Develop Reference

How to close JDialog and save the setting ?

Hi I'm working on a program and I faced a problem when I choose some settings from JDialog then click "ok", which is that the setting didn't save but come back to the original settings.
PS : I'm not English speaker so maybe you observe some mistakes in my text above.
picture
enter image description here
class DrawingSettingWindow extends JDialog {
public DrawingSettingWindow() {
this.setTitle("Drawing Setting Window");
this.setSize(550, 550);
this.setLocationRelativeTo(null);
this.setModal(true);
this.setLayout(new GridLayout(4, 1));
JLabel selectColorText = new JLabel("Select Drawing Color");
colorsList = new JComboBox(colors);
JPanel panel1 = new JPanel();
panel1.add(selectColorText);
panel1.add(colorsList);
add(panel1);
JLabel selectStyleText = new JLabel("Select Drawing Style");
JPanel panel2 = new JPanel();
normal = new JRadioButton("Normal");
normal.setSelected(true);
filled = new JRadioButton("Filled");
ButtonGroup bg = new ButtonGroup();
bg.add(normal);
bg.add(filled);
panel2.add(selectStyleText);
panel2.add(normal);
panel2.add(filled);
add(panel2);
JButton ok = new JButton("OK");
add(ok);
ok.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
setVisible(false);
}
});
this.pack();
this.setVisible(true);
}

The information is there, you just have to extract it from the dialog after the user is done using it. I would give the code above at least two new methods, one a public getColor() method that returns colorsList.getSelectedItem();, the color selection of the user (I'm not sure what type of object this is, so I can't show the method yet). Also another one that gets the user's filled setting, perhaps
public boolean getFilled() {
return filled.isSelected();
}
Since the dialog is modal, you'll know that the user has finished using it immediately after you set it visible in the calling code. And this is where you call the above methods to extract the data.
In the code below, I've shown this in this section: drawingSettings.setVisible(true);
// here you extract the data
Object color = drawingSettings.getColor();
boolean filled = drawingSettings.getFilled();
textArea.append("Color: " + color + "\n");
textArea.append("Filled: " + filled + "\n");
}
For example (see comments):
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
#SuppressWarnings("serial")
public class UseDrawingSettings extends JPanel {
private JTextArea textArea = new JTextArea(20, 40);
private DrawingSettingWindow drawingSettings;
public UseDrawingSettings() {
JPanel topPanel = new JPanel();
topPanel.add(new JButton(new ShowDrawSettings()));
setLayout(new BorderLayout());
add(new JScrollPane(textArea));
add(topPanel, BorderLayout.PAGE_START);
}
private class ShowDrawSettings extends AbstractAction {
public ShowDrawSettings() {
super("Get Drawing Settings");
}
#Override
public void actionPerformed(ActionEvent e) {
if (drawingSettings == null) {
Window win = SwingUtilities.getWindowAncestor(UseDrawingSettings.this);
drawingSettings = new DrawingSettingWindow(win);
}
drawingSettings.setVisible(true);
// here you extract the data
Object color = drawingSettings.getColor();
boolean filled = drawingSettings.getFilled();
textArea.append("Color: " + color + "\n");
textArea.append("Filled: " + filled + "\n");
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
private static void createAndShowGui() {
UseDrawingSettings mainPanel = new UseDrawingSettings();
JFrame frame = new JFrame("UseDrawingSettings");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}
#SuppressWarnings("serial")
class DrawingSettingWindow extends JDialog {
private static final String TITLE = "Drawing Setting Window";
private JComboBox<String> colorsList;
private JRadioButton normal;
private JRadioButton filled;
// not sure what colors is, but I'll make it a String array for testing
private String[] colors = {"Red", "Orange", "Yellow", "Green", "Blue"};
public DrawingSettingWindow(Window win) {
super(win, TITLE, ModalityType.APPLICATION_MODAL);
// this.setTitle("Drawing Setting Window");
this.setSize(550, 550); // !! this is not recommended
this.setLocationRelativeTo(null);
this.setModal(true);
this.setLayout(new GridLayout(4, 1));
JLabel selectColorText = new JLabel("Select Drawing Color");
colorsList = new JComboBox(colors);
JPanel panel1 = new JPanel();
panel1.add(selectColorText);
panel1.add(colorsList);
add(panel1);
JLabel selectStyleText = new JLabel("Select Drawing Style");
JPanel panel2 = new JPanel();
normal = new JRadioButton("Normal");
normal.setSelected(true);
filled = new JRadioButton("Filled");
ButtonGroup bg = new ButtonGroup();
bg.add(normal);
bg.add(filled);
panel2.add(selectStyleText);
panel2.add(normal);
panel2.add(filled);
add(panel2);
JButton ok = new JButton("OK");
add(ok);
ok.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
setVisible(false);
}
});
this.pack();
// this.setVisible(true); // this should be the calling code's responsibility
}
public Object getColor() {
return colorsList.getSelectedItem();
}
public boolean getFilled() {
return filled.isSelected();
}
public static void main(String[] args) {
JFrame frame = new JFrame("Foo");
}
}
Side notes:
I've changed your class's constructor to accept a Window parameter, the base class for JFrame, JDialog, and such, and have added a call to the super's constructor. This way, the dialog is a true child window of the calling code (or you can pass in null if you want it not to be).
I recommend not making the dialog visible within its constructor. It is the calling code's responsibility for doing this, and there are instances where the calling code will wish to not make the dialog visible after creating it, for example if it wanted to attach a PropertyChangeListener to it before making it visible. This is most important for modal dialogs, but is just good programming practice.
I didn't know the type of objects held by your combo box, and so made an array of String for demonstration purposes.

