Elements in Layouts in Java all in same position

Question

I'm coding in Java Swing and for some reason, when I add two elements to a gridlayout, they both assume the same position. I have tried simplifying it into something that would not fail and then building up from there, but alas, it's still not working.

The misbehaving code within the program is:

        bodyPanelMain.setLayout(new GridLayout(4, 1, 10, 10));
        JTextArea one = new JTextArea("Hi");
        one.setLineWrap(true);
        one.setSize(100, 100);
        JTextArea two = new JTextArea("Goodbye");
        two.setLineWrap(true);
        two.setSize(100, 100);
        bodyPanelMain.add(one);
        bodyPanelMain.add(two);
        bodyPanelMain.repaint();

If I make JTextArea's width 200 and background a different color, it's clear that it's visible behind it, so it's most certainly adding all the proper elements, their positions are just wrong.

EDIT: Here's a very very short version of what I am trying to do.

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


public class minimessageboard extends Applet implements ActionListener {

JPanel mainPanel;
JPanel buttonPanel;
JButton announcements, websites;
JPanel bodyPanel, bodyPanelMain;

public minimessageboard() {
    this.setSize(600, 400);

    mainPanel = new JPanel(new BorderLayout());
    mainPanel.setPreferredSize(new Dimension(this.getWidth(), this.getHeight()));
    this.add(mainPanel);

    buttonPanel = new JPanel(new GridLayout(6, 1, 10, 10));
    mainPanel.add(buttonPanel, BorderLayout.WEST);

    announcements = new JButton("Announcements");
    this.formatButton(announcements);
    announcements.setActionCommand("announcements");
    buttonPanel.add(announcements);

    websites = new JButton("Websites");
    this.formatButton(websites);
    websites.setActionCommand("websites");
    buttonPanel.add(websites);

    bodyPanel = new JPanel(new BorderLayout());
    bodyPanel.setSize(200, 500);
    bodyPanel.setPreferredSize(new Dimension(200, 500));
    mainPanel.add(bodyPanel, BorderLayout.CENTER);

    bodyPanelMain = new JPanel(new BorderLayout());
    bodyPanel.add(bodyPanelMain, BorderLayout.CENTER);
    bodyPanelMain.setLayout(new GridLayout(4, 1, 10, 10));
    JButton one = new JButton("Roar");
    bodyPanelMain.add(one);
    bodyPanelMain.revalidate();
    bodyPanelMain.repaint();
}

public static void main(String args[]) {
    JFrame overall = new JFrame(); 
    overall.pack();
    overall.setVisible(true);
    overall.add(new minimessageboard());
}

public void formatButton(JButton b){
    b.setPreferredSize(new Dimension(150, 33));
    b.addActionListener(this);
}

public void actionPerformed(ActionEvent arg0) {
    String action = arg0.getActionCommand();
    bodyPanelMain.removeAll();
    if (action.equals("websites")){
        System.out.println("Fires!");
        bodyPanelMain.setLayout(new GridLayout(4, 1, 10, 10));
        JButton one = new JButton("Hi");
        JButton two = new JButton("Goodbye");
        bodyPanelMain.add(one);
        bodyPanelMain.add(two);
        bodyPanelMain.revalidate();
    }
    bodyPanelMain.repaint();
}
}

Basically, when you click on websites, "Hi" and "Bye" should show up. If I move the code within the block in the websites if statement (if (action.equals("websites")) up to the original constructor, it appears perfectly fine. The code outputs "Fires!", so I am 100% certain it gets to that part. For note, I changed it from JTextArea to JButton because I will be using JButtons, not JTextArea.

Answer 1

Don't set the size of a JTextArea as it won't work well when your text extends beyond the text area size and you find that it just won't scroll. Instead set the preferred row and column values, and then let the JTextArea size itself. On to your problem: are you adding these components after the GUI has rendered itself? If so, do you call revalidate() on the bodyPanelMain after it receives the JTextAreas? If this doesn't help, consider creating and posting an sscce.

For example, this works fine for me:

import java.awt.GridLayout;
import javax.swing.*;

public class SwingFoo {
   private static final int ROWS = 10;
   private static final int COLS = 16;

   private static void createAndShowGui() {
      JPanel bodyPanelMain = new JPanel();
      bodyPanelMain.setLayout(new GridLayout(4, 1, 10, 10));
      JTextArea one = new JTextArea("Hi", ROWS, COLS);
      one.setLineWrap(true);
      // one.setSize(100, 100);
      JTextArea two = new JTextArea("Goodbye", ROWS, COLS);
      two.setLineWrap(true);
      // two.setSize(100, 100);
      bodyPanelMain.add(new JScrollPane(one));
      bodyPanelMain.add(new JScrollPane(two));
      // bodyPanelMain.repaint();

      JFrame frame = new JFrame("SwingFoo");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(bodyPanelMain);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}