How to fill JComboBox after user fills necessary text fields? - java

I want to add a JComboBox to my main panel and fill it with an ArrayList I made in a different method named rectSizeList (which right now prints the ArrayList to the console), this method gets its parameters from another static method named actionPerformed. I cant figure a way to take the filled array after user input to fill my ComboBox. Any help will be appreciated.
All comment is this format are to aid question:
/*
* Like so
*
*/
All other comments are to help whomever my want to compile and run, so that they might understand what is going on.
Main class
import javax.swing.*;
public class ductulatorApp
{
public static void main(String[] args)
{
JFrame frame = new DuctulatorFrame();
frame.setVisible(true);
}
}
Frame class
import javax.swing.*;
import java.awt.*;
public class DuctulatorFrame extends JFrame
{
private static final long serialVersionUID = 1L;
public DuctulatorFrame()
{
setTitle("Test Scores");
setSize(267, 200);
centerWindow(this);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new DuctulatorPanel();
this.add(panel);
}
private void centerWindow(Window w)
{
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension d = tk.getScreenSize();
setLocation((d.width-w.getWidth())/2, (d.height-w.getHeight())/2);
}
}
Panel class
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.ArrayList;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class DuctulatorPanel extends JPanel implements ActionListener
{
private static final long serialVersionUID = 1L;
private JTextField staticTextField,
cfmTextField,
rductTextField,
sqductTextField;
private JLabel staticLabel,
cfmLabel,
rductLabel,
sqductLabel;
private JButton calculateButton,
exitButton,
clearButton;
private JComboBox ductSizes; //JComboBox instance
private String[] ductList; //Array to fill JComboBox
double staticP; //static pressure entered by user
double cfm; //cfm entered by user
double deSQ;
double de; //round duct diameter
double pi = 3.14;
double ca; //round duct surface area
double radious;
double sqrA; //rectangular duct area
//two sides of rectangular duct
double a = 4;
double b = 4;
String squareduct;
public DuctulatorPanel()
{
// Creates main panel for labels and text fields
JPanel displayPanel = new JPanel();
displayPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
staticLabel = new JLabel("Static pressure:");
displayPanel.add(staticLabel);
staticTextField = new JTextField(10);
displayPanel.add(staticTextField);
cfmLabel = new JLabel(" CFM:");
displayPanel.add(cfmLabel);
cfmTextField = new JTextField(10);
displayPanel.add(cfmTextField);
rductLabel = new JLabel("Round Duct:");
displayPanel.add(rductLabel);
rductTextField = new JTextField(15);
rductTextField.setEditable(false);
rductTextField.setFocusable(false);
displayPanel.add(rductTextField);
sqductLabel = new JLabel("Square Duct:");
displayPanel.add(sqductLabel);
/*
* This is where I want to add my JComboBox problem is I want to populate ductList arr
* with the array inside rectSizeList(int number) BELOW
* right now this method only prints my array to the console
* this method takes its parameters from the value assigned to
* actionperformed(ActionEvent e)
* below is comboBox commented out
*/
//ductList = new String[list.size]; THIS IS ASSUMING I COULD SOME HOW TRANSFER
//ductList = list.toArray(ductList); ARRAYLIST UP HERE AND NAME IT LIST AND USE IT
//ductSizes = new JComboBox(ductList);
//ductSizes.setSelectedIndex(1);
//displayPanel.add(ductSizes);
sqductTextField = new JTextField(10);
sqductTextField.setEditable(false);
sqductTextField.setFocusable(false);
displayPanel.add(sqductTextField);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
calculateButton = new JButton("Calculate");
calculateButton.addActionListener(this);
buttonPanel.add(calculateButton);
clearButton = new JButton("Clear");
clearButton.addActionListener(this);
buttonPanel.add(clearButton);
exitButton = new JButton("Exit");
exitButton.addActionListener(this);
buttonPanel.add(exitButton);
this.setLayout(new BorderLayout());
this.add(displayPanel, BorderLayout.CENTER);
this.add(buttonPanel, BorderLayout.SOUTH);
}
public void actionPerformed(ActionEvent e)
{
NumberFormat number = NumberFormat.getNumberInstance();
number.setMaximumFractionDigits(1);
Object source = e.getSource();
if(source == exitButton)System.exit(0);
else if(source == clearButton)
{
staticTextField.setText("");
cfmTextField.setText("");
rductTextField.setText("");
sqductTextField.setText("");
staticP = 0;
cfm = 0;
deSQ = 0;
}
else if(source == calculateButton)
{
try
{
staticP = Double.parseDouble(staticTextField.getText());
cfm = Double.parseDouble(cfmTextField.getText());
}
catch(NumberFormatException nfe)
{
staticTextField.setText("Invalid input");
staticP = 0;
cfm = 0;
deSQ = 0;
de = 0;
}
deSQ = staticP * (0.109136 * Math.pow(cfm, 1.9)); //Calculate round duct
de = Math.pow(deSQ, 0.199) * 2.5; //diameter
// Calculate round duct surface area
radious = de/2;
ca = (radious * radious) * pi;
ca = (int)ca;
rectSizeList((int)ca);
double i = 0;
for(i=0; i<ca; i++)
{
a = a + 0.5;
b = b + 0.5;
i = a * b; // convert round duct to rectangular duct
}
sqrA = i;
a = (int)a;
b = (int)b;
rductTextField.setText(number.format(de));
squareduct = (a + " x " + b);
sqductTextField.setText(squareduct);
}
}
public ArrayList<String> rectSizeList(int number)
{
if (number <= 0) throw new IllegalArgumentException("The number should be greater than 0.");
int i = 0;
int j = 0;
/*
* This is the array list I am hoping to use in order to fill array for
* comboBox
*/
ArrayList<String> rectangularDucts = new ArrayList<String>(); //Create array for rectangular duct
// Fill array for rectangular duct using nested for loop
/*
* If statement will ensure the result is with in range of surface
* area of duct
*/
for(i=4; i<=50; i++)
{
for(j=4; j<=50; j++)
{
if(number == i*j || (i*j)+1 == number || (i*j)-2 == number)
{
rectangularDucts.add(i + " x " + j);
}
}
if(number == i*j || (i*j)+1 == number || (i*j)-2 == number)
{
rectangularDucts.add(i + " x " + j);
}
}
System.out.println(rectangularDucts);
return rectangularDucts;
}
}

