Java - Broken JLabel after proper disposal of different JFrame - java

I'm currently making our project and I'm having problem reseting JLabel back to "0". Here's the code
main code snippet (check note 1 for frame disposal method used):
import javax.swing.*; //import library
import java.awt.event.*;
import java.awt.*;
import java.util.*;
public class draft_main //class name
{
public static void main(String[] args)
{ //method name
JFrame f0 = new JFrame("POS"); //frame
JPanel p0 = new JPanel(); //panel inside the frame
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
JPanel p4 = new JPanel();
JPanel p5 = new JPanel();
JPanel p6 = new JPanel();
JPanel p7 = new JPanel();
JLabel l0 = new JLabel("Amount:"); //label inside the panel
JLabel l1 = new JLabel("0");
JLabel l2 = new JLabel("Menu Code: ");
JLabel l3 = new JLabel("--Menu--");
JTextField tf0 = new JTextField("", 12); //user input for menu code
JButton b0 = new JButton("Checkout"); //buttons
JButton b1 = new JButton("Cancel");
JButton b2 = new JButton("Exit");
JButton b4 = new JButton("Accept");
JButton b7 = new JButton("Remove");
JOptionPane jop = new JOptionPane(); //JOptionPane
JTextField tf1 = new JTextField("1. Hot Pockets Pizza", 20); //list of menu
JTextField tf2 = new JTextField("2. Burger with Fries", 20);
JTextField tf3 = new JTextField("3. Sticky Rice (Bico)", 20);
ArrayList<String> ar = new ArrayList<String>(); //list of array
try{
b4.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e) //what the accept button does
{
String order = tf0.getText(), tots="", temp="";
int o = Integer.parseInt(order);
int tot=0;
switch(o) //menu choice
{
case 1 : temp = l1.getText(); tot=Integer.parseInt(temp); tot=tot+250; tots = Integer.toString(tot); l1.setText(tots); ar.add("Hot Pockets Pizza"); break;
case 2 : temp = l1.getText(); tot=Integer.parseInt(temp); tot=tot+65; tots = Integer.toString(tot); l1.setText(tots); ar.add("Burger with Fries"); break;
case 3 : temp = l1.getText(); tot=Integer.parseInt(temp); tot=tot+12; tots = Integer.toString(tot); l1.setText(tots); ar.add("Sticky Rice (Bico)"); break;
default : jop.showMessageDialog(null, "Menu code not listed in menu", "Error", jop.INFORMATION_MESSAGE); break;
}
}
});
b0.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e) //what the checkout button does
{
JFrame f1 = new JFrame("Checkout");
JFrame f2 = new JFrame("Order");
JPanel p8 = new JPanel();
JPanel p9 = new JPanel();
JPanel p10 = new JPanel();
JPanel p11 = new JPanel();
JPanel p12 = new JPanel();
JPanel p13 = new JPanel();
JPanel p14 = new JPanel();
JLabel l5 = new JLabel("Order list");
JLabel l6 = new JLabel(/*convert ArrayList to String then put here*/);
JLabel l4 = new JLabel("Cash");
JTextField tf4 = new JTextField("", 14);
JButton b5 = new JButton("Accept");
JButton b6 = new JButton("Cancel");
JButton b7 = new JButton("Ok");
b5.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String cas = l1.getText(), in = tf4.getText();
int cash = Integer.parseInt(cas), inp = Integer.parseInt(in), cahs=0;
if(cash>inp)
{
jop.showMessageDialog(null, "Insufficient funds", "Lacking cash? Work for it.", jop.INFORMATION_MESSAGE);
}
else if(cash<inp)
{
cahs = inp - cash;
jop.showMessageDialog(null, "Change: " +cahs+". Thank you");
f1.dispatchEvent(new WindowEvent(f1, WindowEvent.WINDOW_CLOSING));
}
else if(cash==inp)
{
jop.showMessageDialog(null, "Thank you.", "Thank you.", jop.INFORMATION_MESSAGE);
f1.dispatchEvent(new WindowEvent(f1, WindowEvent.WINDOW_CLOSING));
}
}
});
b6.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
f1.dispatchEvent(new WindowEvent(f1, WindowEvent.WINDOW_CLOSING));
}
});
b7.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
f2.dispatchEvent(new WindowEvent(f2, WindowEvent.WINDOW_CLOSING));
}
});
p9.add(l0);
p9.add(l1);
p10.add(l4);
p10.add(tf4);
p11.add(b5);
p11.add(b6);
p12.add(l5);
p12.add(l6);
p13.add(b7);
p14.add(p12);
p14.add(p13);
p8.add(p10);
p8.add(p11);
p8.add(p9);
f1.add(p8);
f1.pack();
f1.setSize(240,170);
f1.setLocationRelativeTo(null);
f1.setResizable(false);
f1.setDefaultCloseOperation(f1.DISPOSE_ON_CLOSE);
f1.setVisible(true);
f2.add(p14);
f2.pack();
f2.setSize(270,100);
f2.setResizable(false);
f2.setLocationRelativeTo(null);
f2.setDefaultCloseOperation(f2.DISPOSE_ON_CLOSE);
f2.setVisible(true);
}
});
b1.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
l1.setText("0");
}
});
b2.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
f0.dispose();
}
});
}
catch(Exception e)
{
jop.showMessageDialog(null, "Error");
}
tf1.setEditable(false);
tf2.setEditable(false);
tf3.setEditable(false);
p4.add(tf1);
p5.add(tf2);
p6.add(tf3);
p7.add(l3);
p3.add(l2);
p3.add(tf0);
p3.add(b4);
p1.add(l0);
p1.add(l1);
p2.add(b0);
p2.add(b1);
p2.add(b2);
p0.add(p3);
p0.add(p1);
p0.add(p2);
p0.add(p7);
p0.add(p4);
p0.add(p5);
p0.add(p6);
f0.add(p0);
f0.pack();
f0.setSize(303,280);
f0.setLocationRelativeTo(null);
f0.setResizable(false);
f0.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f0.setVisible(true);
}
}
what happens is when the main window opens it asks for which from the menu did a guy order then it displays the price. During checkout the user will be asked to input amount of cash given and gives change if there's any. After then the checkout frame is then "properly" disposed (so as I think so), exposing the main frame. However the JLabel does not seem to update when I place another order or clear the current order and it bothers me since the main frame is supposed to be fully interactive until the main frame is closed.
note #1: I have used different methods on how to dispose the 2nd and 3rd frame which pops up since I thought it may have been because of the dispose(); does not really destroys the frame but let's it run in the background.
note #2: yes the program is not finished yet, but those don't matter for now for those will just be some minor features of the application.

You've several problems with this code, but the major ones that I see (and I haven't gone through all of it yet, so there may be more)
First and foremost, those JFrame sub-windows shouldn't be JFrames at all, but rather should be modal JDialogs. The reason for this is this gives you complete control over program flow when these dialogs are used, since you'll then know that the main program flow will be put on hold while the modal dialog is visible, and then the flow will resume as soon as the dialog is no longer visible. This way you can query the state of the dialog after it has been dealt with, and then use this information to update your GUI.
Your amount is shown in the l1 variable, and this will never change unless you specifically call setText(...) on this variable. You don't seem to be doing it when the order has been processed. Again modal dialogs will help you with this.
Your variable naming is bad. Instead of using meaningless letters and numbers for names, use names that make sense and that make your code self-commenting. So for instance, instead of l1, use amountLabel or something similar.
Your code is one huge god class with everything stuffed into the static main method, and this makes for a debugging nightmare. Java is an object-oriented language, and if used properly OOP techniques can help you reduce program complexity making your code easier for yourself and for us to understand. Start OOP-ifying your program and you'll see immediate dividends.
