We Keep Coding

Using one button to change the color of multiple JPanels

So i have three panels that i have three different buttons for to change them each to their respective colors. I need to add a fourth button that will return all three panels to their original default light gray color. I add this "reset" button and it only changes the first panel back. What am i doing wrong?
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.FlowLayout;
import java.awt.Color;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class PanelDemo extends JFrame implements ActionListener
{
public static final int WIDTH = 300;
public static final int HEIGHT = 200;
private JPanel redPanel;
private JPanel whitePanel;
private JPanel bluePanel;
public static void main(String[] args)
{
PanelDemo gui = new PanelDemo();
gui.setVisible(true);
}
public PanelDemo()
{
super("Panel Demonstration");
setSize(WIDTH, HEIGHT);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
JPanel biggerPanel = new JPanel();
biggerPanel.setLayout(new GridLayout(1, 3));
redPanel = new JPanel();
redPanel.setBackground(Color.LIGHT_GRAY);
biggerPanel.add(redPanel);
whitePanel = new JPanel();
whitePanel.setBackground(Color.LIGHT_GRAY);
biggerPanel.add(whitePanel);
bluePanel = new JPanel();
bluePanel.setBackground(Color.LIGHT_GRAY);
biggerPanel.add(bluePanel);
add(biggerPanel, BorderLayout.CENTER);
JPanel buttonPanel = new JPanel();
buttonPanel.setBackground(Color.LIGHT_GRAY);
buttonPanel.setLayout(new FlowLayout());
JButton redButton = new JButton("Red");
redButton.setBackground(Color.RED);
redButton.addActionListener(this);
buttonPanel.add(redButton);
JButton whiteButton = new JButton("White");
whiteButton.setBackground(Color.WHITE);
whiteButton.addActionListener(this);
buttonPanel.add(whiteButton);
JButton blueButton = new JButton("Blue");
blueButton.setBackground(Color.BLUE);
blueButton.addActionListener(this);
buttonPanel.add(blueButton);
JButton resetButton = new JButton("Reset");
resetButton.setBackground(Color.LIGHT_GRAY);
resetButton.addActionListener(this);
buttonPanel.add(resetButton);
add(buttonPanel, BorderLayout.SOUTH);
}
#Override
public void actionPerformed(ActionEvent e)
{
String buttonString = e.getActionCommand();
if (buttonString.equals("Red"))
redPanel.setBackground(Color.RED);
else if (buttonString.equals("White"))
whitePanel.setBackground(Color.WHITE);
else if (buttonString.equals("Blue"))
bluePanel.setBackground(Color.BLUE);
else if (buttonString.equals("Reset"))
redPanel.setBackground(Color.LIGHT_GRAY);
else if (buttonString.equals("Reset"))
bluePanel.setBackground(Color.LIGHT_GRAY);
else if (buttonString.equals("Reset"))
whitePanel.setBackground(Color.LIGHT_GRAY);
else
System.out.println("Unexpected error.");
}
}

Here was your problem. You had if else's on each panel for the reset. Compare the code below to what you have. It was just a simple logic issue.
public void actionPerformed(ActionEvent e) {
String buttonString = e.getActionCommand();
if (buttonString.equals("Red"))
redPanel.setBackground(Color.RED);
else if (buttonString.equals("White"))
whitePanel.setBackground(Color.WHITE);
else if (buttonString.equals("Blue"))
bluePanel.setBackground(Color.BLUE);
else if (buttonString.equals("Reset")) {
redPanel.setBackground(Color.LIGHT_GRAY);
bluePanel.setBackground(Color.LIGHT_GRAY);
whitePanel.setBackground(Color.LIGHT_GRAY);
}
else
System.out.println("Unexpected error.");
And a couple of suggestions.
Don't extend JFrame. Just use an instance of it. It's better technique.
Put the following as the last statement in your constructor. It will center the panel on your screen.
setLocationRelativeTo(null);
// or when using a frame instance.
frame.setLocationRelativeTo(null);

How to make two colors in one window?

