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How to request focus on JComponent after changing JPanel in JFrame

I have these two classes:
class Test:
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Test {
//frame
private static JFrame frame = new JFrame() {
private static final long serialVersionUID = 1L;
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 200);
setLocationRelativeTo(null);
setLayout(new BorderLayout());
viewPanel = new JPanel(new BorderLayout());
add(viewPanel);
}
};
private static JPanel viewPanel;
//change the panels
public static void showView(JPanel panel) {
viewPanel.removeAll();
viewPanel.add(panel, BorderLayout.CENTER);
viewPanel.revalidate();
viewPanel.repaint();
}
//main method
public static void main (String [] args) {
SwingUtilities.invokeLater(() -> showView(Panels.panel1));
SwingUtilities.invokeLater(() -> {
frame.setVisible(true);
});
}
}
class Panels:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
//panels
public class Panels {
//first panel
static JPanel panel1 = new JPanel() {
private static final long serialVersionUID = 1L;
{
JButton button = new JButton("Click here!");
add(button);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
SwingUtilities.invokeLater(() -> Test.showView(panel2));
}
});
}
};
//second panel
static JPanel panel2 = new JPanel() {
private static final long serialVersionUID = 1L;
{
JTextField textField = new JTextField(5);
add(textField);
}
};
}
And as you can see, the JPanel changes inside the JFrame, after clicking the JButton: How can I change the JPanel from another Class?
But how can I now set the focus on the JTextField, after changing panel1 to panel2?
I've tried to add grabFocus(); to the JTextField, but it didn't work and requestFocus(); didn't work as well.
Thanks in advance!

There's no need to call showView(...) with invokeLater. Your ActionListener is being called on the EDT, so this is unnecessary code.
If you had a handle to the JTextField, you could call requestFocusInWindow() on it after making it visible, and it should have focus.
For example:
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// SwingUtilities.invokeLater(() -> Test.showView(panel2)); // not needed
Test.showView(panel2);
Component[] comps = panel2.getComponents();
if (comps.length > 0) {
comps[0].requestFocusInWindow();
}
}
});
Myself, I would use CardLayout to do my swapping and would not use the kludge of getting components via getComponents() but rather using much less brittle method calls.
For example:
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyPanelTest extends JPanel {
private TextFieldPanel textFieldPanel = new TextFieldPanel();
private CardLayout cardLayout = new CardLayout();
public MyPanelTest() {
JPanel buttonPanel = new JPanel();
buttonPanel.add(new JButton(new ButtonAction("Press Me")));
setPreferredSize(new Dimension(400, 200));
setLayout(cardLayout);
add(buttonPanel, "button panel");
add(textFieldPanel, TextFieldPanel.NAME);
}
private class ButtonAction extends AbstractAction {
public ButtonAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.show(MyPanelTest.this, TextFieldPanel.NAME);
textFieldPanel.textFieldRequestFocus();
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("My Panel Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new MyPanelTest());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
#SuppressWarnings("serial")
class TextFieldPanel extends JPanel {
public static final String NAME = "TEXT_FIELD_PANEL";
private JTextField textField = new JTextField(10);
public TextFieldPanel() {
add(textField);
}
public void textFieldRequestFocus() {
textField.requestFocusInWindow();
}
}

