Develop Reference

Open new window in swing - Contents not visible

I am completely new to programming: I have two classes in my Java Swing application, and when I press the button a new window opens, but only the frame is visible and not the content of the frame.
I appreciate any help.
The first class:
public class Learning {
private JFrame mainFrame;
private JLabel headerLabel;
private JLabel statusLabel;
private JPanel controlPanel;
public Learning(){
prepareGUI();
}
public static void main(String[] args) {
Learning swingControlDemo = new Learning();
swingControlDemo.showEventDemo();
}
private void prepareGUI() {
mainFrame = new JFrame("software component architecture quizess");
mainFrame.setSize(600,400);
mainFrame.setLayout(new GridLayout(3, 1));
headerLabel = new JLabel("",JLabel.CENTER );
statusLabel = new JLabel("",JLabel.CENTER);
statusLabel.setSize(350,100);
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showEventDemo() {
headerLabel.setText("Learning invironment for CBSC and SOA");
JButton okButton = new JButton("Drag and Drop");
JButton submitButton = new JButton("multiple choice quizess");
JButton cancelButton = new JButton("true false quizzes");
JButton newButton = new JButton("Component Description Language");
okButton.setActionCommand("Drag and Drop");
submitButton.setActionCommand("multiple choice quizess");
cancelButton.setActionCommand("true false quizzes");
newButton.setActionCommand("true false quizzes");
controlPanel.add(okButton);
controlPanel.add(submitButton);
controlPanel.add(cancelButton);
controlPanel.add(newButton);
mainFrame.setVisible(true);
newButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
mainFrame.dispose();
new DLC1();
}
});
}
}
And the second class:
public class DLC1 {
private JFrame mainFrame;
private JLabel headerLabel;
private JLabel statusLabel;
private JPanel controlPanel;
private JLabel msglabel;
public DLC1(){
prepareGUI();
}
public static void main(String[] args){
DLC1 swingLayoutDemo = new DLC1();
swingLayoutDemo.showBorderLayoutDemo();
}
private void prepareGUI(){
mainFrame = new JFrame("component description language");
mainFrame.setSize(600,400);
mainFrame.setLayout(new GridLayout(3, 1));
headerLabel = new JLabel("",JLabel.CENTER );
statusLabel = new JLabel("",JLabel.CENTER);
statusLabel.setSize(350,100);
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showBorderLayoutDemo(){
headerLabel.setText("Layout in action: BorderLayout");
JPanel panel = new JPanel();
panel.setBackground(Color.darkGray);
panel.setSize(300,300);
BorderLayout layout = new BorderLayout();
layout.setHgap(10);
layout.setVgap(10);
panel.setLayout(layout);
panel.add(new JButton("dlgggggggggc"),BorderLayout.CENTER);
panel.add(new JButton("Line Start"),BorderLayout.LINE_START);
panel.add(new JButton("Line End"),BorderLayout.LINE_END);
panel.add(new JButton("East"),BorderLayout.EAST);
panel.add(new JButton("West"),BorderLayout.WEST);
panel.add(new JButton("North"),BorderLayout.NORTH);
panel.add(new JButton("South"),BorderLayout.SOUTH);
controlPanel.add(panel);
mainFrame.setVisible(true);
}
}

how to edit awt textfield via code

I can't find out how to change text in my AWT textboxes. I already tried this:
textBox1.setText("text");
textBox1.validate();
or
textBox1.setText("text");
textBox1.repaint();
None of them works. What could be this issue?

Look this example how I am setting text to text field
import java.awt.*;
import java.awt.event.*;
public class AwtControlDemo {
private Frame mainFrame;
private Label headerLabel;
private Label statusLabel;
private Panel controlPanel;
public AwtControlDemo(){
prepareGUI();
}
public static void main(String[] args){
AwtControlDemo awtControlDemo = new AwtControlDemo();
awtControlDemo.showTextFieldDemo();
}
private void prepareGUI(){
mainFrame = new Frame("Java AWT Examples");
mainFrame.setSize(400,400);
mainFrame.setLayout(new GridLayout(3, 1));
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
headerLabel = new Label();
headerLabel.setAlignment(Label.CENTER);
statusLabel = new Label();
statusLabel.setAlignment(Label.CENTER);
statusLabel.setSize(350,100);
controlPanel = new Panel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showTextFieldDemo(){
headerLabel.setText("Control in action: TextField");
Label namelabel= new Label("User ID: ", Label.CENTER);
final TextField userText = new TextField(16);
userText.setText("name");
Button displayButton = new Button("Display");
displayButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String data = "Username: " + userText.getText();
statusLabel.setText(data);
}
});
controlPanel.add(namelabel);
controlPanel.add(userText);
controlPanel.add(displayButton);
mainFrame.setVisible(true);
}
}

Java grid layout GUI - how to enter new pane on event?

