A simple keyboard test
/*
DEVELOPING GAME IN JAVA
Caracteristiques
Editeur : NEW RIDERS
Auteur : BRACKEEN
Parution : 09 2003
Pages : 972
Isbn : 1-59273-005-1
Reliure : Paperback
Disponibilite : Disponible a la librairie
*/
import java.awt.Color;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.lang.reflect.InvocationTargetException;
import java.util.LinkedList;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
/**
* A simple keyboard test. Displays keys pressed and released to the screen.
* Useful for debugging key input, too.
*/
public class KeyTest extends GameCore implements KeyListener {
public static void main(String[] args) {
new KeyTest().run();
}
private LinkedList messages = new LinkedList();
public void init() {
super.init();
Window window = screen.getFullScreenWindow();
// allow input of the TAB key and other keys normally
// used for focus traversal
window.setFocusTraversalKeysEnabled(false);
// register this object as a key listener for the window
window.addKeyListener(this);
addMessage("KeyInputTest. Press Escape to exit");
}
// a method from the KeyListner interface
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
// exit the program
if (keyCode == KeyEvent.VK_ESCAPE) {
stop();
} else {
addMessage("Pressed: " + KeyEvent.getKeyText(keyCode));
// make sure the key isn't processed for anything else
e.consume();
}
}
// a method from the KeyListner interface
public void keyReleased(KeyEvent e) {
int keyCode = e.getKeyCode();
addMessage("Released: " + KeyEvent.getKeyText(keyCode));
// make sure the key isn't processed for anything else
e.consume();
}
// a method from the KeyListener interface
public void keyTyped(KeyEvent e) {
// this is called after the key is released - ignore it
// make sure the key isn't processed for anything else
e.consume();
}
/**
* Add a message to the list of messages.
*/
public synchronized void addMessage(String message) {
messages.add(message);
if (messages.size() >= screen.getHeight() / FONT_SIZE) {
messages.remove(0);
}
}
/**
* Draw the list of messages
*/
public synchronized void draw(Graphics2D g) {
Window window = screen.getFullScreenWindow();
g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
// draw background
g.setColor(window.getBackground());
g.fillRect(0, 0, screen.getWidth(), screen.getHeight());
// draw messages
g.setColor(window.getForeground());
int y = FONT_SIZE;
for (int i = 0; i < messages.size(); i++) {
g.drawString((String) messages.get(i), 5, y);
y += FONT_SIZE;
}
}
}
/**
* Simple abstract class used for testing. Subclasses should implement the
* draw() method.
*/
abstract class GameCore {
protected static final int FONT_SIZE = 24;
private static final DisplayMode POSSIBLE_MODES[] = {
new DisplayMode(800, 600, 32, 0), new DisplayMode(800, 600, 24, 0),
new DisplayMode(800, 600, 16, 0), new DisplayMode(640, 480, 32, 0),
new DisplayMode(640, 480, 24, 0), new DisplayMode(640, 480, 16, 0) };
private boolean isRunning;
protected ScreenManager screen;
/**
* Signals the game loop that it's time to quit
*/
public void stop() {
isRunning = false;
}
/**
* Calls init() and gameLoop()
*/
public void run() {
try {
init();
gameLoop();
} finally {
screen.restoreScreen();
}
}
/**
* Sets full screen mode and initiates and objects.
*/
public void init() {
screen = new ScreenManager();
DisplayMode displayMode = screen
.findFirstCompatibleMode(POSSIBLE_MODES);
screen.setFullScreen(displayMode);
Window window = screen.getFullScreenWindow();
window.setFont(new Font("Dialog", Font.PLAIN, FONT_SIZE));
window.setBackground(Color.blue);
window.setForeground(Color.white);
isRunning = true;
}
public Image loadImage(String fileName) {
return new ImageIcon(fileName).getImage();
}
/**
* Runs through the game loop until stop() is called.
*/
public void gameLoop() {
long startTime = System.currentTimeMillis();
long currTime = startTime;
while (isRunning) {
long elapsedTime = System.currentTimeMillis() - currTime;
currTime += elapsedTime;
// update
update(elapsedTime);
// draw the screen
Graphics2D g = screen.getGraphics();
draw(g);
g.dispose();
screen.update();
// take a nap
try {
Thread.sleep(20);
} catch (InterruptedException ex) {
}
}
}
/**
* Updates the state of the game/animation based on the amount of elapsed
* time that has passed.
*/
public void update(long elapsedTime) {
// do nothing
}
/**
* Draws to the screen. Subclasses must override this method.
*/
public abstract void draw(Graphics2D g);
}
/**
* The ScreenManager class manages initializing and displaying full screen
* graphics modes.
*/
class ScreenManager {
private GraphicsDevice device;
/**
* Creates a new ScreenManager object.
