Gui Freeze after pressing a button - java

I have a problem that my whole gui freezes when I try to press button level 1. my main problem is to set a new panel which is empty one for now.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Guibach extends JFrame implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
private JPanel mainPanel;
private JPanel choosingPanel;
private JPanel x;
private JButton exit;
private JButton but1;
private JButton but2;
private JButton but3;
private JButton but4;
private JButton but5;
private JButton but6;
private JButton but7;
private JButton but8;
private JButton but9;
private JButton but10;
public Guibach() {
this.setSize(900, 900);
this.setLayout(null);
mainPanel = new JPanel();
mainPanel.setSize(900, 900);
mainPanel.setBackground(Color.GRAY);
mainPanel.setLayout(null);
x = new JPanel();
x.setSize(900, 900);
x.setBackground(Color.RED);
x.setLayout(new BorderLayout());
choosingPanel = new JPanel();
choosingPanel.setSize(900, 450);
choosingPanel.setBackground(Color.BLUE);
choosingPanel.setLayout(new FlowLayout());
but1 = new JButton();
but1.setText("Level 1");
but1.setSize(10, 5);
but1.setActionCommand("but1");
but1.addActionListener(this);
choosingPanel.add(but1);
but2 = new JButton();
but2.setText("Level 2");
but2.setActionCommand("but2");
but2.addActionListener(this);
choosingPanel.add(but2);
but3 = new JButton();
but3.setText("Level 3");
but3.setActionCommand("but3");
but3.addActionListener(this);
choosingPanel.add(but3);
but4 = new JButton();
but4.setText("Level 4");
but4.setActionCommand("but4");
but4.addActionListener(this);
choosingPanel.add(but4);
but5 = new JButton();
but5.setText("Level 5");
but5.setActionCommand("but5");
but5.addActionListener(this);
choosingPanel.add(but5);
but6 = new JButton();
but6.setText("Level 6");
but6.setActionCommand("but6");
but6.addActionListener(this);
choosingPanel.add(but6);
but7 = new JButton();
but7.setText("Level 7");
but7.setActionCommand("but7");
but7.addActionListener(this);
choosingPanel.add(but7);
but8 = new JButton();
but8.setText("Level 8");
but8.setActionCommand("but8");
but8.addActionListener(this);
choosingPanel.add(but8);
but9 = new JButton();
but9.setText("Level 9");
but9.setActionCommand("but9");
but9.addActionListener(this);
choosingPanel.add(but9);
but10 = new JButton();
but10.setText("Level 10");
but10.setActionCommand("but10");
but10.addActionListener(this);
choosingPanel.add(but10);
exit = new JButton();
exit.setText("Exit");
exit.setActionCommand("exit");
exit.addActionListener(this);
choosingPanel.add(exit);
mainPanel.add(choosingPanel);
this.add(mainPanel);
this.setVisible(true);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("but1")) {
choosingPanel.setVisible(false);
mainPanel.removeAll();
getContentPane().removeAll();
getContentPane().add(x);
x.setVisible(true);
revalidate();
}
if (e.getActionCommand().equals("but2")) {
}
if (e.getActionCommand().equals("but3")) {
}
if (e.getActionCommand().equals("but4")) {
}
if (e.getActionCommand().equals("but5")) {
}
if (e.getActionCommand().equals("but6")) {
}
if (e.getActionCommand().equals("but7")) {
}
if (e.getActionCommand().equals("but8")) {
}
if (e.getActionCommand().equals("but9")) {
}
if (e.getActionCommand().equals("but10")) {
}
if (e.getActionCommand().equals("exit")) {
WindowDestroyer myListener = new WindowDestroyer();
this.addWindowListener(myListener);
System.exit(0);
}
}
public static void main(String[] args) {
new Guibach();
}
}
I need to clear all the things and place a new empty panel which is X in my code.

