import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

/**
 * a simple applet used to demo the SkinLayout layout manager.<br>
 * This is written for JDK1.1.  Porting to JDK1.0.2 should be relatively simple - only
 * requiring changes to the event handling (in other words, remove the listeners and replace
 * with 1.0.2 event handling code)
 */
public class TestApplet extends java.applet.Applet {

 /**
  * offscreen image size
  */
  private Dimension dimOffScreen;
  
 /**
  * offscreen image - used for double-buffering
  */
  private Image imgOffScreen;
  
 /**
  * offscreen graphics context - used for double-buffering
  */
  private Graphics gOffScreen;

 /**
  * layout for the applet
  */
  SkinLayout layout;
  
 /**
  * 'toolbar' back button
  */
  ImageButton backButton;

 /**
  * 'toolbar' forward button
  */
  ImageButton forwardButton;
  
 /**
  * 'toolbar' stop button
  */
  ImageButton stopButton;
  
 /**
  * image used for the end of the toolbar
  */
  ImageLabel end;
  
 /**
  * button used to change to layout 1
  */
  ImageButton layout1Button;
  
 /**
  * button used to change to layout 2
  */
  ImageButton layout2Button;  
  
  
 /**
  * initialise the applet
  */  
  public void init () {
    try {
      // call setup at the beginning so any class can load images using a static 'function' call
      Utils.setup(this);
    
      // create a new layout
      layout = new SkinLayout(Utils.getFileFromServer(getCodeBase() + "layout1.properties"));
      this.setLayout(layout);

      // construct buttons      
      backButton = new ImageButton();
      forwardButton = new ImageButton();
      stopButton = new ImageButton();
      end = new ImageLabel();
      layout1Button = new ImageButton();
      layout2Button = new ImageButton();
      
      this.add(backButton,"back");
      this.add(forwardButton,"forward");      
      this.add(stopButton,"stop");
      this.add(end,"end");
      this.add(layout1Button,"layout1");
      this.add(layout2Button,"layout2");

      // the action listener used for changing layouts
      TestAppletActionListener listener = new TestAppletActionListener(this);
      layout1Button.addActionListener(listener);
      layout2Button.addActionListener(listener);
      
      this.doLayout();
      this.setVisible(true);
      
    }
    catch (Exception e) {
      e.printStackTrace(); 
      this.stop();
    }
  }

  
 /**
  * handle button clicks
  */
  public void processActionEvent(ActionEvent e) {

    // change to layout 1
    if (e.getSource().equals(layout1Button)) {

      try {
        layout.setLayoutFile(Utils.getFileFromServer(getCodeBase() + "layout1.properties"));
      }
      catch (IOException ex) {
        ex.printStackTrace();
      }
      this.doLayout();
      this.repaint();
    }
    // change to layout 2
    else if (e.getSource().equals(layout2Button)) {

      try {
        layout.setLayoutFile(Utils.getFileFromServer(getCodeBase() + "layout2.properties"));
      }
      catch (IOException ex) {
        ex.printStackTrace();
      }
      this.doLayout();
      this.repaint();      
    }
  }



 /**
  * overrides the applet paint method (for double-buffering)
  */
  public void paint(Graphics g) {
    update(g);
  }

 /**
  * overrides the applet update method (for double-buffering).  Drawing of lightweight components happens here
  */
  public void update(Graphics g) {
    int x,y;

    Dimension d = getSize();

    //Create the offscreen graphics context, if no good one exists.
    if (gOffScreen == null || 
        d.width != dimOffScreen.width || 
        d.height != dimOffScreen.height) {
      dimOffScreen = d;
      imgOffScreen = createImage(d.width, d.height);
      gOffScreen = imgOffScreen.getGraphics();
    }
    
    // clear the offscreen graphics context
    gOffScreen.clearRect(0,0,d.width,d.height);

    // paint buttons
    if (backButton.isVisible())
      backButton.paint(gOffScreen);
      
    if (forwardButton.isVisible())
      forwardButton.paint(gOffScreen);
    
    if (stopButton.isVisible())
      stopButton.paint(gOffScreen);
      
    if (end.isVisible())
      end.paint(gOffScreen);

    if (layout1Button.isVisible())
      layout1Button.paint(gOffScreen);
      
    if (layout2Button.isVisible())
      layout2Button.paint(gOffScreen);

    g.drawImage(imgOffScreen,0,0,this);
    d = null;
    
  }
 
}

/**
 * action listener for the applet
 */
class TestAppletActionListener implements ActionListener {

  TestApplet parent;
 
  public TestAppletActionListener(TestApplet parent) {
    this.parent = parent;
  }
 
  public void actionPerformed(ActionEvent e) {
    parent.processActionEvent(e);
  }
}