Repainting a JPanel

I have two frames with contents . The first one has a jlabel and jbutton which when it is clicked it will open a new frame. I need to repaint the first frame or the panel that has the label by adding another jlabel to it when the second frame is closed.
//Edited
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class FirstFrame extends JPanel implements KeyListener{
private static String command[];
private static JButton ok;
private static int count = 1;
private static JTextField text;
private static JLabel labels[];
private static JPanel p ;
private static JFrame frame;
public int getCount(){
return count;
}
public static void createWindow(){
JFrame createFrame = new JFrame();
JPanel panel = new JPanel(new GridLayout(2,1));
text = new JTextField (30);
ok = new JButton ("Add");
ok.requestFocusInWindow();
ok.setFocusable(true);
panel.add(text);
panel.add(ok);
text.setFocusable(true);
text.addKeyListener(new FirstFrame());
createFrame.add(panel);
createFrame.setVisible(true);
createFrame.setSize(600,300);
createFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
createFrame.setLocationRelativeTo(null);
createFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent) {
System.out.println(command[count]);
if(command[count] != null){
p.add(new JLabel("NEW LABEL"));
p.revalidate();
p.repaint();
count++;
System.out.println(count);
}
}
});
if(count >= command.length)
count = 1;
ok.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
if(command[count] == null)
command[count] = text.getText();
else
command[count] = command[count]+", "+text.getText();
text.setText("");
}
});
}
public FirstFrame(){
p = new JPanel();
JButton create = new JButton ("CREATE");
command = new String[2];
labels = new JLabel[2];
addKeyListener(this);
create.setPreferredSize(new Dimension(200,100));
//setLayout(new BorderLayout());
p.add(new JLabel("dsafsaf"));
p.add(create);
add(p);
//JPanel mainPanel = new JPanel();
/*mainPanel.setFocusable(false);
mainPanel.add(create);
*/
create.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
createWindow();
}
});
//add(mainPanel, BorderLayout.SOUTH);
}
public static void main(String[] args) {
frame = new JFrame();
frame.add(new FirstFrame());
frame.setVisible(true);
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
#Override
public void keyReleased(KeyEvent e) {
}
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_ENTER)
if(ok.isDisplayable()){
ok.doClick();
return;}
}
}
}
});
}
}

As per my first comment, you're better off using a dialog of some type, and likely something as simple as a JOptionPane. For instance in the code below, I create a new JLabel with the text in a JTextField that's held by a JOptionPane, and then add it to the original GUI:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class FirstPanel2 extends JPanel {
private static final int PREF_W = 600;
private static final int PREF_H = 300;
private JTextField textField = new JTextField("Hovercraft rules!", 30);
private int count = 0;
public FirstPanel2() {
AddAction addAction = new AddAction();
textField.setAction(addAction);
add(textField);
add(new JButton(addAction));
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class AddAction extends AbstractAction {
public AddAction() {
super("Add");
}
#Override
public void actionPerformed(ActionEvent e) {
String text = textField.getText();
final JTextField someField = new JTextField(text, 10);
JPanel panel = new JPanel();
panel.add(someField);
int result = JOptionPane.showConfirmDialog(FirstPanel2.this, panel, "Add Label",
JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);
if (result == JOptionPane.OK_OPTION) {
JLabel label = new JLabel(someField.getText());
FirstPanel2.this.add(label);
FirstPanel2.this.revalidate();
FirstPanel2.this.repaint();
}
}
}
private static void createAndShowGui() {
FirstPanel2 mainPanel = new FirstPanel2();
JFrame frame = new JFrame("My Gui");
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();
}
});
}
}
Also, don't add KeyListeners to text components as that is a dangerous and unnecessary thing to do. Here you're much better off adding an ActionListener, or as in my code above, an Action, so that it will perform an action when the enter key is pressed.
Edit
You ask:
Just realized it is because of the KeyListener. Can you explain please the addAction ?
This is functionally similar to adding an ActionListener to a JTextField, so that when you press enter the actionPerformed(...) method will be called, exactly the same as if you pressed a JButton and activated its ActionListener or Action. An Action is like an "ActionListener" on steroids. It not only behaves as an ActionListener, but it can also give the button its text, its icon and other properties.