I think that your problem is easily solved with just a DefaultComboBoxModel object, or in your situation (I guess), a DefaultComboBoxModel<String> object. Give your class this field, create your JComboBox with this as its model, by passing it into the constructor, and then fill this model object as the need arises.
For example:
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.*;
public class ComboModelEg extends JPanel {
private DefaultComboBoxModel<String> comboModel = new DefaultComboBoxModel<>();
private JComboBox<String> comboBox = new JComboBox<>(comboModel);
private JTextField textField = new JTextField(5);
public ComboModelEg() {
// so combo box is wide enough
comboBox.setPrototypeDisplayValue(" ");
add(comboBox);
add(textField);
add(new JButton(new AddToComboAction("Add Text", KeyEvent.VK_A)));
}
// AbstractAction is like a *super* ActionListener
private class AddToComboAction extends AbstractAction {
public AddToComboAction(String name, int mnemonic) {
super(name); // button's text
putValue(MNEMONIC_KEY, mnemonic); // button's mnemonic key
}
#Override
public void actionPerformed(ActionEvent e) {
String text = textField.getText(); //get text from text field
comboModel.addElement(text); // and put it into combo box's model
}
}
private static void createAndShowGui() {
ComboModelEg mainPanel = new ComboModelEg();
JFrame frame = new JFrame("ComboModelEg");
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();
}
});
}
}
Translated to your code, it could look something like:
for (i = 4; i <= 50; i++) {
for (j = 4; j <= 50; j++) {
if (number == i * j || (i * j) + 1 == number
|| (i * j) - 2 == number) {
// rectangularDucts.add(i + " x " + j); //!!
comboModel.addElement(i + " x " + j); //!!
}
}
if (number == i * j || (i * j) + 1 == number || (i * j) - 2 == number) {
// rectangularDucts.add(i + " x " + j);
comboModel.addElement(i + " x " + j); //!!
}
}

this is how i do it
ArrayList<String> myList = new ArrayList<>();
//some code to populate the list
jComboBox.removeAllItems();
for(int i=0;i<myList.size();i++){
jComboBox.addItem(myList.get(i));
}