I want to do the same like this:
Here's the code:
import java.awt.Color;
import java.awt.event.*;
import javax.swing.*;
class QuizGUI {
public static void main(String args[]) {
JFrame frm = new JFrame("Simple Quiz");
frm.setLayout(null);
JLabel lbl1 = new JLabel("Which Animal can fly?");
JLabel lbl2 = new JLabel("You have selected: ");
JLabel lblOutput = new JLabel();
JRadioButton rCat = new JRadioButton("Cat");
JRadioButton rBird = new JRadioButton("Bird");
JRadioButton rFish = new JRadioButton("Fish");
ButtonGroup bg = new ButtonGroup();
bg.add(rCat);
bg.add(rBird);
bg.add(rFish);
lbl1.setBounds(0, 0, 200, 20);
rCat.setBounds(0, 20, 100, 20);
rBird.setBounds(0, 40, 100, 20);
rFish.setBounds(0, 60, 100, 20);
lbl2.setBounds(0, 80, 200, 20);
lblOutput.setBounds(0, 105, 200, 20);
frm.add(lbl1);
frm.add(rCat);
frm.add(rBird);
frm.add(rFish);
frm.add(lbl2);
frm.add(lblOutput);
rCat.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
if (rCat.isSelected()) {
lblOutput.setText("Cat can't fly, Try again.");
}
}
});
rBird.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
if (rBird.isSelected()) {
lblOutput.setText("Bird can fly, Excellent.");
}
}
});
rFish.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
if (rFish.isSelected()) {
lblOutput.setText("Cat can't fly, Try again.");
}
}
});
frm.setVisible(true);
frm.setSize(350, 200);
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
The problem is, I want the colors of window like image the background is white and the background for choices is gray.
I tried frame.setBackground but doesn't work.
I tried some codes for another examples and the color was white. I don't know why the window is all gray like this:

From the code you posted in your question:
frm.setLayout(null);
This is not a good idea. I recommend always using a layout manager. JFrame is a top-level container. It has a content pane which, by default, is a JPanel. The default layout manager for the content pane is BorderLayout. You can refer to the source code for JFrame in order to confirm this.
In my opinion BorderLayout is suitable for your GUI. One JPanel is the NORTH component and it displays the question, namely Which Animal can fly?, the radio buttons are the CENTER component and the text You have selected: is the SOUTH panel.
Each JPanel can then have its own background color. I am using JDK 13 on Windows 10 and the default background color is gray. Hence, in the code below, I set the background color for the NORTH and SOUTH panels and leave the CENTER panel with its default background color.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.WindowConstants;
public class QuizGUI implements ActionListener, Runnable {
private static final String BIRD = "Bird";
private static final String CAT = "Cat";
private static final String FISH = "Fish";
private JFrame frame;
private JLabel resultLabel;
#Override // java.awt.event.ActionListener
public void actionPerformed(ActionEvent event) {
String actionCommand = event.getActionCommand();
switch (actionCommand) {
case BIRD:
resultLabel.setText(BIRD + " can fly. Excellent.");
break;
case CAT:
resultLabel.setText(CAT + " can't fly. Try again.");
break;
case FISH:
resultLabel.setText(FISH + " can't fly. Try again.");
break;
default:
resultLabel.setText(actionCommand + " is not handled.");
}
}
#Override // java.lang.Runnable
public void run() {
createAndShowGui();
}
private void createAndShowGui() {
frame = new JFrame("Simple Quiz");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(createQuestionPanel(), BorderLayout.PAGE_START);
frame.add(createChoicesPanel(), BorderLayout.CENTER);
frame.add(createOutcomePanel(), BorderLayout.PAGE_END);
frame.setSize(350, 200);
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private void createRadioButton(String text, ButtonGroup bg, JPanel panel) {
JRadioButton radioButton = new JRadioButton(text);
radioButton.addActionListener(this);
bg.add(radioButton);
panel.add(radioButton);
}
private JPanel createChoicesPanel() {
JPanel choicesPanel = new JPanel(new GridLayout(0, 1));
ButtonGroup bg = new ButtonGroup();
createRadioButton(CAT, bg, choicesPanel);
createRadioButton(BIRD, bg, choicesPanel);
createRadioButton(FISH, bg, choicesPanel);
return choicesPanel;
}
private JPanel createOutcomePanel() {
JPanel outcomePanel = new JPanel(new GridLayout(0, 1, 0, 5));
outcomePanel.setBackground(Color.WHITE);
JLabel promptLabel = new JLabel("You have selected:");
setBoldFont(promptLabel);
outcomePanel.add(promptLabel);
resultLabel = new JLabel(" ");
outcomePanel.add(resultLabel);
return outcomePanel;
}
private JPanel createQuestionPanel() {
JPanel questionPanel = new JPanel(new FlowLayout(FlowLayout.LEADING));
questionPanel.setBackground(Color.WHITE);
JLabel questionLabel = new JLabel("Which Animal can fly?");
setBoldFont(questionLabel);
questionPanel.add(questionLabel);
return questionPanel;
}
private void setBoldFont(JLabel label) {
Font boldFont = label.getFont().deriveFont(Font.BOLD);
label.setFont(boldFont);
}
public static void main(String[] args) {
String slaf = UIManager.getSystemLookAndFeelClassName();
try {
UIManager.setLookAndFeel(slaf);
}
catch (ClassNotFoundException |
IllegalAccessException |
InstantiationException |
UnsupportedLookAndFeelException x) {
System.out.println("WARNING (ignored): Failed to set [system] look-and-feel");
x.printStackTrace();
}
EventQueue.invokeLater(new QuizGUI());
}
}

