tomzhi wrote:

Given that they haven't shown us any code at all, it's a fair bet that you're
right, Nigel.

This is a unit converter I am trying to create. Loadtable is class
that loads the data to create the dropdown list on different tab.
I used for loop to create arrays of panels, which becomes tabs. Also
arrays of buttons, dropdown list.

Now, I need to use submit[i] button to call a function to calculate
the conversion factor. However, I can't define which tab the user has
currently selected. I can do it only within the main method, but not
outside. It would become -1 outside. Please help.

import java.io.FileNotFoundException;
import java.io.IOException;
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.*;

public class Main {
    JTabbedPane tab = new JTabbedPane();

       int i, index;
       JComboBox[] box = new JComboBox [10];
       JComboBox[] box_2 = new JComboBox [10];
       JTextField[] text = new JTextField[10];
       JTextField[] text_2 = new JTextField[10];
       JPanel [] panel = new JPanel[10];
       JButton[] exit = new JButton[10];
       JButton[] submit = new JButton[10];

   public Main() {
   }

    public static void main(String[] args) throws
FileNotFoundException, IOException {
       JTabbedPane tab = new JTabbedPane();
       int i;
       JComboBox[] box = new JComboBox [10];
       JComboBox[] box_2 = new JComboBox [10];
       JTextField[] text = new JTextField[10];
       JTextField[] text_2 = new JTextField[10];
       JPanel [] panel = new JPanel[10];
       JButton[] exit = new JButton[10];
       JButton[] submit = new JButton[10];

       String [] name = {"Distance",
"Area","Temperature","Speed","Volume",
"Density","Force","Energy","Frequency","Astronomical"};

       loadtable x =new loadtable();
       x.load();
       for (i=0;i<10;i++) {
          panel[i]=new JPanel();
          box[i]= new JComboBox(x.getdata(name[i]));
          box_2[i]=new JComboBox(x.getdata(name[i]));
          text[i]= new JTextField();
          text_2[i]= new JTextField();
          exit[i]=new JButton("Exit");
          submit[i]= new JButton("Submit");
          text[i].setColumns(10);
          text_2[i].setColumns(10);
          panel[i].add(text[i]);
          panel[i].add(box[i]);
          panel[i].add(text_2[i]);
          panel[i].add(box_2[i]);
          panel[i].add(submit[i],BorderLayout.PAGE_END);
          panel[i].add(exit[i],BorderLayout.PAGE_END);
          tab.add(name[i],panel[i]);

       }

       JFrame frame = new JFrame("Unit Converter");
       frame.add(tab);
       frame.setSize(750,200);
       frame.setLocation(200,200);
       frame.setVisible(true);

       for (i=0;i<10;i++) {
           exit[i].addActionListener(new
java.awt.event.ActionListener () {
               public void actionPerformed(java.awt.event.ActionEvent
evt){
                   exitActionPerformed(evt);
               }
           });

       }

        for (i=0;i<10;i++) {
           exit[i].addActionListener(new
java.awt.event.ActionListener () {
               public void actionPerformed(java.awt.event.ActionEvent
evt){
                   exitActionPerformed(evt);
               }
           });

       }

        for (i=0;i<10;i++) {
           submit[i].addActionListener(new
java.awt.event.ActionListener () {
               public void actionPerformed(java.awt.event.ActionEvent
evt){
                   submitActionPerformed(evt);
               }
           });

       }

   }
      private static void
exitActionPerformed(java.awt.event.ActionEvent evt) {
           System.exit(0);
       }

       private static void
submitActionPerformed(java.awt.event.ActionEvent evt) {
           Main x = new Main();
           System.out.println(x.tab.getSelectedIndex());

       }

      }