//: c14:BangBean2.java // From Thinking in Java, 2nd Edition // Available at http://www.BruceEckel.com // (c) Bruce Eckel 1999 // Copyright notice in Copyright.txt // You should write your Beans this way so they // can run in a multithreaded environment import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.util.*; import java.io.*; public class BangBean2 extends JPanel 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 ArrayList actionListeners = new ArrayList(); 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 paintComponent(Graphics g) { super.paintComponent(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.add(l); } public synchronized void removeActionListener(ActionListener l) { actionListeners.remove(l); } // Notice this isn't synchronized: public void notifyListeners() { ActionEvent a = new ActionEvent(BangBean2.this, ActionEvent.ACTION_PERFORMED, null); ArrayList lv = null; // Make a shallow copy of the vector in case // someone adds a listener while we're // calling listeners: synchronized(this) { lv = (ArrayList)actionListeners.clone(); } // Call all the listener methods: for(int i = 0; i < lv.size(); i++) { ActionListener al = (ActionListener)lv.get(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(); } } 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"); } }); JFrame frame = new JFrame("BangBean2 Test"); frame.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e) { System.exit(0); } }); frame.getContentPane().add(bb); frame.setSize(300,300); frame.setVisible(true); } } ///:~