I'm having trouble with the functionality of dispose for my checkerboard (called Checkers) . For each checkerboard that I have, i want to be able to remove it by using dispose before calling another instance of my interface. Here is my progress so far:
Checkers class:
import java.awt.*;
import javax.swing.*;
import java.awt.Color.*;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.util.Random;
public class Checkers extends JFrame
{
Random random = new Random();
private final int ROWS = 2;
private final int COLS = 5;
private final int GAP = 2;
private final int NUM = ROWS * COLS;
private int i;
public int score;
private JPanel pane = new JPanel(new GridLayout(ROWS,COLS, GAP,GAP));
private JPanel pane2 = new JPanel();
private JPanel pane3 = new JPanel();
private JButton btn1 = new JButton("Play A Game");
private JButton btn2 = new JButton("Exit");
private JButton btn3 = new JButton("Easy");
private JButton btn4 = new JButton("Intermediate");
private JButton btn5 = new JButton("Difficult");
private JLabel lbl1 = new JLabel ("score: " + score);
private JLabel gameLost = new JLabel("You lose! You got: " + score + " points");
private MyPanel [] panel = new MyPanel[NUM];
private Color col1 = Color.RED;
private Color col2 = Color.WHITE;
private Color col3 = Color.GREEN;
private Color tempColor;
public Checkers()
{
super("Checkers");
setSize(600,600);
setVisible(true);
setBackground(Color.BLACK);
setBoard();
}
public void setBoard()
// roates colors on the checkbaord
{
for (int i = 0; i < panel.length; i++) {
panel[i] = new MyPanel(this);
pane.add(panel[i]);
if (i % COLS == 0) {
tempColor = col1;
col1 = col2;
col2 = tempColor;}
if (i % 2 == 0) {
panel[i].setBackground(col1);}
else {
panel[i].setBackground(col2);}
}
//pane background colour and the size of this pane.
pane.setBackground(Color.BLACK);
pane.setPreferredSize(new Dimension(300,300));
//pane background colour and size of this pane.
pane2.setBackground(Color.white);
pane2.setPreferredSize(new Dimension(300,300));
//directions on the board where these panes appear.
add(pane, BorderLayout.WEST);
add(pane2, BorderLayout.EAST);
pane2.add(lbl1);
pane2.setLayout(new BoxLayout(pane2, BoxLayout.PAGE_AXIS));
}
public void incrementScore(){
score++;
lbl1.setText("Score: " + Integer.toString(score));
}
//This is the method for resetting via dispose - only works once.
public void restartBoard(){
this.dispose();
new Checkers();
}
}
And also the MyPanel class
public class MyPanel extends JPanel implements MouseListener {
private final Checkers checkers;
public MyPanel(Checkers checkers) {
this.checkers = checkers;
addMouseListener(this);
}
#Override
public void mouseClicked(MouseEvent e) {
setBackground(Color.BLACK);
checkers.incrementScore();
}
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
}
EXPECTED RESULT - What i'd like to do is be able to close the current version of interface by using the dispose method, and then opening a new instance of said interface.
ACTUAL RESULT - When opening an interface, then calling dispose method, it will work once. once you try to remove the 2nd interface when creating a 3rd interface, dispose will not function, and I cant see why this is.
Any help is welcome.