First create a private JPanel called contentPane in your QuizGUI class. Then in your main method, type:
contentPane = new JPanel();
contentPane.setBackground(Color.WHITE);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
frm.setContentPane(contentPane);
contentPane.setLayout(null);
then, change all frm.add() with contentPane.add()
I hope this helped!

Replace ImageIcon with JButton pressed

I am having trouble replacing ImageIcon with a first ImageIcon whereupon a Jbutton is pressed. So far I have tried replacing the frame, .setIcon(myNewImage);, and .remove();. Not sure what to do now... (I'll need to replace and resize them.) Here is my code. (It is supposed to be like one of those Japanese dating games... please ignore that the pictures are local I have no site to host them yet.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import java.util.Scanner;
import javax.swing.ImageIcon;
import javax.swing.*;
import java.awt.*;
public class NestedPanels extends JPanel {
JPanel southBtnPanel = new JPanel(new GridLayout(3, 2, 1, 1)); //grid layout of buttons and declaration of panel SoutbtnPanel
JButton b = new JButton("Say Hello");//1
JButton c = new JButton("Say You Look Good");//1
JButton d = new JButton("Say Sorry I'm Late");//1
JButton e2 = new JButton("So where are we headed?");//2
JButton f = new JButton("Can we go to your place?");//2
JButton g = new JButton("I don't have any money for our date...");//2
public NestedPanels() { //implemeted class
//add action listener
b.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button1Clicked(e);//when button clicked, invoke method
}
});
c.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button2Clicked(e);//when button clicked, invoke method
}
});
d.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button3Clicked(e);//when button clicked, invoke method
}
});
e2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button4Clicked(e);//when button clicked, invoke method
}
});
f.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button5Clicked(e);//when button clicked, invoke method
}
});
g.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button6Clicked(e);//when button clicked, invoke method
}
});
southBtnPanel.add(b);
southBtnPanel.add(c);
southBtnPanel.add(d);
setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1)); //layout of buttons "Button text"
setLayout(new BorderLayout());
add(Box.createRigidArea(new Dimension(600, 600))); //space size of text box webapp over all
add(southBtnPanel, BorderLayout.SOUTH);
}
private static void createAndShowGui() {//class to show gui
NestedPanels mainPanel = new NestedPanels(); //mainPanel new class of buttons instantiation
JFrame frame = new JFrame("Date Sim 1.0");//title of webapp on top
frame.getContentPane().add(mainPanel);
ImageIcon icon = new ImageIcon("C:/Users/wchri/Pictures/10346538_10203007241845278_2763831867139494749_n.jpg");
JLabel label = new JLabel(icon);
mainPanel.add(label);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
private void button1Clicked(ActionEvent e) {
southBtnPanel.removeAll();
southBtnPanel.add(e2);
southBtnPanel.add(f);
southBtnPanel.add(g);
southBtnPanel.revalidate();
southBtnPanel.repaint();
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "Hey there! Ready to get started?", "Christian feels good!", JOptionPane.PLAIN_MESSAGE); //display button Action
}
private void button2Clicked(ActionEvent e) {
southBtnPanel.removeAll();
southBtnPanel.add(e2);
southBtnPanel.add(f);
southBtnPanel.add(g);
southBtnPanel.revalidate();
southBtnPanel.repaint();
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "Ugh... thanks! You too ready?!", "Christian is a bit... Embarrased.", JOptionPane.PLAIN_MESSAGE); //display button Action
}
private void button3Clicked(ActionEvent e) {
southBtnPanel.removeAll();
southBtnPanel.add(e2);
southBtnPanel.add(f);
southBtnPanel.add(g);
southBtnPanel.revalidate();
southBtnPanel.repaint();
