What is best way to center objects in JPanel horizontally and vertically

Question

I'm trying to add a panel p1 on the left on the panelMain. Since the objects are not center vertically, I tried to add p1 on p2, which has BorderLayout. I guess this is not a good way but it doesn't even work. I didn't use GridLayout because I don't want the objects to fill up the whole JPanel.

JPanel panelMain = new JPanel( new BorderLayout() );

JPanel p1 = new JPanel( new FlowLayout(FlowLayout.CENTER) );
panelText.setPreferredSize( new Dimension( 250, frame.getHeight() ) );
panelText.add( new JLabel( "Name:", SwingConstants.RIGHT) );
panelText.add( new JTextField( "First Last:", 15 ) );
panelText.add( new JLabel( " Tel:", SwingConstants.RIGHT) );
panelText.add( new JTextField( "000-000-0000", 15) );

JPanel p2 = new JPanel( new BorderLayout() );
p2.add( p1, BorderLayout.CENTER );

panelMain.add( p2,BorderLayout.WEST );

See [this answer](http://stackoverflow.com/a/16727593/418556) for two layouts (`GridBagLayout` or `BoxLayout`) that will center a component or container. — Andrew Thompson, Mar 01 '14 at 07:48

Paul Samsotha · Answer 1 · 2014-03-01T05:11:54.787

"What is best way to center objects in JPanel horizontally and vertically"

You can wrap everything in JPanel then wrap that JPanel in another JPanel with a GridBagLayout

JPanel mainPanel = your main panel
JPanel wrapperPanel = new JPanel(new GridBagLayout());
wrapperPanel.add(mainPanel);
frame.add(wrapperPanel);

Example

enter image description here

import java.awt.*;
import javax.swing.*;
import javax.swing.border.TitledBorder;

public class TestCenterGridbagLayout {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                JPanel mainPanel = new JPanel(new GridLayout(3, 3));
                for (int i = 0; i < 9; i++) {
                    mainPanel.add(new JButton("Button"));
                }
                mainPanel.setBorder(new TitledBorder("Main Panel"));

                JPanel wrapperPanel = new JPanel(new GridBagLayout());
                wrapperPanel.setPreferredSize(new Dimension(350, 300));
                wrapperPanel.add(mainPanel);
                wrapperPanel.setBorder(new TitledBorder("Wrapper panel with GridbagLayout"));

                JOptionPane.showMessageDialog(null, wrapperPanel);

            }
        });
    }
}

What is best way to center objects in JPanel horizontally and vertically

1 Answers1