And I found your bug -- you're adding the l1 JLabel to another container, and so it is effectively being removed from the original JFrame. If you minimize your original GUI and then restore it, you'll see the amount l1 JLabel disappear.
Here's some sample code not yet done, but to give you an idea about adding OOP to the program:
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class Draft2 extends JPanel {
private List<MyItem> selectedItems = new ArrayList<>();
private NumberFormat formatter = NumberFormat.getCurrencyInstance();
private double total;
private JLabel totalAmountLabel = new JLabel(formatter.format(total));
private DefaultComboBoxModel<MyItem> comboModel = new DefaultComboBoxModel<>();
private JComboBox<MyItem> menuCombo = new JComboBox<>(comboModel);
public Draft2() {
// monospaced to make names and price line up
menuCombo.setFont(new Font(Font.MONOSPACED, Font.BOLD, 12));
// fill the JComboBox with items
comboModel.addElement(new MyItem("Baseball", 21.5));
comboModel.addElement(new MyItem("Bat", 50.8));
comboModel.addElement(new MyItem("Football", 22.26));
// create a JPanel to hold selection components and add components
JPanel selectionPanel = new JPanel();
selectionPanel.add(new JLabel("Menu:"));
selectionPanel.add(menuCombo);
selectionPanel.add(new JButton(new AcceptAction("Accept", KeyEvent.VK_A)));
// create a JPanel to hold the total amount information
JPanel totalAmountPanel = new JPanel();
totalAmountPanel.add(new JLabel("Total Amount:"));
totalAmountPanel.add(totalAmountLabel);
// create a JPanel to hold buttons, uses grid layout with a single row
JPanel btnPanel = new JPanel(new GridLayout(1, 0, 5, 0));
btnPanel.add(new JButton(new CheckOutAction("Check Out", KeyEvent.VK_C)));
btnPanel.add(new JButton(new CancelAction("Cancel", KeyEvent.VK_N)));
btnPanel.add(new JButton(new ExitAction("Exit", KeyEvent.VK_X)));
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(selectionPanel);
add(Box.createVerticalStrut(5)); // so don't crowd things
add(totalAmountPanel);
add(Box.createVerticalStrut(5));
add(btnPanel);
}
public void setTotalAmount(double total) {
totalAmountLabel.setText(formatter.format(total));
}
private class AcceptAction extends AbstractAction {
public AcceptAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
MyItem myMenuItem = (MyItem) menuCombo.getSelectedItem();
if (myMenuItem == null) {
return; // nothing selected, get out
}
selectedItems.add(myMenuItem);
double total = 0.0;
for (MyItem myItem : selectedItems) {
total += myItem.getCost();
}
setTotalAmount(total);
}
}
private class CheckOutAction extends AbstractAction {
public CheckOutAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Finish....
// open JDialog or JOptionPane
}
}
private class CancelAction extends AbstractAction {
public CancelAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Finish...
}
}
private class ExitAction extends AbstractAction {
public ExitAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("My GUI Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Draft2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
}
class MyItem {
private NumberFormat formatter = NumberFormat.getCurrencyInstance();
private String name;
private double cost;
public MyItem(String name, double cost) {
this.name = name;
this.cost = cost;
}
public String getName() {
return name;
}
public double getCost() {
return cost;
}
#Override
public String toString() {
return String.format("%-10s %s", name, formatter.format(cost));
}
}

Related

JButton shopping cart

Welcome everyone,
This is my first post on this website and I am also quite new to java so go easy on me :)
I am working on a project for my college the task is:
"Design & Build a Java application based on a class linked to a swing
(GUI) application. "
So I Decided to go for a shopping app that will allow you to choose a few games, add them to cart and then display the cart / edit it / remove items etc.
I am having problem with adding items to a cart using a JButton. Here is my code:
Driver:
public class Driver {
public static void main (String[] args) {
MainShop shop= new MainShop ("Welcome to my Shop");
}
}
MainShop:
import java.awt.*;
import java.util.*;
import java.text.*;
import java.math.*;
import javax.swing.*;
import java.awt.event.*;
public class MainShop extends JFrame implements ActionListener, WindowListener {
private Container content;
private JLabel l1 = new JLabel ("Welcome to my Shop");
private JLabel l2 = new JLabel("You want to browse for great games?");
private JLabel l3 = new JLabel ("Choose one of the following 2 platforms: ");
private JLabel l4 = new JLabel ("XBox has no good games. Try PS4 :) ");
private PS4 dialog1 = null ;
private XBox dialog2 = null;
private JButton b1 = new JButton("PS4");
private JButton b2 = new JButton("XBox");
public MainShop (String str) {
super(str);
content = getContentPane();
content.setLayout(new GridLayout(2,2));
content.add(l1);
content.add(l2);
content.add(l3);
content.add(l4);
l4.setVisible(false);
content.add(b1);
b1.addActionListener(this);
content.add(b2);
b2.addActionListener(this);
setSize(800, 150);
content.setBackground(Color.white);
this.addWindowListener(this);
setVisible(true);
}
public void actionPerformed (ActionEvent e) {
Object target = e.getSource();
if (target == b2) {
l4.setVisible(true);
}
if (target == b1) {
l4.setVisible(false);
this.setVisible(false);
new PS4(this, "PS4");
}
}
public void windowActivated(WindowEvent e){}
public void windowClosed(WindowEvent e){}
public void windowClosing(WindowEvent e){System.exit(0);}
public void windowDeactivated(WindowEvent e){}
public void windowDeiconified(WindowEvent e){}
public void windowIconified(WindowEvent e){}
public void windowOpened(WindowEvent e){}
}
PS4 class
import java.awt.*;
import java.util.*;
import java.text.*;
import java.math.*;
import javax.swing.*;
import java.awt.event.*;
class PS4 extends JFrame implements ActionListener, WindowListener{
private JPanel Center = new JPanel();
private JPanel South = new JPanel ();
private JPanel North = new JPanel ();
private JPanel South1 = new JPanel();
private JPanel South2 = new JPanel();
private JPanel Center1 = new JPanel();
private JPanel Center2 = new JPanel ();
private JPanel Center3 = new JPanel ();
private JLabel n1 = new JLabel ("PS4 Games");
private JLabel c1desc = new JLabel ("Name");
private JLabel li1 = new JLabel ("Like it?");
private JLabel c2desc = new JLabel ("Description");
private JLabel c3desc = new JLabel ("Price");
private JButton basket = new JButton ("Proceed to checkout");
private JButton CB = new JButton("Go Back");
private JLabel g1 = new JLabel("Uncharted");
private JButton b1 = new JButton("Add to Basket");
private JLabel d1 = new JLabel (" Action-adventure ");
private JLabel p1 = new JLabel ("59.99€");
private JLabel g2 = new JLabel("Call of Duty");
private JButton b2 = new JButton("Add to Basket");
private JLabel d2 = new JLabel (" First Person Shooter ");
private JLabel p2 = new JLabel ("69.99€");
private JLabel g3 = new JLabel("Fifa 18");
private JButton b3 = new JButton("Add to Basket");
private JLabel d3 = new JLabel (" Sport ");
private JLabel p3 = new JLabel ("69.99€");
private JLabel g4 = new JLabel("Skyrim");
private JButton b4 = new JButton("Add to Basket");
private JLabel d4 = new JLabel (" Open World RPG ");
private JLabel p4 = new JLabel ("49.99€");
private Container content;
private JFrame parent;
public PS4 (JFrame p, String Str) {
super(Str);
parent = p;
getContentPane().add(North, BorderLayout.NORTH);
North.add(n1);
getContentPane().add(Center, BorderLayout.CENTER);
Center.setLayout(new GridLayout(5,4));
Center.add(c1desc);
Center.add(c2desc);
Center.add(c3desc);
Center.add(li1);
Center.add(g1);
Center.add(d1);
Center.add(p1);
Center.add(b1); b1.addActionListener(this);
Center.add(g2);
Center.add(d2);
Center.add(p2);
Center.add(b2); b2.addActionListener(this);
Center.add(g3);
Center.add(d3);
Center.add(p3);
Center.add(b3); b3.addActionListener(this);
Center.add(g4);
Center.add(d4);
Center.add(p4);
Center.add(b4); b4.addActionListener(this);
getContentPane().add(South, BorderLayout.SOUTH);
South.setLayout(new GridLayout(1,2));
South.add(South1);
South.add(South2);
South1.add(CB);
CB.addActionListener(this);
South2.add(basket);
basket.addActionListener(this);
setSize(600,400);
setVisible(true);
this.addWindowListener(this);
}
public void actionPerformed(ActionEvent e) {
Object target = e.getSource();
if (target == b1) {
// THIS IS WHERE I STRUGGLE
}
if (target == b2) {
}
if (target == b3) {
}
if(target == b4) {
}
if(target==CB) {
this.setVisible(false);
parent.setVisible(true);;
}
if (target == basket) {
this.setVisible(false);
new Checkout(this, "");
}
}
public void windowActivated(WindowEvent e){}
public void windowClosed(WindowEvent e){}
public void windowClosing(WindowEvent e){System.exit(0);}
public void windowDeactivated(WindowEvent e){}
public void windowDeiconified(WindowEvent e){}
public void windowIconified(WindowEvent e){}
public void windowOpened(WindowEvent e){}
}
So how do I Add the items I want to a new class by clicking the "Add to cart" JButton?