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "It's ok! Just make sure it doesn't happen again!", "Christian is a bit angry!", JOptionPane.PLAIN_MESSAGE); //display button Action
}
private void button4Clicked(ActionEvent e) {
NestedPanels mainPanel = new NestedPanels(); //mainPanel new class of buttons instantiation
JFrame frame = new JFrame("Date Sim 1.0");//title of webapp on top
frame.getContentPane().add(mainPanel);
JLabel label = new JLabel();
ImageIcon imageTwo = new ImageIcon("C:/Users/wchri/Documents/chrisferry.jpg");
mainPanel.add(label);
label.setIcon(imageTwo);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
frame.getContentPane().add(mainPanel);
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "Let's take the ferry to NYC!", "Christian feels good!", JOptionPane.PLAIN_MESSAGE); //display button Action
}
private void button5Clicked(ActionEvent e) {
NestedPanels mainPanel = new NestedPanels(); //mainPanel new class of buttons instantiation
JFrame frame = new JFrame("Date Sim 1.0");//title of webapp on top
frame.getContentPane().add(mainPanel);
JLabel label = new JLabel();
ImageIcon imageThree = new ImageIcon("C:/Users/wchri/Pictures/Screenshots/chrisart.jpg");
mainPanel.add(label);
label.setIcon(imageThree);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
frame.getContentPane().add(mainPanel);
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "Don't you think it's a bit soon for that?", "Christian is embarrassed...", JOptionPane.PLAIN_MESSAGE); //display button Action
}
private void button6Clicked(ActionEvent e) {
NestedPanels mainPanel = new NestedPanels(); //mainPanel new class of buttons instantiation
JFrame frame = new JFrame("Date Sim 1.0");//title of webapp on top
frame.getContentPane().add(mainPanel);
JLabel label = new JLabel();
ImageIcon imageFour = new ImageIcon("C:/Users/wchri/Downloads/chrismoney.jpg");
mainPanel.add(label);
label.setIcon(imageFour);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
frame.getContentPane().add(mainPanel);
String msg = ((JButton)e.getSource()).getActionCommand() ;
JOptionPane.showMessageDialog(this, "I got money!", "Christian is ballin'", JOptionPane.PLAIN_MESSAGE); //display button Action
}
public static void main(String[] args) {
System.out.println("Welcome to Date Sim 1.0 with we1. Are you ready to play? Yes/No?");
Scanner in = new Scanner(System.in);
String confirm = in.nextLine();
if (confirm.equalsIgnoreCase("Yes")) {
System.out.println("Ok hot stuff... Let's start.");
NestedPanels mainPanel = new NestedPanels();
} else {
System.out.println("Maybe some other time!");
return;
}
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGui();
}
});
}
}

Here is MCVE that demonstrates changing an icon on a JButton when it is clicked:
import java.io.IOException;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class ChangeButtonIcon extends JPanel{
private URL[] urls = {
new URL("https://findicons.com/files/icons/345/summer/128/cake.png"),
new URL("http://icons.iconarchive.com/icons/atyourservice/service-categories/128/Sweets-icon.png"),
new URL("https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcS_FkBgG3_ux0kCbfG8mcRHvdk1dYbZYsm2SFMS01YvA6B_zfH_kg"),
};
private int iconNumber = 0;
private JButton button;
public ChangeButtonIcon() throws IOException {
button = new JButton();
button.setIcon(new ImageIcon(urls[iconNumber]));
button.setHorizontalTextPosition(SwingConstants.CENTER);
button.addActionListener(e -> swapIcon());
add(button);
}
private void swapIcon() {
iconNumber = iconNumber >= (urls.length -1) ? 0 : iconNumber+1;
button.setIcon(new ImageIcon(urls[iconNumber]));
}
public static void main(String[] args) throws IOException{
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.add(new ChangeButtonIcon());
window.pack();
window.setVisible(true);
}
}
I find writting MCVE a very useful technique. Not only it makes helping much easier, it
is a powerful debugging tool. It many case, while preparing one, you are likely to find the problem.
It should represent the problem or the question asked. Not your application.

