Problem with overloading

Question

Hello everyone,
I am trying to create a simple panel with buttons and lines (quite modest, right?).
I have extended JPanel and JButton, and added the new buttons to the new panel, using GridBagConstraints.
For now i've added just one button and drew one line. Both look fine, but i cannot press the button! (nothing happens). The "funny" thing is that there is a place on the panel that when i press it - another button is being drawn there, and the event handler is called.
I should mention that when i add a regular JButton instead of mine (all other code remains the same) - it is being drawn in the same place as the second button appears - the middle of the upper side of the panel - whle i am trying to put it in 100,100 coordinate).
Code:
public class MyButton extends JButton{
     private String name;
     private int x, y; //left upper corner
     public MyButton(String name, int x, int y) {
          super(name);
          this.name = name;
          this.x = x;
          this.y = y;
          setPreferredSize(new Dimension(Consts.NODE_SIZE, Consts.NODE_SIZE));
     public String getName() {
          return name;
     public int getX() {
          return x;
     public int getY() {
          return y;
public class MyDisplay extends JPanel implements ActionListener{
     private Vector nodes = new Vector();
     private GridBagConstraints gbc = new GridBagConstraints();
     public MyDisplay() {                    
setBorder(BasicBorders.getButtonBorder());
setPreferredSize(new Dimension(300, 300));
for (int i=0; i<1; i++) {
     int x = 100;
     int y = 100;
     MyButton b = new MyButton(""+i, x, y);
     //JButton b = new JButton(""+i);
     if (b == null)
          throw new Error("failed creating button");      
     nodes.add(b);
     b.addActionListener(this);
     gbc.gridx = x;
     gbc.gridy = y;
     add(b, gbc);
     public void paintComponent(Graphics graphics){
          super.paintComponent(graphics);
          if (graphics == null) {
               System.out.println("NULL GRAPHICS");
               return;
          graphics.setColor(Color.BLUE);
          graphics.drawLine(50, 50, 100, 100);                    
     public void actionPerformed(ActionEvent ae) {
          for (int i=0; i<nodes.size(); i++)               
               try {
                    MyButton b = (MyButton)nodes.get(i);
                    if (ae.getSource() == b) {          
                         System.out.println("button " + i + " pressed");
                         return;
               } catch (Throwable e) {
                    throw new Error("Received event from non-MyButton");
thank you in advance,
Pavel.

Answer 1

Your overridding doesn't work -
getY() and getX() tells paintComponent where to print your MyButton component
Since your added button is the only one in the GridBagLayout it will be placed on the center of your panel.
Solution: do not use a GridBagLayout - use a null layout
your new constructor could look like this
public MyDisplay() {
super(null);
//super(new GridBagLayout()); -- u should have done this supercall in your old code!
//u could also use do this: setLayout(null);
setBorder(BasicBorders.getButtonBorder());
setPreferredSize(new Dimension(300, 300));
for (int i=0; i<1; i++) {
     int x = 100;
     int y = 100;
     MyButton b = new MyButton(""+i, x, y);
     //JButton b = new JButton(""+i);
     if (b == null)
     throw new Error("failed creating button");
     nodes.add(b);
     b.addActionListener(this);
     add(b);
     b.setSize(b.getPreferredSize());
     b.setLocation(x,y);
}Of course you should delete your overrided methods: getY() and getX().
good luck with your fancy application ;)
imqwerty.