How can I place buttons in the center of the frame in a vertical line?

Question

I will place these buttons in the center of the frame and above each other, like this.

                                     BUTTON
                                     BUTTON
                                     BUTTON

I've searched multiple topics on this forum but everything I tried didn't work for so far. I hope that somebody has the solution.

This is my code for so far:

package ípsen1;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JPanel;

public class Paneel extends JPanel implements ActionListener {
Image achtergrond;
private JButton spelHervatten;
private JButton spelOpslaan;
private JButton spelAfsluiten;


public Paneel(){
    //buttons   
    spelHervatten = new JButton("Spel hervatten");
    spelHervatten.setPreferredSize(new Dimension(380, 65));

    spelOpslaan = new JButton("Spel opslaan");
    spelOpslaan.setPreferredSize(new Dimension(380, 65));

    spelAfsluiten = new JButton("Spel afsluiten");  
    spelAfsluiten.setPreferredSize(new Dimension(380, 65));


    //object Paneel luistert naar button events
    spelAfsluiten.addActionListener(this);

    add (spelHervatten);
    add (spelOpslaan);
    add (spelAfsluiten);
    }

public void paintComponent(Graphics g) {
    //achtergrond afbeelding zetten
    achtergrond = Toolkit.getDefaultToolkit().getImage("hout.jpg");
    //screensize
    g.drawImage(achtergrond, 0,0, 1024,768,this);
}

    //actie na klik op button
            public void actionPerformed(ActionEvent e) {
                if(e.getSource() == spelAfsluiten){
                    System.out.println("Spel afsluiten");
                    System.exit(0);
                    }
                }
            }

`spelOpslaan.setPreferredSize(new Dimension(380, 65));` See [Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?](http://stackoverflow.com/q/7229226/418556) (Yes.) — Andrew Thompson, Apr 08 '14 at 11:38
`public void paintComponent(Graphics g) { //achtergrond afbeelding zetten achtergrond = Toolkit.getDefaultToolkit().getImage("hout.jpg");..` 1) The 1st line should be `super.paintComponent(g);` 2) `achtergrond afbeelding zetten` Comments that aren't in English are noise on SO. 3) Don't load the image in the `paintXxx(..)` methods! Instead load it at start-up and store it as a class attribute. — Andrew Thompson, Apr 08 '14 at 11:41
For better help sooner, post an [MCVE](http://stackoverflow.com/help/mcve) (Minimal Complete and Verifiable Example). — Andrew Thompson, Apr 08 '14 at 11:42

MadProgrammer · Answer 1 · 2014-04-08T10:14:01.163

8

You could use a GridBagLayout

Buttons

setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;

add(new JButton("Button"), gbc);
add(new JButton("Button"), gbc);
add(new JButton("Button"), gbc);
add(new JButton("Button"), gbc);

See How to Use GridBagLayout for more details

edited Apr 08 '14 at 10:14

answered Apr 08 '14 at 10:05

MadProgrammer

343,457
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score 1 · Answer 2 · answered Apr 08 '14 at 10:00

A BoxLayout might be what you're after. You can specify that you want to add components along the y-axis in the constructor for that particular layout manager.

You could add this line to the constructor of your Paneel class.

this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

As for center-aligning everything, I don't know if it's good practice but you can set the horizontal alignment for each of your buttons individually. Example:

spelHervatten.setAlignmentX(CENTER_ALIGNMENT);

score 1 · Answer 3 · answered Apr 08 '14 at 11:32

Uses a GridLayout for a single column of buttons of equal width.

The buttons stretch as the window's size increases. To maintain the button size, put the GridLayout as a single component into a GridBagLayout with no constraint. It will be centered.

enter image description here

The size of the buttons is increased by setting a margin.

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

/*
 * Uses a GridLayout for a single column of buttons of equal width.
 * The buttons stretch as the window's size increases.  To maintain
 * the button size, put the GridLayout as a single component into a 
 * GridBagLayout with no constraint.  It will be centered.
 */
public class CenteredSingleColumnOfButtons {

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                // the GUI as seen by the user (without frame)
                JPanel gui = new JPanel(new GridLayout(0,1,10,10));
                gui.setBorder(new EmptyBorder(20,30,20,30));

                String[] buttonLabels = {
                    "Spel hervatten",
                    "Spel opslaan",
                    "Spel afsluiten"
                };

                Insets margin = new Insets(20,150,20,150);
                JButton b = null;
                for (String s : buttonLabels) {
                    b = new JButton(s);
                    b.setMargin(margin);
                    gui.add(b);
                }

                JFrame f = new JFrame("Centered Single Column of Buttons");
                f.add(gui);
                // Ensures JVM closes after frame(s) closed and
                // all non-daemon threads are finished
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                // See http://stackoverflow.com/a/7143398/418556 for demo.
                f.setLocationByPlatform(true);

                // ensures the frame is the minimum size it needs to be
                // in order display the components within it
                f.pack();
                f.setMinimumSize(f.getSize());
                // should be done last, to avoid flickering, moving,
                // resizing artifacts.
                f.setVisible(true);
                System.out.println(b.getSize());
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency
        SwingUtilities.invokeLater(r);
    }
}

score 0 · Answer 4 · answered Apr 08 '14 at 09:59

0

I thought there is no way to do that.

You should get size of Panel/Frame then calculate manually to find to center position for your button.

answered Apr 08 '14 at 09:59

tana

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Recommendations of absolute layouts don't produce professional or long term sustainable results, especially when there are plenty of other, simpler solutions that would work across platforms – MadProgrammer Apr 08 '14 at 10:15

thinkgruen · Answer 5 · 2014-04-08T10:19:25.730

0

Rephrased some parts:

You might want to try to put the buttons in JFrame's "wind direction"-style BorderLayout: http://www.leepoint.net/notes-java/GUI/layouts/20borderlayout.html

Just create a block in the CENTER with one EAST and WEST block with a certain size around it. Then insert the buttons inside of the center block. If you don't want them to be the full size, just add another EAST and WEST.

edited Apr 08 '14 at 10:19

answered Apr 08 '14 at 10:08

thinkgruen

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Until you want to add more than three buttons or don't want to them to expand the full width or want them to be equal height...interesting idea... – MadProgrammer Apr 08 '14 at 10:14

How can I place buttons in the center of the frame in a vertical line?

5 Answers5