Removing JPanel from a JFrame

I am trying to remove a JPanel not hide it but i can't find anything that works.
This is the code in the panel that needs to remove itself when a button is pressed:
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Frame frame = new Frame(); //referencing to my JFrame class (this class is a JPanel)
//need to remove this panel on this line
frame.ThreeD(); // adds a new panel
}
});
UPDATED
This is the full code:
package ThreeD;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.UIManager;
import Run.Frame;
public class Launcher extends JPanel{
private JButton play, options, help, mainMenu;
private Rectangle rplay, roptions, rhelp, rmainMenu;
private int buttonWidthLocation, buttonWidth, buttonHeight;
private int width = 1280;
public Launcher() {
this.setLayout(null);
drawButtons();
}
private void drawButtons() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception e) {
e.printStackTrace();
}
play = new JButton("Play");
options = new JButton("Options");
help = new JButton("Help");
mainMenu = new JButton("Main Menu");
buttonWidthLocation = (width / 2) - (buttonWidth / 2);
buttonWidth = 80;
buttonHeight = 40;
rplay = new Rectangle(buttonWidthLocation, 150, buttonWidth, buttonHeight);
roptions = new Rectangle(buttonWidthLocation, 300, buttonWidth, buttonHeight);
rhelp = new Rectangle(buttonWidthLocation, 450, buttonWidth, buttonHeight);
rmainMenu = new Rectangle(buttonWidthLocation, 600, buttonWidth, buttonHeight);
play.setBounds(rplay);
options.setBounds(roptions);
help.setBounds(rhelp);
mainMenu.setBounds(rmainMenu);
add(play);
add(options);
add(help);
add(mainMenu);
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Frame frame = new Frame();
//need to remove this panel here
frame.ThreeD();
}
});
options.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("options");
}
});
help.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("help");
}
});
mainMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("mainMenu");
}
});
}
}
And this is my Frame class:
package Run;
import javax.swing.*;
import ThreeD.Display;
import ThreeD.Launcher;
import TowerDefence.Window;
import java.awt.*;
import java.awt.image.BufferedImage;
public class Frame extends JFrame{
public static String title = "Game";
/*public static int GetScreenWorkingWidth() {
return java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().width;
}*/
/*public static int GetScreenWorkingHeight() {
return java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().height;
}*/
//public static Dimension size = new Dimension(GetScreenWorkingWidth(), GetScreenWorkingHeight());
public static Dimension size = new Dimension(1280, 774);
public static void main(String args[]) {
Frame frame = new Frame();
System.out.println("Width of the Frame Size is "+size.width+" pixels");
System.out.println("Height of the Frame Size is "+size.height+" pixels");
}
public Frame() {
setTitle(title);
setSize(size);
setResizable(false);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ThreeDLauncher();
}
public void ThreeDLauncher() {
Launcher launcher = new Launcher();
add(launcher);
setVisible(true);
}
public void TowerDefence() {
setLayout(new GridLayout(1, 1, 0, 0));
Window window = new Window(this);
add(window);
setVisible(true);
}
public void ThreeD() {
BufferedImage cursor = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
Cursor blank = Toolkit.getDefaultToolkit().createCustomCursor(cursor, new Point(0, 0), "blank");
getContentPane().setCursor(blank);
Display display = new Display();
add(display);
setVisible(true);
display.start();
}
}

Basically - you are creating new instance of Frame in line:
Frame frame = new Frame(); //referencing to my JFrame class (this class is a JPanel)
New instance of Frame is not visible, and you're try to remove your Launcher from not visible new Frame. But this is wrong - you should remove Launcher from Frame that you created previously in main function (that is: parent of Launcher component).
Here goes an example:
public class TestFrame extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
TestFrame frame = new TestFrame();
frame.getContentPane().add(new MyPanel(frame));
frame.setSize(200, 200);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
And MyPanel class:
public class MyPanel extends JPanel {
public MyPanel(final TestFrame frame) {
JButton b = new JButton("Play");
add(b);
b.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Container pane = frame.getContentPane();
pane.remove(MyPanel.this);
JPanel otherPanel = new JPanel();
otherPanel.add(new JLabel("OtherPanel"));
pane.add(otherPanel);
pane.revalidate();
}
});
}
}
In your example you should add a reference to Frame in your Launcher constructor:
public Launcher(Frame frame) {
this.frame = frame;
...
Init Launcher:
public void ThreeDLauncher() {
Launcher launcher = new Launcher(this);
and use:
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//need to remove this panel here
frame.getContentPane().remove(Launcher.this);
frame.ThreeD();
}
});

Say your panel is myPanel you can remove it from the main frame by:
frame.getContentPane().remove(myPanel);

How to override windowsClosing event in JFrame

i'm developing a JFrame which has a button to show another JFrame. On the second JFrame i want to override WindowsClosing event to hide this frame but not close all the application. So i do like this:
On second JFrame
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
formWindowClosing(evt);
}
});
private void formWindowClosing(java.awt.event.WindowEvent evt) {
this.dispose();
}
but application still close when i click x button on the windows. why? can you help me?
I can't use
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
because i need to show again that JFrame with some information added in it during operations from first JFrame. So i init second JFrame with attribute visible false. if i use dispose i lose the information added in a second moment by the other JFrame. so i use
private void formWindowClosing(java.awt.event.WindowEvent evt) {
this.setVisible(false);
}
but it still continue to terminate my entire app.

