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BangBean2.javaAPI DocExample6174Mon Apr 06 18:10:22 BST 1998None

BangBean2.java

//: BangBean2.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source. 
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com 
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher 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 Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////

// You should write your Beans this way so they 
// can run in a multithreaded environment.
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

public class BangBean2 extends Canvas 
    implements Serializable {
  private int xm, ym;
  private int cSize = 20; // Circle size
  private String text = "Bang!";
  private int fontSize = 48;
  private Color tColor = Color.red;
  private Vector actionListeners = new Vector();
  public BangBean2() {
    addMouseListener(new ML());
    addMouseMotionListener(new MM());
  }
  public synchronized int getCircleSize() { 
    return cSize; 
  }
  public synchronized void 
  setCircleSize(int newSize) {
    cSize = newSize;
  }
  public synchronized String getBangText() { 
    return text; 
  }
  public synchronized void 
  setBangText(String newText) {
    text = newText;
  }
  public synchronized int getFontSize() { 
    return fontSize; 
  }
  public synchronized void 
  setFontSize(int newSize) {
    fontSize = newSize;
  }
  public synchronized Color getTextColor() {
    return tColor; 
  }
  public synchronized void 
  setTextColor(Color newColor) {
    tColor = newColor;
  }
  public void paint(Graphics g) {
    g.setColor(Color.black);
    g.drawOval(xm - cSize/2, ym - cSize/2, 
      cSize, cSize);
  }
  // This is a multicast listener, which is
  // more typically used than the unicast
  // approach taken in BangBean.java:
  public synchronized void addActionListener (
      ActionListener l) {
    actionListeners.addElement(l);
  }
  public synchronized void removeActionListener(
      ActionListener l) {
    actionListeners.removeElement(l);
  }
  // Notice this isn't synchronized:
  public void notifyListeners() {
    ActionEvent a =
      new ActionEvent(BangBean2.this,
        ActionEvent.ACTION_PERFORMED, null);
    Vector lv = null;
    // Make a copy of the vector in case someone
    // adds a listener while we're 
    // calling listeners:
    synchronized(this) {
      lv = (Vector)actionListeners.clone();
    }
    // Call all the listener methods:
    for(int i = 0; i < lv.size(); i++) {
      ActionListener al = 
        (ActionListener)lv.elementAt(i);
      al.actionPerformed(a);
    }
  }
  class ML extends MouseAdapter {
    public void mousePressed(MouseEvent e) {
      Graphics g = getGraphics();
      g.setColor(tColor);
      g.setFont(
        new Font(
          "TimesRoman", Font.BOLD, fontSize));
      int width = 
        g.getFontMetrics().stringWidth(text);
      g.drawString(text, 
        (getSize().width - width) /2,
        getSize().height/2);
      g.dispose();
      notifyListeners();
    }
  }
  class MM extends MouseMotionAdapter {
    public void mouseMoved(MouseEvent e) {
      xm = e.getX();
      ym = e.getY();
      repaint();
    }
  }
  // Testing the BangBean2:
  public static void main(String[] args) {
    BangBean2 bb = new BangBean2();
    bb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e){
        System.out.println("ActionEvent" + e);
      }
    });
    bb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e){
        System.out.println("BangBean2 action");
      }
    });
    bb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e){
        System.out.println("More action");
      }
    });
    Frame aFrame = new Frame("BangBean2 Test");
    aFrame.addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    aFrame.add(bb, BorderLayout.CENTER);
    aFrame.setSize(300,300);
    aFrame.setVisible(true);
  }
} ///:~