Chat layout with BoxLayout manager

Question

Box layout seems to be quite suitable for the needs of typical chat layout like the one I've made in InkScape.

I have based the structure like this:

MainFrame
  Chat JPanel - BoxLayout.Y_AXIS
    Message list - ScrollablePanel
       the list - BoxLayout.Y_AXIS
    Text field - Just a text field

Now the only problem I seem to have is, that in the inital phase, the space is divided 50% to 50% between text field and the message list.

However, if the message area is filled, as you can see in the image above and I try to resize the chat window, everything goes well:

So:

1. I want the textarea to keep the same size, even when message container is empty.
2. There must be a method to be called to simulate me resizing the window so that the panels update properly.

Here is the chat panel:

public class ChatPanel extends JPanel {
    private BoxLayout layout;
    private TextField input;
    private MessageList messages;
    public ChatPanel() {
      layout = new BoxLayout(this, BoxLayout.Y_AXIS);
      setLayout(layout);
      //Create message list
      messages = new MessageList();
      messages.appendTo(this);
      //Create text field
      input = new TextField();
      add(input);
    }
    public void addMessage(String message) {
      messages.addMessage(message);   
    }
    public void appendTo(JFrame frame) {
       frame.getContentPane().add(this);   
    }
}

And here is the messageList:

public class MessageList extends JPanel {
    public MessageList() {
      setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

    }
    public void addMessage(String message) {
      JLabel lb = new JLabel();
      lb.setText(message);
      add(lb);        
      validate();
    }
    public void appendTo(JPanel frame) {
       frame.add(new JScrollPane(this));   
    }
}

Answer 1

As shown in How to Use BoxLayout: Specifying Component Sizes, you can override the getXxxSize() methods in your chosen JTextComponent subclass.