Related

Adding an image to a frame by button press

I am trying to implement an image appearing when a button is pressed. For this purpose I thought I could just copy the concept of button 4 (which works) and exchange the System.exit(0) with code to add an image, but while I've been able to use that code elsewhere successfully, here it does not seem to work.
import java.awt.EventQueue;
import javax.swing.JFrame;
import java.awt.FlowLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JComboBox;
import javax.swing.JSpinner;
import java.awt.Color;
import java.util.ArrayList;
public class Mainframe {
private JFrame frmOceanlife;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Mainframe window = new Mainframe();
window.frmOceanlife.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Mainframe() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frmOceanlife = new JFrame();
frmOceanlife.setTitle("OceanLife");
frmOceanlife.setBounds(100, 100, 750, 600);
frmOceanlife.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frmOceanlife.getContentPane().setLayout(null);
JButton btnNewButton_4 = new JButton("Quit");
btnNewButton_4.setBounds(640, 6, 81, 29);
frmOceanlife.getContentPane().add(btnNewButton_4);
btnNewButton_4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
JButton btnNewButton_5 = new JButton("Einfügen");
btnNewButton_5.setBounds(410, 34, 103, 29);
frmOceanlife.getContentPane().add(btnNewButton_5);
btnNewButton_5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ImageIcon icon = new ImageIcon("Stone.png");
JLabel label = new JLabel(icon);
// label.setBounds(25,25,50,50);
frmOceanlife.getContentPane().add(label);
}
});
JPanel panel = new JPanel();
panel.setBackground(Color.WHITE);
panel.setBounds(70, 75, 600, 450);
panel.setLayout(new FlowLayout());
JLabel piclabel = new JLabel(new ImageIcon("underwater-600x450.png"));
panel.add(piclabel);
frmOceanlife.getContentPane().add(panel);
JLabel lblNewLabel_2 = new JLabel("Welcome to Oceanlife - Your Ocean size is 600x450!");
lblNewLabel_2.setBounds(6, 539, 334, 16);
frmOceanlife.getContentPane().add(lblNewLabel_2);
}
}

The problem is that you are creating a new JLabel and trying to add it to the frame, once the button is pressed. Instead, you should just change the Icon of the label that is already added to the frame (i.e., piclabel), using piclabel.setIcon(icon);. So, you should declare picLabel at the start of your code, so that it can be accessible in the actionPerformed method of your button.
public class Mainframe {
private JFrame frmOceanlife;
JLabel piclabel;
...
Then, instantiate the label in the initialize() method as below:
...
panel.setBounds(70, 75, 600, 450);
panel.setLayout(new FlowLayout());
piclabel = new JLabel(new ImageIcon("underwater-600x450.png"));
...
Finally, your actionPerformed method for btnNewButton_5 (please consider using descriptive names instead) should look like this:
btnNewButton_5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ImageIcon icon = new ImageIcon("Stone.png");
piclabel.setIcon(icon);
}
});
Update
If, however, what you want is to add a new JLabel each time, and not change the icon of the existing one, you could use Box object with BoxLayout added to a ScrollPane. Then add the ScrollPane to your JFrame. Working example is shown below, based on the code you provided (again, please consider using descriptive names and removing unecessary code):
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.*;
import javax.swing.*;
public class Mainframe {
private JFrame frmOceanlife;
Box box;
JScrollPane scrollPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Mainframe mf = new Mainframe();
mf.initialize();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
JButton insertBtn = new JButton("Einfügen");
insertBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ImageIcon icon = new ImageIcon("Stone.png");
JLabel label = new JLabel(icon);
box.add(Box.createRigidArea(new Dimension(0, 5)));// creates space between the JLabels
box.add(label);
frmOceanlife.repaint();
frmOceanlife.revalidate();
Rectangle bounds = label.getBounds();
scrollPane.getViewport().scrollRectToVisible(bounds);// scroll to the new image
}
});
JButton quitBtn = new JButton("Quit");
quitBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
box = new Box(BoxLayout.Y_AXIS);
JLabel piclabel = new JLabel(new ImageIcon("underwater-600x450.png"));
box.add(piclabel);
scrollPane = new JScrollPane(box);
Dimension dim = new Dimension(box.getComponent(0).getPreferredSize());
scrollPane.getViewport().setPreferredSize(dim);
scrollPane.getVerticalScrollBar().setUnitIncrement(dim.height);
scrollPane.getViewport().setBackground(Color.WHITE);
JPanel controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
controlPanel.add(insertBtn);
controlPanel.add(quitBtn);
JLabel titleLbl = new JLabel("Welcome to Oceanlife - Your Ocean size is 600x450!", SwingConstants.CENTER);
frmOceanlife = new JFrame();
frmOceanlife.getContentPane().add(titleLbl, BorderLayout.NORTH);
frmOceanlife.getContentPane().add(scrollPane, BorderLayout.CENTER);
frmOceanlife.getContentPane().add(controlPanel, BorderLayout.SOUTH);
frmOceanlife.setTitle("OceanLife");
frmOceanlife.pack();
frmOceanlife.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frmOceanlife.setLocationRelativeTo(null);
frmOceanlife.setVisible(true);
}
}

