Develop Reference

How to add spacing between JPanel and JFrame's contentPane?

This is the picture I am trying to replicate
This is what I have (didn't add icon images yet)
I can't seem to find a solution, been staring at it for quite some time.
I am trying to replicate the following picture, using GridLayout for the buttons and the figure out the rest on my own using Java Swing. Furthermore, I've added my buttons into a JPanel and now I'm trying to add spacing between the panel and the pane.
This is what I have, how can I go about it?
super(title);
this.setLayout(new BoxLayout(this.getContentPane(), BoxLayout.PAGE_AXIS));
Container pane = this.getContentPane();
JButton b1 = new JButton();
b1.setBackground(Color.white);
JButton b2 = new JButton();
b2.setBackground(Color.white);
JButton b3 = new JButton();
b3.setBackground(Color.white);
JButton b4 = new JButton();
b4.setBackground(Color.white);
JButton b5 = new JButton();
b5.setBackground(Color.white);
JButton b6 = new JButton();
b6.setBackground(Color.white);
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(2,3,10,10));
panel.setBackground(Color.black);
panel.add(b1);
panel.add(b2);
panel.add(b3);
panel.add(b4);
panel.add(b5);
panel.add(b6);
pane.add(panel);
this.setSize(500,500);
this.setVisible(true);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);

The easiest way to do it would be to add an empty border to your JPanel (see this post on empty borders):
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(3, 2, 10, 10));
// ...
panel.setBorder(new EmptyBorder(50, 50, 50, 50));
Another good approach (depending always on your application needs), if you have the JButton preferred size set, would be to have the main JPanel's grid layout set to have two columns and one row, with another JPanel inside each column. Adding to the interior JPanels a BoxLayout in Y_AXIS mode and aligning the buttons with setAlignmentX() would work great too (note this approach wouldn't center the JButtons vertically) (see How to use BoxLayout):
public class MyFrame extends JFrame {
private String title = "Title";
public MyFrame(){
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new GridLayout(1,2,10,10));
JPanel rightPanel = new JPanel();
rightPanel.setLayout(new BoxLayout(rightPanel, BoxLayout.Y_AXIS));
JPanel leftPanel = new JPanel();
leftPanel.setLayout(new BoxLayout(leftPanel, BoxLayout.Y_AXIS));
mainPanel.add(leftPanel);
mainPanel.add(rightPanel);
JButton b1 = new JButton();
b1.setBackground(Color.white);
//b1.setIcon(new ImageIcon(img1));
b1.setAlignmentX(Component.RIGHT_ALIGNMENT);
leftPanel.add(b1);
JButton b2 = new JButton();
b2.setBackground(Color.white);
//b2.setIcon(new ImageIcon(img2));
b2.setAlignmentX(Component.RIGHT_ALIGNMENT);
leftPanel.add(b2);
JButton b3 = new JButton();
b3.setBackground(Color.white);
//b3.setIcon(new ImageIcon(img3));
b3.setAlignmentX(Component.RIGHT_ALIGNMENT);
leftPanel.add(b3);
JButton b4 = new JButton();
b4.setBackground(Color.white);
//b4.setIcon(new ImageIcon(img4));
b4.setAlignmentX(Component.LEFT_ALIGNMENT);
rightPanel.add(b4);
JButton b5 = new JButton();
b5.setBackground(Color.white);
//b5.setIcon(new ImageIcon(img5));
b5.setAlignmentX(Component.LEFT_ALIGNMENT);
rightPanel.add(b5);
JButton b6 = new JButton();
b6.setBackground(Color.white);
//b6.setIcon(new ImageIcon(img6));
b6.setAlignmentX(Component.LEFT_ALIGNMENT);
rightPanel.add(b6);
add(mainPanel); //Adding our mainPanel to the contentPane of the JFrame
this.setSize(500,500); //or pack();
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setTitle(title);
this.setVisible(true);
}
}

