Hi im am working on my Java project which I have to create a login page for users to enter, and when login is successful, an alert is supposed to tell them that the login was ok. However, I am having some troubles as my application is not showing up at all, I think it is something to do with the code that I have written. Below is the code:
public class UserLoginPage implements ActionListener {
//Put all JLabels,Frames and buttons here etc
JPanel panel = new JPanel();
JFrame frame = new JFrame();
JLabel userLabel = new JLabel("Username");
JLabel passwordLabel = new JLabel("Password");
JTextField userText = new JTextField();
JTextField passwordText = new JTextField();
JButton loginButton = new JButton("Login");
//Label for successful login
JLabel success = new JLabel("Login Successful");
//Default Constructor to add the frames and panels etc
public UserLoginPage(){
panel.setLayout(null);
userLabel.setBounds(10,20,80,25);
panel.add(userLabel);
passwordLabel.setBounds(10,50,80,25);
panel.add(passwordLabel);
userText.setBounds(100,20,165,25);
panel.add(userText);
passwordText.setBounds(100,50,165,25);
panel.add(passwordText);
loginButton.setBounds(10,80,80,25);
loginButton.addActionListener(new UserLoginPage());
panel.add(loginButton);
success.setBounds(10,110,300,25);
panel.add(success);
//success.setText();
frame.setSize(500,500);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.add(panel);
}
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new UserLoginPage();
}
});
}
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Button Clicked");
}
I think the problem lies with loginButton.addActionListener(new UserLoginPage()); But I might be wrong, do let me know of how to solve the problem, thank you.
There are multiple issues in your program:
panel.setLayout(null); and .setBounds(...). You shouldn't be using null-layouts, as Swing has to deal with multiple PLAFs, OS, screen sizes and resolutions. You might end up with issues like this one. Pixel-perfect layouts might seem like the easiest way to create complex UIs but it's not, it'll just lead you to endless issues. Instead use layout managers or combinations of them.
loginButton.addActionListener(new UserLoginPage()); You're creating a new instance of your program every time, and on every instance of it you're creating a new object because all your code is inside the constructor. Just, don't! It's a recursive call that finally creates a java.lang.StackOverflowError, to solve this use this instead of new UserLoginPage()
frame.setVisible(true); this line should always be the last line in your program, after you've added everything to your JFrame, not before.
With the above recommendations, here's an updated version of your code:
import java.awt.BorderLayout;
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.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class UserLoginPage implements ActionListener {
// Put all JLabels,Frames and buttons here etc
private JPanel panel;
private JFrame frame;
private JLabel userLabel;
private JLabel passwordLabel;
private JTextField userText;
private JTextField passwordText;
private JButton loginButton;
// Label for successful login
private JLabel success;
// Default Constructor to add the frames and panels etc
public UserLoginPage() {
}
private void createAndShowGUI() {
frame = new JFrame(getClass().getSimpleName());
panel = new JPanel();
panel.setLayout(new GridLayout(0, 2));
userLabel = new JLabel("Username");
passwordLabel = new JLabel("Password");
userText = new JTextField(10);
passwordText = new JPasswordField(10);
loginButton = new JButton("Login");
success = new JLabel("Login Successful");
loginButton.addActionListener(this);
panel.add(userLabel);
panel.add(userText);
panel.add(passwordLabel);
panel.add(passwordText);
panel.add(loginButton);
frame.add(panel);
frame.add(success, BorderLayout.SOUTH);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new UserLoginPage().createAndShowGUI();;
}
});
}
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Button Clicked");
}
}
You were correct. loginButton.addActionListener(new UserLoginPage()) causes a java.lang.StackOverflowError. The constructor is always calling itself without a base case to default to. You should be passing that very instance of the UserLoginPage as a parameter, not a new instance.
Use this code instead:
loginButton.addActionListener(this);
Related
I am practising Java Swing and I am trying to create a GPA calculator. I am having a hard time with my code, how can I add text fields whenever the JButton "add" is clicked? I also want the text fields to align vertically when the button is clicked. Should I use a layout or something?
You can check my screenshot as well.
