Need help with addActionListener

[Steve Vittoria]

Hi everyone,

I have an array of JButtons, and I don't know how to determine which one was clicked. I know how to do it if each button had a different text (i.e. Ok, Cancel, etc.), but in my case they all have the same exact text (I'm writing a poker game).

Here is a sample of my code...

public Component createComponents() {
 
JButton discardButtons[]= new JButton[5];
 
for(int x = 0; x < 5; x++) {
        discardButtons[x]=new JButton("Discard");
    discardButtons[x].setMnemonic(KeyEvent.VK_I);
    discardButtons[x].addActionListener(this);
    label.setLabelFor(discardButtons[x]);
}
 
}
 
public void actionPerformed(ActionEvent e) {
 
    System.out.println("Action Command: " + e.getActionCommand());
    System.out.println("Source: " + e.getSource());
 
}

What can I do in the actionPerformed method in order to determine which button was pressed?

Thanks!

[Michael Dunn]

here are some of the ways you could do this

1. in actionPerformed() iterate the button array checking if it is the source
(the button array will need the necessary scope)

 
public void actionPerformed(ActionEvent e)
{ 
  for(int x = 0; x < discardButtons.length; x++)
  {
    if(discardButton[x] == e.getSource())
    {
      //do something
      break;
    }
  }
}

2. add a separate actionListener to each button, each with it's own actionPerformed(),
then have a separate method that takes an identifier as a parameter

  final int BUTTON_ID = x;
  discardButtons[x].addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent ae){
      doSomething(BUTTON_ID);}});
  ...
}
public void doSomething(int whichButton)
{
  discardButton[whichButton].do_something_with_it;
}

3. create your own JButton, adding an ID
then, in actionPerformed you cast the source as MyButton, and get the ID

 
MyButton discardButtons[]= new MyButton[5];
discardButtons[x]=new MyButton("Discard",x);
class MyButton extends JButton
{
  int ID;
  public MyButton(String text,int id)
  {
    super(text);    
    ID = id;
  }
}
public void actionPerformed(ActionEvent e)
{
  discardButton[((MyButton)e.getSource()).ID].do_something_with_it;
}

[Jay Aranguren]

I think you can also just set the action command for each of the buttons. But I like the solutions Michael posted above better

[Rachel Swailes]

Instead of option three above, you can use the myButton.setName("my button's name") to give each button an identifier. Then you use .getName() to retrieve the name when you need it.

Cheers,
Rachel

[Steve Vittoria]

Awesome! Thanks Michael!

I tried both option 1 and 2. While option 1 results in less lines of code, I really like how clear and clean option 2 is.

Again thanks!