don't create a new JFrame, for new container use JDialog, if you want to hide the JFrame then better would be override proper e.g DefaultCloseOperations(JFrame.HIDE_ON_CLOSE), method JFrame.EXIT_ON_CLOSE teminating current JVM instance simlair as calll for System.exit(int)
EDIT
but it still continue to terminate my entire app.
1) then there must be another issue, your code maybe call another JFrame or formWindowClosing <> WindowClosing, use implemented method from API
public void windowClosing(WindowEvent e) {
2) I'b preferred DefaultCloseOperations(JFrame.HIDE_ON_CLOSE),
3) use JDialog instead of JFrame
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ClosingFrame extends JFrame {
private JMenuBar MenuBar = new JMenuBar();
private static JFrame frame = new JFrame();
private static JFrame frame1 = new JFrame("DefaultCloseOperation(JFrame.HIDE_ON_CLOSE)");
private static final long serialVersionUID = 1L;
private JMenu File = new JMenu("File");
private JMenuItem Exit = new JMenuItem("Exit");
public ClosingFrame() {
File.add(Exit);
MenuBar.add(File);
Exit.addActionListener(new ExitListener());
WindowListener exitListener = new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
frame.setVisible(false);
/*int confirm = JOptionPane.showOptionDialog(frame,
"Are You Sure to Close this Application?",
"Exit Confirmation", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null, null, null);
if (confirm == JOptionPane.YES_OPTION) {
System.exit(1);
}*/
}
};
JButton btn = new JButton("Show second JFrame");
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame1.setVisible(true);
}
});
frame.add(btn, BorderLayout.SOUTH);
frame.addWindowListener(exitListener);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setJMenuBar(MenuBar);
frame.setPreferredSize(new Dimension(400, 300));
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
}
private class ExitListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
int confirm = JOptionPane.showOptionDialog(frame,
"Are You Sure to Close this Application?",
"Exit Confirmation", JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null, null, null);
if (confirm == JOptionPane.YES_OPTION) {
System.exit(1);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
ClosingFrame cf = new ClosingFrame();
JButton btn = new JButton("Show first JFrame");
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.setVisible(true);
}
});
frame1.add(btn, BorderLayout.SOUTH);
frame1.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame1.setPreferredSize(new Dimension(400, 300));
frame1.setLocation(100, 400);
frame1.pack();
frame1.setVisible(true);
}
});
}
}

Adding a New Code with no WindowListener part as explained by #JBNizet, the very right thing. The default behaviour just hides the window, nothing is lost, you simply have to bring it back, every value inside it will remain as is, below is the sample program for further help :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TwoFrames
{
private SecondFrame secondFrame;
private int count = 0;
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("JFRAME 1");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
secondFrame = new SecondFrame();
secondFrame.createAndDisplayGUI();
secondFrame.tfield.setText("I will be same everytime.");
JPanel contentPane = new JPanel();
JButton showButton = new JButton("SHOW JFRAME 2");
showButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
secondFrame.tfield.setText(secondFrame.tfield.getText() + count);
count++;
if (!(secondFrame.isShowing()))
secondFrame.setVisible(true);
}
});
frame.add(contentPane, BorderLayout.CENTER);
frame.add(showButton, BorderLayout.PAGE_END);
frame.setSize(200, 200);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new TwoFrames().createAndDisplayGUI();
}
});
}
}
class SecondFrame extends JFrame
{
private WindowAdapter windowAdapter;
public JTextField tfield;
public void createAndDisplayGUI()
{
setLocationByPlatform(true);
JPanel contentPane = new JPanel();
tfield = new JTextField(10);
addWindowListener(windowAdapter);
contentPane.add(tfield);
getContentPane().add(contentPane);
setSize(300, 300);
}
}
Is this what you want, try this code :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TwoFrames
{
private SecondFrame secondFrame;
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("JFRAME 1");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
secondFrame = new SecondFrame();
secondFrame.createAndDisplayGUI();
secondFrame.tfield.setText("I will be same everytime.");
JPanel contentPane = new JPanel();
JButton showButton = new JButton("SHOW JFRAME 2");
showButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
if (!(secondFrame.isShowing()))
secondFrame.setVisible(true);
}
});
frame.add(contentPane, BorderLayout.CENTER);
frame.add(showButton, BorderLayout.PAGE_END);
frame.setSize(200, 200);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new TwoFrames().createAndDisplayGUI();
}
});
}
}
class SecondFrame extends JFrame
{
private WindowAdapter windowAdapter;
public JTextField tfield;
public void createAndDisplayGUI()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
JPanel contentPane = new JPanel();
tfield = new JTextField(10);
windowAdapter = new WindowAdapter()
{
public void windowClosing(WindowEvent we)
{
setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
}
};
addWindowListener(windowAdapter);
contentPane.add(tfield);
getContentPane().add(contentPane);
setSize(300, 300);
}
}