Here is my code:
import java.awt.event.ActionEvent;
import javax.swing.*;
public class gwa implements ActionListener, java.awt.event.ActionListener{
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
//button
JButton buttonAdd = new JButton("Add");
buttonAdd.setBounds(30, 30, 80, 34);
buttonAdd.addActionListener(new gwa());
//textfield
JTextField gradeField = new JTextField();
gradeField.setBounds(150, 30, 100, 35);
JTextField unitsField = new JTextField();
unitsField.setBounds(300, 30, 100, 35);
//panel
panel.setLayout(null);
panel.add(buttonAdd);
panel.add(gradeField);
panel.add(unitsField);
//frame
frame.add(panel);
frame.setSize(500,500);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#Override
public void actionPerformed(ActionEvent e) {
}
One way – but not the only way – is to use GridBagLayout.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
public class GwaAdder {
private static final int COLUMNS = 10;
private GridBagConstraints gbc;
private JPanel textFieldsPanel;
private void addTextField(ActionEvent event) {
JTextField textField = new JTextField(COLUMNS);
gbc.gridy++;
textFieldsPanel.add(textField, gbc);
textFieldsPanel.revalidate();
textFieldsPanel.repaint();
}
private void createAndDisplayGui() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createTextFieldsPanel(), BorderLayout.CENTER);
frame.add(createButtons(), BorderLayout.PAGE_END);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JPanel createButtons() {
JPanel panel = new JPanel();
JButton button = new JButton("Add");
button.addActionListener(this::addTextField);
panel.add(button);
return panel;
}
private JScrollPane createTextFieldsPanel() {
textFieldsPanel = new JPanel(new GridBagLayout());
gbc = new GridBagConstraints();
gbc.gridy = 0;
JTextField textField = new JTextField(COLUMNS);
textFieldsPanel.add(textField, gbc);
JScrollPane scrollPane = new JScrollPane(textFieldsPanel);
scrollPane.setPreferredSize(new Dimension(140, 200));
return scrollPane;
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> new GwaAdder().createAndDisplayGui());
}
}
The ActionListener is implemented using method references. When you change the GUI after it is initially displayed (as the above code does in method addTextField), you usually need to call method revalidate (in class javax.swing.JComponent) followed by method repaint (in class java.awt.Component).
How it looks when I run the above code:
You should first give your button's Action event the panel, and then do the Action
My English is not good, so I use translation software to answer, please forgive me
I'm working on a group project and I'm the one making the GUI figuring it'd be good to practice with it. The program is supposed to be a pizza ordering system (pretty standard stuff) and what I'm trying to accomplish is that I have a main class that creates an application window. Inside this window is a panel that uses CardLayout with a button that when pressed calls another JPanel from another class dedicated specifically to that panel and places it as a card in the layout to be swapped back and forth from as normal.
What I have so far are the different panels I wish to call and the main class which has the window and main card panel. I can have it swap easily between panels created within the main class but when I try to use the panels from the other classes it just swaps to a blank panel when it should show the other class's panel.
The main class
package PizzaGUI;
import java.awt.EventQueue;
import java.awt.CardLayout;
import javax.swing.JFrame;
import javax.swing.*;
import java.awt.event.*;
import java.awt.Font;
public class PizzaSystem {
private JFrame frame;
Toppings toppingsPanel;
MainMenu menuPanel;
JButton loginBtn;
JPanel mainPanel;
CardLayout cl;
//MAIN
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
PizzaSystem window = new PizzaSystem();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
//Constructor
public PizzaSystem() {
initialize();
}
//Initialize the GUI
private void initialize() {
cl = new CardLayout();
frame = new JFrame();
frame.setBounds(100, 100, 893, 527);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
mainPanel = new JPanel();
mainPanel.setBounds(10, 10, 859, 470);
frame.getContentPane().add(mainPanel);
mainPanel.setLayout(cl);
JPanel panel_2 = new JPanel();
mainPanel.add(panel_2, "test");
panel_2.setLayout(null);
JLabel lblNewLabel = new JLabel("It Worked");