The worst thing is that we have to present it in 2 weeks and it was given to us on our last class on Friday before eastern break. So we literally have 2 weeks to work on it without any help of our lecturers.
Also, please do not worry about the code structure/layout etc as this will be done at the very end. Right now I'm trying to get the code working.
Now, I know its a long post so any suggestions would be appreciated
If anyone needs screenshots just let me know and I will add them.
Thanks!
I’m currently on my phone, so this answer will be brief for now, however I can help more if required when I get home.
Two options come to mind immediately.
You could create an ArrayList called something like “basket” and add an item to the list, depending on which item’s “add to basket” button you press.
Create a custom object of your own, and use that as the shopping basket.

How do I put label under radio button within a panel with Java Swing/awt

There is 3 panels which I created as seen in the image. The first panel is the "From" panel, second is "To" panel, and third is the buttons panel. So the question is, how can I put a new line for the "Enter Temperature: [ ]" so that it will be under neath the radio buttons? I am very new to Java swing/awt please bear with me.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.awt.*;
public class TemperatureConversion extends JFrame{
// component
JTextField txtFromTemp, txtToTemp;
JLabel lblFromTemp, lblToTemp;
JRadioButton radFromCelsius, radFromFahrenheit, radFromKelvin;
JRadioButton radToCelsius, radToFahrenheit, radToKelvin;
JPanel pnlFromRadioButton, pnlToRadioButton, pnlFromTemp, pnlButton;
ButtonGroup bgFrom, bgTo;
JButton btnConvert, btnExit;
// constructor
public TemperatureConversion(){
super("Temperature");
// assign objects
radFromCelsius = new JRadioButton("Celsius", true);
radFromFahrenheit = new JRadioButton("Fahrenheit");
radFromKelvin = new JRadioButton("Kelvin");
lblFromTemp = new JLabel("Enter Temperature: ");
pnlFromTemp = new JPanel();
btnConvert = new JButton("Convert");
btnExit = new JButton("Exit");
pnlButton = new JPanel();
txtFromTemp = new JTextField(3);
lblToTemp = new JLabel("Comparable Temperature: ");
txtToTemp = new JTextField(3);
// register the button to a listener
btnExit.addActionListener(new MyButtonListener());
btnConvert.addActionListener(new MyButtonListener());
// make the multiple choice exclusive but not a container
bgFrom = new ButtonGroup();
bgFrom.add(radFromCelsius);
bgFrom.add(radFromFahrenheit);
bgFrom.add(radFromKelvin);
// radio buttons
radToCelsius = new JRadioButton("Celsius");
radToFahrenheit = new JRadioButton("Fahrenheit", true);
radToKelvin = new JRadioButton("Kelvin");
// make the multiple choice exclusive
bgTo = new ButtonGroup();
bgTo.add(radToCelsius);
bgTo.add(radToFahrenheit);
bgTo.add(radToKelvin);
pnlFromRadioButton = new JPanel();
pnlToRadioButton = new JPanel();
// decorate the panel
pnlFromRadioButton.setBorder(BorderFactory.createTitledBorder("From"));
pnlToRadioButton.setBorder(BorderFactory.createTitledBorder("To"));
// add radiobutton to panel
pnlFromRadioButton.add(radFromCelsius);
pnlFromRadioButton.add(radFromFahrenheit);
pnlFromRadioButton.add(radFromKelvin);
pnlToRadioButton.add(radToCelsius);
pnlToRadioButton.add(radToFahrenheit);
pnlToRadioButton.add(radToKelvin);
// add button to panel
pnlButton.add(btnConvert);
pnlButton.add(btnExit);
// add label and txt field to panel
pnlFromRadioButton.add(lblFromTemp);
pnlFromRadioButton.add(txtFromTemp);
pnlToRadioButton.add(lblToTemp);
txtToTemp.setEditable(false);
pnlToRadioButton.add(txtToTemp);
// add panels to the frame
add(pnlFromRadioButton, BorderLayout.NORTH);
add(pnlToRadioButton, BorderLayout.CENTER);
add(pnlButton, BorderLayout.SOUTH);
setVisible(true);
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
// private inner class to handle button event
private class MyButtonListener implements ActionListener {
// must override actionPerformed method
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btnConvert) {
if (radFromCelsius.isSelected())
System.out.print("exit");
} else if (e.getSource() == btnExit) {
System.exit(0);
}
}
}
public static void main(String[] args) {
new TemperatureConversion();
}
}
Nest more JPanels and use layout managers
For instance, in the JPanel where you want two lines, give it a BoxLayout oriented along the BoxLayout.PAGE_AXIS, and then add two more JPanels to this BoxLayout-using, a top JPanel with the radio buttons and bottom JPanel with the JLabel and JTextField (or whatever else you want in it).
Side note: this would be a great place to use an enum one called TempScale that had three values: CELSIUS, FAHRENHEIT, KELVIN. You could even give the enum the formulas for conversion to and from Kelvin.