Related

Custom java calculator troubleshooting

New programmer here, I have been working for a few days on this bit of code that is meant to create a UI where I input a basement's perimeter length (textfield integer), if a new pump is needed (combobox string), if there is an outlet nearby (combobox string), and how many hours It will take to prepare a site (textfield integer), and I calculate my costs to complete a job. I was able to set up a UI where I can enter the inputs and press a button to calculate but I'm having trouble connecting the button I made to the formula I made to generate a price. Here is my code:
package packagepackage;
import packagepackage.HintTextFieldUI;
import java.awt.*;
import java.awt.BorderLayout;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CP_GUI implements ActionListener {
String[] sumpo = {"New sump pump","Existing sump pump"};
String[] electo = {"There is an outlet within 6 feet of sump pump","There is no outlet nearby, or I do not need a new one"};
Integer estimatex = 0;
String esto = String.valueOf(estimatex);
public volatile String estimatoof = "Estimated Cost: ${}".format(esto);
private JComboBox sump = new JComboBox(sumpo);
private JComboBox elec = new JComboBox(electo);
private JTextField linear = new JTextField();
private JTextField prep = new JTextField();
private JLabel title = new JLabel("Drain Tile Calculator");
private JButton calculate = new JButton("Calculate!");
public JLabel estimate = new JLabel(estimatoof);
private JFrame frame = new JFrame();
private JPanel panel = new JPanel();
public CP_GUI() {
linear.addActionListener(this);
calculate.addActionListener(this);
elec.addActionListener(this);
sump.addActionListener(this);
prep.addActionListener(this);
// the panel with the button and text
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(400, 400, 100, 100));
panel.setLayout(new GridLayout(0, 1));
panel.add(linear);
panel.add(sump);
panel.add(elec);
panel.add(prep);
frame.add(panel, BorderLayout.CENTER);
panel.add(title);
calculate.addActionListener(this);
panel.add(calculate);
// set up the frame and display it
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Drain Tile Calculator");
frame.pack();
frame.setVisible(true);
linear.setUI(new HintTextFieldUI("Perimeter length", true));
prep.setUI(new HintTextFieldUI("Hours of preptime", true));}
// create one Frame
public static void main(String[] args) {
new CP_GUI();
}
#Override
public void actionPerformed(ActionEvent e){
// TODO Auto-generated method stub
if(e.getSource()==linear) {String input = linear.getText();
Integer pars = Integer.parseInt(input);
Integer distVar = pars *= 13;
estimatex += distVar;
} else if (e.getSource()==sump) {String inputa = sump.getToolTipText();
int sumpa = 0;
if(inputa == "New sump pump" | inputa == "yes") {
sumpa += 260;}
estimatex += sumpa;
} else if (e.getSource()==elec) {String inputb =elec.getToolTipText();
int eleca = 0;
if("There is an outlet within 6 feet of the sump pump".equals(inputb)) {
eleca += 1;
}
eleca *= 280;
estimatex += eleca;
}
else if (e.getSource()==prep) {String inputc = prep.getText();
int parsa = Integer.parseInt(inputc);
int prepCost = parsa += 1;
prepCost *= 110;
estimatex += prepCost;
} else if (e.getSource()==linear) {
String disto = linear.getText();
int di = Integer.parseInt(disto);
di *= 13;
String pumpo = (String)sump.getSelectedItem();
int sumpo = 0;
if ("New sump pump".equals(pumpo)) {
sumpo += 260;
}
String ele = (String)elec.getSelectedItem();
int elc = Integer.parseInt(ele);
elc *= 280;
String clea = prep.getText();
int cla = Integer.parseInt(clea);
cla += 1;
cla *= 110;
int cali = 0;
cali += di;
cali += sumpo;
cali += elc;
cali += cla;
estimatex = cali;
}
}
}
Edit: Made the suggested edits made so far and now the UI opens and works, the only issue is that the estimated price does not show up. Am I connecting the action listener correctly?
Your "primary" problem is right here...
String disto = String.valueOf(linear);
where linear is a JTextField, so the above call will generate something like...
javax.swing.JTextField[,0,0,0x0,invalid,layout=javax.swing.plaf.basic.BasicTextUI$UpdateHandler,alignmentX=0.0,alignmentY=0.0,border=com.apple.laf.AquaTextFieldBorder#4e323305,flags=288,maximumSize=,minimumSize=,preferredSize=,caretColor=javax.swing.plaf.ColorUIResource[r=0,g=0,b=0],disabledTextColor=javax.swing.plaf.ColorUIResource[r=128,g=128,b=128],editable=true,margin=javax.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=0,g=0,b=0],selectionColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=165,g=205,b=255],columns=0,columnWidth=0,command=,horizontalAlignment=LEADING]
which is obviously not what you're looking for.
You should probably be just doing something like...
String disto = linear.getText();
pumpo == "New sump pump" is also not how you compare a String in Java, you should be using "New sump pump".equals(pumpo) ... but I suspect you're going to have the same issues as mentioned above.
I really recommend you take the time to read through Creating a GUI With Swing as well as taking the time to come to grips with the core basics of the language

