Before asking this question, I have done my research and tried several things, but nothing seems to work.
Below I included the simplified version of my code.
I have a program that basically moves a chess piece on a chess table. The table is implemented using class JTable. What I am trying to accomplish is to create a couple seconds of delay between each move.
The table is a class that extends JTable. The constructor creates a chess piece on the table.
public Table (int rows, int columns)
{
ChessPiece piece = new ChessPiece();
}
The table has a menu with an option to move the chess piece. This option will move the chess piece forward by calling the method moveForward().
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Menu");
JMenuItem item = new JMenuItem("Move Chess Piece");
menu.add(item);
menuBar.add(menu);
item.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
piece.moveForward();
}
});
setJMenuBar(menuBar);
To start the program, I do the following:
Table table = new Table();
javax.swing.SwingUtilities.invokeLater( new Runnable()
{ public void run()
{
table.setVisible(true);
}
} );
So in order to create a couple of seconds of delay, I first tried the following:
public void moveForward()
{
// Sleep for a couple of seconds before moving.
try { Thread.sleep(SLEEP_TIME);}
catch(InterruptedException ex) { Thread.currentThread().interrupt(); }
.....<code to move the chess piece forward>....
}
That causes the entire GUI to freeze when I click on the "Move Chess Piece" option. It is not clear to me why the program to behaves so. If someone can explain in plain English to me, I would appreciate!
I looked around and was advised that I should use java.swing.Timer. So I changed my code to following:
public void moveForward()
{
ActionListener taskPerformer = new ActionListener() {
public void actionPerformed(ActionEvent evt)
{
System.out.println("Hello!");
}
};
javax.swing.Timer t = new javax.swing.Timer(10000, taskPerformer);
t.setRepeats(false);
t.start();
.....<code to move the chess piece forward>....
}
The GUI no longer freezes when I click on the Move Chess Piece option, but it does nothing. There is no 10 seconds delay that I expected.
Please advise what is wrong here!
Thanks in advance.
This seems to work perfectly, to move the pawns one by one from the starting position to meeting in a front at the center of the board.
For better help sooner, post a Minimal Complete Tested and Readable Example (like this code) that behaves differently. This MCTRE is based on code seen in Making a robust, resizable Swing Chess GUI.
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.border.*;
import java.net.URL;
import javax.imageio.ImageIO;
public class AnimatedChessGui {
private final JPanel gui = new JPanel(new BorderLayout(3, 3));
private JButton[][] chessBoardSquares = new JButton[8][8];
private Image[][] chessPieceImages = new Image[2][6];
private JPanel chessBoard;
private final JLabel message = new JLabel(
"Chess Champ is ready to play!");
private static final String COLS = "ABCDEFGH";
public static final int QUEEN = 0, KING = 1,
ROOK = 2, KNIGHT = 3, BISHOP = 4, PAWN = 5;
public static final int[] STARTING_ROW = {
ROOK, KNIGHT, BISHOP, KING, QUEEN, BISHOP, KNIGHT, ROOK
};
public static final int BLACK = 0, WHITE = 1;
private Timer timer;
AnimatedChessGui() {
initializeGui();
}
public void animateChessPieces() {
timer = new Timer(1000, new ActionListener() {
int count = 0;
@Override
public void actionPerformed(ActionEvent e) {
if (count % 2 == 0) {
chessBoardSquares[count/2][1].setIcon(null);
chessBoardSquares[count/2][3].setIcon(new ImageIcon(
chessPieceImages[BLACK][PAWN]));
} else {
chessBoardSquares[count/2][6].setIcon(null);
chessBoardSquares[count/2][4].setIcon(new ImageIcon(
chessPieceImages[WHITE][PAWN]));
}
count++;
if (count == 16) {
timer.stop();
}
}
});
timer.start();
}
public final void initializeGui() {
// create the images for the chess pieces
createImages();
// set up the main GUI
gui.setBorder(new EmptyBorder(5, 5, 5, 5));
JToolBar tools = new JToolBar();
tools.setFloatable(false);
gui.add(tools, BorderLayout.PAGE_START);
Action newGameAction = new AbstractAction("New") {
@Override
public void actionPerformed(ActionEvent e) {
setupNewGame();
}
};
tools.add(newGameAction);
tools.add(new JButton("Save")); // TODO - add functionality!
tools.add(new JButton("Restore")); // TODO - add functionality!
tools.addSeparator();
tools.add(new JButton("Resign")); // TODO - add functionality!
tools.addSeparator();
tools.add(message);
gui.add(new JLabel("?"), BorderLayout.LINE_START);
chessBoard = new JPanel(new GridLayout(0, 9)) {
/**
* Override the preferred size to return the largest it can, in a
* square shape. Must (must, must) be added to a GridBagLayout as
* the only component (it uses the parent as a guide to size) with
* no GridBagConstaint (so it is centered).
