Adding components into JPanel inside a JFrame

Question

Since im a beginner and i don't want to get involved with the layout managers, i was simply adding a JPanel into my main JFrame and giving spesific location to each component in the panel. But somehow the output appears way too wrong..

frame = new JFrame(email + " (Offline)");
    frame.setSize(400, 400);
    frame.setLocation(0, 0);
    frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
    frame.setLayout(new FlowLayout());
    frame.addWindowListener(new WindowAdapter()
    {
        public void windowClosing(WindowEvent e)
        {
            // out.println("BYE");
            // out.flush();
            frame.dispose();
            thread.stop();
        }
    });
    panel = new JPanel();
    frame.add(panel);
    chat = new JTextArea();
    chat.setSize(400, 200);
    chat.setLocation(0, 0);
    chat.setEditable(false);
    panel.add(chat);
    panel.validate();
    JLabel you = new JLabel("You:");
    you.setSize(you.getPreferredSize());
    you.setLocation(0, 210);
    panel.add(you);
    panel.validate();
    input = new JTextArea();
    input.setSize(200, 200);
    input.setLocation(0, 220 + chat.getSize().height);
    panel.add(input);
    panel.validate();
    send = new JButton("Send");
    send.setSize(send.getPreferredSize());
    send.setLocation(210, 220 + chat.getSize().height);
    panel.add(send);
    panel.validate();
    frame.setVisible(true);

The outcome of this frame is that text areas are invisible, a You: label in the middle and next to the right of it the button.. What am i missing here?

The whole point of layout managers is to make this *easier*. — Brian Roach, Dec 17 '12 at 01:24
I have to say *amen* to what @BrianRoach just posted. You are doing yourself a big disservice by avoiding use of layout managers. Just have a look at the tutorials on this (Google will help you find them), and give them a go, ... but I'd say avoid GridBagLayout for now since it and GroupLayout are the most complex of them. — Hovercraft Full Of Eels, Dec 17 '12 at 01:28
Oh well.. I've been checking the layouts but it seems that those are not really flexible as i desired. But fortunately, for the people that have the exact same problem with mine, set setLayout to null. Like i do in my code panel.setLayout(null). This will allow you to give location freely to each component in your parent. — Barışcan Kayaoğlu, Dec 17 '12 at 01:35
I won't go into the myriad of things with which doing it this way will cause problems, because obviously you're set on doing it wrong. — Brian Roach, Dec 17 '12 at 01:40
I see no reason why a `LayoutManager` cannot do what you ask, understandably if you dont know `LayoutManager`s it may seem harder than to use `setLayout(null)`. But when the UI becomes really complex `null Layout` will be your downfall. +1 to all comments and HFOEs answer — David Kroukamp, Dec 17 '12 at 06:00

Hovercraft Full Of Eels · Answer 1 · 2012-12-17T02:28:59.573

Again, don't use null layout since it makes updating and maintaining your GUI much more difficult than it should be, and can lead to ugly GUI's if you plan on having them run on multiple platforms. Instead

Use several JPanels, each one holding a core group of components and each using its best layout manager
Nest these JPanels in other JPanels that use the best layout manager to display them
and that will allow your GUI to be resizeable without need of extra code.
Put your JTextAreas in JScrollPanes so that you can see all text even if it goes beyond the text area.
Never set the size of the JTextArea as that will not allow it to scroll. Instead set its columns and rows.

As a very simple example, run this to see what I mean:

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

public class FooSwing2 {
   public static void main(String[] args) {
      JTextArea chatArea = new JTextArea(8, 40);
      chatArea.setEditable(false);
      chatArea.setFocusable(false);
      JScrollPane chatScroll = new JScrollPane(chatArea);
      JPanel chatPanel = new JPanel(new BorderLayout());
      chatPanel.add(new JLabel("Chat:", SwingConstants.LEFT), BorderLayout.PAGE_START);
      chatPanel.add(chatScroll);

      JTextField inputField = new JTextField(40);
      JButton sendBtn = new JButton("Send");
      JPanel inputPanel = new JPanel();
      inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.LINE_AXIS));
      inputPanel.add(inputField);
      inputPanel.add(sendBtn);

      JPanel youLabelPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
      youLabelPanel.add(new JLabel("You:"));

      JPanel mainPanel = new JPanel();
      mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.PAGE_AXIS));
      mainPanel.add(chatPanel);
      mainPanel.add(Box.createVerticalStrut(10));
      mainPanel.add(youLabelPanel);
      mainPanel.add(inputPanel);

      JFrame frame = new JFrame("Foo");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.add(mainPanel);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }
}

This would result in a simple (non-functioning) GUI that looked like this:
enter image description here

Now say you want to change this and add another button, an "exit" JButton to the right of the send JButton. If you used null layout, you'd have to resize your GUI, you'd have to move the send button over to the left and make sure that your math was without error, etc. If you used layout managers, you'd need just two new lines of code (to change the display, not the functionality of course):

  JTextField inputField = new JTextField(40);
  JButton sendBtn = new JButton("Send");
  JButton exitBtn = new JButton("Exit"); // ***** added
  JPanel inputPanel = new JPanel();
  inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.LINE_AXIS));
  inputPanel.add(inputField);
  inputPanel.add(sendBtn);
  inputPanel.add(exitBtn);  // ***** added

That's it, and this would display:
enter image description here

Adding components into JPanel inside a JFrame

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