Java applet – HighLow Game - MYCPLUS - C and C++ Programming Resources

This applet is a simple card game. The user sees a card and tries to predict whether the next card will be higher or lower. Aces are the lowest-valued cards. If the user makes
three correct predictions, the user wins. If not, the user loses.

This version of the game uses images of the cards, stored in a file smallcards.gif. Each card is 40 pixels wide and 60 pixels high. Other than that, the applet is the same as the original HighLowGUI.

The programming of this applet assumes that the applet is set up to be about 316 pixels wide and about 150 pixels high.That width is just big enough to show 4 cards, with spacing and borders. The height is probably a little bigger than necessary, to allow for variations in the size of buttons from one platform to another.

This file defines two class files, the applet class HighLowGUI2.class and a nested class HighLowGUI2$HighLowCanvas.class. Both files are necessary to use the applet.
[sourcecode language=”java”]/*******************************************************
* MYCPLUS Sample Code – https://www.mycplus.com *
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* This code is made available as a service to our *
* visitors and is provided strictly for the *
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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class HighLowGUI2 extends JApplet {

Image cardImages; // This will be an image that contains pictures
// of all the playing cards. It is loaded in the
// init method of the applet and is used in the
// drawCard method in nested class HighLowCanvas.

public void init() {

// The init() method loads the card image and lays out the applet.
// A HighLowCanvas occupies the CENTER position of the layout.
// On the bottom is a panel that holds three buttons. The
// HighLowCanvas object listens for ActionEvents from the
// buttons and does all the real work of the program.

cardImages = getImage( getCodeBase(), “smallcards.gif” );

setBackground( new Color(130,50,40) );

HighLowCanvas board = new HighLowCanvas();
getContentPane().add(board, BorderLayout.CENTER);

JPanel buttonPanel = new JPanel();
buttonPanel.setBackground( new Color(220,200,180) );
getContentPane().add(buttonPanel, BorderLayout.SOUTH);

JButton higher = new JButton( “Higher” );
higher.addActionListener(board);
buttonPanel.add(higher);

JButton lower = new JButton( “Lower” );
lower.addActionListener(board);
buttonPanel.add(lower);

JButton newGame = new JButton( “New Game” );
newGame.addActionListener(board);
buttonPanel.add(newGame);

} // end init()

public Insets getInsets() {
// Specify how much space to leave between the edges of
// the applet and the components it contains. The background
// color shows through in this border.
return new Insets(3,3,3,3);
}

class HighLowCanvas extends JPanel implements ActionListener {

// A nested class that displays the cards and does all the work
// of keeping track of the state and responding to user events.

Deck deck; // A deck of cards to be used in the game.
Hand hand; // The cards that have been dealt.
String message; // A message drawn on the canvas, which changes
// to reflect the state of the game.

boolean gameInProgress; // Set to true when a game begins and to false
// when the game ends.

Font bigFont; // Font that will be used to display the message.
Font smallFont; // Font that will be used to draw the cards.

HighLowCanvas() {
// Constructor. Creates fonts, sets the foreground and
// background colors, and starts the first game.
setBackground( new Color(0,120,0) );
setForeground( Color.green );
smallFont = new Font(“SansSerif”, Font.PLAIN, 12);
bigFont = new Font(“Serif”, Font.BOLD, 14);
doNewGame();
} // end constructor

public void actionPerformed(ActionEvent evt) {
// Respond when the user clicks on a button by calling
// the appropriate procedure. Note that the canvas is
// registered as a listener in applet’s init() method.
String command = evt.getActionCommand();
if (command.equals(“Higher”))
doHigher();
else if (command.equals(“Lower”))
doLower();
else if (command.equals(“New Game”))
doNewGame();
} // end actionPerformed()

