Name: dbT83986 Date: 01/11/99


If you have a JComboBox inside a panel that is using the BoxLayout
manager, and that panel has extra space due to some other component
within the frame, then the combobox's width will be wrong because
the BoxLayout manager stretches it to fill the extra space. Since
the BoxLayout manager is suppose to use preferred sizes this seems
to be a definite bug.

Even when adding "glue" to the BoxLayout manager to try and force
the combobox all the way to the left, the width of the combobox
is still wrong because it is much wider than its widest element.

The following code will display the bug. You can use "noglue"
on the command line to avoid having horizontal glue added. If you
do you'll see the combobox stretched to fill the extra space.
You can also use "notext" on the command line to avoid having
the JTextField component added. If you do then you'll see that
the correct width for the combobox is used.

//~~~~~~~~~~~~~~~~~~~~~~ cut here ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

class bug2 {
    public static void main (String args[]) {
        // Command line options:
        // noglue -> no horizontal glue will be added in toolbar
        // notext -> no JTextField component will be added in lower panel
        boolean addGlue = true;
        boolean addText = true;
        for (int i=0; i < args.length; i++) {
            if (args[i].equals("noglue")) addGlue = false;
            else if (args[i].equals("notext")) addText = false;
        }

        JFrame frame = new JFrame();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);}
        });

        JPanel pane = new JPanel();
        pane.setLayout(new BoxLayout(pane, BoxLayout.X_AXIS));

        JLabel l = new JLabel("Choices : ");
        String s[] = {"Choice1", "Choice Number2"};
        JComboBox cb = new JComboBox(s);

        pane.add(l);
        pane.add(cb);
        if (addGlue)
            pane.add(Box.createHorizontalGlue());

        JTextField txt = new JTextField(40);

        // *** Create main panel to hold two inner containers ***
        JPanel main = new JPanel();
        main.setLayout(new BorderLayout());
        main.add(pane, BorderLayout.NORTH);
        if (addText)
            main.add(txt, BorderLayout.CENTER);

        frame.getContentPane().add(main);
        frame.pack();
        frame.setVisible(true);
    }
}
(Review ID: 52452)
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