For what it's worth, this is an MCVE that shows your likely problem:
import java.awt.Dimension;
import javax.swing.*;
public class CheckersTest {
private static void createAndShowGui() {
Checkers checkers = new Checkers();
JButton restartButton = new JButton("Restart");
restartButton.addActionListener(event -> checkers.restartBoard());
JPanel restartPanel = new JPanel();
restartPanel.setPreferredSize(new Dimension(400, 400));
restartPanel.add(restartButton);
JFrame frame = new JFrame("Checkers Test");
frame.add(restartPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class Checkers extends JFrame {
public Checkers() {
setPreferredSize(new Dimension(200, 200));
pack();
setLocationByPlatform(true);
setVisible(true);
}
public void restartBoard(){
this.dispose();
new Checkers();
}
}
The restart button refers to the original Checkers instance and so will not close any new instances created. The solution would be to get the restart method out of Checkers, create a Checkers field, and make sure the restart method refers to the visible Checkers instance:
import java.awt.Dimension;
import javax.swing.*;
public class CheckersTest {
private static Checkers checkers = new Checkers(); // holds reference
private static void restartBoard() {
if (checkers != null) {
checkers.dispose();
checkers = new Checkers(); // assign to reference field
}
}
private static void createAndShowGui() {
// !! Checkers checkers = new Checkers();
JButton restartButton = new JButton("Restart");
// !! restartButton.addActionListener(event -> checkers.restartBoard());
restartButton.addActionListener(event -> restartBoard());
JPanel restartPanel = new JPanel();
restartPanel.setPreferredSize(new Dimension(400, 400));
restartPanel.add(restartButton);
JFrame frame = new JFrame("Checkers Test");
frame.add(restartPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class Checkers extends JFrame {
public Checkers() {
setPreferredSize(new Dimension(200, 200));
pack();
setLocationByPlatform(true);
setVisible(true);
}
}
Notes:
Again a much better design is not to swap JFrames but rather JPanel views
Note that the MCVE has code that reproduces the problem but avoids code not related to the problem. So it shows the restartBoard method, it compiles, but avoids game code since this is not relevant to the problem.
Related
I am trying to have a dialog showing a progress bar with a label. I have set my label to be center aligned with JLabel.Center and the use of a box.
Initially, the label is shown as centered, which is what I am looking for. However, when changing the label's text (by using the code "creatingQueriesLabel.setText(text)", the label is now displayed as left aligned.
Any help will be greatly appreciated! Here is my code.
JFrame frame = new JFrame("Creating queries ...");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Box box = Box.createVerticalBox();
JPanel panel = new JPanel();
panel.setLayout(null);
creatingQueriesLabel = new JLabel("Initializing ... ");
creatingQueriesLabel.setSize(480, 160);
creatingQueriesLabel.setLocation(10, 10);
creatingQueriesLabel.setAlignmentX(JLabel.CENTER_ALIGNMENT);
box.setLocation(0, 10);
box.setSize(480, 160);
box.add(creatingQueriesLabel);
progressBar = new JProgressBar();
progressBar.setSize(480, 50);
progressBar.setValue(0);
progressBar.setStringPainted(true);
progressBar.setLocation(creatingQueriesLabel.getX(),
creatingQueriesLabel.getY() + creatingQueriesLabel.getHeight());
panel.add(progressBar);
frame.add(box);
frame.add(panel);
// Display the window.
frame.pack();
frame.setSize(520, 280);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
/**
* Invoked when task's progress property changes.
*/
public void propertyChange(PropertyChangeEvent evt)
{
if ("progress" == evt.getPropertyName())
{
int progress = (Integer) evt.getNewValue();
progressBar.setValue(progress);
}
if ("currentQueryText" == evt.getPropertyName())
{
String text = (String) evt.getNewValue();
creatingQueriesLabel.setText(text);
}
}
Problems:
You're setting sizes and positions using absolute positioning -- don't as that's not how Swing works and this will lead to GUI's that are very hard to maintain and enhance, as you're finding out.
Use the SwingConstants.CENTER int when constructing the JLabel so that its text is centered
Add it to a container that uses BorderLayout, probably in the BorderLayout.PAGE_START position.
Unrelated problem -- don't do this: if ("currentQueryText" == evt.getPropertyName()) {. This tests for reference equality which is not what you want to test for. Use the equals method instead.
This GUI looks like it should be a dialog window, a temporary window that is displaying information not shown in the main parent window (the JFrame window), and so it should be displayed in a JDialog, not a JFrame.