Here's a little demonstration I whipped up.
All Swing applications must start with a call to the SwingUtilities invokeLater method. This method ensures that all Swing components are created and executed on the Event Dispatch Thread.
You don't set the size of the JFrame and try and make the Swing components fit. You let the JFrame pack with all the Swing components.
You create a GridLayout JPanel inside of a FlowLayout JPanel. The FlowLayout JPanel uses an empty border of the appropriate size.
I used the image the OP provided to get the icons.
Here's the complete runnable code.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class EmptySpaceDemo implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new EmptySpaceDemo());
}
private Image[] images;
public EmptySpaceDemo() {
this.images = createImages();
}
private Image[] createImages() {
BufferedImage image = readImage();
Image[] images = new Image[6];
images[0] = image.getSubimage(155, 113, 110, 90);
images[1] = image.getSubimage(276, 113, 110, 90);
images[2] = image.getSubimage(155, 217, 110, 90);
images[3] = image.getSubimage(276, 217, 110, 90);
images[4] = image.getSubimage(155, 321, 110, 90);
images[5] = image.getSubimage(276, 321, 110, 90);
return images;
}
#Override
public void run() {
JFrame frame = new JFrame("Empty Space Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createMainPanel(), BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JPanel createMainPanel() {
JPanel panel = new JPanel(new FlowLayout());
panel.setBackground(Color.BLACK);
panel.setBorder(BorderFactory.createEmptyBorder(40, 100, 40, 100));
JPanel innerPanel = new JPanel(new GridLayout(0, 2, 10, 10));
innerPanel.setBackground(Color.BLACK);
for (int i = 0; i < images.length; i++) {
JButton button = new JButton(new ImageIcon(images[i]));
innerPanel.add(button);
}
panel.add(innerPanel);
return panel;
}
private BufferedImage readImage() {
try {
return ImageIO.read(getClass().getResourceAsStream("/icons.png"));
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}

How do I open a JFrame from a button click

I making a game but I have a main meny and too outer menys and I want to open one of the menys by clicking on the respective button in the JFrame.
code of main.java
package main;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import game.client.mainClient;
import game.server.mainServer;
public class main extends JPanel {
/**
*
*/
private static final long serialVersionUID = 6590770928148744094L;
private JLabel jcomp1;
private JButton jcomp5;
private JButton jcomp6;
private JLabel jcomp8;
private JLabel jcomp9;
private JLabel jcomp10;
public main() {
//construct components
jcomp1 = new JLabel ("test game");
jcomp5 = new JButton ("singel player");
jcomp6 = new JButton ("multiplayer");
jcomp8 = new JLabel ("this game is made by kebe_");
jcomp9 = new JLabel ("gui is made in guigenie");
jcomp10 = new JLabel ("game verision dev 1.0");
//adjust size and set layout
setPreferredSize (new Dimension (681, 466));
setLayout (null);
//add components
add (jcomp1);
add (jcomp5);
add (jcomp6);
add (jcomp8);
add (jcomp9);
add (jcomp10);
//set component bounds (only needed by Absolute Positioning)
jcomp1.setBounds (295, 5, 70, 25);
jcomp5.setBounds (265, 30, 115, 30);
jcomp6.setBounds (265, 65, 115, 30);
jcomp8.setBounds (0, 430, 180, 25);
jcomp9.setBounds (0, 415, 155, 20);
jcomp10.setBounds (0, 445, 140, 25);
// close and open
// singleplayer
jcomp5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
System.exit(0);
mainClient mc = new mainClient();
mc.setVisible(true);
}
});
// multiplayer
jcomp6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
System.exit(0);
mainServer ms = new mainServer();
ms.setVisible(true);
}
});
}
public static void main (String[] args) {
JFrame frame = new JFrame ("Test game");
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add (new main());
frame.pack();
frame.setVisible (true);
}
}
code of mainClient.java
package game.client;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class mainClient extends JPanel
{
/**
*
*/
private static final long serialVersionUID = -1271816540338950462L;
private JLabel jcomp1;
private JComboBox jcomp2;
private JButton jcomp3;
public mainClient() {
//construct preComponents
String[] jcomp2Items = {"save 1", "save 2", "save 3", "save 4", "save 5"};
//construct components
jcomp1 = new JLabel ("singel player");
jcomp2 = new JComboBox (jcomp2Items);
jcomp3 = new JButton ("play selected save");
//adjust size and set layout
setPreferredSize (new Dimension (681, 466));
setLayout (null);
//add components
add (jcomp1);
add (jcomp2);
add (jcomp3);
//set component bounds (only needed by Absolute Positioning)
jcomp1.setBounds (290, 5, 85, 25);
jcomp2.setBounds (280, 30, 100, 25);
jcomp3.setBounds (255, 70, 150, 25);
jcomp3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
}
public static void main (String[] args) {
JFrame frame = new JFrame ("Singel player");
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add (new mainClient());
frame.pack();
frame.setVisible (true);
}
}
code of mainServer
package game.server;
import java.awt.*;
import javax.swing.*;
public class mainServer extends JPanel
{
/**
*
*/
private static final long serialVersionUID = 2726545572728204122L;
private JLabel jcomp1;
private JButton jcomp2;
private JButton jcomp3;
public mainServer() {
//construct components
jcomp1 = new JLabel ("multiplayer");
jcomp2 = new JButton ("host game");
jcomp3 = new JButton ("join game");
//adjust size and set layout
setPreferredSize (new Dimension (681, 466));
setLayout (null);
//add components
add (jcomp1);
add (jcomp2);
add (jcomp3);
//set component bounds (only needed by Absolute Positioning)
jcomp1.setBounds (300, 0, 75, 25);
jcomp2.setBounds (285, 25, 100, 25);
jcomp3.setBounds (285, 50, 100, 25);
}
public static void main (String[] args) {
JFrame frame = new JFrame ("Multiplayer");
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add (new mainServer());
frame.pack();
frame.setVisible (true);
}
}
how can I open the JFrame in mainClient.java when I click on the singleplayer button, and the JFrame in mainServer.java when I click on the multiplayer button?

