click2.java

java语言规范

/*
 * Copyright 2002 Sun Microsystems, Inc. All  Rights Reserved.
 *  
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following 
 * conditions are met:
 * 
 * -Redistributions of source code must retain the above copyright  
 *  notice, this list of conditions and the following disclaimer.
 * 
 * -Redistribution in binary form must reproduce the above copyright 
 *  notice, this list of conditions and the following disclaimer in 
 *  the documentation and/or other materials provided with the 
 *  distribution.
 *  
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY 
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF OR 
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR 
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE 
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, 
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER 
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF 
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *  
 * You acknowledge that Software is not designed, licensed or 
 * intended for use in the design, construction, operation or 
 * maintenance of any nuclear facility. 
 */

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;
  }   
}