void doHigher() {
// Called by actionPerformmed() when user clicks “Higher” button.
// Check the user’s prediction. Game ends if user guessed
// wrong or if the user has made three correct predictions.
if (gameInProgress == false) {
// If the game has ended, it was an error to click “Higher”,
// So set up an error message and abort processing.
message = “Click \”New Game\” first!”;
repaint();
return;
}
hand.addCard( deck.dealCard() ); // Deal a card to the hand.
int cardCt = hand.getCardCount();
Card thisCard = hand.getCard( cardCt – 1 ); // Card just dealt.
Card prevCard = hand.getCard( cardCt – 2 ); // The previous card.
if ( thisCard.getValue() < prevCard.getValue() ) { gameInProgress = false; message = "Too bad! You lose."; } else if ( thisCard.getValue() == prevCard.getValue() ) { gameInProgress = false; message = "Too bad, you lose on ties!"; } else if ( cardCt == 4) { gameInProgress = false; message = "OK! You win!"; } else { message = "Right! Try for " + cardCt + "."; } repaint(); } // end doHigher()void doLower() { // Called by actionPerformmed() when user clicks "Lower" button. // Check the user's prediction. Game ends if user guessed // wrong or if the user has made three correct predictions. if (gameInProgress == false) { // If the game has ended, it was an error to click "Lower", // So set up an error message and abort processing. message = "Click \"New Game\" first!"; repaint(); return; } hand.addCard( deck.dealCard() ); // Deal a card to the hand. int cardCt = hand.getCardCount(); Card thisCard = hand.getCard( cardCt - 1 ); // Card just dealt. Card prevCard = hand.getCard( cardCt - 2 ); // The previous card. if ( thisCard.getValue() > prevCard.getValue() ) {
gameInProgress = false;
message = “Too bad! You lose.”;
}
else if ( thisCard.getValue() == prevCard.getValue() ) {
gameInProgress = false;
message = “Too bad, you lose on ties.”;
}
else if ( cardCt == 4) {
gameInProgress = false;
message = “Great! You win!”;
}
else {
message = “Right! Try for ” + cardCt + “.”;
}
repaint();
} // end doLower()

void doNewGame() {
// Called by the constructor, and called by actionPerformed() if
// the use clicks the “New Game” button. Start a new game.
if (gameInProgress) {
// If the current game is not over, it is an error to try
// to start a new game.
message = “Finish the game first!”;
repaint();
return;
}
deck = new Deck(); // Create the deck and hand to use for this game.
hand = new Hand();
deck.shuffle();
hand.addCard( deck.dealCard() ); // Deal the first card into the hand.
message = “Is the next card higher or lower?”;
gameInProgress = true;
repaint();
} // end doNewGame()

public void paintComponent(Graphics g) {
// This method draws the message at the bottom of the
// canvas, and it draws all of the dealt cards spread out
// across the canvas. If the game is in progress, an
// extra card is dealt representing the card to be dealt next.
super.paintComponent(g);
g.setFont(bigFont);
g.drawString(message,10,getSize().height-10);
g.setFont(smallFont);
int cardCt = hand.getCardCount();
for (int i = 0; i < cardCt; i++) drawCard(g, hand.getCard(i), 30 + i * 70, 10); if (gameInProgress) drawCard(g, null, 30 + cardCt * 70, 10); } // end paintComponent()void drawCard(Graphics g, Card card, int x, int y) { // Draws a card as a 40 by 60 rectangle with // upper left corner at (x,y). The card is drawn // in the graphics context g. If card is null, then // a face-down card is drawn. The cards are taken // from an image file, smallcards.gif. if (card == null) { // Draw a face-down card g.setColor(Color.blue); g.fillRect(x,y,40,60); g.setColor(Color.white); g.drawRect(x+3,y+3,33,53); g.drawRect(x+4,y+4,31,51); } else { int row = 0; switch (card.getSuit()) { case Card.CLUBS: row = 0; break; case Card.HEARTS: row = 1; break; case Card.SPADES: row = 2; break; case Card.DIAMONDS: row = 3; break; } int sx, sy; // coords of upper left corner in the source image. sx = 40*(card.getValue() - 1); sy = 60*row; g.drawImage(cardImages, x, y, x+40, y+60, sx, sy, sx+40, sy+60, this); } }} // end nested class HighLowCanvas} // end class HighLowGUI [/sourcecode]