FileDocCategorySizeDatePackage
Click2.javaAPI DocExample3272Wed Apr 19 11:22:18 BST 2000None

Click2.java

import java.awt.*;
import java.awt.event.*;
import java.applet.*;


/*
 * This version of the Click applet fixes Click1 by extending
 * the nested TargetListener class with methods that redispatch
 * the mouse motion events from the target columns to the applet.
 * Note that we're translating the events coordinates from the
 * source components coordinate system to the applets coordinate
 * system. 
 * 
 * This applet runs correctly in HotJava, it requires JDK 1.1.
 */

public class Click2 extends Applet
{
  Color puckColor = new Color(200, 0, 10);
  Box puck = new Box(puckColor);
  ColumnOfBoxes[] targets = new ColumnOfBoxes[8];

  private final static class TargetListener 
    extends MouseAdapter implements MouseMotionListener
  {
    private Color newBackground;
    private Color oldBackground;

    TargetListener(Color newBackground) {
      this.newBackground = newBackground;
    }

    public void mouseEntered(MouseEvent e) {
      oldBackground = e.getComponent().getBackground();
      e.getComponent().setBackground(newBackground);
    }

    public void mouseExited(MouseEvent e) {
      e.getComponent().setBackground(oldBackground);
    }

    private void redispatch(MouseEvent e) {
      Point origin = e.getComponent().getLocation();
      e.translatePoint(origin.x, origin.y);
      e.getComponent().getParent().dispatchEvent(e);
    }

    public void mouseMoved(MouseEvent e) {  redispatch(e); }
    public void mouseDragged(MouseEvent e) { redispatch(e); }
    public void mouseClicked(MouseEvent e) { redispatch(e); }
  }

  public Click2()
  {
    MouseMotionListener movePuck = new MouseMotionAdapter() {
      public void mouseMoved(MouseEvent e)
      {
	int x = e.getX();
	int y = getSize().height - puck.getSize().height;
	puck.setLocation(x, y);
      }
    };

    /* Create a row of targets, i.e. columns of boxes, along
     * the top of the applet.  Each target column contains
     * between one and four boxes.
     */

    for(int i = 0; i < targets.length; i++) {
      int nBoxes = 1 + (int)(Math.random() * 4.0);
      float boxHue = (float)i / (float)targets.length;
      Color boxColor = Color.getHSBColor(boxHue, 0.5f, 0.85f);
      TargetListener tl = new TargetListener(boxColor.brighter());
      targets[i] = new ColumnOfBoxes(boxColor, nBoxes);
      targets[i].addMouseListener(tl);
      targets[i].addMouseMotionListener(tl);
      add(targets[i]);
    }

    add(puck);
    addMouseMotionListener(movePuck);
  }

  public static void main(String[] args)
  {
    WindowListener l = new WindowAdapter()
      {
	public void windowClosing(WindowEvent e) {System.exit(0);}
      };

    Frame f = new Frame("Click");
    f.addWindowListener(l); 
    f.add(new Click2());
    f.setSize(600, 400);
    f.show();
  }

  public String getAppletInfo() 
  { 
    return "Click2 by Hans Mueller.  This version of the Click applet fixes Click1 by extending the nested TargetListener class with methods that redispatch the mouse motion events from the target columns to the applet.  Note that we're translating the events coordinates from the source components coordinate system to the applets coordinate system. This applet requires JDK 1.1.";
  }
  
  public String[][] getParameterInfo() {
    return null;
  }   
}