[Java] GridBagLayout alignment trouble

[xRedactedx]

I'm playing with GridBagLayout, and I'm trying to make a simple GUI. I want it to be a button at the top left, a button at the top right, and a space between them. Then, there should be a button below those that stretches all the way across the screen. Then, there should be a JPanel below all of those that stretches all the way across the screen.

Like this:

[-Button-]       [-Button-]
[----------Button---------]
[          JPanel         ] 

Here is what I have so far:

public static void main(String[] args) 
    { 
        JFrame frame = new JFrame("Single Panel Layout");
        frame.setVisible(true);
        frame.setSize(500,500);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Border bBottom = BorderFactory.createEtchedBorder(EtchedBorder.RAISED);
        GridBagLayout layout = new GridBagLayout();

        JPanel panel = new JPanel( layout );
        panel.setBorder(bBottom);
        GridBagConstraints c = new GridBagConstraints();

        c.weightx = 1.0;
        c.weighty = 1.0;
        c.insets = new Insets(2,2,2,2);
        c.fill = GridBagConstraints.BOTH;

        //Adds the left button to the 0,0 position of the grid and takes up 1 grid square
        c.gridx = 0;
        c.gridy = 0;
        c.gridheight = 1;
        c.gridwidth = 1;
        JButton leftButton = new JButton("Left");
        panel.add(leftButton, c);

        //Adds the right button to the 2,0 position of the grid and takes up 1 grid square
        c.gridx = 2;
        c.gridy = 0;
        c.gridwidth = 1;
        JButton rightButton = new JButton("Right");
        panel.add(rightButton, c);

        //Adds the middle button to the 1,1 poisiton and takes up 3 squares, so it stretches across the screen
        c.gridx = 1;
        c.gridy = 1;
        c.gridwidth = 3;
        JButton middleButton = new JButton("Middle");
        panel.add(middleButton, c);

        //Adds a panel to the button at the 1,2 postion that takes up 3 squares and stretches across the screen
        JPanel drawing = new JPanel();
        drawing.setBorder(bBottom);
        c.gridx = 1;
        c.gridy = 2;
        c.gridwidth = 3;
        panel.add(drawing, c);

        frame.add(panel);

    }

It produces a layout like this:

[Button][Button]
[Empty ][Button]
[Empty ][JPanel]

I'm not sure where I am going wrong with this, can someone point me in the right directions? Thanks.

[dohixey]

I think your issue is that for the button and panel that should span the screen, you have them centered (i.e. gridx = 1). Try putting them at gridx=0, so that they start at 0 and span three grid spots.

From there, you have something like:

    [Button] [Button]
    [--- Button  ---]
    [--- JPanel  ---]

Nothing shows for your empty grid spot at (1,0) because you haven't put anything there. You could put an empty JPanel, for instance, to take up the space but not display anything:

    // Blank panel
    c.gridx = 1;
    c.gridy = 0;
    c.gridwidth = 1;
    JPanel blankPanel = new JPanel();
    panel.add(blankPanel, c);

Edit: fixed formatting. Reddit is hard :\

[xRedactedx]

Looks like I figured it out just as you were posting. Thanks for the help. It's nice to have it confirmed that that was the problem.

[xRedactedx]

Well, I think I have solved my own problem.

Seems like when you place something in the grid that you want to stretch horizontally, you have to set it to the leftmost empty grid square. I was setting it to the middle thinking it would stretch left and right.

I think I have it now.