How do I anchor JPanel location?

From:

Todd <todd.heidenthal@lmco.com>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 20 Sep 2007 08:41:01 -0700

Message-ID:

<1190302861.336611.260060@57g2000hsv.googlegroups.com>

Hello all,

The subject to this may make you think that I have a rather simple
problem - and hopefully it is for some guru out there.

I have created a JTabbedPane into which I place JPanel's to create the
tabs. Each of these JPanel's contains three more panels which are
extensions of JPanel.

The class for the sub-panels provides a JPanel with the ability to be
"collapsed" - the height of the JPanel is adjusted and other objects
within the parent pane are relocated appropriately.

Here is the problem: When I expand one of the collapsed sub-panels in
one tab, the other tabs take on the expanded size of the original tab
(which I really don't want, so if you have ideas how to prevent that,
please feel free to expound), and move their corresponding sub-panels
to the center of the tabbed JPanel. How do I prevent the sub-panels
from centering? If the sub-panels could stay anchored to the upper
left of the parent JPanel, then I would have a way to ensure
consistent layout.

I have tried multiple layout schemes, but none of them maintain the
positioning of the sub-panels (furthermore, only the GridBagLayout
seems to layout my sub-panels appropriately). Here is the code that I
am currently using:

    /** Creates a new instance of TrajectoryTabJPanel */
    public rajectoryTabJPanel()
    {
        StateVectorJPanel stateVectorJPanel = new StateVectorJPanel();
        PerturbationJPanel perturbationJPanel = new
PerturbationJPanel();
        ConstraintJPanel ConstraintJPanel = new ConstraintJPanel();

        // Add the subpanels to the subpanel vector
        addSubPanel( stateVectorJPanel );
        addSubPanel( perturbationJPanel );
        addSubPanel( constraintJPanel );

        // Define the layout for the subpanels
        GridBagLayout layout = new GridBagLayout();
        this.setLayout( layout );

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = GridBagConstraints.RELATIVE;

        gbc.insets = new Insets( 10, 0, 5, 0 );
        this.add( stateVectorJPanel, gbc );

        gbc.insets = new Insets( 5, 0, 5, 0 );
        this.add( perturbationJPanel, gbc );

        gbc.insets = new Insets( 5, 0, 10, 0 );
        this.add( deboostConstraintJPanel, gbc );
    }

Thanks for any suggestions (beyond SSCP - I always try that before
posting),
Todd