lblNewLabel.setFont(new Font("Tahoma", Font.PLAIN, 45));
lblNewLabel.setBounds(282, 118, 312, 103);
panel_2.add(lblNewLabel);
JPanel panel_1 = new JPanel();
loginBtn = new JButton();
loginBtn.setText("Login");
loginBtn.setBounds(175, 72, 199, 154);
loginBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
showCard("menu");
}
});
panel_1.add(loginBtn);
mainPanel.add(panel_1, "loginPanel");
JPanel menuPanel = new MainMenu();
mainPanel.add(menuPanel, "menu");
showCard("loginPanel");
}
//Call card matching the key
public void showCard(String key) {
cl.show(mainPanel, key);
}
}
and one of the classes with the panel (format is messed up but should work still)
package PizzaGUI;
import java.awt.Color;
import java.awt.Font;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
import javax.swing.SwingConstants;
import javax.swing.border.BevelBorder;
public class MainMenu extends JPanel {
public MainMenu() {
JPanel panel1 = new JPanel();
panel1.setBounds(100, 100, 893, 572);
panel1.setBackground(Color.PINK);
panel1.setLayout(null);
panel1.setVisible(true);
JLabel logoLabel = new JLabel("");
logoLabel.setBounds(10, 10, 100, 110);
panel1.add(logoLabel);
ImageIcon image1 = new ImageIcon("C:\\Users\\thera\\eclipse-workspace\\PizzaSystem\\Images\\MamaJane1.png");
logoLabel.setIcon(new ImageIcon("C:\\Users\\thera\\eclipse-workspace\\PizzaSystem\\Images\\MamaJane.png"));
JTabbedPane tabbedPane = new JTabbedPane(JTabbedPane.TOP);
tabbedPane.setBounds(133, 113, 548, 402);
tabbedPane.setBorder(new BevelBorder(BevelBorder.LOWERED, null, null, null, null));
tabbedPane.setBackground(Color.PINK);
tabbedPane.setForeground(Color.GRAY);
tabbedPane.setFont(new Font("Tahoma", Font.PLAIN, 20));
tabbedPane.setToolTipText("");
panel1.add(tabbedPane);
JPanel panel = new JPanel();
tabbedPane.addTab("MENU", null, panel, null);
panel.setLayout(null);
//*******************************************************************************************************
//Pepperoni menu section
JLabel pizza1Image = new JLabel("IMAGE");
pizza1Image.setBounds(6, 25, 100, 100);
panel.add(pizza1Image);
ImageIcon image2 = new ImageIcon("C:\\Users\\thera\\eclipse-workspace\\PizzaSystem\\Images\\Pepperoni.jpg");
Image pizza1 = image2.getImage();
Image pepperoni = pizza1.getScaledInstance(100, 100, java.awt.Image.SCALE_SMOOTH);
image2 = new ImageIcon(pepperoni);
pizza1Image.setIcon(image2);
JLabel pepperoniLabel = new JLabel("PEPPERONI");
pepperoniLabel.setHorizontalAlignment(SwingConstants.CENTER);
pepperoniLabel.setBounds(110, 25, 86, 48);
pepperoniLabel.setFont(new Font("Tahoma", Font.PLAIN, 12));
panel.add(pepperoniLabel);
JButton pepperoniOrderBtn = new JButton("ORDER");
pepperoniOrderBtn.setBounds(110, 79, 86, 47);
panel.add(pepperoniOrderBtn);
pepperoniOrderBtn.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent e) {
}
});
//Pepperoni End
JButton accountButton = new JButton("Account");
accountButton.setBounds(10, 414, 113, 39);
accountButton.setBackground(Color.WHITE);
panel.add(accountButton);
JButton checkoutButton = new JButton("Checkout");
checkoutButton.setBounds(713, 438, 138, 31);
panel.add(checkoutButton);
JButton logoutButton = new JButton("Logout");
logoutButton.setBounds(10, 463, 113, 52);
panel.add(logoutButton);
JTextArea txtrOrderInfoGoes = new JTextArea();
txtrOrderInfoGoes.setBounds(703, 10, 154, 418);
txtrOrderInfoGoes.setText("Order Info\r\nGoes Here\r\n\r\nPepperoni Pizza x1\r\n$6.50");
panel.add(txtrOrderInfoGoes);
JButton clearOrderButton = new JButton("Clear");
clearOrderButton.setBounds(723, 479, 113, 36);
panel.add(clearOrderButton);
JLabel titleLabel = new JLabel("MAMA JANE'S PIZZERIA");
titleLabel.setBounds(147, 10, 534, 65);
panel.add(titleLabel);
titleLabel.setFont(new Font(titleLabel.getFont().getName(), Font.PLAIN, 50));
JLabel storeInfoLabel = new JLabel("<html>1234 Fakelane Rd <br> 10001, Faketopia, USA <br> 111-11-PIZZA <br> Mon-Fri 11AM to 10pm <br> Sat-Sun 10AM to 11pm");
storeInfoLabel.setBounds(10, 130, 113, 274);
panel.add(storeInfoLabel);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setBounds(406, 85, 2, 2);
panel.add(scrollPane);
logoutButton.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
}
}
I can't tell where I've gone wrong and I've spent roughly the last three hours trying to fix this and searching the internet for answers to no avail so thank you in advance if you can help me out.
