Return the index of clicked button?

Question

I have got an array of 30 buttons []. I have a variable buttonClicked. When I press the button how can I get the index and store the index number in the buttonClicked?

Answer 1

You can find the button in ActionEvent.getSource(). To find the index it is just a matter of iterating through the array, looking for that particular button.

Answer 2

I prefer the strategy suggested by aioobe, but here is another way.

buttons[btnNumber - 1] = new JButton("label " + btnNumber);
buttons[btnNumber - 1].setActionCommand("" + btnNumber);
// ...

// ...later.. in the actionPerformed() method
String num = actionEvent.getActionCommand();
int index = Integer.parseInt(num);
// ..proceed..

Answer 3

The prettiest way is using Component.setName. Then you don't even need to maintain variables with your components - you can go straight off of the name

Answer 4

1) putClientProperty

buttons[i][j].putClientProperty("column", i);
buttons[i][j].putClientProperty("row", j);
buttons[i][j].addActionListener(new MyActionListener());

and getClientProperty

public class MyActionListener implements ActionListener {

@Override
public void actionPerformed(ActionEvent e) {
    JButton btn = (JButton) e.getSource();
    System.out.println("clicked column " + btn.getClientProperty("column")
            + ", row " + btn.getClientProperty("row"));
}

2) ActionCommand