Why is my ItemListener program not allowing me to select an option from two different JComboBoxes in Java?

My program will only do one JcomboBox at a time when I am trying to get both numbers to be added together to display the final number.
It allows me to run the program, but it will not display the final price because it does not want to select two things at once.
Here is the code for my program:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CottageRental2 extends JFrame implements ItemListener{
// Declare all instance data (primitives and objects used)
private int WIDTH = 676;
private int HEIGHT = 321;
Container con;
private JLabel label1;
private JLabel label2;
private JLabel label3;
JComboBox cbox1;
JComboBox cbox2;
String [ ] roomChoice = {"1 Bedroom: $600","2 Bedroom: $800","3 Bedroom: $1000"};
String [ ] activityChoice = {"Horse Back Riding: $60","Rafting: $40","Row Boat Rental: $50"};
ImageIcon icon1 = new ImageIcon("C:\\Users\\Coding\\Desktop\\cottage.jpeg");
Font f1 = new Font("Ariel", Font.BOLD, 30);
//constructor
public CottageRental2(){
super("Cottage Rental");
con = getContentPane();
con.setLayout(new BorderLayout());
con.setBackground(Color.GRAY);
setSize(WIDTH, HEIGHT);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void createGUI(){
label1 = new JLabel("Woodberry Cottage Rental", JLabel.CENTER);
label1.setFont(f1);
label1.setForeground(Color.WHITE);
label2 = new JLabel("Rental Amount Due: $660", JLabel.CENTER);
label2.setFont(f1);
label2.setForeground(Color.WHITE);
label3 = new JLabel(icon1);
cbox1 = new JComboBox();
cbox1.addItem(roomChoice[0]);
cbox1.addItem(roomChoice[1]);
cbox1.addItem(roomChoice[2]);
cbox1.addItemListener(this);
cbox2 = new JComboBox();
cbox2.addItem(activityChoice[0]);
cbox2.addItem(activityChoice[1]);
cbox2.addItem(activityChoice[2]);
cbox2.addItemListener(this);
con.add(label1, BorderLayout.NORTH);
con.add(label2, BorderLayout.SOUTH);
con.add(label3, BorderLayout.CENTER);
con.add(cbox1, BorderLayout.WEST);
con.add(cbox2, BorderLayout.EAST);
}
public void itemStateChanged(ItemEvent event){
Object source = event.getSource();
int price1 = 0;
int price2 = 0;
if(source == cbox1){
int roomIndex = cbox1.getSelectedIndex();
if(roomIndex == 0){
price1 = 600;
}
if(roomIndex == 1){
price1 = 800;
}
if(roomIndex == 2){
price1 = 1000;
}
}
if(source == cbox2){
int activityIndex = cbox2.getSelectedIndex();
if(activityIndex == 0){
price2 = 60;
}
if(activityIndex == 1){
price2 = 40;
}
if(activityIndex == 2){
price2 = 50;
}
}
label2.setText("Rental Amount Due: $" + (price1 + price2));
}
public static void main(String[] args){
CottageRental2 object = new CottageRental2();
object.createGUI();
object.setSize(675, 320);
}
}
Your problem is your if (source == ...) if blocks which prevent the program from getting the selected item from the other JComboBox, the one that isn't being actively selected.
One solution: get rid of the offending if blocks that test for the source of the event in the listener:
public void itemStateChanged(ItemEvent event) {
// Object source = event.getSource();
int price1 = 0;
int price2 = 0;
// if(source == cbox1){
int roomIndex = cbox1.getSelectedIndex();
if (roomIndex == 0) {
price1 = 600;
} else if (roomIndex == 1) {
price1 = 800;
} else if (roomIndex == 2) {
price1 = 1000;
}
// }
// if(source == cbox2){
int activityIndex = cbox2.getSelectedIndex();
if (activityIndex == 0) {
price2 = 60;
} else if (activityIndex == 1) {
price2 = 40;
} else if (activityIndex == 2) {
price2 = 50;
}
// }
label2.setText("Rental Amount Due: $" + (price1 + price2));
}
Also, it would be safer if you use some else if blocks in your item selection statements.