How can I set a button to link to a completely different grid pane? If I click the JButton "More options" for example, I want it to link me to a new page with more JButton options. Right now, everything is static.
The program right now just calculates the area of a rectangle given an length and width when you press "Calculate." The grid layout is 4 x 2, denoted by JLabel, JTextField, and JButton listed below.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class RectangleProgram extends JFrame
{
private static final int WIDTH = 400;
private static final int HEIGHT = 300;
private JLabel lengthL, widthL, areaL;
private JTextField lengthTF, widthTF, areaTF;
private JButton calculateB, exitB;
//Button handlers:
private CalculateButtonHandler cbHandler;
private ExitButtonHandler ebHandler;
public RectangleProgram()
{
lengthL = new JLabel("Enter the length: ", SwingConstants.RIGHT);
widthL = new JLabel("Enter the width: ", SwingConstants.RIGHT);
areaL = new JLabel("Area: ", SwingConstants.RIGHT);
lengthTF = new JTextField(10);
widthTF = new JTextField(10);
areaTF = new JTextField(10);
//SPecify handlers for each button and add (register) ActionListeners to each button.
calculateB = new JButton("Calculate");
cbHandler = new CalculateButtonHandler();
calculateB.addActionListener(cbHandler);
exitB = new JButton("Exit");
ebHandler = new ExitButtonHandler();
exitB.addActionListener(ebHandler);
setTitle("Sample Title: Area of a Rectangle");
Container pane = getContentPane();
pane.setLayout(new GridLayout(4, 2));
//Add things to the pane in the order you want them to appear (left to right, top to bottom)
pane.add(lengthL);
pane.add(lengthTF);
pane.add(widthL);
pane.add(widthTF);
pane.add(areaL);
pane.add(areaTF);
pane.add(calculateB);
pane.add(exitB);
setSize(WIDTH, HEIGHT);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private class CalculateButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
double width, length, area;
length = Double.parseDouble(lengthTF.getText()); //We use the getText & setText methods to manipulate the data entered into those fields.
width = Double.parseDouble(widthTF.getText());
area = length * width;
areaTF.setText("" + area);
}
}
public class ExitButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}
public static void main(String[] args)
{
RectangleProgram rectObj = new RectangleProgram();
}
}

You can use CardLayout. It allows the two or more components share the same display space.
Here is a simple example
public class RectangleProgram {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("Area of a Rectangle");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField lengthField = new JTextField(10);
JTextField widthField = new JTextField(10);
JTextField areaField = new JTextField(10);
JButton calculateButton = new JButton("Calculate");
JButton exitButton = new JButton("Exit");
final JPanel content = new JPanel(new CardLayout());
JButton optionsButton = new JButton("More Options");
optionsButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
CardLayout cardLayout = (CardLayout) content.getLayout();
cardLayout.next(content);
}
});
JPanel panel = new JPanel(new GridLayout(0, 2)) {
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 100);
}
};
panel.add(new JLabel("Enter the length: ", JLabel.RIGHT));
panel.add(lengthField);
panel.add(new JLabel("Enter the width: ", JLabel.RIGHT));
panel.add(widthField);
panel.add(new JLabel("Area: ", JLabel.RIGHT));
panel.add(areaField);
panel.add(calculateButton);
panel.add(exitButton);
JPanel optionsPanel = new JPanel();
optionsPanel.add(new JLabel("Options", JLabel.CENTER));
content.add(panel, "Card1");
content.add(optionsPanel, "Card2");
frame.add(content);
frame.add(optionsButton, BorderLayout.PAGE_END);
frame.pack();
frame.setVisible(true);
}
});
}
}
Read How to Use CardLayout

How to position JButton in a JFrame window?

