array of Jbutton - how to use event.getSource()

[Peter Primrose]

So....

Assuming I have an array of buttons (30) how can I tell which one is pressed when it gets to the actionPerformed area.

say I have this class:

Class ABC implements ActionListener
{

private JButton myButton[] = new JButton ("na");

public ABC()
{
//initilizing

}
.
.
.
if (event.getSource()==myButton[i])
{
//Question - what is i ???
// do somthing here
}

do i have to write 30 if (event.getSource()

thanks for any help

[Dror Guzman]

Do this:

public void actionPerformed(ActionEvent e){

for(int i=0; i<MyButton.length; i++){
if(e.getSource() == MyButton[i])
// do your event here.....
}
}

[Jeff Grant]

Dror is correct assuming that your array is globally available.

I have run into a similar question as this topic numerous times dealing with either arrays which are not globally accessable or the JButton (or whatever) were not saved at all as the screen was dynamically created. In this case I would use JButton.setActionCommand(String) where the String I would give it would be which button it is... ie: Button 1, Button 2, etc..

[Ilja Preuss]

I typically prefer to have one ActionListener per button.

How do the buttons get created, and what should happen if you press them?

[Stan James]

I like one action listener per button. I also like an alternative with one action listener per window and a command per button.

// For every button ...
commands.put( theButton, new ICommand()
{
    public void execute()
    {
        mController.executeCompare( getQuery(), getColCount(), options );
    }
} );
 
// One listener (to bind them all!) like this:
private class MyActionListener implements java.awt.event.ActionListener
{
    public void actionPerformed(java.awt.event.ActionEvent evt)
    {
        ICommand command = (ICommand) commands.get( evt.getSource());
        if (null != command)
            command.execute();
        else
            JOptionPane.showMessageDialog( frame, "Command not yet implemented" );
    }
}

This could just as easily be a listener per button since the code is so darned short. I tend to use "collection of commands to replace if-else-if" a lot. It might be the "when your only tool is a hammer everything looks like a nail" syndrome.

[Ilja Preuss]

The Command solution looks nice if you want to decouple the creation of the buttons from the definition of what the buttons actually do (for example if you build some kind of reusable gui).

Otherwise it just seems to be more complex and opens the door for bugs that can't happen with the one-listener-per-button approach (such as not finding a command for a button), without any benefits?