Java syntax for separating action listeners

Please help me out to separate these ActionListeners in a periodic table that I am attempting to complete. When I execute the program and click on 'H', it opens all the other elements and when the others are clicked, it does not work. So I need a way to separate these using any method...
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class PeriodicTable
{
public static void main (String[] args)
{
JFrame frame = new JFrame("Elements");
frame.setVisible(true);
frame.setSize(1000,1500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.add(panel);
JButton button1 = new JButton("H");
panel.add(button1);
button1.addActionListener (new Action1());
JButton button2 = new JButton("He");
panel.add(button2);
button2.addActionListener (new Action2());
JButton button3 = new JButton("Li");
panel.add(button3);
button3.addActionListener (new Action2());
}
static class Action1 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame2 = new JFrame("H");
frame2.setVisible(true);
frame2.setSize(1000,1500);
JLabel label = new JLabel("Hydrogen");
JPanel panel = new JPanel();
frame2.add(panel);
panel.add(label);
}
}
static class Action2 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame3 = new JFrame("He");
frame3.setVisible(true);
frame3.setSize(1000,1500);
JLabel label = new JLabel("Helium");
JPanel panel = new JPanel();
frame3.add(panel);
panel.add(label);
}
}
static class Action3 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame4 = new JFrame("Li");
frame4.setVisible(true);
frame4.setSize(1000,1500);
JLabel label = new JLabel("Lithium");
JPanel panel = new JPanel();
frame4.add(panel);
panel.add(label);
}
}
}
Thanks in advance.
(note: only the first 3 elements are coded for...)