Update JLabel text

I'm working on a simple GUI. On Button press i want to increase/decrease a variable and update the corresponding JLabel.
class JFrameSetUp
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JFrameSetUp extends JFrame implements ActionListener {
private int RecHeight = 0;
private int RecWidth = 0;
//Here Buttons
JButton HeightIncrease = new JButton("+");
JButton HeightDecrease = new JButton("-");
JLabel height = new JLabel(Integer.toString(RecHeight));
JLabel width = new JLabel(Integer.toString(RecWidth));
GridLayout gridLayout = new GridLayout(2, 4);
public JFrameSetUp(){
}
public void addComponentsToPane(final Container pane){
//Create GridPanel and set Layout
JPanel grid = new JPanel();
grid.setLayout(gridLayout);
//Create buttondrawPanel and set Layout
JPanel buttondraw = new JPanel();
buttondraw.setLayout(new GridLayout(2, 0));
//Adding Components to GridPanel
//Adding Layouts to pane
pane.add(grid, BorderLayout.NORTH);
pane.add(new JSeparator(), BorderLayout.CENTER);
pane.add(buttondraw, BorderLayout.SOUTH);
}
#Override
public void actionPerformed(ActionEvent e) {
//Setting up ActionListener to Buttons
if (e.getSource() == this.HeightDecrease) {
RecHeight -= 1;
height.setText(Integer.toString(RecHeight));
} else if (e.getSource() == this.HeightIncrease) {
RecHeight += 1;
height.setText(Integer.toString(RecHeight));
}
}
}
Class with MainMethod
import javax.swing.JFrame;
public class Program {
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
private static void createAndShowGUI() {
//Create and set up the window.
JFrameSetUp frame = new JFrameSetUp();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Set up the content pane.
frame.addComponentsToPane(frame.getContentPane());
//Display the window.
frame.pack();
frame.setVisible(true);
}
}
I'm aware, that's kind a newbish question. I think I'm wrong with my Code Structure. Any help is appreciated.
Thanks in advance.

You never register any ActionListeners to the buttons...
HeightIncrease.addActionListener(this);
HeightDecrease.addActionListener(this);
You also never add the buttons to the GUI
buttondraw.add(HeightIncrease);
buttondraw.add(HeightDecrease);
You also never add the labels to the GUI either...
grid.add(height);
grid.add(width);
I reworked the code, because your example was messing with my mind, hope you don't mind...
It's conceptually the same idea, just done slightly more efficently
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private int recHeight = 0;
private int recWidth = 0;
//Here Buttons
JButton heightIncrease = new JButton("+");
JButton heightDecrease = new JButton("-");
JLabel height = new JLabel(Integer.toString(recHeight));
JLabel width = new JLabel(Integer.toString(recWidth));
GridLayout gridLayout = new GridLayout(2, 4);
public TestPane() {
setLayout(new BorderLayout());
//Create GridPanel and set Layout
JPanel grid = new JPanel();
grid.setLayout(gridLayout);
grid.add(height);
grid.add(width);
//Create buttondrawPanel and set Layout
JPanel buttondraw = new JPanel();
buttondraw.setLayout(new GridLayout(2, 0));
heightIncrease.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
recHeight += 1;
height.setText(Integer.toString(recHeight));
}
});
heightDecrease.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
recHeight -= 1;
height.setText(Integer.toString(recHeight));
}
});
buttondraw.add(heightIncrease);
buttondraw.add(heightDecrease);
//Adding Components to GridPanel
//Adding Layouts to pane
add(grid, BorderLayout.NORTH);
add(new JSeparator(), BorderLayout.CENTER);
add(buttondraw, BorderLayout.SOUTH);
}
}
}
I would encourage you to spend some time having a look at How to Use Buttons, Check Boxes, and Radio Buttons and How to Write an Action Listeners for more details

After changing the value call
frame.repaint();

Good to see you learning Java! A few things I should point out.
Firstly, your variable names are good, but they don't follow the Java naming convention. Even though it seems small, it's just good practice to follow.
Of course, your actual problem; the action listener you've implemented is on the JFrame. (See how you extend JFrame and implement ActionListener?) This ActionListener should be on the button. You'll can do this a few ways.
Method 1: By adding it inline with your code
JButton heightButton = new JButton("Increase Height");
heightButton.addActionListener(new ActionListener(){
#Override
public void run(){
//run method here
}
});
Method 2: Create a class which implements ActionListener
class ButtonListener implements ActionListener{
#Override
public void run(){
//actionListener code here
}
}
And then instantiate an object of this type and add it directly to your code.
ActionListner buttonListener = new ButtonListener(); //or ButtonListener buttonListener = new ButtonListener();
JButton heightButton = new JButton("Increase Height");
heightButton.addActionListener(buttonListener);
Of course, as in MadProgrammers answer, don't forget to add the labels and such to your JFrame or JPanel. Good luck learning Java!