Here is a sample application demonstrating the use of CardLayout. Note that I used [Eclipse] WindowBuilder. All the below code was generated by WindowBuilder apart from the ActionListener implementations. Also note that the ActionListener implementation for quitButton uses a lambda expression while the insertButton implementation uses a method reference.
More notes after the code.
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import javax.swing.JLabel;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import javax.swing.ImageIcon;
import javax.swing.JButton;
public class MainFram {
private JFrame frame;
private JPanel cardsPanel;
private JPanel firstPanel;
private JLabel firstLabel;
private JPanel secondPanel;
private JLabel secondLabel;
private JPanel buttonsPanel;
private JButton insertButton;
private JButton quitButton;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MainFram window = new MainFram();
window.frame.setVisible(true);
}
catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public MainFram() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(getCardsPanel(), BorderLayout.CENTER);
frame.getContentPane().add(getButtonsPanel(), BorderLayout.SOUTH);
}
private JPanel getCardsPanel() {
if (cardsPanel == null) {
cardsPanel = new JPanel();
cardsPanel.setLayout(new CardLayout(0, 0));
cardsPanel.add(getFirstPanel(), "first");
cardsPanel.add(getSecondPanel(), "second");
}
return cardsPanel;
}
private JPanel getFirstPanel() {
if (firstPanel == null) {
firstPanel = new JPanel();
firstPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
firstPanel.add(getFirstLabel());
}
return firstPanel;
}
private JLabel getFirstLabel() {
if (firstLabel == null) {
firstLabel = new JLabel("");
firstLabel.setIcon(new ImageIcon(getClass().getResource("underwater-600x450.png")));
}
return firstLabel;
}
private JPanel getSecondPanel() {
if (secondPanel == null) {
secondPanel = new JPanel();
secondPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
secondPanel.add(getLabel_1());
}
return secondPanel;
}
private JLabel getLabel_1() {
if (secondLabel == null) {
secondLabel = new JLabel("");
secondLabel.setIcon(new ImageIcon(getClass().getResource("Stone.png")));
}
return secondLabel;
}
private JPanel getButtonsPanel() {
if (buttonsPanel == null) {
buttonsPanel = new JPanel();
buttonsPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
buttonsPanel.add(getInsertButton());
buttonsPanel.add(getQuitButton());
}
return buttonsPanel;
}
private JButton getInsertButton() {
if (insertButton == null) {
insertButton = new JButton("Einfügen");
insertButton.addActionListener(this::insertAction);
}
return insertButton;
}
private JButton getQuitButton() {
if (quitButton == null) {
quitButton = new JButton("Quit");
quitButton.addActionListener(e -> System.exit(0));
}
return quitButton;
}
private void insertAction(ActionEvent event) {
CardLayout cardLayout = (CardLayout) cardsPanel.getLayout();
cardLayout.next(cardsPanel);
}
}
The above code requires that the image files, i.e. underwater-600x450.png and Stone.png, be located in the same directory as file MainFram.class. Refer to How to Use Icons.
When you click on the insertButton, the panel containing the underwater-600x450.png image is hidden and the panel containing the Stone.png image is displayed. Clicking the insertButton a second time will hide Stone.png and display underwater-600x450.png. In other words, clicking the insertButton toggles the images.