*/
public ScreenManager() {
GraphicsEnvironment environment = GraphicsEnvironment
.getLocalGraphicsEnvironment();
device = environment.getDefaultScreenDevice();
}
/**
* Returns a list of compatible display modes for the default device on the
* system.
*/
public DisplayMode[] getCompatibleDisplayModes() {
return device.getDisplayModes();
}
/**
* Returns the first compatible mode in a list of modes. Returns null if no
* modes are compatible.
*/
public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
DisplayMode goodModes[] = device.getDisplayModes();
for (int i = 0; i < modes.length; i++) {
for (int j = 0; j < goodModes.length; j++) {
if (displayModesMatch(modes[i], goodModes[j])) {
return modes[i];
}
}
}
return null;
}
/**
* Returns the current display mode.
*/
public DisplayMode getCurrentDisplayMode() {
return device.getDisplayMode();
}
/**
* Determines if two display modes "match". Two display modes match if they
* have the same resolution, bit depth, and refresh rate. The bit depth is
* ignored if one of the modes has a bit depth of
* DisplayMode.BIT_DEPTH_MULTI. Likewise, the refresh rate is ignored if one
* of the modes has a refresh rate of DisplayMode.REFRESH_RATE_UNKNOWN.
*/
public boolean displayModesMatch(DisplayMode mode1, DisplayMode mode2)
{
if (mode1.getWidth() != mode2.getWidth()
|| mode1.getHeight() != mode2.getHeight()) {
return false;
}
if (mode1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
&& mode2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
&& mode1.getBitDepth() != mode2.getBitDepth()) {
return false;
}
if (mode1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
&& mode2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
&& mode1.getRefreshRate() != mode2.getRefreshRate()) {
return false;
}
return true;
}
/**
* Enters full screen mode and changes the display mode. If the specified
* display mode is null or not compatible with this device, or if the
* display mode cannot be changed on this system, the current display mode
* is used.
* <p>
* The display uses a BufferStrategy with 2 buffers.
*/
public void setFullScreen(DisplayMode displayMode) {
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setUndecorated(true);
frame.setIgnoreRepaint(true);
frame.setResizable(false);
device.setFullScreenWindow(frame);
if (displayMode != null && device.isDisplayChangeSupported()) {
try {
device.setDisplayMode(displayMode);
} catch (IllegalArgumentException ex) {
}
// fix for mac os x
frame.setSize(displayMode.getWidth(), displayMode.getHeight());
}
// avoid potential deadlock in 1.4.1_02
try {
EventQueue.invokeAndWait(new Runnable() {
public void run() {
frame.createBufferStrategy(2);
}
});
} catch (InterruptedException ex) {
// ignore
} catch (InvocationTargetException ex) {
// ignore
}
}
/**
* Gets the graphics context for the display. The ScreenManager uses double
* buffering, so applications must call update() to show any graphics drawn.
* <p>
* The application must dispose of the graphics object.
*/
public Graphics2D getGraphics() {
Window window = device.getFullScreenWindow();
if (window != null) {
BufferStrategy strategy = window.getBufferStrategy();
return (Graphics2D) strategy.getDrawGraphics();
} else {
return null;
}
}
/**
* Updates the display.
*/
public void update() {
Window window = device.getFullScreenWindow();
if (window != null) {
BufferStrategy strategy = window.getBufferStrategy();
if (!strategy.contentsLost()) {
strategy.show();
}
}
// Sync the display on some systems.
// (on Linux, this fixes event queue problems)
Toolkit.getDefaultToolkit().sync();
}
/**
* Returns the window currently used in full screen mode. Returns null if
* the device is not in full screen mode.
*/
public JFrame getFullScreenWindow() {
return (JFrame) device.getFullScreenWindow();
}
/**
* Returns the width of the window currently used in full screen mode.
* Returns 0 if the device is not in full screen mode.
*/
public int getWidth() {
Window window = device.getFullScreenWindow();
if (window != null) {
return window.getWidth();
} else {
return 0;
}
}
/**
* Returns the height of the window currently used in full screen mode.
* Returns 0 if the device is not in full screen mode.
*/
public int getHeight() {
Window window = device.getFullScreenWindow();
if (window != null) {
return window.getHeight();
} else {
return 0;
}
}
/**
* Restores the screen's display mode.
*/
public void restoreScreen() {
Window window = device.getFullScreenWindow();
if (window != null) {
window.dispose();
}
device.setFullScreenWindow(null);
}
/**
* Creates an image compatible with the current display.
*/
public BufferedImage createCompatibleImage(int w, int h, int transparancy) {
Window window = device.getFullScreenWindow();
if (window != null) {
GraphicsConfiguration gc = window.getGraphicsConfiguration();
return gc.createCompatibleImage(w, h, transparancy);
}
return null;
}
}
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