When I execute the program and click on 'H', it opens all other elements
Only one frame opens for me.
and when the others are clicked, it does not work.
Each button opens a single frame for me.
However, button 3 opens the wrong frame because you add the wrong listener to the button:
//button3.addActionListener (new Action2());
button3.addActionListener (new Action3());
Other issues:
You should add the components to the frame BEFORE making the frame visible.
Don't hardcode screen sizes, you never know what size screen other users will be using
So the order of your code might be something like:
JLabel label = new JLabel("Helium");
JPanel panel = new JPanel();
panel.add(label);
JFrame frame3 = new JFrame("He");
frame3.add(panel);
frame3.pack();
frame3.setVisible(true);
And of course you really don't want to create dozens of separate ActionListeners. You want to make the listener more generic so it can be shared.
Something like:
static class Action implements ActionListener
{
public Action(String element, String description)
{
this.element = element;
this.description = description;
}
public void actionPerformed (ActionEvent e)
{
JLabel label = new JLabel(description);
JPanel panel = new JPanel();
panel.add(label);
JFrame frame3 = new JFrame(element);
frame3.add(panel);
frame3.pack();
frame3.setVisible(true);
}
}
Then when you create the listener you use:
button3.addActionListener (new Action("HE", "Helium"));

How do you open a new JPanel window on a click of a button?

I am new to JSwing and I would like to ask a question regarding opening new JPanels on a click of a button.
public class GUIDriver extends JFrame implements ActionListener {
private JPanel mainPanel;
private JButton regButton;
private JButton loginButton;
private JButton acctButton;
public GUIDriver(){
super("FriendBook");
mainPanel = new JPanel();
regButton = new JButton("Register Account");
loginButton = new JButton("Login");
acctButton = new JButton("View Accounts");
mainPanel.add(regButton);
mainPanel.add(loginButton);
mainPanel.add(acctButton);
regButton.addActionListener(this);
loginButton.addActionListener(this);
acctButton.addActionListener(this);
getContentPane().add(mainPanel);
setSize(300,300);
}
public static void main(String[] args){
GUIDriver myDriver = new GUIDriver();
myDriver.setVisible(true);
myDriver.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#Override
public void actionPerformed(ActionEvent e){
if(e.getSource() == regButton){
JPanel register = new JPanel();
register.setSize(new Dimension(400,100));
JLabel username = new JLabel("Username");
JLabel password = new JLabel("Password");
JButton registerBT = new JButton("Register Account");
JTextField uname = new JTextField(20);
JTextField pass = new JTextField(20);
register.add(username);
register.add(uname);
register.add(password);
register.add(pass);
register.add(registerBT);
register.setVisible(true);
}
else if(e.getSource() == loginButton){
System.out.print("LOGIN");
}
else if (e.getSource() == acctButton){
System.out.print("VIEW ACCOUNTS");
}
}
}
The programs shows three buttons (Register, Login and View). I would like to open a new JPanel window when I click on the Register button but it does not show. Please help me, I am new to JSwing/Java GUI. Thank you!

A JPanel needs something that wraps around in order to be displayed; you have to create another "windows"; for example a JDialog. Then you add the created panel to that "window".
In other words: just creating a JPanel is not sufficient to make it visible.

Working with JFrames

hi I'm basically give up. Ok so this is what I am trying to do. So far I have written code to create a JFrame which contains a text field and combo box. The code is supposed to calculate the area of an input in the text field depending on what shape is selected from the combo box and output the result on the JFrame!
Here's is what the output should look like
And here is my code so far. it's a bit messed up but any help would be much appreciated. Thanks in advance
import javax.swing. *;
import java.awt.event. *;
import java.awt.FlowLayout;
import java.lang.Math;
public class AreaFrame3 extends JFrame
{
double Area;
double input;
public static void main(String[]args)
{
//Create array containing shapes
String[] shapes ={"(no shape selected)","Circle","Equilateral Triangle","Square"};
//Use combobox to create drop down menu
JComboBox comboBox=new JComboBox(shapes);
JLabel label1 = new JLabel("Select shape:");
JPanel panel1 = new JPanel(new FlowLayout()); //set frame layout
JLabel label2 = new JLabel("(select shape first)");
JTextField text = new JTextField(10); //create text field
text.setEnabled(false);
panel1.add(label1);
panel1.add(comboBox);
panel1.add(label2);
panel1.add(text);
JFrame frame=new JFrame("Area Calculator Window");//create a JFrame to put combobox
frame.setLayout(new FlowLayout()); //set layout
frame.add(panel1);
frame.add(text);
//JButton button = new JButton("GO"); //create GO button
//frame.add(button);
//set default close operation for JFrame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
//set JFrame ssize
frame.setSize(400,250);
//make JFrame visible. So we can see it
frame.setVisible(true);
// public void actionPerformed(ActionEvent e)
//{
}
public void AreaCalc()
{
JButton button = new JButton("GO"); //create GO button
frame.add(button);
button.addActionListener(
new ActionListener(){
public void actionPerformed(ActionEvent e)
{
int input = double.parseDouble(text.getText());
if(e.getSource() == button)
{
String shape = (String).comboBox.getSelectedItem();
if(shape == "(no shape selected)")
{
text.setEnabled(false);
}
else{
text.setEnabled(true);
}
if(input > 1 && shape == "Circle")
{
// label2.getText() = "Enter the radius of the circle: ";
Area = (Math.PI * (input * input));
}
}
else{}
}
}
);
}
}