You could avoid the listener completely and use
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
Note that the default value is HIDE_ON_CLOSE, so the behavior you want should be the default behavior. Maybe you registered another listener that exits the application.
See http://docs.oracle.com/javase/6/docs/api/javax/swing/JFrame.html#setDefaultCloseOperation%28int%29

It's hard to pinpoint exactly why you are experiencing the behavior stated without seeing a little more of the set-up code, however it may be due to defaultCloseOperation set to EXIT_ON_CLOSE.
Here's a link to a demo displaying the properties you are looking for although the structure is a bit different. Have a look: http://docs.oracle.com/javase/tutorial/uiswing/examples/components/FrameworkProject/src/components/Framework.java

GUI multiple frames switch

I am writing a program for a black jack game. It is an assignment we are not to use gui's but I am doing it for extra credit I have created two frames ant they are working. On the second frame I want to be able to switch back to the first when a button is pressed. How do I do this?
first window.............
import javax.swing.* ;
import java.awt.event.* ;
import java.awt.* ;
import java.util.* ;
public class BlackJackWindow1 extends JFrame implements ActionListener
{
private JButton play = new JButton("Play");
private JButton exit = new JButton("Exit");
private JPanel pane=new JPanel();
private JLabel lbl ;
public BlackJackWindow1()
{
super();
JPanel pane=new JPanel();
setTitle ("Black Jack!!!!!") ;
JFrame frame = new JFrame("");
setVisible(true);
setSize (380, 260) ;
setLocation (450, 200) ;
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE) ;
setLayout(new FlowLayout());
play = new JButton("Start");
exit = new JButton("exit");
lbl = new JLabel ("Welcome to Theodores Black Jack!!!!!");
add (lbl) ;
add(play, BorderLayout.CENTER);
play.addActionListener (this);
add(exit,BorderLayout.CENTER);
exit.addActionListener (this);
}
#Override
public void actionPerformed(ActionEvent event)
{
// TODO Auto-generated method stub
BlackJackWindow2 bl = new BlackJackWindow2();
if (event.getSource() == play)
{
bl.BlackJackWindow2();
}
else if(event.getSource() == exit){
System.exit(0);
}
}
second window....
import javax.swing.* ;
import java.awt.event.* ;
import java.awt.* ;
import java.util.* ;
public class BlackJackWindow2 extends JFrame implements ActionListener
{
private JButton hit ;
private JButton stay ;
private JButton back;
//private JLabel lbl;
public void BlackJackWindow2()
{
// TODO Auto-generated method stub
JPanel pane=new JPanel();
setTitle ("Black Jack!!!!!") ;
JFrame frame = new JFrame("");
setVisible(true);
setSize (380, 260) ;
setLocation (450, 200) ;
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE) ;
setLayout(new FlowLayout());
hit = new JButton("Hit");
stay = new JButton("stay");
back = new JButton("return to main menu");
// add (lbl) ;
add(hit, BorderLayout.CENTER);
hit.addActionListener (this) ;
add(stay,BorderLayout.CENTER);
stay.addActionListener (this) ;
add(back,BorderLayout.CENTER);
back.addActionListener (this) ;
}
#Override
public void actionPerformed(ActionEvent event)
{
// TODO Auto-generated method stub
BlackJackWindow1 bl = new BlackJackWindow1();
if (event.getSource() == hit)
{
//code for the game goes here i will complete later
}
else if(event.getSource() == stay){
//code for game goes here i will comeplete later.
}
else
{
//this is where i want the frame to close and go back to the original.
}
}
}

The second frame needs a reference to the first frame so that it can set the focus back to the first frame.
Also your classes extend JFrame but they are also creating other frames in their constructors.