a simple GUI multiplication table

I'm supposed to create a simple multiplication table using GUI and for the most part, it's doing what it is supposed to do. But I just can't figure out the bottom portion of it where if you click on a specific button, a text will say what the two numbers are being multiplied and the answer.
No matter what button I click, it'll only tell me the numbers I input and multiply them together. Here is my 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.JOptionPane;
public class MultiplicationTable {
int clickedCount;
int rowCount;
int colCount;
JFrame frame;
JPanel buttonPanel, countPanel;
JLabel countLabel;
private void createAndShowGui(){
rowCount = Integer.parseInt(JOptionPane
.showInputDialog("How many rows do you want your multiplication table to be? "));
colCount = Integer
.parseInt(JOptionPane
.showInputDialog("How many columns do you want your multiplication table to be? "));
frame = new JFrame ("Simple Multiplication Table");
frame.setLayout(new BorderLayout());
buttonPanel = new JPanel();
buttonPanel.setLayout(new GridLayout(rowCount, colCount));
countPanel = new JPanel();
countLabel = new JLabel("? x ? = ?");
for(int rowCounter = 1; rowCounter <= rowCount; rowCounter++)
for(int colCounter = 1; colCounter <= colCount; colCounter++){
final JButton j = new JButton(Integer.toString(rowCounter * colCounter));
j.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent event) {
for(int rc = 1; rc <= rowCount; rc++)
for(int cc = 1; cc <= colCount; cc++){
countLabel.setText(rc + " x " + cc + " = " + String.valueOf(rc * cc));
}
}
});
buttonPanel.add(j);
}
frame.add(buttonPanel, BorderLayout.NORTH);
countPanel.add(countLabel);
frame.add(countPanel, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args){
MultiplicationTable c = new MultiplicationTable();
c.createAndShowGui();
}
}
Your current ActionListener has no context, it doesn't know what two values were used to generate the value you gave the button.
What you could do is create a ActionListener which takes the values used to produce the button's text, this would then be capable of updating the label accordingly. For example...
public class MultiplerActionListener implements ActionListener {
private int[] values;
private JLabel label;
public MultiplerActionListener(JLabel label, int... valuesToMultiple) {
values = valuesToMultiple;
this.label = label;
}
#Override
public void actionPerformed(ActionEvent event) {
int answer = 1;
StringBuilder sb = new StringBuilder(64);
for (int value : values) {
if (sb.length() > 0) {
sb.append(" x ");
}
sb.append(value);
answer *= value;
}
sb.append(" = ");
sb.append(answer);
label.setText(sb.toString());
}
}
Then you would simply need to apply it when you create the buttons
for(int rowCounter = 1; rowCounter <= rowCount; rowCounter++) {
for(int colCounter = 1; colCounter <= colCount; colCounter++){
final JButton j = new JButton(Integer.toString(rowCounter * colCounter));
j.addActionListener(new MultiplerActionListener(countLabel, rowCounter, colCounter));
buttonPanel.add(j);
}
}