*/
@Override
public final Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
Dimension prefSize = null;
Component c = getParent();
if (c == null) {
prefSize = new Dimension(
(int) d.getWidth(), (int) d.getHeight());
} else if (c != null
&& c.getWidth() > d.getWidth()
&& c.getHeight() > d.getHeight()) {
prefSize = c.getSize();
} else {
prefSize = d;
}
int w = (int) prefSize.getWidth();
int h = (int) prefSize.getHeight();
// the smaller of the two sizes
int s = (w > h ? h : w);
return new Dimension(s, s);
}
};
chessBoard.setBorder(new CompoundBorder(
new EmptyBorder(8, 8, 8, 8),
new LineBorder(Color.BLACK)));
// Set the BG to be ochre
Color ochre = new Color(204, 119, 34);
chessBoard.setBackground(ochre);
JPanel boardConstrain = new JPanel(new GridBagLayout());
boardConstrain.setBackground(ochre);
boardConstrain.add(chessBoard);
gui.add(boardConstrain);
// create the chess board squares
Insets buttonMargin = new Insets(0, 0, 0, 0);
for (int ii = 0; ii < chessBoardSquares.length; ii++) {
for (int jj = 0; jj < chessBoardSquares[ii].length; jj++) {
JButton b = new JButton();
b.setMargin(buttonMargin);
// our chess pieces are 64x64 px in size, so we'll
// 'fill this in' using a transparent icon..
ImageIcon icon = new ImageIcon(
new BufferedImage(64, 64, BufferedImage.TYPE_INT_ARGB));
b.setIcon(icon);
if ((jj % 2 == 1 && ii % 2 == 1)
//) {
|| (jj % 2 == 0 && ii % 2 == 0)) {
b.setBackground(Color.WHITE);
} else {
b.setBackground(Color.BLACK);
}
chessBoardSquares[jj][ii] = b;
}
}
/*
* fill the chess board
*/
chessBoard.add(new JLabel(""));
// fill the top row
for (int ii = 0; ii < 8; ii++) {
chessBoard.add(
new JLabel(COLS.substring(ii, ii + 1),
SwingConstants.CENTER));
}
// fill the black non-pawn piece row
for (int ii = 0; ii < 8; ii++) {
for (int jj = 0; jj < 8; jj++) {
switch (jj) {
case 0:
chessBoard.add(new JLabel("" + (9 - (ii + 1)),
SwingConstants.CENTER));
default:
chessBoard.add(chessBoardSquares[jj][ii]);
}
}
}
}
public final JComponent getGui() {
return gui;
}
private final void createImages() {
try {
URL url = new URL("http://i.stack.imgur.com/memI0.png");
BufferedImage bi = ImageIO.read(url);
for (int ii = 0; ii < 2; ii++) {
for (int jj = 0; jj < 6; jj++) {
chessPieceImages[ii][jj] = bi.getSubimage(
jj * 64, ii * 64, 64, 64);
}
}
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
}
}
/**
* Initializes the icons of the initial chess board piece places
*/
private final void setupNewGame() {
message.setText("Make your move!");
// set up the black pieces
for (int ii = 0; ii < STARTING_ROW.length; ii++) {
chessBoardSquares[ii][0].setIcon(new ImageIcon(
chessPieceImages[BLACK][STARTING_ROW[ii]]));
}
for (int ii = 0; ii < STARTING_ROW.length; ii++) {
chessBoardSquares[ii][1].setIcon(new ImageIcon(
chessPieceImages[BLACK][PAWN]));
}
// set up the white pieces
for (int ii = 0; ii < STARTING_ROW.length; ii++) {
chessBoardSquares[ii][6].setIcon(new ImageIcon(
chessPieceImages[WHITE][PAWN]));
}
for (int ii = 0; ii < STARTING_ROW.length; ii++) {
chessBoardSquares[ii][7].setIcon(new ImageIcon(
chessPieceImages[WHITE][STARTING_ROW[ii]]));
}
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
AnimatedChessGui acg = new AnimatedChessGui();
JFrame f = new JFrame("ChessChamp");
f.add(acg.getGui());
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// ensures the minimum size is enforced.
f.setMinimumSize(f.getSize());
f.setVisible(true);
acg.setupNewGame();
acg.animateChessPieces();
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
