/**Class Browser is a simple Java Browser
*for retrieving information without interpreting it.
*Internet Programming 1 - Course
*@author Martin Carlsson
*/
import javax.swing.*;
import java.awt.*;
import java.net.*;
import java.io.*;
import java.awt.event.*;


public class Browser extends JFrame {

    
    private JTextField urlField; 
    private String oldTextArea, defaultUrl = "http://www.dsv.su.se/~pierre/";
    private JButton jb;
    private JTextArea  textArea ;
    
    Browser() {
        super("Java Web browser");
        // North panel
        Container con = getContentPane();
        JPanel up = new JPanel();
        up.setLayout(new FlowLayout(FlowLayout.CENTER));
        up.setBackground(Color.lightGray);
        up.add(urlField = new JTextField(55));
        urlField.setText(defaultUrl);
        urlField.requestFocus();
        urlField.addActionListener(new EnterButtonListener()); // Adds a listener for the text field
        up.add(jb = new JButton("Get url"));
        jb.addActionListener(new EnterButtonListener()); // Listener for the button
        con.add(up, BorderLayout.NORTH);
        
        
        // Middle text area
        textArea=new JTextArea();
        JScrollPane jsp=new JScrollPane(textArea);
        con.add(jsp,BorderLayout.CENTER);
        setDefaultCloseOperation( EXIT_ON_CLOSE );
        
        
        // Size of the frame
        setSize(800,600);
        show(); 
        
        
        // retrieving information from wherever the defaultURL points to
        try {
            URL u = new URL(urlField.getText());
            InputStream in = u.openStream();
            in = new BufferedInputStream(in);
            Reader r = new InputStreamReader(in);
            int c;
            while((c = r.read()) != -1)
                textArea.setText(textArea.getText() + (char)c);
        }
        catch(Exception e){
            textArea.setText(textArea.getText()+e+" (something wrong with either your"+ 
            " Internet connection or the address you're trying to look up!)");
        }
    } 
    
    
    // Called at each actionEvent to empty the text area
    public void clearTextArea() {
        
        textArea.setText(" ");
    }
    
    
    // Listener class that listens to when users press "GET URL" or "Enter"
    class  EnterButtonListener implements ActionListener {
        
        public void actionPerformed(ActionEvent ae) {
        
            try {
                clearTextArea(); 
                URL u = new URL(urlField.getText());
                InputStream in = u.openStream();
                in = new BufferedInputStream(in);
                Reader r = new InputStreamReader(in);
                int c;
                while((c = r.read()) != -1)
                textArea.setText(textArea.getText() + (char)c);
            }
            catch(UnknownHostException uHe){
                textArea.setText(textArea.getText() + uHe);
            }
            catch(MalformedURLException mUe){
                textArea.setText(textArea.getText() + mUe);
            }
            catch(IOException iE){
                textArea.setText(textArea.getText() + iE);
            }
            
        } 
    } // End EnterButtonListenerklassen
    
    
    
    //Main
    public static void main(String[] args)  throws IOException {
        new Browser();
    }
}//End Browserklassen