My program is about a supermarket. I want to position the JButton 'b1' just below JLabel 'l1' and also below JTextField 'jt1'. I want the JButton 'b1' to also be in the centre but below 'l1' and 'jt1'. Below is the delivery() method of my program:
public static void delivery()
{
final JFrame f1 = new JFrame("Name");
f1.setVisible(true);
f1.setSize(600,200);
f1.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f1.setLocation(700,450);
JPanel p1 = new JPanel();
final JLabel l1 = new JLabel("Enter your name: ");
final JTextField jt1 = new JTextField(20);
JButton b1 = new JButton("Ok");
b1.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
input1 = jt1.getText();
f1.setVisible(false);
}
});
p1.add(b1);
p1.add(l1);
p1.add(jt1);
f1.add(p1);
final JFrame f2 = new JFrame("Address");
f2.setVisible(true);
f2.setSize(600,200);
f2.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f2.setLocation(700,450);
JPanel p2 = new JPanel();
final JLabel l2 = new JLabel("Enter your address: ");
final JTextField jt2 = new JTextField(20);
JButton b2 = new JButton("Ok");
b2.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
input2 = jt2.getText();
f2.setVisible(false);
}
});
p2.add(b2);
p2.add(l2);
p2.add(jt2);
f2.add(p2);
}
}

You can use multiple JPanels to get close to what you want:
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class MyGui {
public static void delivery()
{
JFrame f1 = new JFrame("Name");
f1.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f1.setBounds(200, 100, 500, 300);
Container cpane = f1.getContentPane();
JPanel p1 = new JPanel();
p1.setLayout(new BoxLayout(p1, BoxLayout.LINE_AXIS)); //Horizontal
JLabel l1 = new JLabel("Enter your name: ");
JTextField jt1 = new JTextField(20);
jt1.setMaximumSize( jt1.getPreferredSize() );
p1.add(l1);
p1.add(jt1);
JPanel p2 = new JPanel();
p2.setLayout(new BoxLayout(p2, BoxLayout.PAGE_AXIS)); //Vertical
p2.add(p1);
JButton b1 = new JButton("Ok");
p2.add(b1);
cpane.add(p2);
f1.setVisible(true);
}
}
public class SwingProg {
private static void createAndShowGUI() {
MyGui.delivery();
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

Use the GridBagLayout Class. It's for custom designing using Constraints.

CardLayout issue

I have a card layout, first card is a menu.
I Select the second card, and carry out some action. We'll say add a JTextField by clicking a button. If I return to the menu card, and then go back to the second card, that JTextField I added the first time will still be there.
I want the second card to be as I originally constructed it each time I access it, with the buttons, but without the Textfield.

Make sure the panel you're trying to reset has code that takes it back to its "as it was originally constructed" state. Then, when you process the whatever event that causes you to change cards, call that code to restore the original state before showing the card.

