Re: GridBagLayout disease

[kynn]

   Date: Mon, 22 Oct 2001 15:47:45 -0400
   To: [EMAIL PROTECTED]
   From: Paul Brinkley <[EMAIL PROTECTED]>
   Subject: Re: GridBagLayout disease

   At 02:29 PM 10/22/2001 -0400, [EMAIL PROTECTED] wrote:
   >I have a GUI consisting of three areas:
   >
   >    ___ ___
   >   |   | B |
   >   | A |---|
   >   |   | C |
   >   |___|___|
   >
   >* Area A contains a JTree inside a JScrollPane.
   >
   >* Area B contains a JTextField, a JButton, and 3 JRadioButtons.
   >
   >* Area C contains a JSplitPane, which in turn contains a JList within
   >   a JScrollPane in the top pane, and a JTree within a JScrollPane in
   >   the bottom pane.
   >[snip]


   First, in GBLs, the weight constraints govern how to allocate a -change- in
   dimension, as opposed to total dimension.

Thanks, that was useful.

I wrote a small class that shows some of the pathologic behavior I'm
getting (see source code below).  Running it produces a GUI of the
form:

   ___ ___
  |   |   |
  | A | B |
  |   |   |
  |___|___|

To see the problem, just shorten the window *vertically* (keeping the
width constant).  Even a slight shortening will do.  The result will
look like
   __ ____
  |  |    |
  |A | B  |
  |__|____|

i.e., vertically shorter, but A is narrower, and B wider, than before,
even though there was no horizontal resizing at all.

This sure looks like a bug to me.  Is there a way around it?

KJ

/* Class: Sick */
import javax.swing.*;
import java.awt.*;

public class Sick extends JPanel {

  private static JFrame frame;
  private JScrollPane scrollPane;
  private JPanel panel;
  private JTree tree;
  private JButton button;

  public Sick() {
    super();
    setLayout(new GridBagLayout());

    GridBagConstraints gbc;

    tree = new JTree();
    scrollPane = new JScrollPane(tree);
    gbc = getBaseConstraints();
    gbc.gridx = 0;
    add(scrollPane, gbc);

    panel = new JPanel();
    button = new JButton("button");
    panel.add(button);
    gbc = getBaseConstraints();
    gbc.gridx = 1;
    add(panel, gbc);
  }

  private GridBagConstraints getBaseConstraints() {
    GridBagConstraints baseGbc = new GridBagConstraints();
    baseGbc.weightx = baseGbc.weighty = 1.;
    baseGbc.fill = GridBagConstraints.BOTH;
    baseGbc.gridy = 0;
    return baseGbc;
  }

  public static void main(String[] args) {
    frame = new JFrame();
    frame.getContentPane().add(new Sick(), "Center");
    frame.pack();
    frame.show();
  }
}


_______________________________________________
Swing mailing list
[EMAIL PROTECTED]
http://eos.dk/mailman/listinfo/swing