Create ActionListeners for your buttons. Define your frames, and you can access them with your class name. For example;
class mainClient extends JPanel {
JFrame mainClientFrame = new JFrame();
}
and then;
mainClient mc = new mainClient();
mc.mainClientFrame.setVisible(true);
if you want to use this frames in your main void, define them static.
class mainClient extends JPanel {
static JFrame mainClientFrame = new JFrame();
}

JAVA JTextField doesnt show up

So Im trying to make a little program to calculate the area of a specific shape.
The user should be able to make a input via a textfield (Like the height and stuff of the shapes). The he should press a button and the price should get printed.
But it doesnt show up.
Code:
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Rechner extends JFrame implements ActionListener{
private static JButton button1;
private static JButton button2;
private static JButton button3;
private static JButton button4;
private static JTextField numberField;
private JPanel jpanel;
public Rechner(String titel){
super(titel);
jpanel = new JPanel();
numberField = new JTextField(1500);
add(numberField, BorderLayout.CENTER);
button1 = new JButton("Rechteck");
button1.setBounds(10, 10, 150, 30);
button1.addActionListener(this);
add(button1);
button2 = new JButton("Dreieck");
button2.setBounds(170, 10, 150, 30);
button2.addActionListener(this);
add(button2);
button3 = new JButton("Trapez");
button3.setBounds(330, 10, 150, 30);
button3.addActionListener(this);
add(button3);
button4 = new JButton("Parallelogramm");
button4.setBounds(490, 10, 150, 30);
button4.addActionListener(this);
add(button4);
setResizable(false);
}
public static void main(String[] args) {
Rechner frame = new Rechner("Menu");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(660, 400);
frame.setLayout(null);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if(e.getSource() == button1){
System.out.println("fff");
}
String numberStr = numberField.getText();
}
}

The default layout manager of a JFrame (well, of its content pane in fact) is BorderLayout.
Without specified constraints , the component is added to BorderLayout.CENTER, so
add(component);
is the same as
add(component, BorderLayout.CENTER);
and each component added this way will replace the last component added to the center.
Also note that setBounds will have no effect if there is a layout manager, and that you create a JPanel that you never use.
Finally, you may want to have a look at this guide : A Visual Guide to Layout Managers

This line is mainly the problem:
add(numberField, BorderLayout.CENTER);
Is causing the TextField to fill the entire space. Then, the next time you add a component to the JFrame with BorderLayout.CENTER, the JTextField gets replaced. To fix this:
super(titel);
jpanel = new JPanel();
add(jpanel, BorderLayout.NORTH); //adding the jpanel
button1 = new JButton("Rechteck");
jpanel.add(button1);
button1.setBounds(10, 10, 150, 30);
//adding the other buttons to the JPanel...
//...
//...
button4.addActionListener(this);
button3.addActionListener(this);
button2.addActionListener(this);
button1.addActionListener(this);
numberField = new JTextField(1500);
add(numberField);//this will cause it to fill the remaining space
setResizable(false);
Explanation:
The buttons should go into the JPanel you created, and the JPanel should go into the JFrame's NORTH. That way they don't cover the JFrame