For example:
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.Dialog.ModalityType;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
#SuppressWarnings("serial")
public class CreatingSpeciesPanel extends JPanel {
public static final String INITIALIZING = "Initializing...";
public static final String DONE = "DONE!";
private static final int PREF_W = 480;
private static final int PREF_H = 150;
private static final int GAP = 20;
private static final float TITLE_SIZE = 24f;
private JLabel title = new JLabel(INITIALIZING, SwingConstants.CENTER);
private JProgressBar progressBar = new JProgressBar();
public CreatingSpeciesPanel() {
title.setFont(title.getFont().deriveFont(Font.BOLD, TITLE_SIZE));
progressBar.setValue(0);
progressBar.setStringPainted(true);
JPanel centerPanel = new JPanel(new BorderLayout());
centerPanel.add(progressBar, BorderLayout.PAGE_END);
setLayout(new BorderLayout());
setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
add(title, BorderLayout.PAGE_START);
add(centerPanel, BorderLayout.CENTER);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
public void setValue(int value) {
progressBar.setValue(value);
}
public void setTitleLabelText(String text) {
title.setText(text);
}
private static void createAndShowGui() {
final CreatingSpeciesPanel creatingSpeciesPanel = new CreatingSpeciesPanel();
final JFrame mainFrame = new JFrame("Main Frame");
JButton createSpeciesBtn = new JButton(new AbstractAction("Create Species") {
#Override
public void actionPerformed(ActionEvent e) {
creatingSpeciesPanel.setTitleLabelText(CreatingSpeciesPanel.INITIALIZING);
final JDialog dialog = new JDialog(mainFrame, "Creating Species", ModalityType.APPLICATION_MODAL);
dialog.add(creatingSpeciesPanel);
dialog.pack();
dialog.setLocationRelativeTo(mainFrame);
new Timer(200, new ActionListener() {
private int doneCount = 0;
private int value = 0;
private static final int MAX_DONE_COUNT = 10;
#Override
public void actionPerformed(ActionEvent e) {
if (value < 100) {
value += (int) Math.random() * 5 + 5;
value = Math.min(100, value);
creatingSpeciesPanel.setValue(value);
if (value == 100) {
creatingSpeciesPanel.setTitleLabelText(CreatingSpeciesPanel.DONE);
}
} else {
// let's display the dialog for 2 more seconds
doneCount++;
if (doneCount >= MAX_DONE_COUNT) {
((Timer) e.getSource()).stop();
dialog.setVisible(false);
}
}
}
}).start();
dialog.setVisible(true);
}
});
JPanel panel = new JPanel();
panel.add(createSpeciesBtn);
panel.setPreferredSize(new Dimension(500, 400));
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.getContentPane().add(panel);
mainFrame.pack();
mainFrame.setLocationRelativeTo(null);
mainFrame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
So I'm working on making a database system built on top of a Java Swing GUI... I have one button that works to add a person/thing to a vector (in this case the database):
// Database
Vector<String> db = new Vector<String>();
Here is the button's actionlistener to add:
new ActionListener() {
public void actionPerformed(ActionEvent e) {
String newStudent = student.getText();
db.addElement(newStudent);
This part all seems to be working fine, however, when I go to print out the vector on a JTextArea using a string buffer, there are odd spacing issues in the text on the JTextArea
Here is the StringBuffer and section where I print the vector onto the JTextArea:
StringBuffer dbb = new StringBuffer();
for (int i = 0; i < db.size(); i++) {
dbb.append(db.get(i) + '\n');
}
// printDB is the JTextArea
printDB.setText(dbb.toString());
add(printDB);
Screenshot of spacing issues:
Screenshot
Any Ideas on what might be causing this? The spacing seems to be linear as well (1space, 2spaces, 3spaces...)
