GridBagLayout Problem

[Axel Leucht]

I do have a problem with the GUI-Layout.

Problem is: Initially everything looks ok. But whenever I resize the panel to a very small size, the JTextfields "jump" to their minimum size. which looks very bad.

Here is some code to demonstrate what I mean and I would appreciate any help on this issue.

public class AboutPanel extends JPanel {
    private GridBagLayout gridBagLayout1 = new GridBagLayout();
    private JLabel lblAbout = new JLabel();
    private JLabel lblVersion = new JLabel();
    private JTextField javaCersion = new JTextField();
    private JLabel lblTotMemory = new JLabel();
    private JTextField totalMemory = new JTextField();
    private JLabel jLabel1 = new JLabel();
    private JLabel jLabel2 = new JLabel();
    private JTextField operatingSystem = new JTextField();
    private JTextField maxMemory = new JTextField();
    private JButton btnOk = new JButton();

    public AboutPanel() {
        try {
            jbInit();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void jbInit() throws Exception {
        this.setLayout(gridBagLayout1);
        lblAbout.setText("About");
        lblVersion.setText("Java-Version:");
        javaCersion.setColumns(10);
        javaCersion.setEditable(false);
        lblTotMemory.setText("Total memory:");
        totalMemory.setColumns(10);
        totalMemory.setEditable(false);
        jLabel1.setText("Max memory:");
        jLabel2.setText("Operating system:");
        operatingSystem.setColumns(10);
        operatingSystem.setEditable(false);
        maxMemory.setColumns(10);
        maxMemory.setEditable(false);
        btnOk.setText("Ok");
        btnOk.setActionCommand("btnOk");
        this.add(lblAbout, 
                 new GridBagConstraints(0, 0, 2, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 0, 0, 0), 0, 0));
        this.add(lblVersion, 
                 new GridBagConstraints(0, 2, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 0, 0, 0), 0, 0));
        this.add(javaCersion, 
                 new GridBagConstraints(1, 2, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 5, 0, 5), 0, 0));
        this.add(lblTotMemory, 
                 new GridBagConstraints(0, 3, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 0, 0, 0), 0, 0));
        this.add(totalMemory, 
                 new GridBagConstraints(1, 3, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 5, 0, 5), 0, 0));
        this.add(jLabel1, 
                 new GridBagConstraints(0, 4, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 0, 0, 0), 0, 0));
        this.add(jLabel2, 
                 new GridBagConstraints(0, 1, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 0, 0, 0), 0, 0));
        this.add(operatingSystem, 
                 new GridBagConstraints(1, 1, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 5, 0, 5), 0, 0));
        this.add(maxMemory, 
                 new GridBagConstraints(1, 4, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(5, 5, 0, 5), 0, 0));
        this.add(btnOk, 
                 new GridBagConstraints(0, 5, 2, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, 
                                        new Insets(17, 0, 11, 0), 0, 0));
    }
    
    public static void main(String[] args) {
	JFrame frame = new JFrame("Test");
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.add(new AboutPanel());
	frame.pack();
	frame.setVisible(true);
    }
}

[pete stein]

Perhaps setting weights of your components will help. Myself, I would avoid GridBagLayout unless forced. Instead I nest simpler layouts. For instance:

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.util.HashMap;
import java.util.Map;

import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;

public class AboutPanel2
{
  private JPanel mainPanel = new JPanel();
  enum ABOUT_KEY
  {
    OPERATING_SYSTEM("Operating System:"), 
    JAVA_VERSION("Java-Version:"), 
    TOTAL_MEMORY("Total Memory:"), 
    MAX_MEMORY("Max Memory:");
    
    private String text;
    private ABOUT_KEY(String text)
    {
      this.text = text;
    }
    
    public String getText()
    {
      return text;
    }
  };
  private static final float TITLE_POINTS = 40;
  private static final String TITLE_STRING = "About";
  private static final int FIELD_COLS = 20;
  private Map<ABOUT_KEY, JTextField> fieldmap = new HashMap<ABOUT_KEY, JTextField>();
  
  public AboutPanel2()
  {
    JLabel titleLabel = new JLabel(TITLE_STRING, SwingConstants.CENTER);
    titleLabel.setFont(titleLabel.getFont().deriveFont(Font.BOLD, TITLE_POINTS));
    
    int gridVGap = 10;
    int gridHGap = 0;
    JPanel labelPanel = new JPanel(new GridLayout(0, 1, gridHGap, gridVGap));
    JPanel fieldPanel = new JPanel(new GridLayout(0, 1, gridHGap, gridVGap));
    for (ABOUT_KEY key : ABOUT_KEY.values())
    {
      JLabel label = new JLabel(key.getText());
      JTextField field = new JTextField(FIELD_COLS);
      field.setEditable(false);
      fieldmap.put(key, field);
      
      labelPanel.add(label);
      fieldPanel.add(field);
    }
    
    int ebGap = 5;
    int blHGap = 30;
    int blVGap = 10;
    mainPanel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
    mainPanel.setLayout(new BorderLayout(blVGap, blHGap));
    
    mainPanel.add(titleLabel, BorderLayout.NORTH);
    mainPanel.add(labelPanel, BorderLayout.WEST);
    mainPanel.add(fieldPanel, BorderLayout.CENTER);
    
  }
  
  public void setFieldText(ABOUT_KEY key, String text)
  {
    fieldmap.get(key).setText(text);
  }

  public JComponent getComponent()
  {
    return mainPanel;
  }

  private static void createAndShowUI()
  {
    JFrame frame = new JFrame("AboutPanel2");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();
    frame.setLocationRelativeTo(null);
    //frame.setVisible(true);
    
    AboutPanel2 about2 = new AboutPanel2();
    about2.setFieldText(ABOUT_KEY.OPERATING_SYSTEM, "Windoz 7.zzzzz");
    about2.setFieldText(ABOUT_KEY.JAVA_VERSION, "THE LATEST & GREATEST!");
    about2.setFieldText(ABOUT_KEY.TOTAL_MEMORY, "A Gazillion!");
    about2.setFieldText(ABOUT_KEY.MAX_MEMORY, "Always less than you thought");
    
    JOptionPane.showMessageDialog(frame, about2.getComponent(), 
        "General Information", JOptionPane.INFORMATION_MESSAGE);
    
    frame.dispose();
  }

  public static void main(String[] args)
  {
    java.awt.EventQueue.invokeLater(new Runnable()
    {
      public void run()
      {
        createAndShowUI();
      }
    });
  }
}

[Mikko Kohtamäki]

Try adding your panel to JScrollPane, that way components wont slide to left when resizing and you may want to set preferred size for labels.

        JScrollPane scroll= new JScrollPane(panel, JScrollPane.VERTICAL_SCROLLBAR_NEVER,
                JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
        scroll.setBorder(new EmptyBorder(0, 0, 0, 0));

[Michael Dunn]

this seems to work OK, but GridBagLayout has a habit of 'fixing one thing, breaks another 2'
so just needs a lot of testing to see how it stands up.

1) get rid of the column setting for each textfield
//javaCersion.setColumns(10);

2) include an ipadx of 100 (2nd last argument), but only for the 4 textFields
//new Insets(5, 5, 0, 5), 0, 0));
new Insets(5, 5, 0, 5), 100, 0));

this should get you close to the size you want for the textfields, if not, modify the 100

[Maneesh Godbole]

Check out MigLayout if you are interested.
http://www.miglayout.com/