package com.macfaq;

import java.beans.*;
import java.awt.*;
import java.net.*;
import java.io.*;
import java.awt.event.*;
import java.awt.image.*;


public class URLWatcher extends Panel 
 implements Runnable {

  protected URL url = null;
  protected int interval = 0;

  protected TextField theURL = new TextField();
  protected TextArea thePage = new TextArea(20, 60);
  protected Button reloadButton = new Button("Reload");
  protected ImageCanvas theImage = new ImageCanvas(); 
  protected Label URLLabel = new Label("URL: ");

  // either thePage or theImage, depending on whether
  // or not we're looking at an image or a text page
  private Component loaded = thePage;

  public void setURL(URL url) {
    try {
      this.url = new URL(url.toString());
      theURL.setText(url.toString());
      reload();
    }
    catch (MalformedURLException e) {
    }
  }

  public URL getURL() {
    return url;
  }

  public int getRefreshInterval() {
    return interval;
  }

// possible customizer for instructions
  public void setRefreshInterval(int r) {
    interval = r;
  }

  public String getText() {
    return theURL.getText();
  }

  public Image getImage() {
    return theImage.getImage();
  }
  
  public Font getLabelFont() {
    return URLLabel.getFont();
  }
  
  public void setLabelFont(Font f) {
    URLLabel.setFont(f);
  }
  
  public Font getTheURLFont() {
    return theURL.getFont();
  }
  
  public void setTheURLFont(Font f) {
    theURL.setFont(f);
  }
  
  public Font getThePageFont() {
    return thePage.getFont();
  }
  
  public void setThePageFont(Font f) {
    thePage.setFont(f);
  }
  
  public boolean getUserCanEditURL() {
    return theURL.isEditable();
  }
  
  public void setUserCanEditURL(boolean allowEdits) {
    theURL.setEditable(allowEdits);
  }
  
  protected boolean showReloadButton = true;
  protected boolean showTheURL = true;
  protected Panel north = new Panel();
  protected Panel south = new Panel();
  
  public synchronized void setShowReloadButton(boolean b) {

    if (showReloadButton != b) { // change required
      if (!b) remove(south);
      else add("South", south);
      showReloadButton = b;
    }

  }
  
  public boolean getShowReloadButton() {
    return showReloadButton;
  }
  
  public synchronized void setShowTheURL(boolean b) {

    if (showTheURL != b) { // change required
      if (!b) remove(north);
      else add("North", north);
      showTheURL = b;
    }

  }
  
  public boolean getShowTheURL() {
    return showTheURL;
  }
  
  protected void init() {
    setLayout(new BorderLayout());
    north.setLayout(new BorderLayout());
    north.add("West", URLLabel);
    north.add("Center", theURL);
    reloadButton.addActionListener(new Reloader());
    theURL.addActionListener(new Reloader());
    south.add(reloadButton);
    Panel theData = new Panel();
    thePage.setEditable(false);
    theData.add("Center", thePage);
    if (showReloadButton) add("South", south);
    add("Center", thePage);
    if (showTheURL) add("North", north);
    Thread t = new Thread(this);
    t.setDaemon(true);
    t.start();
  }
  
  public URLWatcher() throws MalformedURLException {
    
    this(new URL("http://sunsite.unc.edu/nywc/"), 0);  

  }
  
  public URLWatcher(URL u) {
    this(u, 0);
  } 
  
  public URLWatcher(int refreshInterval) throws MalformedURLException {

    this(new URL("http://sunsite.unc.edu/nywc/"), refreshInterval);  
    
  } 
  
  public URLWatcher(String url) throws MalformedURLException {
    this(new URL(url), 0);
  } 
  
  public URLWatcher(String url, int refreshInterval) throws MalformedURLException {
    this(new URL(url), refreshInterval);
  } 
  
  public URLWatcher(URL u, int refreshInterval) {
    url = u;
    interval = refreshInterval;
    init();
  }
  

  public synchronized void reload() {
    if (url != null) {
      try {
        Object o = url.getContent();
        if (o instanceof InputStream) {
          if (loaded != thePage) {
            remove(loaded);
            add(thePage);
            loaded = thePage;
         }
          InputStream is = (InputStream) o;
          String text = readStream(is);
          thePage.setText(text);
        }
        else if (o instanceof ImageProducer) {
          if (loaded != theImage) {
            remove(loaded);
            add(theImage);
            loaded = theImage;
          }
          // draw the image
          ImageProducer ip = (ImageProducer) o;
          Image image = getToolkit().createImage(ip);
          theImage.setImage(image);
          theImage.repaint();
        }
        else {
          if (loaded != thePage) {
            remove(loaded);
            add(thePage);
            loaded = thePage;
          }
          thePage.setText("Unknown Content Type: " + o.getClass());
        }
      }
      catch (IOException e) {
      }
    }
    else {
      System.err.println("the null URL");
    }
  }

  protected String readStream(InputStream is) {

   StringBuffer sb = new StringBuffer();
   try {
      InputStreamReader isr = new InputStreamReader(is);  
      int c;
      while ((c = isr.read()) != -1) {
        sb.append((char) c);
      }
    }
    catch (IOException e) {
    }

    return sb.toString();
  } 

  public void run() {

    while (true) {
      try {
        if (interval > 0) {
          Thread.sleep(interval * 60000L);
          reload();
        }
        else {
          Thread.sleep(60000L);
        }  
      }
      catch(InterruptedException e) {
      }    
    }
    
  }

  public void addTextListener(TextListener l) {
    thePage.addTextListener(l);
  }

  public void removeTextListener(TextListener l) {
    thePage.removeTextListener(l);  
  }

  public static void main(String[] args) {

    for (int i = 0; i < args.length; i++) {
      try {
        URL u = new URL(args[i]);
        URLWatcher u1 = new URLWatcher();
        Frame f = new Frame("URLWatcher " + i);
        u1.setURL(u);
        f.add("Center", u1);
        f.setSize(300, 200);
        f.setLocation(50 + i*15, 50+i*15);
        f.setVisible(true);
      }
      catch (MalformedURLException e) {
      }
    }

  }

  class Reloader implements ActionListener {
  
    public void actionPerformed(ActionEvent evt) {

      try {
        setURL(new URL(theURL.getText()));
        reload();   
      }
      catch (MalformedURLException ex) {
      }          

    }
  
  }

}