The first thing to do is using layout managers instead of setting bounds manually:
import java.awt.*;
import javax.swing.*;
public class Mainframe {
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
try {
new Mainframe();
} catch (Exception e) {
e.printStackTrace();
}
});
}
/**
* Create the application.
*/
public Mainframe() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
JFrame frmOceanlife = new JFrame();
frmOceanlife.setTitle("OceanLife");
//frmOceanlife.setBounds(100, 100, 750, 600);
frmOceanlife.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frmOceanlife.getContentPane().setLayout(null);
frmOceanlife.setLayout(new BoxLayout(frmOceanlife.getContentPane(), BoxLayout.PAGE_AXIS));
JButton btnNewButton_4 = new JButton("Quit");
btnNewButton_4.addActionListener(e -> System.exit(0));
//btnNewButton_4.setBounds(640, 6, 81, 29);
JPanel quitPanel = new JPanel();
quitPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
quitPanel.add(btnNewButton_4);
frmOceanlife.getContentPane().add(quitPanel);
JPanel stonesPanel = new JPanel();
frmOceanlife.getContentPane().add(stonesPanel);
JButton btnNewButton_5 = new JButton("Insert");
//btnNewButton_5.setBounds(410, 34, 103, 29);
btnNewButton_5.addActionListener(e -> {
ImageIcon icon = new ImageIcon("Stone.png");
JLabel label = new JLabel(icon);
//label.setBounds(25,25,50,50);
stonesPanel.add(label);
frmOceanlife.revalidate();
});
JPanel insertPanel = new JPanel();
insertPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
insertPanel.add(btnNewButton_5);
frmOceanlife.getContentPane().add(insertPanel);
JPanel panel = new JPanel();
panel.setBackground(Color.WHITE);
//panel.setBounds(70, 75, 600, 450);
panel.setLayout(new FlowLayout());
panel.setPreferredSize(new Dimension(700,550));
JLabel piclabel = new JLabel(new ImageIcon("underwater-600x450.png"));
panel.add(piclabel);
frmOceanlife.getContentPane().add(panel);
JLabel lblNewLabel_2 = new JLabel("Welcome to Oceanlife - Your Ocean size is 600x450!");
//lblNewLabel_2.setBounds(6, 539, 334, 16);
JPanel infoPanel = new JPanel();
infoPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
infoPanel.add(lblNewLabel_2);
frmOceanlife.getContentPane().add(infoPanel);
frmOceanlife.pack();
frmOceanlife.setVisible(true);
}
}
Next, let's introduce better names and use publicly available images to make the code more readable and more of an mre:
import java.awt.*;
import java.net.*;
import javax.swing.*;
public class Mainframe {
private static final String STONE = "https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/32x32/Circle_Red.png",
OCEAN ="https://media-gadventures.global.ssl.fastly.net/media-server/dynamic/blogs/posts/robin-wu/2014/12/PB110075.jpg";
public Mainframe() {
initialize();
}
private void initialize() {
JFrame frmOceanlife = new JFrame();
frmOceanlife.setTitle("OceanLife");
frmOceanlife.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frmOceanlife.setLayout(new BoxLayout(frmOceanlife.getContentPane(), BoxLayout.PAGE_AXIS));
JButton quitBtn = new JButton("Quit");
quitBtn.addActionListener(e -> System.exit(0));
JPanel quitPanel = new JPanel();
quitPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
quitPanel.add(quitBtn);
frmOceanlife.getContentPane().add(quitPanel);
JPanel stonesPanel = new JPanel();
frmOceanlife.getContentPane().add(stonesPanel);
JButton insertBtn = new JButton("Insert");
insertBtn.addActionListener(e -> {
try {
ImageIcon icon = new ImageIcon(new URL(STONE));
JLabel stoneLbl = new JLabel(icon);
stonesPanel.add(stoneLbl);
frmOceanlife.revalidate();
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
});
JPanel insertPanel = new JPanel();
insertPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
insertPanel.add(insertBtn);
frmOceanlife.getContentPane().add(insertPanel);
JPanel oceanPanel = new JPanel();
oceanPanel.setBackground(Color.WHITE);
oceanPanel.setLayout(new FlowLayout());
oceanPanel.setPreferredSize(new Dimension(700,550));
try {
JLabel oceanLbl = new JLabel(new ImageIcon(new URL(OCEAN)));
oceanPanel.add(oceanLbl);
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
frmOceanlife.getContentPane().add(oceanPanel);
JLabel infoLabel = new JLabel("Welcome to Oceanlife - Your Ocean size is 600x450!");
JPanel infoPanel = new JPanel();
infoPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
infoPanel.add(infoLabel);
frmOceanlife.getContentPane().add(infoPanel);
frmOceanlife.pack();
frmOceanlife.setVisible(true);
}
public static void main(String[] args) {
//no change in main
}
}
And add some final touchups :
public class Mainframe {
private static final String STONE = "https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/32x32/Circle_Red.png",
OCEAN ="https://media-gadventures.global.ssl.fastly.net/media-server/dynamic/blogs/posts/robin-wu/2014/12/PB110075.jpg";
private ImageIcon oceanIcon;
public Mainframe() {
initialize();
}
private void initialize() {
JFrame frmOceanlife = new JFrame();
frmOceanlife.setTitle("OceanLife");
frmOceanlife.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frmOceanlife.setLayout(new BoxLayout(frmOceanlife.getContentPane(), BoxLayout.PAGE_AXIS));
JButton quitBtn = new JButton("Quit");
quitBtn.addActionListener(e -> System.exit(0));
JPanel quitPanel = new JPanel();
quitPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
quitPanel.add(quitBtn);
frmOceanlife.getContentPane().add(quitPanel);
JPanel stonesPanel = new JPanel();
JLabel stoneLbl = new JLabel();
stonesPanel.add(stoneLbl);
frmOceanlife.getContentPane().add(stonesPanel);
JButton insertBtn = new JButton("Insert");
insertBtn.addActionListener(e -> {
try {
ImageIcon icon = new ImageIcon(new URL(STONE));
stoneLbl.setIcon(icon);
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
});
JPanel insertPanel = new JPanel();
insertPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
insertPanel.add(insertBtn);
frmOceanlife.getContentPane().add(insertPanel);
try {
oceanIcon = new ImageIcon(new URL(OCEAN));
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
JLabel oceanLbl = new JLabel();
oceanLbl.setIcon(oceanIcon);
JPanel oceanPanel = new JPanel(){
#Override
public Dimension getPreferredSize() {
return new Dimension(oceanIcon.getIconWidth()+100, oceanIcon.getIconHeight());
};
};
oceanPanel.add(oceanLbl);
oceanPanel.setBackground(Color.WHITE);
oceanPanel.setLayout(new GridBagLayout()); //center image in panel
frmOceanlife.getContentPane().add(oceanPanel);
JLabel infoLabel = new JLabel("Welcome to Oceanlife - Your Ocean size is "+oceanIcon+oceanIcon.getIconWidth()+
"x"+oceanIcon.getIconHeight()+"!");
JPanel infoPanel = new JPanel();
infoPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
infoPanel.add(infoLabel);
frmOceanlife.getContentPane().add(infoPanel);
frmOceanlife.pack();
frmOceanlife.setVisible(true);
}
public static void main(String[] args) {
//no change in main
}
}