Link to full project if needed (Sorry for bad code in general lol i'm just beginning): Full Code
Sorry if linear isn't the right word btw I couldn't think of another way to describe it
Code:
import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import java.util.*;
import java.util.Vector.*;
import javax.swing.*;
public class Database extends JFrame implements ActionListener, EventListener {
// Database
Vector<String> db = new Vector<String>();
// Main Menu Buttons:
JButton addStudent = new JButton("Add Student");
JButton deleteStudent = new JButton("Delete Button");
JButton deleteAll = new JButton("Delete All Students");
JButton printAll = new JButton("Print Database");
JTextArea welcome = new JTextArea("Welcome!");
// Add Student Menu:
JTextField student = new JTextField();
JButton submit = new JButton("Add Student");
// Print Students
JTextArea printDB = new JTextArea();
JButton returnMenu = new JButton("Return to Menu");
public Database() {
super("DatabaseGUI");
setSize(800, 600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(null);
setResizable(false);
welcome.setBackground(this.getForeground());
add(welcome);
welcome.setSize(60, 15);
welcome.setLocation(386, 300);
add(addStudent);
addStudent.setSize(150, 50);
addStudent.setLocation(25, 100);
add(deleteStudent);
deleteStudent.setSize(150, 50);
deleteStudent.setLocation(625, 100);
add(deleteAll);
deleteAll.setLocation(225, 100);
deleteAll.setSize(150, 50);
add(printAll);
printAll.setLocation(425, 100);
printAll.setSize(150, 50);
addStudent.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
welcome.setVisible(false);
addStudent.setVisible(false);
deleteStudent.setVisible(false);
deleteAll.setVisible(false);
printAll.setVisible(false);
add(student);
add(submit);
submit.setVisible(true);
submit.setSize(150, 30);
submit.setLocation(425, 250);
student.setVisible(true);
student.setSize(150, 30);
student.setLocation(275, 250);
submit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String newStudent = student.getText();
db.addElement(newStudent);
student.setText(null);
student.setVisible(false);
submit.setVisible(false);
welcome.setVisible(true);
addStudent.setVisible(true);
deleteStudent.setVisible(true);
deleteAll.setVisible(true);
printAll.setVisible(true);
}
});
}
});
printAll.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
welcome.setVisible(false);
addStudent.setVisible(false);
deleteStudent.setVisible(false);
deleteAll.setVisible(false);
printAll.setVisible(false);
StringBuffer dbb = new StringBuffer();
for (int i = 0; i < db.size(); i++) {
dbb.append(db.get(i) + '\n');
}
printDB.setText(dbb.toString());
add(printDB);
printDB.setSize(300, 400);
printDB.setEditable(false);
printDB.setLocation(100, 100);
printDB.setVisible(true);
add(returnMenu);
returnMenu.setVisible(true);
returnMenu.setSize(200, 30);
returnMenu.setLocation(500, 400);
returnMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
returnMenu.setVisible(false);
printDB.setVisible(false);
welcome.setVisible(true);
addStudent.setVisible(true);
deleteStudent.setVisible(true);
deleteAll.setVisible(true);
printAll.setVisible(true);
}
});
}
});
setVisible(true);
}
public static void main(String[] args) {
Database student = new Database();
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}
You're adding an ActionListener to the submit button repeatedly within the addStudent ActionListener, meaning as addStudent is pressed, more and more ActionListeners will be added to submit and this is not what you want.
Suggestions:
Add an ActionListener just once to your JButtons and not within other event listeners which may be called multiple times. Consider adding all ActionListeners within your class constructor.
Side recs:
Don't use absolute positioning and null layouts. While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.
Learn how to use and then use CardLayout to allow you to cleanly and easily swap your views.