For example:
import java.awt.Component;
import java.awt.event.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
#SuppressWarnings("serial")
public class TempConversion2 extends JPanel {
private ToFromPanel fromPanel = new ToFromPanel("From", true);
private ToFromPanel toPanel = new ToFromPanel("To", false);
private ButtonPanel buttonPanel = new ButtonPanel(fromPanel, toPanel);
public TempConversion2() {
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(fromPanel);
add(toPanel);
add(buttonPanel);
}
private static void createAndShowGui() {
TempConversion2 mainPanel = new TempConversion2();
JFrame frame = new JFrame("Temp Convert");
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(() -> createAndShowGui());
}
}
#SuppressWarnings("serial")
class ButtonPanel extends JPanel {
public ButtonPanel(ToFromPanel fromPanel, ToFromPanel toPanel) {
add(new JButton(new ConvertAction("Convert", fromPanel, toPanel)));
add(new JButton(new ExitAction("Exit", KeyEvent.VK_X)));
}
}
#SuppressWarnings("serial")
class ConvertAction extends AbstractAction {
private ToFromPanel fromPanel;
private ToFromPanel toPanel;
public ConvertAction(String name, ToFromPanel fromPanel, ToFromPanel toPanel) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
this.fromPanel = fromPanel;
this.toPanel = toPanel;
}
#Override
public void actionPerformed(ActionEvent e) {
String text = fromPanel.getText();
try {
double fromTemp = Double.parseDouble(text.trim());
TempScale fromScale = fromPanel.getTempScalesPanel().getSelectedTempScale();
double kelvinValue = fromScale.convertToKelvin(fromTemp);
TempScale toScale = toPanel.getTempScalesPanel().getSelectedTempScale();
double toValue = toScale.convertFromKelvin(kelvinValue);
String toValueString = String.format("%.2f", toValue);
toPanel.setText(toValueString);
} catch (NumberFormatException e1) {
Component parentComponent = fromPanel;
String message = "Text must be a valid number: " + text;
String title = "Invalid Text Entered";
int messageType = JOptionPane.ERROR_MESSAGE;
JOptionPane.showMessageDialog(parentComponent, message, title, messageType);
fromPanel.setText("");
}
}
}
#SuppressWarnings("serial")
class ExitAction extends AbstractAction {
public ExitAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
#SuppressWarnings("serial")
class ToFromPanel extends JPanel {
private String title;
private TempScalesPanel tempScalesPanel = new TempScalesPanel();
private JTextField tempTextField = new JTextField(3);
public ToFromPanel(String title, boolean textFieldEnabled) {
this.title = title;
tempTextField.setFocusable(textFieldEnabled);
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new BoxLayout(bottomPanel, BoxLayout.LINE_AXIS));
bottomPanel.setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2));
bottomPanel.add(new JLabel("Temperature:"));
bottomPanel.add(Box.createHorizontalStrut(8));
bottomPanel.add(tempTextField);
setBorder(BorderFactory.createTitledBorder(title));
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(tempScalesPanel);
add(bottomPanel);
}
public String getTitle() {
return title;
}
public TempScalesPanel getTempScalesPanel() {
return tempScalesPanel;
}
public String getText() {
return tempTextField.getText();
}
public void setText(String text) {
tempTextField.setText(text);
}
}
#SuppressWarnings("serial")
class TempScalesPanel extends JPanel {
private ButtonGroup buttonGroup = new ButtonGroup();
private Map<ButtonModel, TempScale> buttonTempMap = new HashMap<>();
public TempScalesPanel() {
for (TempScale tempScale : TempScale.values()) {
JRadioButton radioButton = new JRadioButton(tempScale.getName());
add(radioButton);
buttonGroup.add(radioButton);
buttonTempMap.put(radioButton.getModel(), tempScale);
// set first button as selected by default
if (buttonGroup.getSelection() == null) {
buttonGroup.setSelected(radioButton.getModel(), true);
}
}
}
public TempScale getSelectedTempScale() {
ButtonModel model = buttonGroup.getSelection();
return buttonTempMap.get(model);
}
}
This is the enum that I was talking about. Note that if you change the enum, and for instance add another temperature scale element, the program will automatically include it in the GUI and in the calculations. God I love Java and OOP.
public enum TempScale {
CELSIUS("Celsius", 1.0, -273.15),
FAHRENHEIT("Fahrenheit", 5.0 / 9.0, -459.67),
KELVIN("Kelvin", 1.0, 0.0);
private TempScale(String name, double ratioToKelvin, double absZero) {
this.name = name;
this.ratioToKelvin = ratioToKelvin;
this.absZero = absZero;
}
private String name;
private double ratioToKelvin;
private double absZero;
public String getName() {
return name;
}
public double getRatioToKelvin() {
return ratioToKelvin;
}
public double getAbsZero() {
return absZero;
}
public double convertToKelvin(double value) {
return (value - absZero) * ratioToKelvin;
}
public double convertFromKelvin(double kelvinValue) {
return (kelvinValue / ratioToKelvin) + absZero;
}
}
Always consider posting an MCVE.
For example you layout can be simplified and demonstrated with :
import java.awt.BorderLayout;
import java.awt.Label;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TemperatureConversion extends JFrame{
JPanel pnlFromRadioButton, pnlToRadioButton, pnlFromTemp, pnlButton;
// constructor
public TemperatureConversion(){
pnlFromRadioButton = new JPanel();
pnlFromRadioButton.add(new Label("From Panel"));
pnlToRadioButton = new JPanel();
pnlToRadioButton.add(new Label("To Panel"));
pnlButton = new JPanel();
pnlButton.add(new Label("Buttons Panel"));
// add panels to the frame
add(pnlFromRadioButton, BorderLayout.NORTH);
add(pnlToRadioButton, BorderLayout.CENTER);
add(pnlButton, BorderLayout.SOUTH);
setVisible(true);
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
new TemperatureConversion();
}
}
Suppose you want to an "Enter Temperature: [ ]" label to show in a different "line" under From buttons, your constructor will change to :
public TemperatureConversion(){
//set a layout manger. You could use grid layout
//GridLayout gridLayout = new GridLayout(4, 1);
//Or BoxLayout
BoxLayout boxLayout = new BoxLayout(getContentPane(), BoxLayout.Y_AXIS); // top to bottom
setLayout(boxLayout);
pnlFromRadioButton = new JPanel();
pnlFromRadioButton.add(new Label("From Panel"));
//create a panel to hold the desired label
pnlFromTemp = new JPanel();
pnlFromTemp.add(new JLabel("Enter Temperature: [ ]"));//add label
pnlToRadioButton = new JPanel();
pnlToRadioButton.add(new Label("To Panel"));
pnlButton = new JPanel();
pnlButton.add(new Label("Buttons Panel"));
// add panels to the frame
//the panel will show in the order added
add(pnlFromRadioButton);
add(pnlFromTemp);
add(pnlToRadioButton);
add(pnlButton);
setVisible(true);
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
Sorry I am new to forums and am not familiar with posting etiquette for codes #c0der. But using GridLayout solved my problem and I want to show you what I did, it is a big mess but here it is. Here is my bizarre code but don't know how to reduce it any further. This is how it is suppose to look as I wanted and because now I understand what you mean by "Nest more JPanels and use layout managers" #Hovercraft Full of Eels:
my temperature program
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.awt.*;
public class TemperatureConversion extends JFrame {
// component
JTextField txtFromTemp, txtToTemp;
JLabel lblFromTemp, lblToTemp, lblToTempbox;
JRadioButton radFromCelsius, radFromFahrenheit, radFromKelvin;
JRadioButton radToCelsius, radToFahrenheit, radToKelvin;
JPanel pnlFromRadioButton, pnlToRadioButton, pnlFrom, pnlTo, pnlButton;
JPanel pnlEnterTemp, pnlComparableTemp;
ButtonGroup bgFrom, bgTo;
JButton btnConvert, btnExit;
// constructor
public TemperatureConversion() {
super("Temperature");
// assign objects
radFromCelsius = new JRadioButton("Celsius", true);
radFromFahrenheit = new JRadioButton("Fahrenheit");
radFromKelvin = new JRadioButton("Kelvin");
lblFromTemp = new JLabel("Enter Temperature: ");
pnlFrom = new JPanel();
btnConvert = new JButton("Convert");
btnExit = new JButton("Exit");
pnlButton = new JPanel();
txtFromTemp = new JTextField(3);
lblToTemp = new JLabel("Comparable Temperature: ");
txtToTemp = new JTextField(3);
pnlTo = new JPanel();
pnlEnterTemp = new JPanel();
pnlComparableTemp = new JPanel();
pnlFromRadioButton = new JPanel();
pnlToRadioButton = new JPanel();
// register the button to a listener
btnExit.addActionListener(new MyButtonListener());
btnConvert.addActionListener(new MyButtonListener());