Issue with displaying information on a program using swing, JButtons,etc

I'm making a multiplication table using swing.Its basically made up of JButtons. The table is formed from input from the user. The user selects the size of the table by entering a number. The last thing i need to do with this is create a heading that displays the numbers of the table created. Here is my sample code, if you run it, you'll see that its done for the vertical numbers. How can i get the numbers above and properly formatted to represent each column. Thank you.
package lab7;
import java.awt.BorderLayout;
import java.awt.GridBagLayout;
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.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class GUIMultiplicationTable{
JFrame theFrame;
int number = 0;
JPanel panel, answerPanel, topPanel, leftPanel;
JLabel answerLabel, topLabel, leftLabel;
private void createAndShowGui(){
String x;
do{
x = JOptionPane.showInputDialog(null, "Enter the number");
number = Integer.parseInt(x);
}while (number <= 0);
theFrame = new JFrame("Multiplication Table");
panel = new JPanel(new GridLayout(number, number));
answerPanel = new JPanel();
answerLabel = new JLabel();
topPanel = new JPanel();
topLabel = new JLabel();
leftPanel = new JPanel();
leftLabel = new JLabel();
for (int i = 0; i < number; i++){
JLabel blah = new JLabel(Integer.toString(i + 1));
panel.add(blah);//add center to label
for (int j = 0; j < number; j++){
JButton button = new JButton();
if (i == 0){
button.setText(String.valueOf(j + 1));
}
if (j == 0){
button.setText(String.valueOf(i + 1));
}
for (int k = 1; k < number; k++)
{
if (i == k)
{
button.setText(String.valueOf((j + 1) * (k + 1)));
}
}
button.addActionListener(new ButtonsTableActionListener(i, j));
panel.add(button);
}
}
answerPanel.add(answerLabel);
theFrame.add(answerPanel, BorderLayout.SOUTH);
topPanel.add(topLabel);
theFrame.add(topPanel, BorderLayout.NORTH);
theFrame.add(panel);
theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
theFrame.pack();
theFrame.setLocationRelativeTo(null);
theFrame.setVisible(true);
}
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable(){
public void run(){
GUIMultiplicationTable h = new GUIMultiplicationTable();
h.createAndShowGui();
}
});
}
private class ButtonsTableActionListener implements ActionListener{
private int theRow, theColumn;
public ButtonsTableActionListener(int row, int column){
theRow = row;
theColumn = column;
}
#Override
public void actionPerformed(ActionEvent e){
int value = (theRow + 1) * (theColumn + 1);
answerLabel.setText("The value is: " + value + ".\nI got that by multiplying \n" + (theRow + 1) + "x" + (theColumn + 1));
}
};
}
An easy way to do this is to store the position of the button in the ActionListener, you can accomplish this by making your own class extending ActionListener, instead of doing an anonymous class. This way the code executed by the button will already have the information it needs to accomplish whatever you want.
Also you don't need the array of buttons, just add a button in the panel at a time, and at the same time add the actionListener.
This is your code cleaned up and working properly. Now, instead of showing a dialog do whatever you want to do.
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.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class GUIMultiplicationTable
{
JFrame theFrame;
int number = 0;
JPanel panel;
private void createAndShowGui()
{
String x;
do
{
x = JOptionPane.showInputDialog(null, "Enter the number");
number = Integer.parseInt(x);
} while (number <= 0);
theFrame = new JFrame("Multiplication Table");
panel = new JPanel(new GridLayout(number, number));
for (int i = 0; i < number; i++)
{
for (int j = 0; j < number; j++)
{
JButton button = new JButton();
if (i == 0)
{
button.setText(String.valueOf(j + 1));
}
if (j == 0)
{
button.setText(String.valueOf(i + 1));
}
for (int k = 1; k < number; k++)
{
if (i == k)
{
button.setText(String.valueOf((j + 1) * (k + 1)));
}
}
button.addActionListener(new ButtonsTableActionListener(i, j));
panel.add(button);
}
}
theFrame.add(panel);
theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
theFrame.pack();
theFrame.setLocationRelativeTo(null);
theFrame.setVisible(true);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable() {
public void run()
{
GUIMultiplicationTable h = new GUIMultiplicationTable();
h.createAndShowGui();
}
});
}
private class ButtonsTableActionListener implements ActionListener
{
private int _row, _column;
public ButtonsTableActionListener(int row, int column)
{
_row = row;
_column = column;
}
#Override
public void actionPerformed(ActionEvent e)
{
// /do something
int value = (_row + 1) * (_column + 1);
String message = "I'm the button in the position (" + _row + ", " + _column + ")\nMy value is " + value + " = " + (_row + 1) + "*" + (_column + 1);
JOptionPane.showMessageDialog(theFrame, message);
}
};
}
Everything you need to do is just putting a JLabel somewhere.
final JLabel resultLabel = new JLabel("Select a button!");
Note that it should be final to be able to use it in the ActionListener. In the ActionListener you already had the right way, just look at these few lines to make it happen:
ActionListener first = new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
for(int i = 0; i < number; i++){
for(int j = 0; j < number; j++){
if(buttons[i][j] == e.getSource()){
// write the equation to the label
resultLabel.setText(buttons[i][j].getText()
+ " = " + (i+1) + " * "
+ (j+1));
// since you found the button you can now break
break;
}
}
}
}
};
Note the i+1 and j+1. The buttons are indexed from 0 to number-1, so the button at (0,0) actually shows the result of 1*1.
This is also important for your next two lines of code:
// you used i=1 and j=1, but you have to start with 0 to make it work for all buttons
for(int i = 0; i < number; i++){
for(int j = 0; j < number; j++){
buttons[i][j].addActionListener(first);
}
}
At a last step you also have to show the the label. If you just add it to the frame, as you do with the panel, you will see that you will not see it.
theFrame.add(resultLabel);
theFrame.add(panel);
The problem is that theFrame doesn't have a layoutmanager yet. So use a new Layout here as well:
theFrame.setLayout(new GridLayout(2,1));
Of course there will be better choices or some nice tweeks to make the layout more beautiful.
So as in sum how to change your code from top to bottom:
set a Layout for theFrame
create a new JLabel for the result of the click, make it final
set the label's text in the actionPerformed() method
add the label to theFrame
You can also consider putting the Label into a new JPanel and add that Panel to theFrame.
The loop in your actionListener is not required, the source of the event is the button that triggered it, so you can simply do...
JButton source = (JButton) e.getSource();
JOptionPane.showMessageDialog(theFrame, source.getText());
Instead.
Now having said that, I would, personally, use some kind of Map to link the JButton to the value, removing the need to have to try and cast the text of the button back to a numeric value (which I believe would be your next step), or store other information you might need to work with for the button (such as the values required to produce the answer)...
private Map<JButton, int[]> answers = new HashMap<JButton, int[]>(25);
//...
for(int i = 0; i < number; i++){
for(int j = 0; j < number; j++){
buttons[i][j] = new JButton();
if(i == 0) {
buttons[i][j].setText(String.valueOf(j+1));
}
if(j == 0) {
buttons[i][j].setText(String.valueOf(i+1));
}
for(int k = 1; k < number; k++){
if(i == k){
buttons[i][j].setText(String.valueOf((j+1) * (k+1)));
}
}
panel.add(buttons[i][j]);
// Store the answer here...
answers.put(buttons[i][j], new int[]{i, j});
}
}
//...
public void actionPerformed(ActionEvent evt) {
JButton source = (JButton) e.getSource();
int[] answer = answers.get(source);
JPanel panel = new JPanel();
JTextField[] fields = new JTextField[]{
new JTextField(2),
new JTextField(2)
};
panel.add(fields[0]);
panel.add(new JLabel("x"));
panel.add(fields[1]);
panel.add(new JLabel(" = " + source.getText()));
JOptionPane.showMessageDialog(theFrame, panel);
// check the values of the fields against the
// values of the answer
}