I try to understand what you did here:
panel1.add(label1);
panel1.add(comboBox);
panel1.add(label2);
panel1.add(text); // <---
JFrame frame=new JFrame("Area Calculator Window");//create a JFrame to put combobox
frame.setLayout(new FlowLayout()); //set layout
frame.add(panel1);
frame.add(text); // <---
Especially frame.add(text); and panel1.add(text);. Don't add text to JFrame. Use JPanel.
Further,
public class AreaFrame3 extends Frame
Use public class AreaFrame3 extends JFrame so you don't need create additional JFrame:
JFrame frame=new JFrame("Area Calculator Window");
Something like:
super.setLayout(new FlowLayout()); //set layout
super.add(panel1);
super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
super.pack();
//set JFrame ssize
super.setSize(400,250);
//make JFrame visible. So we can see it
super.setVisible(true);
At last Ill give you some tamplate to start with (that will help you):
public class FrameExmpl extends JFrame{
private static final long serialVersionUID = 1L;
private JTabbedPane tabbedPane;
private JPanel topPanel;
private JTextField txtf_loadDS_;
public static int valueInt = 0; // responsible for Task status updating
public static Boolean isFinish = false;
public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException{
UIManager.setLookAndFeel( "com.sun.java.swing.plaf.windows.WindowsLookAndFeel" );
FrameExmpl UI_L = new FrameExmpl();
UI_L.buildGUI();
UI_L.setVisible(true);
}
public void buildGUI(){
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
dispose();
}
});
setSize(435, 225);
setLocation(285, 105);
setResizable(false);
topPanel = new JPanel();
topPanel.setLayout(new BorderLayout());
getContentPane().add(topPanel);
txtf_loadDS_ = new JTextField();
txtf_loadDS_.setBounds(22, 22, 382, 25);
topPanel.add(txtf_loadDS_);
finishBuildGUI();
}
public void finishBuildGUI(){
tabbedPane = new JTabbedPane();
topPanel.add(tabbedPane, BorderLayout.CENTER);
}
}

There are multiple issues with this application such as extending from Frame rather than JFrame & attempting to assign an int from Double.parseDouble. I would recommend that you start again building a small but working application and incrementally add functionality, this way errors are easier to fix.