Also I apologize in advance, I know I end up misusing the proper terminology for programming alot, I understand what things are just forget what to properly call them sometimes.
So, basically, I took out all the null layouts and "manual" layout code, as it's just going to mess with you to no end AND added add(panel1); to the end of the MainMenu constructor - as, I've said, NOTHING was added to MainMenu, so, nothing was going to get displayed.
Before you tell me that "this isn't the layout I want", understand that I understand that, but my point is, null layouts are a really bad idea, as almost the entire Swing API relies the layout managers in one way or another.
I appreciate that layout management can seem like a complex subject, but it solves some very complex problems and it's worth taking the time to learn them. Remember, you're not stuck to a single layout manager, you can use component components to adjust individual containers to their individual needs.
You can take a look at:
Layout using Java Swing
Which Layout Manager to use?
How I can do swing complex layout Java
How to use Java Swing layout manager to make this GUI?
*Which java swing layout should I use
to some ideas how you might approach designing a complex UI.
You should also take a look at Laying Out Components Within a Container
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagLayout;
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.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
import javax.swing.SwingConstants;
public class PizzaSystem {
private JFrame frame;
// Toppings toppingsPanel;
MainMenu menuPanel;
JButton loginBtn;
JPanel mainPanel;
CardLayout cl;
//MAIN
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
PizzaSystem window = new PizzaSystem();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
//Constructor
public PizzaSystem() {
initialize();
}
//Initialize the GUI
private void initialize() {
cl = new CardLayout();
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPanel = new JPanel(cl);
frame.getContentPane().add(mainPanel);
JPanel panel_1 = new JPanel(new GridBagLayout());
loginBtn = new JButton();
loginBtn.setText("Login");
loginBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
showCard("menu");
}
});
panel_1.add(loginBtn);
mainPanel.add(panel_1, "loginPanel");
JPanel menuPanel = new MainMenu();
mainPanel.add(menuPanel, "menu");
frame.pack();
showCard("loginPanel");
}
//Call card matching the key
public void showCard(String key) {
cl.show(mainPanel, key);
}
public class MainMenu extends JPanel {
public MainMenu() {
JPanel panel1 = new JPanel(new BorderLayout());
JLabel logoLabel = new JLabel("Logo");
panel1.add(logoLabel, BorderLayout.NORTH);
JTabbedPane tabbedPane = new JTabbedPane(JTabbedPane.TOP);
tabbedPane.setToolTipText("");
panel1.add(tabbedPane, BorderLayout.CENTER);
JPanel panel = new JPanel();
tabbedPane.addTab("MENU", null, panel, null);
//*******************************************************************************************************
//Pepperoni menu section
JLabel pizza1Image = new JLabel("IMAGE");
panel.add(pizza1Image);
JLabel pepperoniLabel = new JLabel("PEPPERONI");
pepperoniLabel.setHorizontalAlignment(SwingConstants.CENTER);
panel.add(pepperoniLabel);
JButton pepperoniOrderBtn = new JButton("ORDER");
pepperoniOrderBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
}
});
//Pepperoni End
JButton accountButton = new JButton("Account");
panel.add(accountButton);
JButton checkoutButton = new JButton("Checkout");
panel.add(checkoutButton);
JButton logoutButton = new JButton("Logout");
panel.add(logoutButton);
JTextArea txtrOrderInfoGoes = new JTextArea(10, 20);
txtrOrderInfoGoes.setText("Order Info\r\nGoes Here\r\n\r\nPepperoni Pizza x1\r\n$6.50");
panel.add(txtrOrderInfoGoes);
JButton clearOrderButton = new JButton("Clear");
panel.add(clearOrderButton);
JLabel titleLabel = new JLabel("MAMA JANE'S PIZZERIA");
panel.add(titleLabel);
titleLabel.setFont(new Font(titleLabel.getFont().getName(), Font.PLAIN, 50));
JLabel storeInfoLabel = new JLabel("<html>1234 Fakelane Rd <br> 10001, Faketopia, USA <br> 111-11-PIZZA <br> Mon-Fri 11AM to 10pm <br> Sat-Sun 10AM to 11pm");
panel.add(storeInfoLabel);
JScrollPane scrollPane = new JScrollPane();
panel.add(scrollPane);
logoutButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
add(panel1);
}
}
}
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Welcome
{
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setBounds(100, 100, 700, 500);
frame.setVisible(true);
JButton btn = new JButton("next");
btn.setBounds(100, 100, 100, 100);
JLabel label1 = new JLabel();
JLabel label2 = new JLabel();
JLabel label3 = new JLabel();
//first label
label1.setBackground(Color.BLACK);
label1.add(btn);
frame.getContentPane().add(label1);
btn.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
frame.getContentPane().remove(label1);
frame.getContentPane().repaint();
frame.getContentPane().revalidate();
frame.getContentPane().add(label2);
}
});
//second
JLabel label2.setBackground(Color.RED);
JButton btn2 = new JButton("next");
btn2.setBounds(100, 100, 100, 100);
label2.add(btn2);
btn2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
frame.getContentPane().remove(label1);
frame.getContentPane().repaint();
frame.getContentPane().revalidate();
frame.getContentPane().add(label3);
}
});
//third JLabel
label3.setBackground(Color.BLUE);
}
}
Don't use setBounds().Swing was designed to be used with layout managers.
