeyCode() == e.VK_ENTER){
				try{
					editorPane.setPage(textField.getText());
				}catch(IOException ioe){
					editorPane.setText(ioe.toString());
				}
				pointer++;
				size++;
				nav[pointer] = textField.getText();
				if (pointer == 1)
					prev.setEnabled(true);
			  if (pointer + 1 < size){
					size = pointer + 1;
					next.setEnabled(false);
				}
			}
		}
		public void keyReleased(KeyEvent e){
		}
		public void keyTyped(KeyEvent e){
		}
	}
	
	class LinkListener implements HyperlinkListener{
		public void hyperlinkUpdate(HyperlinkEvent he){
			if (he.getEventType() == HyperlinkEvent.EventType.ACTIVATED){
				if ((he.getURL()).getRef() == null){
					try{
						editorPane.setPage(he.getURL());
						textField.setText(he.getURL().toString());
					}catch(IOException ioe){
						editorPane.setText(ioe.toString());
					}
					pointer++;
					size++;
					nav[pointer] = he.getURL().toString();
					if (pointer == 1)
						prev.setEnabled(true);
					if (pointer + 1 < size){
						size = pointer + 1;
						next.setEnabled(false);
					}
				}
				else
					editorPane.scrollToReference((he.getURL()).getRef());
			}
		}
	}
}