https://bpaste.net/show/09a7053e3805 <-------- LinkList https://bpaste.net/show/

Question

https://bpaste.net/show/09a7053e3805 <-------- LinkList

https://bpaste.net/show/9cb5358e28f6 <--------- Main

I am making this gui of a linked list, the gui to input is working but my legend to let the user know what commands are a loud aren't showing up. it should show up in a seperate window. could someone help me with my issue. or explain what I am doing wrong. I still have to do more to this code. However, I just want to make sure my gui is working as suppose to. Thank you for the help.

Explanation / Answer

You need to add a KeyListener to the TextField not ActionListener. I've bolded the modified code.

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

/**
* This class is used to demonstrate the operations in the LinkedList1 class.
*/

public class Chp20Pc02Demo extends JFrame {
   private final LinkedList1 ll;
   private final JTextArea listView;
   private final JTextField cmdTextField;
   private final JTextField resultTextField;

   public Chp20Pc02Demo() {
       ll = new LinkedList1();
       listView = new JTextArea();
       cmdTextField = new JTextField();
       resultTextField = new JTextField();

       // Create a panel and label for result field
       JPanel resultPanel = new JPanel(new GridLayout(1, 2));
       resultPanel.add(new JLabel("Command Result"));
       resultPanel.add(resultTextField);
       resultTextField.setEditable(false);
       add(resultPanel, BorderLayout.NORTH);

       // Put the textArea in the center of the frame
       add(listView);
       listView.setEditable(false);
       listView.setBackground(Color.WHITE);

       // Create a panel and label for the command text field
       JPanel cmdPanel = new JPanel(new GridLayout(1, 2));
       cmdPanel.add(new JLabel("Command:"));
       cmdPanel.add(cmdTextField);
       add(cmdPanel, BorderLayout.SOUTH);

       cmdTextField.addKeyListener(new CmdTextListener());

       // Set up the frame
       setTitle("Linked List Demo");
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       pack();
       setVisible(true);
   }

   /**
   * Private class that responds to the command that the user types into the
   * command entry text field.
   */

   private class CmdTextListener implements KeyListener {
       public void keyTyped(KeyEvent e) {
       }

       public void keyPressed(KeyEvent e) {
           if (e.getKeyCode() == KeyEvent.VK_ENTER) {

               Scanner sc = new Scanner(cmdText);
               String cmd = sc.next();
               if (cmd.equals("add")) {
                   if (sc.hasNextInt()) {
                       // add index element
                       int index = sc.nextInt();
                       String element = sc.next();
                       ll.add(index, element);
                   } else {
                       // add element
                       String element = sc.next();
                       ll.add(element);
                   }
                   listView.setText(ll.toString());
                   pack();
               }

               if (cmd.equals("remove")) {
                   if (sc.hasNextInt()) {
                       // remove index
                       int index = sc.nextInt();
                       String res = ll.remove(index);
                       resultTextField.setText(res);
                   } else {
                       // remove element
                       String element = sc.next();
                       boolean res = ll.remove(element);
                       String resText = String.valueOf(res);
                       resultTextField.setText(resText);
                   }
                   listView.setText(ll.toString());
                   pack();
                   return;
               }
               if (cmd.equals("isempty")) {
                   String resText = String.valueOf(ll.isEmpty());
                   resultTextField.setText(resText);
                   return;
               }
               if (cmd.equals("size")) {
                   String resText = String.valueOf(ll.size());
                   resultTextField.setText(resText);
               }
               if (cmd.equals("sort")) {
                   String resText = String.valueOf(ll.size());
                   resultTextField.setText(resText);
               }
           }
       }

       public void keyReleased(KeyEvent e) {
       }

   }

   /**
   * The main method creates an instance of the LinkedList1Demo class which
   * causes it to display its window.
   *
   * @param args
   */

   public static void main(String[] args) {
       new Chp20Pc02Demo();
   }
}

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