// make the multiple choice exclusive but not a container
bgFrom = new ButtonGroup();
bgFrom.add(radFromCelsius);
bgFrom.add(radFromFahrenheit);
bgFrom.add(radFromKelvin);
// radio buttons
radToCelsius = new JRadioButton("Celsius");
radToFahrenheit = new JRadioButton("Fahrenheit", true);
radToKelvin = new JRadioButton("Kelvin");
// make the multiple choice exclusive
bgTo = new ButtonGroup();
bgTo.add(radToCelsius);
bgTo.add(radToFahrenheit);
bgTo.add(radToKelvin);
pnlFrom.setLayout(new GridLayout(2, 1));
pnlFrom.add(pnlFromRadioButton);
pnlFrom.add(pnlEnterTemp);
pnlTo.setLayout(new GridLayout(2, 1));
pnlTo.add(pnlToRadioButton);
pnlTo.add(pnlComparableTemp);
// decorate the panel
pnlFrom.setBorder(BorderFactory.createTitledBorder("From"));
pnlTo.setBorder(BorderFactory.createTitledBorder("To"));
// add radiobutton to panel
pnlFromRadioButton.add(radFromCelsius);
pnlFromRadioButton.add(radFromFahrenheit);
pnlFromRadioButton.add(radFromKelvin);
pnlToRadioButton.add(radToCelsius);
pnlToRadioButton.add(radToFahrenheit);
pnlToRadioButton.add(radToKelvin);
// add button to panel
pnlButton.add(btnConvert);
pnlButton.add(btnExit);
// add label and txt field to panel
pnlEnterTemp.add(lblFromTemp);
pnlEnterTemp.add(txtFromTemp);
pnlComparableTemp.add(lblToTemp);
txtToTemp.setEditable(false);
pnlComparableTemp.add(txtToTemp);
// add panels to the frame
add(pnlFrom, BorderLayout.NORTH);
add(pnlTo, BorderLayout.CENTER);
add(pnlButton, BorderLayout.SOUTH);
setVisible(true);
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
// private inner class to handle button event
private class MyButtonListener implements ActionListener {
// must override actionPerformed method
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btnConvert) {
if (radFromCelsius.isSelected() && radToFahrenheit.isSelected()) {
int strInput = Integer.parseInt(txtFromTemp.getText());
int celsius = strInput * 9 / 5 + 32;
txtToTemp.setText(Integer.toString(celsius));
} else if (radFromCelsius.isSelected() && radToCelsius.isSelected() ||
radFromFahrenheit.isSelected() && radToFahrenheit.isSelected() ||
radFromKelvin.isSelected() && radToKelvin.isSelected()) {
txtToTemp.setText(txtFromTemp.getText());
} else if (radToCelsius.isSelected() && radFromFahrenheit.isSelected()) {
int strInput = Integer.parseInt(txtFromTemp.getText());
int fahrenheit = (strInput - 32) * 5 / 9;
txtToTemp.setText(Integer.toString(fahrenheit));
} else if (radFromKelvin.isSelected() && radToCelsius.isSelected()) {
double strInput = Integer.parseInt(txtFromTemp.getText());
double celsius = strInput - 273.15;
txtToTemp.setText(Double.toString(celsius));
} else if (radFromKelvin.isSelected() && radToFahrenheit.isSelected()) {
double strInput = Integer.parseInt(txtFromTemp.getText());
double fahrenheit = strInput - 459.67;
txtToTemp.setText(Double.toString(fahrenheit));
} else if (radFromCelsius.isSelected() && radToKelvin.isSelected()) {
double strInput = Integer.parseInt(txtFromTemp.getText());
double celsius = strInput + 273.15;
txtToTemp.setText(Double.toString(celsius));
} else if (radFromFahrenheit.isSelected() && radToKelvin.isSelected()) {
double strInput = Integer.parseInt(txtFromTemp.getText());
double fahrenheit = strInput + 255.37;
txtToTemp.setText(Double.toString(fahrenheit));
}
} else if (e.getSource() == btnExit) {
System.exit(0);
}
}
}
public static void main(String[] args) {
new TemperatureConversion();
}
}
By the way #Hovercraft Full Of Eels, your solution is way more efficient and advanced than my level of thinking. I am newbie to programming in general so bear with me on my messy code and organization lol. I have barely dipped my feet into OOP. I do have a sense of how you used enum for TempScale and I thank you for your suggestion. I will keep these in my notes as references.

Implementing CardLayout within a JFrame and switching cards based on specific button presses

I've posted my code below. I have the simple task of creating a navigable GUI. I've spent the past few hours doing research on how to accomplish this, and this is the code that I've put together.
Originally I wanted to perform the navigation without any layouts or anything. I need the home panel to display after the user clicks on the "login" button on the welcome panel.
It displays the welcome card just fine, but when I get to the validateLogin method(which is activated when the login button is press, and upon successful login it should show the home panel within cards) it simply stays on the welcome panel even though I have validated that my program reaches the loop to change cards via the system.out.Println()
Please help. I spent my entire Saturday trying to solve this one problem through trials and research, but with no success. This is a last resort for me so if anyone can show me my flaws then I'll happily be on my way and fix it. Then apply that fix to the many other cards that are required for my program.
enter code here
public class mainGUI implements ActionListener{
JFrame main;
JPanel cards = new JPanel(new CardLayout());
CardLayout cl = (CardLayout)(cards.getLayout());
//Items for the welcome panel
JPanel welcome = welcomePanel();
JButton login;
JButton register;
JTextField username;
JTextField password;
//home panel
JPanel home = homePanel();
//WelcomePanel welcome = new WelcomePanel();
ArrayList<Student> students = new ArrayList<Student>();
Student workingStudent;
/**
* calls load() at start and save() on exit
*
*/
public mainGUI(){
load();
main = new JFrame();
main.setSize(900, 600);
main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
main.setTitle("MyCourses 2k16");
main.setContentPane(welcomePanel());
//fill out the cards
cards.add(welcome, "Welcome");
cards.add(home, "Home");
//display welcome card
cl.show(cards, "welcome");
main.setVisible(true);
saveState();
}
private JPanel welcomePanel() {
JPanel welcome = new JPanel();
welcome.setLayout(null);
welcome.setBackground(Color.DARK_GRAY);
JLabel hi = new JLabel("Welcome to MyCourses 2K16");
hi.setSize(800, 100);
hi.setLocation(50,50);
hi.setFont(new Font("Serif", Font.BOLD, 48));
hi.setForeground(Color.WHITE);
JLabel select = new JLabel("Fill in the information, then click login or register to proceed, no special characters allowed");
select.setSize(700,100);
select.setLocation(75,100);
select.setFont(new Font("Serif", Font.PLAIN, 18));
select.setForeground(Color.WHITE);
login = new JButton( "login");
login.setSize(100, 50);
login.setLocation(50, 200);
login.addActionListener(this);
register = new JButton( "register");
register.setSize(100,50);
register.setLocation(200, 200);
register.addActionListener(this);
JLabel un = new JLabel("username");
un.setSize(100, 30);
un.setLocation(50, 270);
un.setForeground(Color.WHITE);
username = new JTextField();
username.setSize(200, 30);
username.setLocation(50,300);
JLabel pw = new JLabel("password");
pw.setSize(100, 30);
pw.setLocation(50, 350);
pw.setForeground(Color.WHITE);
password = new JTextField();
password.setSize(200, 30);
password.setLocation(50,380);
welcome.add(hi);
welcome.add(select);
welcome.add(login);
welcome.add(register);
welcome.add(un);
welcome.add(username);
welcome.add(pw);
welcome.add(password);
return welcome;
}
private JPanel homePanel() {
JPanel home = new JPanel();
home.setLayout(null);
home.setBackground(Color.DARK_GRAY);
JLabel hi = new JLabel("HOME");
hi.setSize(800, 100);
hi.setLocation(50,50);
hi.setFont(new Font("Serif", Font.BOLD, 48));
hi.setForeground(Color.WHITE);
return home;
}
public void load(){
}
private void saveState(){
Iterator<Student> it = students.iterator();
while(it.hasNext()){
it.next().saveStudent();
}
}
public static void main(String[] args) {
new mainGUI();
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource()==login){
System.out.println("Logging in...");
validateLogin(students);
}
else if (e.getSource()==register){
}
}
private void validateLogin(ArrayList<Student> students){
boolean valid = false;
for(int i = 0; i < students.size(); i++){
if(username.getText().equals(students.get(i).getUsername())
&& password.getText().equals(students.get(i).getPassword()))
{
valid = true;
workingStudent=(students.get(i));
System.out.println("Successful Login!");
cl.show(cards, "home");
}
}
if(valid == false){
System.out.println("Invalid Login, try again");
}
}
}
You create a JPanel that uses CardLayout, cards, but you add it to nothing, so it will of course not display itself, nor its cards. Solution: add this JPanel to your GUI.