For example,
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class Database2 extends JPanel {
// constants for the cards
public static final String WELCOME = "welcome";
public static final String ADD_STUDENT = "add student";
public static final String DISPLAY_DATA = "display data";
private JTextArea displayTextArea = new JTextArea(15, 20);
private JTextField addStudentField = new JTextField(10);
private CardLayout cardLayout = new CardLayout();
private List<String> db = new ArrayList<>();
public Database2() {
// prepare JTextArea
displayTextArea.setWrapStyleWord(true);
displayTextArea.setLineWrap(true);
displayTextArea.setFocusable(false);
// set layout as CardLayout and add all JPanels with constants
setLayout(cardLayout);
add(createWelcomePanel(), WELCOME);
add(createAddStudentPanel(), ADD_STUDENT);
add(createDisplayDataPanel(), DISPLAY_DATA);
}
private JPanel createWelcomePanel() {
ShowStudentPanelAction showStudentAction = new ShowStudentPanelAction("Add Student");
DisplayDataAction displayDataAction = new DisplayDataAction("Display Data");
JButton addStudentButton = new JButton(showStudentAction);
JButton displayDataButton = new JButton(displayDataAction);
JPanel topPanel = new JPanel(new GridLayout(1, 0, 5, 0));
topPanel.add(addStudentButton);
topPanel.add(displayDataButton);
topPanel.add(new JButton(new ExitAction("Exit", KeyEvent.VK_X)));
JLabel welcomeLabel = new JLabel("Welcome", SwingConstants.CENTER);
// make JLabel text bigger
welcomeLabel.setFont(welcomeLabel.getFont().deriveFont(Font.BOLD, 42f));
// and give it a border 30 points wide
int ebGap = 30;
welcomeLabel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap,
ebGap, ebGap));
JPanel welcomePanel = new JPanel(new BorderLayout());
ebGap = 4;
welcomePanel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
welcomePanel.add(topPanel, BorderLayout.PAGE_START);
welcomePanel.add(welcomeLabel, BorderLayout.CENTER);
return welcomePanel;
}
private JPanel createAddStudentPanel() {
AddStudentAction addStudentAction = new AddStudentAction("Add Student");
addStudentField.setAction(addStudentAction);
JPanel addStudentPanel = new JPanel();
addStudentPanel.add(addStudentField);
addStudentPanel.add(new JButton(addStudentAction));
return addStudentPanel;
}
private JPanel createDisplayDataPanel() {
JPanel displayDataPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(displayTextArea);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
displayDataPanel.add(scrollPane);
displayDataPanel.add(new JButton(new ReturnToWelcomeAction("Return")));
return displayDataPanel;
}
private class ShowStudentPanelAction extends AbstractAction {
public ShowStudentPanelAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.show(Database2.this, ADD_STUDENT);
addStudentField.requestFocusInWindow();
addStudentField.selectAll();
}
}
private class DisplayDataAction extends AbstractAction {
public DisplayDataAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
StringBuilder sb = new StringBuilder();
for (String studentName : db) {
sb.append(studentName + "\n");
}
displayTextArea.setText(sb.toString());
cardLayout.show(Database2.this, DISPLAY_DATA);
}
}
private class AddStudentAction extends AbstractAction {
public AddStudentAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
String studentText = addStudentField.getText();
db.add(studentText);
cardLayout.show(Database2.this, WELCOME);
}
}
private class ReturnToWelcomeAction extends AbstractAction {
public ReturnToWelcomeAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.show(Database2.this, WELCOME);
}
}
private class ExitAction extends AbstractAction {
public ExitAction(String name, int mnemonic) {
super(name);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
Window window = SwingUtilities.getWindowAncestor(Database2.this);
if (window != null) {
window.dispose();
}
}
}
private static void createAndShowGui() {
Database2 mainPanel = new Database2();
JFrame frame = new JFrame("Database2");
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();
}
});
}
}
I have created 2 classes that are working together to show pictures by clicking different buttons. In my EventEvent class I tried to make it so that when you press the "Picture 1" button, the variable ImageIcon xpic gets the value of ImageIcon vpic (which holds an image), after xpic has the same value as vpic my frame is supposed to somehow refresh so that xpic's new value applies and gets then shows the picture.
