ActionListener question

If you have an array of objects, TextFields or buttons in a frame, how can you reference that object's index in the actionlistener? For example, I have 7 TextFields set up as an array and need to pass it's index as a string to a method when it gets the focus.


What I have is:

public static void main(String[] args) {

//other code
ASimpleClass asc = new ASimpleClass();
JTextField[] loc = new JTextField[7];
for(int i=0; i<7;i++){

loc[i] = new JTextField(""+i,3);
loc[i].addFocusListener(this);
add(loc[i]);

}
//more code

}

public void FocusGained(FocusEvent e){

/* Alternatively I could do this but it seems brute force.
JTextField source = (JTextField)e.getComponent();
String mystring = asc.getResult(source.getText());
*/

String mystring = asc.getResult("the index of the textfield that got Focus");
//do some stuff

}

public class ASimpleClass(){

public String getResult(String str) {

String result = str;
return result;

}

}

Consider creating and posting a very small, simple compilable and runnable program that shows your problem, an SSCCE.

Ok, so here's a little app. Right now I have each text field hold the number of the index which I use to compare with the location of Waldo. I'd like to be able to reference the TextField's index (if that's possible). If not, is there a more elegant way that I could do this. I'd like to extend this out to a multi-dimentional array of TextFields.

Code:

---

import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;

public class WhereIsWaldo extends JFrame implements FocusListener {

        private JPanel contentPane;
        private JPanel gridPane;
        private JPanel messagePane;
        int waldoIsHere = (int) (Math.random()*5); //generate a random number between 0-4
        ASimpleClass dot;
        JLabel msg;
       
        public WhereIsWaldo() {
                super("Where is Waldo");
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                setBounds(100, 100, 450, 300);
                contentPane = new JPanel();
                contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
                contentPane.setLayout(new BorderLayout(0, 0));
                setContentPane(contentPane);
                gridPane = new JPanel();
                JTextField[] loc = new JTextField[5];
                for(int i=0; i<loc.length;i++){
                        loc[i] = new JTextField(""+i,3);
                        loc[i].addFocusListener(this);
                        gridPane.add(loc[i]);
                }               
                messagePane = new JPanel();
                msg = new JLabel("Where is Waldo?.");
                messagePane.add(msg);       
                contentPane.add("North", gridPane);
                contentPane.add("South", messagePane);
                setVisible(true);       
                dot = new ASimpleClass();
                dot.setLocation(waldoIsHere);
        }
       
        public void focusGained(FocusEvent e){
                JTextField source = (JTextField)e.getComponent();       
                if (dot.getLocation()==Integer.parseInt(source.getText())){
                        msg.setText("You've found Waldo!");
                } else{
                        msg.setText("Try Again!");
                }       
        }
       
        public void focusLost(FocusEvent e){               
        }

        public static void main(String[] args) {
                WhereIsWaldo frame = new WhereIsWaldo();
                frame.setVisible(true);                       
        }
}
class ASimpleClass{
        int location;
       
        public int getLocation() {
                return location;
        }
        public void setLocation(int locs){
                location = locs;
        }
}

---

To do what you wish, all you need to do is make loc a class field, not a variable that is local to the constructor. Then in the actionPerformed use a for loop to iterate through loc[i] to see if the source == loc[i], and if so, check if i == whereiswaldo. That's it.

thanks. got it to work.

Good deal, and thanks for getting back to us with your success!