error: illegal start of expression 1 error

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import java.lang.*;
import java.util.*;
public class Life {
public static void main (String[] args){
JFrame frame = new JFrame("Interest Calculator");
frame.setVisible(true);
frame.setSize(300,100);
frame.setBackground(Color.magenta);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.add(panel);
JButton button = new JButton("Simple Interest");
panel.add(button);
button.addActionListener (new Action1());
JButton button2 = new JButton("Compound Interest");
panel.add(button2);
button2.addActionListener (new Action2());
}
static class Action1 implements ActionListener {
public void actionPerformed (ActionEvent e) {
JFrame frame2 = new JFrame("Simple");
frame2.setVisible(true);
frame2.setSize(300,100);
JPanel panel = new JPanel();
frame2.add(panel);
JButton button = new JButton("Ordinary");
panel.add(button);
button.addActionListener (new Ordinary());
JButton button2 = new JButton("Exact");
panel.add(button2);
button2.addActionListener (new Exact());
}
}
static class Action2 implements ActionListener {
public void actionPerformed (ActionEvent e) {
JFrame frame3 = new JFrame("Compound Interest");
frame3.setVisible(true);
frame3.setSize(300,100);
JPanel panel = new JPanel();
frame3.add(panel);
JButton button = new JButton("Compounded");
panel.add(button);
JButton button2 = new JButton("Continously");
panel.add(button2);
}
}
static class Ordinary implements ActionListener {
public void actionPerformed (ActionEvent e) {
JFrame frame4 = new JFrame("Simple");
frame4.setVisible(true);
frame4.setSize(300,100);
JPanel panel = new JPanel();
frame4.add(panel);
JButton button = new JButton("Approximate");
panel.add(button);
button.addActionListener (new Approximate());
JButton button2 = new JButton("Actual");
panel.add(button2);
}
}
static class Exact implements ActionListener {
public void actionPerformed (ActionEvent e) {
JFrame frame5 = new JFrame("Exact");
frame5.setVisible(true);
frame5.setSize(300,100);
JPanel panel = new JPanel();
frame5.add(panel);
JButton button = new JButton("Approximate");
panel.add(button);
JButton button2 = new JButton("Actual");
panel.add(button2);
}
}
static class Approximate implements ActionListener {
public void actionPerformed (ActionEvent e) {
JFrame frame6 = new JFrame("Simple");
frame6.setVisible(true);
frame6.setSize(300,100);
JPanel panel = new JPanel();
frame6.add(panel);
frame6.setVisible(true);
frame6.setSize(300,300);
frame6.setLayout(null);
frame6.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField P = new JTextField();
panel.add(P);
P.setText("Enter Principal");
JTextField r = new JTextField();
panel.add(r);
r.setText("Enter Rate");
JTextField t = new JTextField();
panel.add(t);
t.setText("Enter Year");
JButton button = new JButton("Calculate");
panel.add(button);
button.addActionListener (new button());
static class button implements ActionListener {
public void actionPerformed (ActionEvent e) {
float P,r,t,result ;
P = Float.parseFloat(P.getText());
r = Float.parseFloat(r.getText());
t = Float.parseFloat(t.getText());
result = P*r/100*t/360;
button.setText(String.valueof(result));
}
}
}
}
}
So this is my code to create a compound calculator but I have a problem it is the illegal start of expression.please help me for my project.