Why doesn't my image show up even though the button press repaints the JPanel the image is in?
Main class:
import java.awt.*;
import javax.swing.*;
public class EventMain extends JFrame{
EventEvent obje = new EventEvent(this);
// Build Buttons
JButton picB1;
JButton picB2;
JButton picB3;
JButton picB4;
JButton picB5;
//Build Panels
JPanel row0;
//Build Pictures
ImageIcon xpic;
ImageIcon vpic;
public EventMain(){
super("Buttons");
setLookAndFeel();
setSize(470, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GridLayout layout1 = new GridLayout(3,4);
setLayout(layout1);
picB1 = new JButton("Picture 1");
picB2 = new JButton("Picture 2");
picB3 = new JButton("Picture 3");
picB4 = new JButton("Picture 4");
picB5 = new JButton("Picture 5");
vpic = new ImageIcon(getClass().getResource("Images/vanessa.png"));
// Set up Row 0
row0 = new JPanel();
JLabel statement = new JLabel("Choose a picture: ", JLabel.LEFT);
JLabel picture = new JLabel(xpic);
// Set up Row 1
JPanel row1 = new JPanel();
// Set up Row 2
JPanel row2 = new JPanel();
//Listeners
picB1.addActionListener(obje);
FlowLayout grid0 = new FlowLayout (FlowLayout.CENTER);
row0.setLayout(grid0);
row0.add(statement);
row0.add(picture);
add(row0);
FlowLayout grid1 = new FlowLayout(FlowLayout.CENTER);
row1.setLayout(grid1);
row1.add(picB1);
row1.add(picB2);
add(row1);
FlowLayout grid2 = new FlowLayout(FlowLayout.CENTER);
row2.setLayout(grid2);
row2.add(picB3);
row2.add(picB4);
row2.add(picB5);
add(row2);
setVisible(true);
}
private void setLookAndFeel() {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.NimbusLookAndFeel");
} catch (Exception exc) {
}
}
public static void main(String[] args) {
EventMain con = new EventMain();
}
}
Class containing events:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class EventEvent implements ActionListener {
EventMain gui;
public EventEvent(EventMain in){
gui = in;
}
public void actionPerformed(ActionEvent event) {
String command = event.getActionCommand();
if (command.equals("Picture 1")){
gui.xpic = gui.vpic;
gui.row0.repaint();
}
}
}
You're confusing variables with objects. Just because you change the object associated with the xpic variable, don't assume that this will change the object (the Icon) held by the JLabel. There is no magic in Java, and changing the object that a variable refers to will have no effect on the prior object.
In other words, this:
gui.xpic = gui.vpic;
gui.row0.repaint();
will have no effect on the icon that the picture JLabel is displaying
To swap icons, you must call setIcon(...) on the JLabel. Period. You will need to make the picture JLabel a field, not a local variable, and give your GUI class a public method that allows outside classes to change the state of the JLabel's icon.
Also, you should not manipulate object fields directly. Instead give your gui public methods that your event object can call.