I bet that your program just shows nothing, isn't it? That's because in addComponentsToPane method, you didn't add any component but empty JPanels. After the comment //Adding Components to GridPanel, you should:
buttondraw.add(HeightIncrease);
buttondraw.add(HeightDecrease);
grid.add(height);
grid.add(width);
Then, to listen to button event, you should also add :
HeightIncrease.addActionListener(this);
HeightDecrease.addActionListener(this);
"this" is because your frame JFrameSetUp implements ActionListener, so when either bootton is clicked the method actionPerformed is invoked.
As JLabel.setText method will repaint itself and consequently its component hierarchi is repainted as well, you haven't to do anything othr.

JCheckBox not appearing

I have checked everwhere for a fix but nothing can work to make my checkbox appear. I added it to the panel and added the panel to the window. The button is appearing so it must be a problem with the checkbox. Here is my code:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainApplication {
public static Toolkit tk = Toolkit.getDefaultToolkit();
public static void main(String[] args) {
MainApplication instance = new MainApplication();
instance.start();
}
private JFrame window;
private JPanel mainPanel;
private JPanel contingencyPanel;
private JButton applyButton = new JButton("Apply Changes");
private JCheckBox autoRedLightBox = new JCheckBox("Red Light");
private JCheckBox autoYellowLightBox = new JCheckBox("Yellow Light");
private JCheckBox autoGreenLightBox = new JCheckBox("Green Light");
private JCheckBox autoBlueLightBox = new JCheckBox("Blue Light");
public void start() {
window = new JFrame("Main Control Window");
mainPanel = new JPanel();
contingencyPanel = new JPanel();
window.setSize(1280, 720);
window.setResizable(false);
window.setFocusable(true);
window.setFocusTraversalKeysEnabled(true);
int screenWidth = (int)tk.getScreenSize().getWidth();
int screenHeight = (int)tk.getScreenSize().getHeight();
window.setLocation((screenWidth/2)-(window.getWidth()/2), (screenHeight/2)-(window.getHeight()/2));
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPanel.setLayout(null);
contingencyPanel.setLayout(null);
applyButton.setToolTipText("Changes will be applied to the arduino.");
applyButton.setSize(new Dimension(120, 30));
applyButton.setLocation(new Point((1280-120)-10, (720-56)-10));
autoRedLightBox.setSelected(true);
autoRedLightBox.setLocation(new Point(30, 30));
autoRedLightBox.setMnemonic(KeyEvent.VK_R);
mainPanel.add(applyButton);
mainPanel.add(autoRedLightBox, BorderLayout.CENTER);
window.add(mainPanel);
window.setVisible(true);
}
}
Desired Outcome:

That's well suited to a GridLayout.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class ButtonsAndChecks {
private JComponent ui = null;
ButtonsAndChecks() {
initUI();
}
public void initUI() {
if (ui!=null) return;
// adjust last two numbers to need..
ui = new JPanel(new GridLayout(0,5,20,20));
ui.setBorder(new EmptyBorder(4,4,4,4));
// adjust numbers to need..
for (int i=1; i<26; i++) {
ui.add(new JButton("Button " + i));
}
// adjust numbers to need..
for (int i=1; i<26; i++) {
ui.add(new JCheckBox("Check " + i, i%2==0));
}
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
ButtonsAndChecks o = new ButtonsAndChecks();
JFrame f = new JFrame(o.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}

Read a bit about LayoutManagers in Swing. Every panel needs a layout to hold components, if you don't specify layout for JPanel it uses default one (FlowLayout).
The problem was in this line, when you set null for layout
mainPanel.setLayout(null);
just comment it and you will see buttons on form.
Also, for putting your form in center of screen you can call this method
window.setLocationRelativeTo(null);