Below is partially fixed part of the code which causes problems. Next time include full error code, and try to show only relevant part of the code.
ActionListener listener = new ActionListener() {
public void actionPerformed (ActionEvent e) {
float P,r,t,result ;
//P = Float.parseFloat(P.getText()); // P makes no sens here - its float !!! and uninitialized
//r = Float.parseFloat(r.getText()); // same for r
//t = Float.parseFloat(t.getText()); // same for t
result = P*r/100*t/360;
button.setText(String.valueOf(result));
}
};
button.addActionListener (listener);

How am I to run my GUI? Or to be more exact, what do I put in my main?

public class StatsGUI extends JFrame implements ActionListener {
JLabel label;
JLabel label2;
JTextField input;
JTextField output;
JButton getButton;
JButton exitButton;
public StatsGUI()
{
JPanel panel = new JPanel();
label = new JLabel("Enter number");
panel.add(label);
input = new JTextField(10);
input.addActionListener(this);
panel.add(input);
label2 = new JLabel("Statistics");
output = new JTextField(10);
output.setEditable(false);
panel.add(output);
getButton = new JButton("Go");
getButton.addActionListener(this);
panel.add(getButton);
exitButton = new JButton("Exit");
exitButton.addActionListener(this);
panel.add(exitButton);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == exitButton)
{
System.exit(0);
}
else
{
String text = input.getText();
output.setText(text + "COUNTER");
}
}
public static void main(String[] args)
{
}
This is my simple GUI program. I have placed all buttons and other gadgets within the constructor. However, I am not sure what I should be putting inside my main in order to get my GUI to actually show up. I am sure I am missing something incredibly simple here however I am not sure what. Help would be much appreciated.

You are not that far from getting things to work. Just a few things to know:
Your UI should be started on the Event dispatching thread (EDT)
You actually need to add your panels/components to your frame
You need to pack() your Window/Frame
You need to make it visible
(Design stuff, optional but when you are at it, why not just fix that as well), no need to extend JFrame, so let's just drop that.
So eventually, taking these advices into consideration leads you to something like this:
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.JTextField;
import javax.swing.SwingUtilities;
public class StatsGUI implements ActionListener {
JLabel label;
JLabel label2;
JTextField input;
JTextField output;
JButton getButton;
JButton exitButton;
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == exitButton) {
System.exit(0);
} else {
String text = input.getText();
output.setText(text + "COUNTER");
}
}
public void initUI() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
label = new JLabel("Enter number");
panel.add(label);
input = new JTextField(10);
input.addActionListener(this);
panel.add(input);
label2 = new JLabel("Statistics");
output = new JTextField(10);
output.setEditable(false);
panel.add(output);
getButton = new JButton("Go");
getButton.addActionListener(this);
panel.add(getButton);
exitButton = new JButton("Exit");
exitButton.addActionListener(this);
panel.add(exitButton);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new StatsGUI().initUI();
}
});
}
}

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class StatsGUI extends JFrame implements ActionListener {
JLabel label;
JLabel label2;
JTextField input;
JTextField output;
JButton getButton;
JButton exitButton;
public StatsGUI()
{
JPanel panel = new JPanel();
label = new JLabel("Enter number");
panel.add(label);
input = new JTextField(10);
input.addActionListener(this);
panel.add(input);
label2 = new JLabel("Statistics");
output = new JTextField(10);
output.setEditable(false);
panel.add(output);
getButton = new JButton("Go");
getButton.addActionListener(this);
panel.add(getButton);
exitButton = new JButton("Exit");
exitButton.addActionListener(this);
panel.add(exitButton);
add(panel);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == exitButton)
{
System.exit(0);
}
else
{
String text = input.getText();
output.setText(text + "COUNTER");
}
}
public static void main(String[] args)
{
StatsGUI s= new StatsGUI();
s.setVisible(true);
s.setSize(1000,1000);
}
}
You are not calling a contructor .call costructor like 'StatsGUI s= new StatsGUI();' or 'new StatsGUI();' .