for loop for array only processing one element in java?

I can't figure out why whenever I cycle through my array using the for-loop it only produces one element (the first) to console? I'm pretty sure it's a rookie-mistake I'm looking over, so any tips and suggestions would help.
I'm making a program for fun that compares two strings typed in a text field and if they don't exist in the array it produces a JOPtionPane message on the contrary. It's for a battle-hack I may produce in the future for vBulletin forum, but I'm messing around with algorithms before I move to that step. Thanks, guys!
package battleoptionspart1;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.lang.*;
import javax.swing.border.*;
public class BattleOptionsPart1 extends JFrame{
JButton newthread, previewpost;
JRadioButton battle1;
JTextField postcount, oppA, oppB;
JLabel battle2, max;
JPanel panel;
String [] array = {"Bill","Tom","Wendy", "Paula"};
public BattleOptionsPart1 () {
panel = new JPanel();
Toolkit tool = Toolkit.getDefaultToolkit();
Dimension dim = tool.getScreenSize();
this.setSize(500, 500);
this.setTitle("Battle Options");
GridLayout grid = new GridLayout(0,1,2,2);
this.setLayout(grid);
newthread = new JButton("Post New Thread");
previewpost = new JButton("Preview Post");
postcount = new JTextField("", 4);
oppA = new JTextField("",10);
oppB = new JTextField("",10);
battle1 = new JRadioButton();
battle2 = new JLabel("Would you like to start a recorded battle?");
max = new JLabel("Enter max post count user must have to vote");
ListenForButton listen = new ListenForButton();
newthread.addActionListener(listen);
previewpost.addActionListener(listen);
JPanel opponents = new JPanel();
Border oppBorder = BorderFactory.createTitledBorder("Battlers");
opponents.setBorder(oppBorder);
opponents.add(oppA);
opponents.add(oppB);
JPanel battle = new JPanel();
Border battleBorder = BorderFactory.createTitledBorder("Start Battle");
battle.setBorder(battleBorder);
battle.add(battle1);
battle.add(battle2);
JPanel buttons = new JPanel();
Border buttonBorder = BorderFactory.createTitledBorder("Create Thread");
buttons.setBorder(buttonBorder);
buttons.add(newthread);
buttons.add(previewpost);
JPanel restriction = new JPanel();
Border resBorder = BorderFactory.createTitledBorder("Restrictions");
restriction.setBorder(buttonBorder);
restriction.add(postcount);
restriction.add(max);
this.add(opponents);
this.add(battle);
this.add(restriction);
this.add(buttons);
this.add(panel);
int xPos = (dim.width / 2) - (this.getWidth() / 2);
int yPos = (dim.height / 2) - (this.getHeight() / 2);
this.setLocation(xPos,yPos); //places form in the middle
this.setVisible(true); // users can see form
this.setResizable(false); //users can't resize the form
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private class ListenForButton implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
String compareA = oppA.getText();
String compareB = oppB.getText();
if (e.getSource() == newthread)
{
System.out.println(compareA + "\n" + compareB);
for(int j = 0; j < array.length; j++)
{
System.out.println(array[j]);
if(!compareA.equals(array[j]))
{
JOptionPane.showMessageDialog(null, compareA + " doesn't exist!", "Error Message", JOptionPane.ERROR_MESSAGE);
oppA.requestFocus();
break;
}
if (!compareB.equals(array[j]))
{
JOptionPane.showMessageDialog(null, compareB + " doesn't exist!", "Error Message", JOptionPane.ERROR_MESSAGE);
oppB.requestFocus();
break;
}
else
{
JOptionPane.showMessageDialog(null, "New thread created successfully!", "Success", JOptionPane.INFORMATION_MESSAGE);
break;
}
}
}
else if (e.getSource() == previewpost)
{
System.exit(0);
}
}
}
public static void main(String[] args) {
BattleOptionsPart1 battle = new BattleOptionsPart1();
}
}
In each of the possible options in your loop, you use break, which leaves the loop immediately. If you remove those statements, you'll process each object in the array.
If you want to check if there's a match, you need to go through every element and do your processing after going through the whole array. Here is an example for an array of type int:
boolean contains = false;
for (int i = 0; i < arr.length; i++)
{
if (arr[i] == searchKey)
{
contains = true;
break;
}
}
You're breaking out of the loop. with the break; command after the first array element

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