A couple of suggestions:
You're adding components to a JPanel that uses FlowLayout but are using BorderLayout constants when doing this which you shouldn't do as it doesn't make sense:
add(play, BorderLayout.CENTER);
Rather, if using FlowLayout, just add the components without those constants.
Also, rather than swap JFrames, you might want to consider using a CardLayout and swapping veiws in a single JFrame. For instance:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class FooBarBazDriver {
private static final String INTRO = "intro";
private static final String GAME = "game";
private CardLayout cardlayout = new CardLayout();
private JPanel mainPanel = new JPanel(cardlayout);
private IntroPanel introPanel = new IntroPanel();
private GamePanel gamePanel = new GamePanel();
public FooBarBazDriver() {
mainPanel.add(introPanel.getMainComponent(), INTRO);
mainPanel.add(gamePanel.getMainComponent(), GAME);
introPanel.addBazBtnActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cardlayout.show(mainPanel, GAME);
}
});
gamePanel.addBackBtnActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cardlayout.show(mainPanel, INTRO);
}
});
}
private JComponent getMainComponent() {
return mainPanel;
}
private static void createAndShowUI() {
JFrame frame = new JFrame("Foo Bar Baz");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new FooBarBazDriver().getMainComponent());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class IntroPanel {
private JPanel mainPanel = new JPanel();
private JButton baz = new JButton("Baz");
private JButton exit = new JButton("Exit");
public IntroPanel() {
mainPanel.setLayout(new FlowLayout());
baz = new JButton("Start");
exit = new JButton("exit");
mainPanel.add(new JLabel("Hello World"));
mainPanel.add(baz);
mainPanel.add(exit);
exit.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Window win = SwingUtilities.getWindowAncestor(mainPanel);
win.dispose();
}
});
}
public void addBazBtnActionListener(ActionListener listener) {
baz.addActionListener(listener);
}
public JComponent getMainComponent() {
return mainPanel;
}
}
class GamePanel {
private static final Dimension MAIN_SIZE = new Dimension(400, 200);
private JPanel mainPanel = new JPanel();
private JButton foo;
private JButton bar;
private JButton back;
public GamePanel() {
foo = new JButton("Foo");
bar = new JButton("Bar");
back = new JButton("return to main menu");
mainPanel.add(foo);
mainPanel.add(bar);
mainPanel.add(back);
mainPanel.setPreferredSize(MAIN_SIZE);
}
public JComponent getMainComponent() {
return mainPanel;
}
public void addBackBtnActionListener(ActionListener listener) {
back.addActionListener(listener);
}
}

Since I had to test it myself if it is in fact so easy to implement, I built this simple example. It demonstrates a solution to your problem. Slightly inspired by #jzd's answer (+1 for that).
import java.awt.Color;
import java.awt.HeadlessException;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class FocusChangeTwoFrames
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createGUI();
}
});
}
private static void createGUI() throws HeadlessException
{
final JFrame f2 = new JFrame();
f2.getContentPane().setBackground(Color.GREEN);
final JFrame f1 = new JFrame();
f1.getContentPane().setBackground(Color.RED);
f1.setSize(400, 300);
f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f1.setVisible(true);
MouseListener ml = new MouseAdapter()
{
#Override
public void mousePressed(MouseEvent e)
{
if(f1.hasFocus())
f2.requestFocus();
else
f1.requestFocus();
}
};
f1.addMouseListener(ml);
f2.setSize(400, 300);
f2.setLocation(200, 150);
f2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f2.setVisible(true);
f2.addMouseListener(ml);
}
}
Enjoy, Boro.