import java.io.*; 
import javax.swing.*; 
import javax.swing.event.*;
import java.lang.*;
import java.net.URL;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
import javax.swing.text.html.parser.*;


public class htm3 extends JInternalFrame  {
 String s;
 Object o;
 static int i =0;
 static  JEditorPane pane = new JEditorPane();
 static JTextField t = new JTextField("",30);

 String st;
 //JFrame frame = new  JFrame();
 JPanel up = new  JPanel(new FlowLayout());
 JPanel down = new  JPanel(new FlowLayout());
 JPanel bottom=new JPanel(new FlowLayout());
 JPanel middle=new JPanel(new FlowLayout());
 final  JPanel verybottom=new JPanel(new FlowLayout());
 JPanel top=new JPanel(new FlowLayout());


 static Vector v = new Vector(20);
 Vector combo = new Vector();

 public htm3(String urlstring)
   {
     super("WebBrowser", true, true, true, true);  
     try{
      
        //pane = new JEditorPane();
        pane.setEditable(false);
        }catch (Exception e) {
        System.out.println("error1");
	}
        try
        { 
         pane.setPage(urlstring); 
        }catch (IOException e) {System.out.println("cannot set page"+e);}   
         
         pane.addHyperlinkListener(new HyperlinkListener() {
         public void hyperlinkUpdate(HyperlinkEvent ev) {
         if (ev.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
            {
            try{
           // i=i+1;
            String filname;
            int loopvar;
            char c='/';
              //pane.setPage(ev.getURL());
               URL url;
              url = ev.getURL();
              loadpage(url);
             st=url.toString();
                      }catch (Exception e1) {System.out.println("it is here");}
                   
                   
               //System.out.println(" i is incresed to "+i);

               }

                                  }
                 });
                 
 up.setLayout(new BorderLayout());
 up.add(bottom,BorderLayout.SOUTH);
 up.add(middle,BorderLayout.CENTER);
 bottom.setLayout(new BorderLayout());
 bottom.add(top,BorderLayout.NORTH);
 bottom.add(verybottom,BorderLayout.SOUTH);

         JButton b = new JButton("GO");
         JButton b1 = new JButton("HOME");
         JButton b2 = new JButton("<<BACK");
         JButton b3 = new JButton("BookMark");
       final   JComboBox com = new JComboBox(combo);



try {   
     BufferedReader DIS = new BufferedReader(new InputStreamReader(new FileInputStream("book.txt")));
     try {
     String cop = DIS.readLine();
       while (cop!=null)
     {
      combo.addElement(cop);
      //System.out.println("THe op is "+cop);
      cop=DIS.readLine();
      }}catch(EOFException eof){}
 } catch (IOException  e) { System.out.println("combo box error"+e);}

     getContentPane().add(up);
     up.add(new JScrollPane(pane),BorderLayout.CENTER);
     top.add(t);
     v.addElement(urlstring);
     t.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
          st = t.getText();
        }
        });

         
         
        top.add(b);        
        b.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
          
         try{
          i=i+1;
         v.addElement(st);
         pane.setPage(st);
           }catch (IOException e) {System.out.println("it is go button"+e);}   
        
        }
        });
        top.add(b1);
        
        
           b1.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
         try{
           pane.setPage(new String("http://www.npac.syr.edu/users/haupt/WebFlow/Help/Help.html"));
           t.setText("http://www.npac.syr.edu/users/haupt/WebFlow/Help/Help.html");
           }catch (IOException e) {System.out.println("it is home buton"+e);}   
        //System.out.println("Button pressed");
        }
        });
        
        top.add(b2);
        
         b2.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
         try{
        
        System.out.println("The value of  i at present>>"+i+"        "+v.size());
         
    Enumeration enum= v.elements();
    while (enum.hasMoreElements())
      System.out.println(enum.nextElement());

          if (i>0)
          {
           o = v.elementAt(i-1);
           System.out.println("the page to be disp --"+o.toString());
           pane.setPage(o.toString());
           t.setText(o.toString());
           if (v.elementAt(i)!=null)
           {
           o= v.elementAt(i);
           v.removeElement(o);
             System.out.println("i is decreased to   "+i);
	   }
              i=i-1;
	  }
          }catch (Exception e) {System.out.println("error is"+e);}   
        System.out.println("Button pressed");
        }
              });
        
        top.add(b3);
        
         b3.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
          
         try{
          DataOutputStream DOS = new DataOutputStream(new FileOutputStream("book.txt",true));
          String st1= t.getText();
          DOS.writeBytes(st1+"\n");
          com.addItem(st1);
            
          /*try {   
     BufferedReader DIS = new BufferedReader(new InputStreamReader(new FileInputStream("book.txt")));
     try {
     String cop = DIS.readLine();
       while (cop!=null)
     {
      combo.addElement(cop);
      //System.out.println("THe op is "+cop);
      cop=DIS.readLine();
      }}catch(EOFException eof){}
 } catch (IOException  e) { System.out.println(e);}*/
         //verybottom.add(com);

                
           }catch (IOException e) {System.out.println("file exceptio"+e);}   
       
        }
        });
        verybottom.add(com);
             
               com.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ev) {
         try{
          String cbox = (String)com.getSelectedItem();
          URL url1 = new URL(cbox);
           //pane.setPage(cbox);
           //t.setText(cbox);
           loadpage(url1 );
           }catch (IOException e) {System.out.println("this is the error"+e);}   
      
        }
        });

    
        

              
	       //frame.setSize(950,500);   
         show();
          
          
          
          
         }
       

static void loadpage(URL url){
  try {
              Reader r;
              boolean bad=false;
              String st = url.toString();
              HTMLEditorKit hk = new HTMLEditorKit();
              HTMLEditorKit.ParserCallback pc;
              HTMLDocument hd = new HTMLDocument();
              InputStreamReader isr = new InputStreamReader(url.openStream());
               pc =hd.getReader(1);

              ParserDelegator pd = new ParserDelegator();
              hk.read(isr,hd,0);
              ElementIterator it = new ElementIterator(hd);
              javax.swing.text.Element e = it.first();
              do {
              //System.out.println(e.getName());
                if (e.getName().equals("applet"))
                 {
                 bad=true;
                 System.out.println("this contains applets");
                  pane.setPage("http://osprey4.npac.syr.edu:8001/Browser/applet.html");                  
                  i=i+1;
                  v.addElement("http://osprey4.npac.syr.edu:8001/Browser/applet.html");
                 }
              //System.out.print(e.getElementCount()); 
              e=it.next();
             // System.out.println();
              }while (e!=null);
              
              if (bad==false)
              {
              pane.setPage(url);
               // i=i+1;

                  }
              
              t.setText(st);
              //System.out.println("The string is "+st);
              i=i+1;
              v.addElement(st);
                            System.out.println("i is increased to   "+i);
                             }catch (Exception e) {System.out.println("The error is obviously is "+e);
               try {
               //System.out.println("this contains applets");
              i=i+1;
                  pane.setPage("http://osprey4.npac.syr.edu:8001/Browser/applet.html");
                  v.addElement("http://osprey4.npac.syr.edu:8001/Browser/applet.html");
                  t.setText("http://osprey4.npac.syr.edu:8001/Browser/applet.html");
                      }catch (IOException e1) {System.out.println("it is here");}
                   
                   }

 }





   
 }
   
   
  /*class listen implements HyperlinkListener
   {
       
     }*/