So instead of:
main.setContentPane(welcomePanel());
do:
main.setContentPane(cards);
Issue number 2:
Use String constants when using Strings as a type of key. Note that you add one JPanel to the cards JPanel thusly:
cards.add(home, "Home");
But then try to display it like so:
cl.show(cards, "home");
But Home isn't the same as home.
Instead declare a constant, HOME:
public static final String HOME = "home";
and use the same constant to add the JPanel and to display it.
For a simplistic example:
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class MainGui2 extends JPanel {
private CardLayout cardLayout = new CardLayout();
private WelcomePanel welcomePanel = new WelcomePanel(this);
private HomePanel homePanel = new HomePanel();
public MainGui2() {
setLayout(cardLayout);
add(welcomePanel, WelcomePanel.NAME);
add(homePanel, HomePanel.NAME);
}
public void showCard(String name) {
cardLayout.show(this, name);
}
private static void createAndShowGui() {
MainGui2 mainPanel = new MainGui2();
JFrame frame = new JFrame("MainGui2");
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();
}
});
}
}
class WelcomePanel extends JPanel {
public static final String NAME = "welcome panel";
private MainGui2 mainGui2;
public WelcomePanel(final MainGui2 mainGui2) {
this.mainGui2 = mainGui2;
add(new JLabel(NAME));
add(new JButton(new AbstractAction("Logon") {
#Override
public void actionPerformed(ActionEvent e) {
mainGui2.showCard(HomePanel.NAME);
}
}));
}
}
class HomePanel extends JPanel {
public static final String NAME = "home panel";
public HomePanel() {
add(new JLabel(NAME));
}
}

Java swing: managing integers/doubles with Listeners and J*Fields

EDITED
I've probably just stared at the screen for WAYYY too long but I feel the need to submit this question prior to going to sleep incase my delirium remains true...
The problem I'm having is I'm trying to get an int/double from the JTextField textField and convert it to a(n) int/double to use later in a listener, after retrieving it from a listener... ListenForText implements KeyListener, specifically KeyTyped, to obtain, through toString(), and store it in a String txtFldAmnt. After which I will store the result of Integer.parseInt(txtFldAmnt) into fldAmnt (fldAmnt = Integer.pareseInt(txtFldAmnt)) LINE 99 if copied to an editor. Once it's converted into an int I want to be able to manipulate it and then use it again, at LINE 173, to display, in a new window, the fldAmnt. Honestly, I don't really care about whether it's an int or String displayed, but I know a String is required for JTextField. What magic am I missing? Answers are always welcome but I prefer a chance to learn. Also, as I'm fairly new to Java, off topic pointers, criticism, and better ways to implement this code is greatly welcomed :)
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GUI extends JFrame{
/**
* wtf is the serial version UID = 1L
*/
private static final long serialVersionUID = 1L;
private JButton wdBtn;
private JButton dpBtn;
private JButton xferBtn;
private JButton balBtn;
private JRadioButton chkRadio;
private JRadioButton savRadio;
private JTextField textField;
private static String txtFldAmnt;
private static int fldAmnt = 0;
private static Double chkBal = 0.00;
private static Double savBal = 0.00;
public static void main(String[] args){
new GUI();
}
public GUI() {
//default location and size
this.setSize(300,182);
this.setLocationRelativeTo(null);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("ATM Machine");
//add buttons
wdBtn = new JButton("Withdraw");
dpBtn = new JButton("Deposit");
xferBtn = new JButton("Transfer");
balBtn = new JButton("Show Balance");
chkRadio = new JRadioButton("Checking");
chkRadio.setSelected(false);
savRadio = new JRadioButton("Savings");
savRadio.setSelected(false);
textField = new JTextField("", 20);
final JLabel textLabel = new JLabel("Enter amount: ");
textField.setToolTipText("Enter amount");
//Listener class to pass button listeners
ListenForButton lForButton = new ListenForButton();
wdBtn.addActionListener(lForButton);
dpBtn.addActionListener(lForButton);
xferBtn.addActionListener(lForButton);
balBtn.addActionListener(lForButton);
chkRadio.addActionListener(lForButton);
savRadio.addActionListener(lForButton);
ListenForText textFieldListener = new ListenForText();
textField.addKeyListener(textFieldListener);
//Configure layouts
JPanel PANEL = new JPanel();
PANEL.setLayout(new FlowLayout(FlowLayout.CENTER));
JPanel panel1 = new JPanel();
panel1.setLayout(new GridLayout(2,2, 5, 10));
JPanel panel2 = new JPanel();
panel2.setLayout(new GridLayout(1,2,10,10));
panel2.setLayout(new FlowLayout(FlowLayout.CENTER));
JPanel panel3 = new JPanel();
panel3.setLayout(new GridLayout(2,1));
//add buttons to their panels
panel1.add(wdBtn);
panel1.add(dpBtn);
panel1.add(xferBtn);
panel1.add(balBtn);
panel2.add(chkRadio);
panel2.add(savRadio);
panel3.add(textLabel);
panel3.add(textField);
PANEL.add(panel1);
PANEL.add(panel2);
PANEL.add(panel3);
this.add(PANEL);
//this.setAlwaysOnTop(true);
this.setVisible(true);
}
//implement listeners
private class ListenForText implements KeyListener {
#Override
public void keyTyped(KeyEvent e) {
txtFldAmnt = (e.toString());
fldAmnt = Integer.parseInt(txtFldAmnt);
}
#Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
}
#Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
}
private class ListenForButton implements ActionListener {
public void actionPerformed(ActionEvent e){
//maybe do case/switch statements
if (e.getSource() == wdBtn) {
JFrame newFrame = new JFrame("Withdraw Title");
newFrame.setResizable(false);
newFrame.setLocationRelativeTo(null);
newFrame.setSize(300, 91);
JPanel panel = new JPanel();
JLabel newLbl = new JLabel("Withdraw Frame", JLabel.CENTER);
panel.add(newLbl);
newFrame.add(panel);
newFrame.setVisible(true);
}
if (e.getSource() == dpBtn) {
JFrame newFrame = new JFrame("Deposit Title");
/*
* Set the newFrame.setSize(300,182); to this comment in the if statement to place
* the window directly over current window
*/
newFrame.setResizable(false);
newFrame.setLocationRelativeTo(null);
newFrame.setSize(300, 91);
JPanel panel = new JPanel();
JLabel newLbl = new JLabel("Deposit Frame", JLabel.CENTER);
panel.add(newLbl);
newFrame.add(panel);
newFrame.setVisible(true);
}
if (e.getSource() == xferBtn) {
JFrame newFrame = new JFrame("Transfer Title");
newFrame.setResizable(false);
newFrame.setLocationRelativeTo(null);
newFrame.setSize(300, 91);
JPanel panel = new JPanel();
JLabel newLbl = new JLabel("Transfer Frame", JLabel.CENTER);
panel.add(newLbl);
newFrame.add(panel);
newFrame.setVisible(true);
}
if (e.getSource() == balBtn){
JFrame newFrame = new JFrame("Balance Title");
newFrame.setResizable(false);
newFrame.setLocationRelativeTo(null);
newFrame.setSize(300, 91);
JPanel panel = new JPanel();
JTextField newLbl = new JTextField(Integer.toString(fldAmnt));
panel.add(newLbl);
newFrame.add(panel);
newFrame.setVisible(true);
}
}
}
}
-cheers
EDITED BELOW
Thank for the answers, and I'm sorry for the horrible description... but I found a work around, thoguh I'm not sure if it's appropriate.