Changing the background of a label doesn't do anything. By default a JLabel is transparent so the background is not painted. To see the background you first need to use label.setOpaque(true);
Don't use remove/add logic. To swap a component in the same position in the frame use a CardLayout. Read the section from the Swing tutorial on How to Use CardLayout.
Start with the working code and then make changes. The code in the tutorial is better structured than your current code and demonstrates how to use the Event Dispatch Thread (EDT). All Swing components should be created and modified on the EDT.
I have a method which asks the user a question and in my GUI I have a JTextArea where they type in the answer. Since the method which asks the question is in a different class, how would I get the users answer to return to the method?
GUI (JFrame class):
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class GUI extends JFrame{
public GUI(String name) {
super(name);
//setSize(700,700);
setLayout(new BorderLayout());
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
JPanel myPanel1 = new GUIPanel("Center");
add(myPanel1, BorderLayout.CENTER);
pack();
setVisible(true);
setResizable(true);
}
public static void main(String[] args) {
GUI frame = new GUI("Game");
}
}
GUIPanel (JPanel class):
package javaapplication2;
import java.awt.*;
import javax.swing.*;
public class GUIPanel extends JPanel {
JLabel label1;
JTextField textField1;
JLabel label2;
JTextArea textArea1;
public GUIPanel(String position) {
if (position.equals("Center")) {
createCenterPanel();
}
}
public void createCenterPanel() {
setLayout(new GridLayout(2,2,10,10));
label1 = new JLabel("Type Here: ");
textField1 = new JTextField();
textField1.setPreferredSize(new Dimension(110, 25));
label2 = new JLabel("Game Output: ");
textArea1 = new JTextArea();
add(label1);
add(textField1);
add(label2);
add(textArea1);
}
}
I have not yet added the method call or ActionListener class yet but basically it will call a method which will ask a question and then the user has to answer. This is what I am stuck on. I do not know how I can get the method to "detect" that the user has entered something and then retrieve the data.
I thought about making the textfield static and making a static boolean which gets changed to true when the action performed (user presses enter) gets triggered but that would mean the method would have to have a while loop to check so there must be a better way out there.
I'm not sure if this is what are you looking for because I don't know if i understood right what do you need but I tried
The only code i added was the method getTextField1Text() and called it inside createCenterPanel(), if you have anything to add please let me know, I hope this helps you a bit
public void createCenterPanel() {
setLayout(new GridLayout(2, 2, 10, 10));
label1 = new JLabel("Type Here: ");
textField1 = new JTextField();
textField1.setPreferredSize(new Dimension(110, 25));
label2 = new JLabel("Game Output: ");
textArea1 = new JTextArea();
getTextField1Text();
add(label1);
add(textField1);
add(label2);
add(textArea1);
}
public void getTextField1Text() {
textField1.addActionListener(e -> {
textArea1.setText(e.getActionCommand());
textField1.setText("");
});
}
-------------------------------------------------------------
After discussing in comment section i tried to come up with something
new(which i hope i did) to help you I added 2 methods to get the answer
(NOTE: I used System.out.println(); only for testing)
These methods are added on GUIPanel class
public void getAnswer() {
textArea1.addActionListener(e -> {
textArea1.setText(e.getActionCommand());
testAnswer(textArea1.getText());
});
}
public String testAnswer(String s) {
String saveParam = s;
System.out.println(saveParam);
return saveParam;
}
On GUI class i did some small changes so i can test if the methods is printing the answer,
GUIPanel myPanel1 = new GUIPanel("Center");
public GUI(String name) {
super(name);
//setSize(700,700);
setLayout(new BorderLayout());
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
add(myPanel1, BorderLayout.CENTER);
pack();
setVisible(true);
setResizable(true);
}
public GUIPanel getMyPanel1() {
return myPanel1;
}
public static void main(String[] args) {
GUI frame = new GUI("Game");
frame.getMyPanel1().getAnswer();
}
I want to call My JPanel with button. My Jpanel is actually a sub JPanel from main Panel with card layout.
to do that, i am using card layout api method HERE to show the JPanel after a button was clicked.
