Question

I am trying to align the RadioButtons in my program here. Can someonee help me? I am not exactly sure how to go about it. I have searched here and elsewhere and cannnot seem to find an applicable example. Here is, what I believe the relevant portion of my code. If more is needed, I will edit.

final class SplitPanel extends JFrame {
    private FlowLayout flowLayout = new FlowLayout();
    private GridLayout gridLayout = new GridLayout(4, 1);
    private DiagLayout diagLayout = new DiagLayout();

    private JRadioButton jrbFlowLayout = new JRadioButton("Horizontal");
    private JRadioButton jrbGridLayout = new JRadioButton("Verticle");
    private JRadioButton jrbDiagLayout = new JRadioButton("Diagonal");

    private JButton jbt1 = new JButton("Button 1");
    private JButton jbt2 = new JButton("Button 2");
    private JButton jbt3 = new JButton("Button 3");
    private JButton jbt4 = new JButton("Button 4");

    private JSplitPane jSplitPane;
    private JPanel jPanel1, jPanel2;

    public SplitPanel() {
        this.setTitle("Split Panel with Diagonalization");
        this.setSize(600, 400);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        createPanel1();
        createPanel2();

        jSplitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
                jPanel1, jPanel2);
        jSplitPane.setOneTouchExpandable(true);
        jSplitPane.setContinuousLayout(true);
        jSplitPane.setDividerLocation(150);

        getContentPane().add(jSplitPane);
    }

    public void createPanel1() {
        jPanel1 = new JPanel();
        jPanel1.setBorder(new TitledBorder("Select a Layout Manger"));
        jPanel1.add(jrbFlowLayout);
        jPanel1.add(jrbGridLayout);
        jPanel1.add(jrbDiagLayout);

        ButtonGroup buttonGroup1 = new ButtonGroup();
        buttonGroup1.add(jrbFlowLayout);
        buttonGroup1.add(jrbGridLayout);
        buttonGroup1.add(jrbDiagLayout);

    }

    public void createPanel2() {
        jPanel2 = new JPanel();
        jPanel2.setLayout(diagLayout);
        jPanel2.add(jbt1);
        jPanel2.add(jbt2);
        jPanel2.add(jbt3);
        jPanel2.add(jbt4);

        jrbFlowLayout.addActionListener (new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                jPanel2.setLayout(flowLayout);
                jPanel2.validate();
            }
        });

        jrbGridLayout.addActionListener (new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                jPanel2.setLayout(gridLayout);
                jPanel2.validate();
            }
        });

        jrbDiagLayout.addActionListener (new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                jPanel2.setLayout(diagLayout);
                jPanel2.validate();
            }
        });

    }

Thank you for your help!

Answer 1

The default layout of a JPanel is a FlowLayout.
http://docs.oracle.com/javase/tutorial/uiswing/layout/using.html

You might want to set the panels layout to a GridLayout or even a BoxLayout.

in

createPanel1(){
// create panel.
jPanel1.setLayout(new GridLayout(0,1));