Edit
For example:
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyGui extends JPanel {
public static final String IMAGE_PATH = "https://duke.kenai.com/cards/.Midsize/CardFaces.png.png";
private static final int ROWS = 4;
private static final int COLS = 13;
private BufferedImage largeImg;
private List<ImageIcon> iconList = new ArrayList<>();
private JLabel pictureLabel = new JLabel();
private JButton swapPictureBtn = new JButton(new SwapPictureAction(this, "Swap Picture"));
private int iconIndex = 0;
public MyGui() throws IOException {
add(pictureLabel);
add(swapPictureBtn);
URL imgUrl = new URL(IMAGE_PATH);
largeImg = ImageIO.read(imgUrl);
for (int i = 0; i < ROWS; i++) {
for (int j = 0; j < COLS; j++) {
int x = (j * largeImg.getWidth()) / COLS;
int y = (i * largeImg.getHeight()) / ROWS;
int w = largeImg.getWidth() / COLS;
int h = largeImg.getHeight() / ROWS;
iconList.add(new ImageIcon(largeImg.getSubimage(x, y, w, h)));
}
}
pictureLabel.setIcon(iconList.get(iconIndex));
}
public void swapPicture() {
iconIndex++;
iconIndex %= iconList.size();
pictureLabel.setIcon(iconList.get(iconIndex));
}
private static void createAndShowGui() {
MyGui mainPanel;
try {
mainPanel = new MyGui();
JFrame frame = new JFrame("MyGui");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
#SuppressWarnings("serial")
class SwapPictureAction extends AbstractAction {
private MyGui myGui;
public SwapPictureAction(MyGui myGui, String name) {
super(name);
this.myGui = myGui;
}
#Override
public void actionPerformed(ActionEvent e) {
myGui.swapPicture();
}
}
See the createAction() method below and how it creates an AbstractAction. See also the tutorial related to using actions with buttons. http://docs.oracle.com/javase/tutorial/uiswing/misc/action.html
import javax.swing.*;
import javax.swing.plaf.nimbus.NimbusLookAndFeel;
import java.awt.*;
import java.awt.event.ActionEvent;
public class EventMain {
private static final ImageIcon PICTURE_1 = new ImageIcon(EventMain.class.getResource("images/v1.png"));
private static final ImageIcon PICTURE_2 = new ImageIcon(EventMain.class.getResource("images/v2.png"));
private JFrame frame;
EventMain create() {
setLookAndFeel();
frame = createFrame();
frame.getContentPane().add(createContent());
return this;
}
void show() {
frame.setSize(470, 300);
frame.setVisible(true);
}
private JFrame createFrame() {
JFrame frame = new JFrame("Buttons");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
return frame;
}
private Component createContent() {
final JLabel picture = new JLabel();
JButton picB1 = new JButton(createAction("Picture 1", picture, PICTURE_1));
JButton picB2 = new JButton(createAction("Picture 2", picture, PICTURE_2));
JButton picB3 = new JButton(createAction("Picture 3", picture, PICTURE_1));
JButton picB4 = new JButton(createAction("Picture 4", picture, PICTURE_2));
JButton picB5 = new JButton(createAction("Picture 5", picture, PICTURE_1));
JLabel statement = new JLabel("Choose a picture: ", JLabel.LEFT);
// Create rows 1, 2, 3
JPanel panel = new JPanel(new GridLayout(3, 4));
panel.add(createRow(statement, picture));
panel.add(createRow(picB1, picB2));
panel.add(createRow(picB3, picB4, picB5));
return panel;
}
/**
* Create an action for the button. http://docs.oracle.com/javase/tutorial/uiswing/misc/action.html
*/
private Action createAction(String label, final JLabel picture, final Icon icon) {
AbstractAction action = new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
picture.setIcon(icon);
}
};
action.putValue(Action.NAME, label);
return action;
}
private Component createRow(Component... componentsToAdd) {
JPanel row = new JPanel(new FlowLayout(FlowLayout.CENTER));
for (Component component : componentsToAdd) {
row.add(component);
}
return row;
}
private void setLookAndFeel() {
try {
UIManager.setLookAndFeel(new NimbusLookAndFeel());
} catch (UnsupportedLookAndFeelException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new EventMain().create().show();
}
});
}
}
I have a JFrame which contains 2 JPanel subclass and 2 JLabel in BorderLayout. One of the JPanel contains JButtons and the other is used for displaying graphics. The JLabels are in north and south, the button JPanel in the west and the display JPanel in center.
The display JPanel requires constant refresh, so i invoke its repaint() method via the action event generated by swing timer. I also override its paintComponent() method to do my drawings.