Insert JTextArea into a JPanel with a JLabel

I am trying to display the drawing that I have posted. When my code runs and the user clicks Account, the panel only displays the buttons "OK" and "Cancel" (see screenshot). I have added three JTextAreas with a JLabel for each to the panel accountPanel but they don't display. My code is below.
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Component;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JRadioButton;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
public class TestApplication implements ActionListener {
public static void main(String[] args) {
JLabel input = new JLabel();
final JFrame frame = new JFrame();
frame.setSize(1000, 1000);
frame.setTitle("RBA Test Application");
frame.add(input);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
JRadioButton apprve = new JRadioButton("Approve");
JRadioButton decline = new JRadioButton("Decline");
JRadioButton ethernet = new JRadioButton("Ethernet");
ethernet.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog esettings = new JDialog(frame);
esettings.setTitle("Ethernet Settings");
esettings.setSize(400, 400);
esettings.pack();
esettings.setVisible(true);
}
});
JRadioButton rs = new JRadioButton("RS232");
rs.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog rsettings = new JDialog(frame);
rsettings.setTitle("RS232 Settings");
rsettings.setSize(400, 400);
rsettings.pack();
rsettings.setVisible(true);
}
});
JRadioButton usbcdc = new JRadioButton("USB_CDC");
usbcdc.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog usbc = new JDialog(frame);
usbc.setTitle("USB_CDC Settings");
usbc.setSize(400, 400);
usbc.pack();
usbc.setVisible(true);
}
});
JRadioButton usbhid = new JRadioButton("USB_HID");
usbhid.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog usbh = new JDialog(frame);
usbh.setTitle("USB_HID Settings");
usbh.setSize(400, 400);
usbh.pack();
usbh.setVisible(true);
}
});
JButton next = new JButton("Next");
JButton aok = new JButton("OK");
JButton bok = new JButton("OK");
JButton cok = new JButton("OK");
JButton acancel = new JButton("Cancel");
JButton bcancel = new JButton("Cancel");
JButton ccancel = new JButton("Cancel");
JButton dcancel = new JButton("Cancel");
JLabel cardLabel = new JLabel("Card Number: ");
JLabel expLabel = new JLabel("Exp. Date: ");
JLabel cvvLabel = new JLabel("CVV: ");
JTextArea card = new JTextArea();
card.add(cardLabel);
JTextArea expDate = new JTextArea();
expDate.add(expLabel);
JTextArea cvv = new JTextArea();
cvv.add(cvvLabel);
final JPanel PortSettings = new JPanel();
PortSettings.add(ethernet);
PortSettings.add(rs);
PortSettings.add(usbcdc);
PortSettings.add(usbhid);
PortSettings.add(next);
PortSettings.add(bcancel);
final JPanel accountPanel = new JPanel();
accountPanel.add(bok);
accountPanel.add(ccancel);
accountPanel.add(card);
accountPanel.add(expDate);
accountPanel.add(cvv);
final JPanel apprvordecl = new JPanel();
apprvordecl.add(apprve);
apprvordecl.add(decline);
apprvordecl.add(aok);
apprvordecl.add(acancel);
final JPanel amountPanel = new JPanel();
amountPanel.add(cok);
amountPanel.add(dcancel);
input.setFont(new java.awt.Font("Tahoma", 3, 18));
input.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
input.setText("Input / Output Log");
JButton initialize = new JButton("Initialize");
JButton connect = new JButton("Connect");
JButton disconnect = new JButton("Disconnect");
JButton shutdown = new JButton("Shut Down");
JButton portsettings = new JButton("Port Settings");
portsettings.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog port = new JDialog(frame);
port.setTitle("Port Settings");
port.setSize(400, 400);
port.add(PortSettings);
port.pack();
port.setVisible(true);
}
});
JButton online = new JButton("Go Online");
JButton offline = new JButton("Go Offline");
JButton status = new JButton("Status");
JButton reboot = new JButton("Reboot");
JButton account = new JButton("Account");
account.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog accountDialog = new JDialog(frame);
accountDialog.setTitle("Account");
accountDialog.setSize(400, 400);
accountDialog.add(accountPanel);
accountDialog.pack();
accountDialog.setVisible(true);
}
});
JButton amount = new JButton("Amount");
amount.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog amount2 = new JDialog(frame);
amount2.setTitle("Amount");
amount2.setSize(400, 400);
amount2.add(amountPanel);
amount2.pack();
amount2.setVisible(true);
}
});
JButton reset = new JButton("Reset");
JButton approvordecl = new JButton("Approve / Decline");
approvordecl.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog apprv = new JDialog(frame);
apprv.setTitle("Approve / Decline");
apprv.setSize(400, 400);
apprv.add(apprvordecl);
apprv.pack();
apprv.setVisible(true);
}
});
JButton test = new JButton("Test Button #1");
JButton testing = new JButton("Test Button #2");
JRadioButton button = new JRadioButton("Radio Button");
JRadioButton button2 = new JRadioButton("Radio Button");
JCheckBox checkbox = new JCheckBox("Check Box");
JCheckBox checkbox2 = new JCheckBox("Check Box");
ButtonGroup group = new ButtonGroup();
group.add(usbhid);
group.add(usbcdc);
group.add(ethernet);
group.add(rs);
ButtonGroup approvegroup = new ButtonGroup();
approvegroup.add(apprve);
approvegroup.add(decline);
JPanel testPanel = new JPanel();
testPanel.add(button);
testPanel.add(button2);
testPanel.add(checkbox2);
JPanel posPanel = new JPanel();
posPanel.add(test);
posPanel.add(testing);
posPanel.add(checkbox);
JPanel llpPanel = new JPanel();
llpPanel.add(online);
llpPanel.add(offline);
llpPanel.add(status);
llpPanel.add(reboot);
llpPanel.add(account);
llpPanel.add(amount);
llpPanel.add(reset);
llpPanel.add(approvordecl);
JPanel buttonPanel = new JPanel();
buttonPanel.add(initialize);
buttonPanel.add(connect);
buttonPanel.add(disconnect);
buttonPanel.add(shutdown);
buttonPanel.add(portsettings);
frame.add(buttonPanel);
frame.add(buttonPanel, BorderLayout.NORTH);
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.addTab("LLP", null, llpPanel, "Low Level Protocol");
tabbedPane.addTab("POS",null, posPanel, "Point Of Sale");
tabbedPane.addTab("Test", null, testPanel, "Test");
JPanel tabsPanel = new JPanel(new BorderLayout());
tabsPanel.add(tabbedPane);
frame.add(tabsPanel, BorderLayout.CENTER);
frame.pack();
}
#Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
}
}