with the above example:
fldAmnt = Integer.pareseInt(txtFldAmnt)
i just added a .getText() //Though I rewrote the entire source code
fldAmnt = Integer.pareseInt(txtFldAmnt.getText())
it's worked for me for my entire program.
I wish I didn't have to post my entire code below but I haven't decided on a great place to store all of my code yet.
(SUGGESTIONS ARE WELCOME :D)
but here it is:
import javax.swing.;
import java.awt.GridLayout;
import java.awt.event.;
import javax.swing.border.*;
public class ATM extends JFrame{
//buttons needed
JButton wBtn;
JButton dBtn;
JButton xBtn;
JButton bBtn;
//radios needed
JRadioButton cRadio;
JRadioButton sRadio;
//Text field needed
JTextField txt;
JLabel txtLabel;
static int withdraw = 0;
Double amount = 0.00;
Double cBal = 100.00;
Double sBal = 100.00;
double number1, number2, totalCalc;
public static void main(String[] args){
new Lesson22();
}
public ATM(){
this.setSize(400, 200);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("My Third Frame");
wBtn = new JButton("Withdraw");
dBtn = new JButton("Deposit");
xBtn = new JButton("Transfer");
bBtn = new JButton("Show Balance");
cRadio = new JRadioButton("Checking");
sRadio = new JRadioButton("Savings");
txtLabel = new JLabel("Amount: $");
txt = new JTextField("", 10);
JPanel thePanel = new JPanel();
// Create an instance of ListenForEvents to handle events
ListenForButton lForButton = new ListenForButton();
wBtn.addActionListener(lForButton);
dBtn.addActionListener(lForButton);
xBtn.addActionListener(lForButton);
bBtn.addActionListener(lForButton);
// How to add a label --------------------------
// Creates a group that will contain radio buttons
// You do this so that when 1 is selected the others
// are deselected
ButtonGroup operation = new ButtonGroup();
// Add radio buttons to the group
operation.add(cRadio);
operation.add(sRadio);
// Create a new panel to hold radio buttons
JPanel operPanel = new JPanel();
JPanel btnPanel1 = new JPanel();
JPanel btnPanel2 = new JPanel();
btnPanel1.setLayout(new GridLayout(1,2));
btnPanel2.setLayout(new GridLayout(1,2));
Border btnBorder = BorderFactory.createEmptyBorder();
btnPanel1.setBorder(btnBorder);
btnPanel1.add(wBtn);
btnPanel1.add(dBtn);
btnPanel2.setBorder(btnBorder);
btnPanel2.add(xBtn);
btnPanel2.add(bBtn);
Border operBorder = BorderFactory.createBevelBorder(1);
// Set the border for the panel
operPanel.setBorder(operBorder);
// Add the radio buttons to the panel
operPanel.add(cRadio);
operPanel.add(sRadio);
// Selects the add radio button by default
cRadio.setSelected(true);
JPanel txtPanel = new JPanel();
txtPanel.add(txtLabel);
txtPanel.add(txt);
thePanel.add(btnPanel1);
thePanel.add(btnPanel2);
thePanel.add(operPanel);
thePanel.add(txtPanel);
thePanel.setLayout(new GridLayout(4,2));
this.add(thePanel);
this.setVisible(true);
txt.requestFocus();
}
private class ListenForButton implements ActionListener{
// This method is called when an event occurs
public void actionPerformed(ActionEvent e){
/******************************************************
* THIS IS FOR CHECKING
*****************************************************/
// Check if the source of the event was the button
if(cRadio.isSelected()){
if(e.getSource() == wBtn){
try {
amount = Double.parseDouble(txt.getText());
cBal -= amount;
}
catch(NumberFormatException excep){
JOptionPane.showMessageDialog(ATM.this,
"Please enter a valid number in multiples of 20",
"ERROR", JOptionPane.ERROR_MESSAGE);
}
}
if(e.getSource() == bBtn){
JFrame bFrame = new JFrame();
bFrame.setSize(300, 182);
bFrame.setLocationRelativeTo(null);
JPanel panel = new JPanel();
JLabel cLabel = new JLabel(Double.toString(cBal));
JLabel CLBL = new JLabel("Checking: ");
panel.add(CLBL);
panel.add(cLabel);
bFrame.add(panel);
bFrame.setVisible(true);
}
if(e.getSource() == dBtn){
amount = Double.parseDouble(txt.getText());
cBal += amount;
}
if(e.getSource() == xBtn){
amount = Double.parseDouble(txt.getText());
if (sBal >= 0 && sBal >= amount){
cBal += amount;
sBal -= amount;
}
else if (sBal < amount) {
JOptionPane.showMessageDialog(ATM.this,
"INSUFFICENT FUNDS", "ERROR",
JOptionPane.ERROR_MESSAGE);
}
}
}
/******************************************************
* THIS IS FOR SAVINGS
*****************************************************/
if(sRadio.isSelected()){
if(e.getSource() == wBtn){
try {
amount = Double.parseDouble(txt.getText());
if(sBal >= 0 && sBal >= amount){
sBal -= amount;
}
else if (sBal < amount) {
JOptionPane.showMessageDialog(ATM.this,
"INSUFFICENT FUNDS", "ERROR",
JOptionPane.ERROR_MESSAGE);
}
}
catch(NumberFormatException excep){
JOptionPane.showMessageDialog(ATM.this,
"Please enter a valid number in multiples of 20",
"ERROR", JOptionPane.ERROR_MESSAGE);
}
}
if(e.getSource() == bBtn){
JFrame bFrame = new JFrame();
bFrame.setSize(300, 182);
bFrame.setLocationRelativeTo(null);
JPanel panel = new JPanel();
JLabel sLabel = new JLabel(Double.toString(sBal));
JLabel SLBL = new JLabel("Savings: ");
panel.add(SLBL);
panel.add(sLabel);
bFrame.add(panel);
bFrame.setVisible(true);
}
if(e.getSource() == dBtn){
try{
amount = Double.parseDouble(txt.getText());
sBal += amount;
}
catch(NumberFormatException excep){
JOptionPane.showMessageDialog(ATM.this,
"Please enter a valid number!",
"ERROR", JOptionPane.ERROR_MESSAGE);
}
}
if(e.getSource() == xBtn){
amount = Double.parseDouble(txt.getText());
if (cBal >= 0 && cBal >= amount){
sBal += amount;
cBal -= amount;
}
else if (cBal < amount) {
JOptionPane.showMessageDialog(ATM.this,
"INSUFFICENT FUNDS", "ERROR",
JOptionPane.ERROR_MESSAGE);
}
}
}
}
}
}
...and by the way can anyone explain this warning message:
The serializable class ATM does not declare a static final serialVersionUID field of type long
If not simply don't bother. I'll keep researching into it when I have time.
