A polygon button ?

Question

Ok, i've created a polygon which is an extension of a Component.
When the polygon is clicked it needs to repaint but the background colour will have changed.
The problem is it doesnt seem to register my clicking of the polygon and the result is nothing happens.
Here is my code for the clicking and creation of the MouseListener...
import java.awt.*;
import java.lang.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
class MakeWindow extends Frame implements MouseListener
private AnswerBox answerBoxes [] = new AnswerBox [4];
public MakeWindow ()
super ("Who Wants To Be A Billionaire");
setLayout (null);
// Create the menu items.               **** Menu Items are created, i've just left them out here.
setBackground (Color.blue);
setVisible (true);
pack ();
show ();
} // MakeWindow constructor
// Creates windows for Money Ladder and Answer Boxes
public void paint (Graphics g)
answerBoxes [0] = new AnswerBox ('A');
answerBoxes [0].setText ("A: ");
answerBoxes [0].paint (g);
answerBoxes [0].addMouseListener (this);
public void mouseClicked (MouseEvent e)
Object src = e.getSource ();
if (src == answerBoxes [0])
answerBoxes [0].setSelected (true, 'A');
The code for my AnswerBox goes as follows......
import java.awt.*;
import java.lang.*;
public class AnswerBox extends Component
private String text;
private Color backColor;
private char Box;
public AnswerBox (char currBox)
super ();
text = "";
backColor = Color.black;
Box = currBox;
public void paint (Graphics g)
int xChange;
int yChange;
switch (Box)
case 'A':
xChange = 0;
yChange = 0;
break;
default:
xChange = 0;
yChange = 0;
break;
int xPoints [] = {140 + (xChange * 285), 120 + (xChange * 285), 140 + (xChange * 285), 290 + (xChange * 285), 310 + (xChange * 285), 290 + (xChange * 285) };
int yPoints [] = {380 + (yChange * 70), 400 + (yChange * 70), 420 + (yChange * 70), 420 + (yChange * 70), 400 + (yChange * 70), 380 + (yChange * 70) };
g.setColor (backColor);
g.fillPolygon (xPoints, yPoints, 6);
g.setColor (Color.white);
g.drawPolygon (xPoints, yPoints, 6);
g.drawString (text, 150 + (xChange * 285), 405 + (yChange * 70));
public void setText (String newText)
text = newText;
public void setSelected (boolean b, char currBox)
if (b)
backColor = Color.orange;
Box = currBox;
this.repaint ();
else
backColor = Color.black;
Box = currBox;
this.repaint ();
Here is the application code...
import java.awt.*;
import BuildCanvas.*;
public class User
public static void main (String [] args)
MakeWindow userInterface = new MakeWindow ();
userInterface.setSize (800, 600);
userInterface.setLocation (100, 100);
If someone could work through this it would be greatly appreciated, i dont have much programming experience so the problem is probably somehting very stupid.
Thanks
Andrew.

Answer 1

I never done a custom component before and, since I was a little bored this afternoon, I tried. Here is my result, feel free to use some of its code... Of course, it is not perfect, I was just fooling around!
To use it:
CircleButton cb = new CircleButton("Button 1");
cb.addActionListener(/*your action listener here*/);Enough blah, blah, here's the code...
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
public class CircleButton extends Component implements MouseListener {
   // Instance variables
   ActionListener actionListener;
   Color borderColor;
   Color foregroundColor;
   Color backgroundColor;
   Color originalBackgroundColor;
   String text;
   String actionCommand;
   Dimension preferredSize;
   // Constructors
   public CircleButton(String text) {
      super();
      this.text = text;
      borderColor = Color.black;
      foregroundColor = Color.black;
      backgroundColor = Color.white;
      originalBackgroundColor = backgroundColor;
      actionCommand = this.text;
      Font buttonFont = new Font("SansSerif",Font.BOLD,12);
      FontMetrics textMetrics = getFontMetrics(buttonFont);    
      int textWidth  = textMetrics.stringWidth(this.text);
      preferredSize = new Dimension(Math.max(30,textWidth + 10), Math.max(30, textWidth + 10));
      this.addMouseListener(this);
   public void paint(Graphics g) {
      Graphics2D g2 = (Graphics2D) g;
      g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON); // For text antialiasing
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); // For general antialiasing
      Color originalColor = g.getColor();
      int dim = Math.min(this.getWidth(), this.getHeight()) - 4;
      int horizontalOffset = Math.max(0, this.getWidth() / 2 - dim / 2);
      int verticalOffset = Math.max(0, this.getHeight() / 2 - dim / 2);
      g2.setPaint(new GradientPaint(0, dim, Color.red, dim, 0, Color.white, false));     
      g2.fillOval(horizontalOffset, verticalOffset, dim, dim);
      g2.setColor(borderColor);
      g2.drawOval(horizontalOffset, verticalOffset, dim, dim);
      Font buttonFont = new Font("SansSerif",Font.BOLD,12);
      FontMetrics textMetrics = getFontMetrics(buttonFont);    
      int textWidth  = textMetrics.stringWidth(this.text);
      int textHeight = textMetrics.getAscent();
      g2.setColor(foregroundColor);
      g2.drawString(text, this.getWidth() / 2 - textWidth / 2, this.getHeight() / 2 + textHeight / 2);
      g2.setColor(originalColor);
   public void addActionListener(ActionListener actionListener) {
      this.actionListener = actionListener;
   public Dimension getPreferredSize() {
      return preferredSize;
   public void setPreferredSize(Dimension newSize) {
       preferredSize = newSize;
   public Dimension getMinimumSize() {
      return getPreferredSize();
   // Implementation of MouseListener
   public void mousePressed(MouseEvent e) {}
   public void mouseReleased(MouseEvent e) {}
   public void mouseClicked(MouseEvent e) {
      actionListener.actionPerformed(new ActionEvent(this, 0, actionCommand));
   public void mouseEntered(MouseEvent e) {}
   public void mouseExited(MouseEvent e) {}
}