Instead of displaying what i have drawn, the "content of the JFrame" is being drawn onto the display JPanel. I am aware that i can simply "clear" the display JPanel by using g.fillRect() or super.paintComponent() before doing my drawings.
I am just curious why this happens.
i'm using jdk 1.6u27. below is my code:
package test;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class Main {
public static void main(String[] args) {
Simulation sim = new Simulation();
}
}
class Simulation extends JFrame {
public JLabel state;
private JLabel id;
private ButtonPanel control;
private Display display;
public Simulation() {
id = new JLabel("Test");
state = new JLabel("Test");
control = new ButtonPanel();
display = new Display(this);
this.setLayout(new BorderLayout());
this.add(id, BorderLayout.NORTH);
this.add(control, BorderLayout.WEST);
this.add(display, BorderLayout.CENTER);
this.add(state, BorderLayout.SOUTH);
this.setSize(500, 600);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public ButtonPanel getControl() {
return this.control;
}
}
class ButtonPanel extends JPanel implements ActionListener {
public JButton b[] = new JButton[8];
public boolean bp[] = new boolean[8];
public ButtonPanel() {
this.setLayout(new GridLayout(8, 1));
for (int i = 0; i < b.length; i++) {
b[i] = new JButton(""+i);
b[i].addActionListener(this);
bp[i] = false;
this.add(b[i]);
}
}
public void actionPerformed(ActionEvent e) {
//do something
}
}
class Display extends JPanel implements ActionListener {
private Timer tm;
private int yco;
private Simulation sim;
public Display(Simulation sim) {
tm = new Timer(100, this);
tm.start();
yco = 0;
this.sim = sim;
}
#Override
public void paintComponent(Graphics g) {
//draw something
g.drawLine(0, yco, 100, 100);
}
public void actionPerformed(ActionEvent e) {
yco ++;
this.repaint();
}
}
Without super.paintComponent(g), the result depends on your platform's default for the opacity property of the JPanel UI delegate, PanelUI. Mine happens to be true, but you can experiment on your platform, as suggested below.
Addendum: "If you do not honor the opaque property you will likely see visual artifacts."—paintComponent(). The artifact you observe will vary by platform, but it is not atypical. In effect, you are breaking the promise to draw every pixel, and you see whatever is left over in some buffer.
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
public class Main {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
Simulation sim = new Simulation();
}
});
}
}
class Simulation extends JFrame {
public JCheckBox state;
private JLabel id;
private ButtonPanel control;
private Display display;
public Simulation() {
id = new JLabel("Test");
state = new JCheckBox("Opaque");
control = new ButtonPanel();
display = new Display(this);
this.setLayout(new BorderLayout());
this.add(id, BorderLayout.NORTH);
this.add(control, BorderLayout.WEST);
this.add(display, BorderLayout.CENTER);
this.add(state, BorderLayout.SOUTH);
state.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
display.setOpaque(e.getStateChange() == ItemEvent.SELECTED);
}
});
state.setSelected(true);
this.pack();
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public ButtonPanel getControl() {
return this.control;
}
}
class ButtonPanel extends JPanel {
private static final int N = 8;
private List<JToggleButton> list = new ArrayList<JToggleButton>(N);
public ButtonPanel() {
this.setLayout(new GridLayout(0, 1));
for (int i = 0; i < N; i++) {
final JToggleButton b = new JToggleButton(String.valueOf(i));
b.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
//System.out.println(b.isSelected());
}
});
list.add(b);
this.add(b);
}
}
}
class Display extends JPanel {
private Simulation sim;
private Timer tm;
private int yco;
public Display(Simulation sim) {
this.setPreferredSize(new Dimension(320, 320));
this.setOpaque(true);
this.sim = sim;
tm = new Timer(100, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
yco++;
repaint();
}
});
tm.start();
}
#Override
public void paintComponent(Graphics g) {
//super.paintComponent(g);
g.drawLine(0, yco, getWidth() / 2, getHeight() / 2);
}
}
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.