This is still not complete, but thank you all for your help!
KeyListener on any JTextComponent is a bad idea.
To monitor changes to a text component, use a DocumentListener, to filter the content that a text component can handle, use a DocumentFilter. See Listening for Changes on a Document, Implementing a Document Filter and DocumentFilter Examples for more details.
In your case, it'd probably better to use a JSpinner or JFormattedTextField as they are designed to handle (amongst other things) numbers
See How to Use Spinners and How to Use Formatted Text Fields for more details

Cannot find a way to create a loading screen

I was just messing around with GUI in Java and created a little game. In it, 105 randomly placed buttons are created and then an instruction screen pops up, telling the user which button to find. I've tried to figure out how to program a "Loading..." JDialog, which will pop up while the buttons are being created in the background. The trouble is, when I run the program the JDialog doesn't load until AFTER all the buttons have been created, which kind of defeats the purpose of the box in the first place. How can I force the "Loading..." box to load BEFORE the buttons begin to be created??? Thanks in advance.
Because I've just been tinkering, my code is not perfect but here it is:
import java.util.Scanner;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.Random;
import java.awt.Color;
import javax.swing.JButton;
import javax.swing.ProgressMonitor;
public class ButtonGame {
private static int butNum = 1;
private static JFrame frame;
private static ActionListener notIt;
private static ActionListener it;
private static Random rand = new Random();
private static int butToFind = rand.nextInt(105);
private static JFrame frameToClose;
//private static int mouseClicks;
//private static double time;
public static void main(String[] args) {
//actionlistener for all incorrect buttons (buttons that are "not it")
notIt = new ActionListener() {
public void actionPerformed(ActionEvent e) {
Component component = (Component) e.getSource();
JFrame frame5 = (JFrame) SwingUtilities.getRoot(component);
frame5.dispose();
}
};
//actionlistener for the correct button (the button that's "it")
it = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFrame youWin = new JFrame("YOU WON!");
//removes all panels to begin game again
JButton again = new JButton("Play again");
again.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
java.awt.Window windows[] = java.awt.Window.getWindows();
for(int i=0;i<windows.length;i++){
if (windows[i] != frame) { windows[i].dispose(); }
butToFind = rand.nextInt(105);
butNum = 1;
youWin.dispose();
}
frame.setVisible(true);
}
});
//quits game
JButton win = new JButton("Quit");
win.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
//layout
youWin.setSize(775, 300);
youWin.setLayout(new FlowLayout());
JLabel label1 = new JLabel("Fantastic!");
Font font1 = new Font("Courier", Font.BOLD,120);
label1.setFont(font1);
label1.setHorizontalAlignment(JLabel.CENTER);
JLabel label2 = new JLabel("You beat the game!");
Font font2 = new Font("Courier", Font.BOLD,60);
label2.setFont(font2);
label2.setHorizontalAlignment(JLabel.CENTER);
youWin.add(label1);
youWin.add(label2);
JPanel panel = new JPanel();
youWin.add(panel);
panel.add(again);
panel.add(win);
youWin.setLocation(260, 100);
youWin.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
youWin.setVisible(true);
java.awt.Window windows[] = java.awt.Window.getWindows();
}
};
//start window
frame = new JFrame("Window");
frame.setLocation(400, 200);
JButton button1 = new JButton("Click to begin");
//button to begin game
button1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// JDialog load = new JDialog();
// load.setAlwaysOnTop(true);
// load.setSize(500,500);
// load.setVisible(true);
// load.add(new Label("Loading..."));
// load.pack();
frame.setVisible(false); // "start" window's visibility
// try {
// Thread.sleep(100000);
// } catch (Exception t) {
// }
// creates buttons
for (int i = 0; i < 105; i++) {
JFrame nextFrame = newFrame(butNum);
nextFrame.setVisible(true);
butNum++;
}
//creates instructions and tells user what button to find
JFrame instructions = new JFrame("How to play");
instructions.setSize(300,175);
instructions.setLayout(new GridLayout(4,1));
JPanel instPanel = new JPanel();
//button to remove instruction panel
JButton ok = new JButton("Ok");
ok.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
instructions.dispose();
}
});
instPanel.add(ok);
instructions.setLocation(400,200);
//layout of instruction panel
JLabel find = new JLabel("Your goal is to find Button " + butToFind + ".");
find.setHorizontalAlignment(JLabel.CENTER);
JLabel find2 = new JLabel("Click a button to make it disappear.");
find2.setHorizontalAlignment(JLabel.CENTER);
JLabel find3 = new JLabel("Good luck!");
find3.setHorizontalAlignment(JLabel.CENTER);
instructions.add(find);
instructions.add(find2);
instructions.add(find3);
instructions.add(instPanel);
instructions.setVisible(true);
}
});
frame.add(button1);
frame.setSize(150,100);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
//creates frame with button in it
public static JFrame newFrame(int num) {
JFrame frame2 = new JFrame();
JButton button = new JButton("Button " + num);
if (num == butToFind) {
button.addActionListener(it);
frameToClose = frame2;
} else {
button.addActionListener(notIt);
}
frame2.add(button);
frame2.setSize(randNum(90,200), randNum(50,100));
frame2.setLocation(rand.nextInt(1200), rand.nextInt(800));
frame2.getContentPane().setBackground(new Color(rand.nextInt(255),
rand.nextInt(255),
rand.nextInt(255)));
frame2.setVisible(true);
return frame2;
}
//provides random number between high and low
public static int randNum(int low, int high) {
int result = -1;
while (result < low || result > high) {
result = rand.nextInt(high);
}
return result;
}
}
Also, as a side-question, which of the variables defined before main should be static? And how can I get the program to compile without being static? Thanks!
First take a look at The Use of Multiple JFrames, Good/Bad Practice? and understand why I freaked out when I ran your code...
Instead of creating a bunch of frames, why not use something like JButton on another JPanel and add it to the current frame (this would also be a good use for a CardLayout)
JPanel panel = new JPanel(new GridLayout(10, 0));
Random rnd = new Random();
// creates buttons
for (int i = 0; i < 105; i++) {
JButton btn = new JButton(String.valueOf(i));
panel.add(btn);
//JFrame nextFrame = newFrame(butNum);
//nextFrame.setVisible(true);
//butNum++;
}
frame.getContentPane().removeAll();
frame.add(panel);
frame.revalidate();
frame.pack();
Alternatively, if you're really hell bent on using "frames", consider using a JDesktopPane and JInternalFrame instead.
See How to Use Internal Frames for more details
Also, as a side-question, which of the variables defined before main should be static? And how can I get the program to compile without being static?
As much as possible, none. Instead of trying to create the whole thing in the main method, use the classes constructor to initialise the UI and use another method to actually get the game rolling...
public class ButtonGame {
private int butNum = 1;
private JFrame frame;
private ActionListener notIt;
private ActionListener it;
private Random rand = new Random();
private int butToFind = rand.nextInt(105);
private JFrame frameToClose;
//private static int mouseClicks;
//private static double time;
public static void main(String[] args) {
ButtonGame game = new ButtonGame();
game.start();
}
public ButtonGame() {
//... All the code that was once in main...
frame.add(button1);
frame.setSize(150, 100);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void start() {
frame.setVisible(true);
}
Answering to your side questions:
a static method can only accept static global variables
You can put all your code in the constructor and use main to only run the program.
Constructor:
public ButtonGame() {
// All of your code goes here - except the static methods
}
You should also make all other methods non-static.
To run the program:
public static void main(String[] args) {
new ButtonGame();
}

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