Here is the final sorted out version, to remove the card, after doing changes to it, have a look, use the revalidate() and repaint() thingy as usual :-)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ApplicationBase extends JFrame
{
private JPanel centerPanel;
private int topPanelCount = 0;
private String[] cardNames = {
"Login Window",
"TextField Creation"
};
private TextFieldCreation tfc;
private LoginWindow lw;
private JButton nextButton;
private JButton removeButton;
private ActionListener actionListener = new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
if (ae.getSource() == nextButton)
{
CardLayout cardLayout = (CardLayout) centerPanel.getLayout();
cardLayout.next(centerPanel);
}
else if (ae.getSource() == removeButton)
{
centerPanel.remove(tfc);
centerPanel.revalidate();
centerPanel.repaint();
tfc = new TextFieldCreation();
tfc.createAndDisplayGUI();
centerPanel.add(tfc, cardNames[1]);
}
}
};
private void createAndDisplayGUI()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
centerPanel = new JPanel();
centerPanel.setLayout(new CardLayout());
lw = new LoginWindow();
lw.createAndDisplayGUI();
centerPanel.add(lw, cardNames[0]);
tfc = new TextFieldCreation();
tfc.createAndDisplayGUI();
centerPanel.add(tfc, cardNames[1]);
JPanel bottomPanel = new JPanel();
removeButton = new JButton("REMOVE");
nextButton = new JButton("NEXT");
removeButton.addActionListener(actionListener);
nextButton.addActionListener(actionListener);
bottomPanel.add(removeButton);
bottomPanel.add(nextButton);
add(centerPanel, BorderLayout.CENTER);
add(bottomPanel, BorderLayout.PAGE_END);
pack();
setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new ApplicationBase().createAndDisplayGUI();
}
});
}
}
class TextFieldCreation extends JPanel
{
private JButton createButton;
private int count = 0;
public void createAndDisplayGUI()
{
final JPanel topPanel = new JPanel();
topPanel.setLayout(new GridLayout(0, 2));
createButton = new JButton("CREATE TEXTFIELD");
createButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
JTextField tfield = new JTextField();
tfield.setActionCommand("JTextField" + count);
topPanel.add(tfield);
topPanel.revalidate();
topPanel.repaint();
}
});
setLayout(new BorderLayout(5, 5));
add(topPanel, BorderLayout.CENTER);
add(createButton, BorderLayout.PAGE_END);
}
}
class LoginWindow extends JPanel
{
private JPanel topPanel;
private JPanel middlePanel;
private JPanel bottomPanel;
public void createAndDisplayGUI()
{
topPanel = new JPanel();
JLabel userLabel = new JLabel("USERNAME : ", JLabel.CENTER);
JTextField userField = new JTextField(20);
topPanel.add(userLabel);
topPanel.add(userField);
middlePanel = new JPanel();
JLabel passLabel = new JLabel("PASSWORD : ", JLabel.CENTER);
JTextField passField = new JTextField(20);
middlePanel.add(passLabel);
middlePanel.add(passField);
bottomPanel = new JPanel();
JButton loginButton = new JButton("LGOIN");
bottomPanel.add(loginButton);
setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
add(topPanel);
add(middlePanel);
add(bottomPanel);
}
}
If you just wanted to remove the Latest Edit made to the card, try this code :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ApplicationBase extends JFrame
{
private JPanel centerPanel;
private int topPanelCount = 0;
private String[] cardNames = {
"Login Window",
"TextField Creation"
};
private TextFieldCreation tfc;
private LoginWindow lw;
private JButton nextButton;
private JButton removeButton;
private ActionListener actionListener = new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
if (ae.getSource() == nextButton)
{
CardLayout cardLayout = (CardLayout) centerPanel.getLayout();
cardLayout.next(centerPanel);
}
else if (ae.getSource() == removeButton)
{
TextFieldCreation.topPanel.remove(TextFieldCreation.tfield);
TextFieldCreation.topPanel.revalidate();
TextFieldCreation.topPanel.repaint();
}
}
};
private void createAndDisplayGUI()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
centerPanel = new JPanel();
centerPanel.setLayout(new CardLayout());
lw = new LoginWindow();
lw.createAndDisplayGUI();
centerPanel.add(lw, cardNames[0]);
tfc = new TextFieldCreation();
tfc.createAndDisplayGUI();
centerPanel.add(tfc, cardNames[1]);
JPanel bottomPanel = new JPanel();
removeButton = new JButton("REMOVE");
nextButton = new JButton("NEXT");
removeButton.addActionListener(actionListener);
nextButton.addActionListener(actionListener);
bottomPanel.add(removeButton);
bottomPanel.add(nextButton);
add(centerPanel, BorderLayout.CENTER);
add(bottomPanel, BorderLayout.PAGE_END);
pack();
setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new ApplicationBase().createAndDisplayGUI();
}
});
}
}
class TextFieldCreation extends JPanel
{
private JButton createButton;
private int count = 0;
public static JTextField tfield;
public static JPanel topPanel;
public void createAndDisplayGUI()
{
topPanel = new JPanel();
topPanel.setLayout(new GridLayout(0, 2));
createButton = new JButton("CREATE TEXTFIELD");
createButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
tfield = new JTextField();
tfield.setActionCommand("JTextField" + count);
topPanel.add(tfield);
topPanel.revalidate();
topPanel.repaint();
}
});
setLayout(new BorderLayout(5, 5));
add(topPanel, BorderLayout.CENTER);
add(createButton, BorderLayout.PAGE_END);
}
}
class LoginWindow extends JPanel
{
private JPanel topPanel;
private JPanel middlePanel;
private JPanel bottomPanel;
public void createAndDisplayGUI()
{
topPanel = new JPanel();
JLabel userLabel = new JLabel("USERNAME : ", JLabel.CENTER);
JTextField userField = new JTextField(20);
topPanel.add(userLabel);
topPanel.add(userField);
middlePanel = new JPanel();
JLabel passLabel = new JLabel("PASSWORD : ", JLabel.CENTER);
JTextField passField = new JTextField(20);
middlePanel.add(passLabel);
middlePanel.add(passField);
bottomPanel = new JPanel();
JButton loginButton = new JButton("LGOIN");
bottomPanel.add(loginButton);
setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
add(topPanel);
add(middlePanel);
add(bottomPanel);
}
}