GUI elements not showing until resize of window

I have been experimenting with making GUIs in java as opposed to just using "static" all the time and come across the "SwingUtilities.invokeLater()" method. I manage to get everything setup but when it comes to run the application, nothing appears on the JPanel until I resize the window. Is there a fix for this or am I doing it wrong?
Heres my code:
public class main extends JPanel implements ActionListener{
public JLabel userLabel;
public JLabel passLabel;
public JTextField userField;
public JTextField passField;
public JButton login;
public JButton closeLogin;
public JButton help;
public main(){
userLabel = new JLabel("Username: ");
passLabel = new JLabel("Password: ");
userField = new JTextField(16);
passField = new JTextField(16);
login = new JButton("Login");
login.setActionCommand("login");
login.setMnemonic(KeyEvent.VK_L);
closeLogin = new JButton("Close");
closeLogin.setActionCommand("closeLogin");
closeLogin.setMnemonic(KeyEvent.VK_E);
help = new JButton("Help");
help.setActionCommand("helpLogin");
help.setMnemonic(KeyEvent.VK_H);
login.addActionListener(this);
closeLogin.addActionListener(this);
help.addActionListener(this);
add(userLabel);
add(userField);
add(passLabel);
add(passField);
add(login);
add(help);
add(closeLogin);
}
public void actionPerformed(ActionEvent e){
}
public static void initComponents(){
JFrame loginFrame = new JFrame("Encrypted Chat - Login");
loginFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
main loginPanel = new main();
loginPanel.setLayout(new FlowLayout());
loginFrame.setSize(300, 125);
loginFrame.setResizable(false);
loginFrame.setVisible(true);
}
public static void main(String args[]){
SwingUtilities.invokeLater(new Runnable(){
public void run(){
initComponents();
}
});
}
}
EDIT: I know the password JTextField is meant to be a JPasswordField.. so ignore it :P

Two basic advices:
1.) When you use swing, and stuff doesnt show up/update, you should call JPanel.revalidate() and JPanel.repaint() These two functions will update your panel.
If you are using a JFrame and you didn't add any extra panels to it, then you can get the content panel by JFrame.getContentPane()
2.) When you finished adding Components to a panel/frame you should also call pack() on the frame, this will ensure, that all your Components have the prefered size.

You never add your content to the JFrame. The minimal set of changes you need:
public static void main(String args[]){
final main main = new main();
SwingUtilities.invokeLater(new Runnable(){
public void run(){
initComponents(main);
}
});
}
And then modify initComponents to take a main object:
public static void initComponents(main main){
JFrame loginFrame = new JFrame("Encrypted Chat - Login");
loginFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
main loginPanel = new main();
loginPanel.setLayout(new FlowLayout());
loginFrame.setSize(300, 125);
loginFrame.setResizable(false);
loginFrame.setVisible(true);
loginFrame.add(main); // <----- this line is added
}

for built_in FlowLayout (for JPanel) I don't suggest to use pack() for JFrame, sure correct way could be to use proper and better LayoutManager for this job, GridBagLayout or SpringLayout
output by using JFrame#setSize() and without pack()
for example
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
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 MainLogin implements ActionListener {
private JFrame loginFrame = new JFrame("Encrypted Chat - Login");
private JPanel pnl = new JPanel();
private JLabel userLabel;
private JLabel passLabel;
private JTextField userField;
private JTextField passField;
private JButton login;
private JButton closeLogin;
private JButton help;
public MainLogin() {
userLabel = new JLabel("Username: ");
passLabel = new JLabel("Password: ");
userField = new JTextField(16);
passField = new JTextField(16);
login = new JButton("Login");
login.setActionCommand("login");
login.setMnemonic(KeyEvent.VK_L);
closeLogin = new JButton("Close");
closeLogin.setActionCommand("closeLogin");
closeLogin.setMnemonic(KeyEvent.VK_E);
help = new JButton("Help");
help.setActionCommand("helpLogin");
help.setMnemonic(KeyEvent.VK_H);
login.addActionListener(this);
closeLogin.addActionListener(this);
help.addActionListener(this);
pnl.add(userLabel);
pnl.add(userField);
pnl.add(passLabel);
pnl.add(passField);
pnl.add(login);
pnl.add(help);
pnl.add(closeLogin);
loginFrame.add(pnl);
loginFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
loginFrame.setSize(300, 125);
loginFrame.setResizable(false);
loginFrame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
MainLogin mainLogin = new MainLogin();
}
});
}
}

Put
JFrame.setVisible(true); on the last line after adding all components to it.