JPanel uses FlowLayout by default which respects preferred sizes. The default width of the preferred size for the JTextArea's is 0 x 0. You need to give the JTextComponent's a preferred size for them to appear. Use the constructor that specifys rows & columns:
JTextArea card = new JTextArea(5, 10);
Don't forget to make the JTextArea scrollable by enclosing it in a JScrollPane:
accountPanel.add(new JScrollPane(card));

JButton Layout Issue

I'm putting together the basic layout for a contacts book, and I want to know how I can make the 3 test buttons span from edge to edge just as the arrow buttons do.
private static class ButtonHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Code Placeholder");
}
}
public static void main(String[] args) {
//down button
ImageIcon downArrow = new ImageIcon("down.png");
JButton downButton = new JButton(downArrow);
ButtonHandler downListener = new ButtonHandler();
downButton.addActionListener(downListener);
//up button
ImageIcon upArrow = new ImageIcon("up.png");
JButton upButton = new JButton(upArrow);
ButtonHandler upListener = new ButtonHandler();
upButton.addActionListener(upListener);
//contacts
JButton test1Button = new JButton("Code Placeholder");
JButton test2Button = new JButton("Code Placeholder");
JButton test3Button = new JButton("Code Placeholder");
Box box = Box.createVerticalBox();
box.add(test1Button);
box.add(test2Button);
box.add(test3Button);
JPanel content = new JPanel();
content.setLayout(new BorderLayout());
content.add(box, BorderLayout.CENTER);
content.add(downButton, BorderLayout.SOUTH);
content.add(upButton, BorderLayout.NORTH);
JFrame window = new JFrame("Contacts");
window.setContentPane(content);
window.setSize(400, 600);
window.setLocation(100, 100);
window.setVisible(true);
}

Following up on #kloffy's suggestion:
package playground.tests;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import junit.framework.TestCase;
public class ButtonTest extends TestCase {
public void testThreeButtons() throws Exception {
JPanel panel = new JPanel();
panel.setLayout(new GridLayout());
JButton button1 = new JButton("A");
JButton button2 = new JButton("B");
JButton button3 = new JButton("C");
panel.add(button1);
panel.add(button2);
panel.add(button3);
JFrame window = new JFrame("Contacts");
window.setContentPane(panel);
window.setSize(300, 600);
window.pack();
window.setVisible(true);
int width = button1.getWidth();
assertEquals(width, button2.getWidth());
assertEquals(width, button3.getWidth());
}
}

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