JButton btnCallPanel1 = new JButton("Call PanelOne");
btnCallPanel1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card = (CardLayout)mainPanel.getLayout();
card.show(mainPanel, "PanelOne"); //call Panel One
}
output :
nothing appear, panel not called and no error pop out.
My Code is HERE
package wan.dev.sample.cardlayout;
import java.awt.CardLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JLabel;
public class HowToUseCardLayout {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
HowToUseCardLayout window = new HowToUseCardLayout();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public HowToUseCardLayout() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 688, 358);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JPanel mainPanel = new JPanel();
mainPanel.setBounds(0, 0, 672, 260);
frame.getContentPane().add(mainPanel);
mainPanel.setLayout(new CardLayout(0, 0));
JPanel PrePanel = new JPanel();
mainPanel.add(PrePanel, "name_246268073832057");
PrePanel.setLayout(null);
JLabel lblPanel_1 = new JLabel("Pre Panel");
lblPanel_1.setBounds(280, 115, 57, 20);
PrePanel.add(lblPanel_1);
JPanel panelOne = new JPanel();
mainPanel.add(panelOne, "name_246268067657434");
panelOne.setLayout(null);
JLabel lblPanel = new JLabel("panel 1");
lblPanel.setBounds(279, 118, 46, 14);
panelOne.add(lblPanel);
JButton btnPan1 = new JButton("Call PanelOne");
btnPan1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card = (CardLayout) mainPanel.getLayout();
card.show(mainPanel, "PanelOne");
}
});
btnPan1.setBounds(262, 286, 144, 23);
frame.getContentPane().add(btnPan1);
}
}
ANSWER
The reason i cant call my panel because i did not call it by using identifier.
i have to give identifier name to my desire jpanel and use the identifier on my cardLayout.show(..)
Public Static final String PANEL_ONE = "panel one"; //Name of JPanel Identifier
//add panel to main panel and declare panelOne identifier
mainPanel.add(panelOne, PANEL_ONE); //PANEL_ONE function like
//an identifier
JButton btnCallPanel1 = new JButton("Call PanelOne");
btnCallPanel1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card =
(CardLayout)mainPanel.getLayout();
card.show(mainPanel, PANEL_ONE); //call panelOne using PANEL_ONE
//instead of JPanel name
}
As I suspected — You're calling the CardLayout.show(...) method with the String parameter "PanelOne", but yet you've not added any component to the CardLayout-using container using this same String, so it makes sense that it won't work. Solution: don't do this. Use the Same String that you add the component to the CardLayout using container as the one that you use to display it.
i.e., If you want to display container foo and use the String "bar" to add it to the CardLayout-using container, then you must pass "bar" into the CardLayout's show(...) method. Again, use String constants for this so that you reduce the chances of messing up.
Other issues: You're using null layout and setBounds — Don't. Doing this makes for very inflexible GUI's that while they might look good on one platform look terrible on most other platforms or screen resolutions and that are very difficult to update and maintain.
e.g.,
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class CardLayoutFoo extends JPanel {
public static final String BAR = "bar";
public static final String BUTTON_PANEL = "button panel";
private CardLayout cardlayout = new CardLayout();
public CardLayoutFoo() {
setLayout(cardlayout);
JLabel fooLabel = new JLabel("Foo", SwingConstants.CENTER);
add(fooLabel, BAR); // added using String constant, BAR
JButton showFooBtn = new JButton(new AbstractAction("Show Foo") {
#Override
public void actionPerformed(ActionEvent evt) {
// use same String, BAR, to get the fooLabl shown
cardlayout.show(CardLayoutFoo.this, BAR);
}
});
JPanel btnPanel = new JPanel();
btnPanel.add(showFooBtn);
add(btnPanel, BUTTON_PANEL);
cardlayout.show(this, BUTTON_PANEL);
}
private static void createAndShowGui() {
CardLayoutFoo mainPanel = new CardLayoutFoo();
JFrame frame = new JFrame("CardLayoutFoo");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}