Set Layout of panel within CardLayout

I am trying to create a UI for an imaginary vehicle that has both Automatic and Manual modes. When the user sets the vehicle into one of the modes, it should only display the controls relevant to that mode, and I've accomplished this using a CardLayout.
However, I'd also like to be able to specify the location of the various elements of the layout for each card manually - for a static layout I'd do something along the lines of mainPanel.setLayout(null), but this simply gives a blank window when used on a CardLayout (hence the two commented-out lines in the code below).
How would I achieve both of these things? My current code is below:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class UI extends JFrame implements ActionListener{
public UI() {
initUI();
}
private JPanel cardPanel;
private CardLayout cardLayout = new CardLayout();
public final void initUI() {
cardPanel = new JPanel();
cardPanel.setLayout(cardLayout);
JPanel manualPanel = new JPanel();
getContentPane().add(manualPanel);
//manualPanel.setLayout(null);
cardPanel.add(manualPanel, "manual");
JPanel autoPanel = new JPanel();
//autoPanel.setLayout(null);
cardPanel.add(autoPanel, "auto");
JButton startButton = new JButton("START/STOP");
startButton.setBounds(50, 150, 200, 50);
startButton.addActionListener(new startListener());
manualPanel.add(startButton);
autoPanel.add(startButton);
JButton autoButton = new JButton("SWITCH TO AUTO");
autoButton.setBounds(50, 250, 200, 50);
autoButton.addActionListener(new autoListener());
manualPanel.add(autoButton);
JButton upButton = new JButton("^");
upButton.setBounds(125, 320, 50, 50);
upButton.addActionListener(new returnListener());
manualPanel.add(upButton);
JButton downButton = new JButton("\\/");
downButton.setBounds(125, 380, 50, 50);
downButton.addActionListener(new returnListener());
manualPanel.add(downButton);
JButton ccwButton = new JButton("<-");
ccwButton.setBounds(55, 350, 50, 50);
ccwButton.addActionListener(new returnListener());
manualPanel.add(ccwButton);
JButton cwButton = new JButton("->");
cwButton.setBounds(195, 350, 50, 50);
cwButton.addActionListener(new returnListener());
manualPanel.add(cwButton);
JButton ngzButton = new JButton("SOMETHING ELSE");
ngzButton.setBounds(50, 450, 200, 50);
ngzButton.addActionListener(new returnListener());
manualPanel.add(ngzButton);
JButton manualButton = new JButton("SWITCH TO MANUAL");
manualButton.setBounds(50, 250, 200, 50);
manualButton.addActionListener(new manualListener());
autoPanel.add(manualButton);
JButton returnButton = new JButton("SOMETHING ELSE");
returnButton.setBounds(50, 350, 200, 50);
returnButton.addActionListener(new returnListener());
autoPanel.add(returnButton);
setTitle("UI");
setSize(800, 600);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
add(cardPanel, BorderLayout.NORTH);
}
public static void main(String[] args) {
UI ui = new UI();
ui.setVisible(true);
}
public void actionPerformed(ActionEvent e){
}
private class returnListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
}
}
private class autoListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
cardLayout.show(cardPanel, "auto");
}
}
private class startListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
}
}
private class manualListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
cardLayout.show(cardPanel, "manual");
}
}
}

In your example, you create a startButton, but you then attempt to add the same instance to two different panels. Because a component can only occupy one container, you'll need to create two buttons, one for each panel.
As an aside, instead of using a null layout, give each panel BorderLayout, add the buttons to a JPanel having the default FlowLayout, and add the button panel to the SOUTH. You can then nest your illustrations in the CENTER using whatever layout is appropriate.
Addendum: As #Frakcool comments, using a layout will improve the cross-platform appearance of your buttons. Invoke pack() on the enclosing window, and override getPreferredSize() on the nested illustration panel to give it the needed size. In this related example, the CENTER panel is used for drawing only; having no components, its layout then becomes irrelevant.

Put a JTextfield on a JPanel?

Why the textfield is not appearing on my panel which is inside my frame?
I mean is there some additional action necessary to make the components of the panel
visible?
I hope somebody can help me....
public class example1 {
public static void main(String[] args) {
JFrame tt=new TT();
}
}
class TT extends JFrame {
JTextField textField;
JPanel panel;
JButton button1;
JButton button2;
public TT() {
setSize(300, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setTitle("Bla Blubb");
setResizable(false);
setLayout(null);
panel=new JPanel();
panel.setBounds(5, 5, 290, 290);
add(panel);
textField=new JTextField();
textField.setBounds(5, 5, 280, 50);
panel.add(textField);
setVisible(true);
}
}

import java.awt.FlowLayout;
import javax.swing.*;
class TT extends JFrame {
JTextField textField;
JPanel panel;
JButton button1;
JButton button2;
public TT() {
//setSize(300, 300); // better to use pack() (after components added)
//setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // better to use
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
//setLocationRelativeTo(null); // better to use..
setLocationByPlatform(true);
setTitle("Bla Blubb");
setResizable(false);
//setLayout(null); // better to use layouts with padding & borders
// set a flow layout with large hgap and vgap.
panel = new JPanel(new FlowLayout(SwingConstants.LEADING, 10, 10));
// panel.setBounds(5, 5, 290, 290); // better to pack()
add(panel);
//textField = new JTextField(); // suggest a size in columns
textField = new JTextField(8);
//textField.setBounds(5, 5, 280, 50); // to get height, set large font
textField.setFont(textField.getFont().deriveFont(50f));
panel.add(textField);
pack(); // make the GUI the minimum size needed to display the content
setVisible(true);
}
public static void main(String[] args) {
// GUIS should be constructed on the EDT.
JFrame tt = new TT();
}
}