Deck.java

/*
 * Copyright (C) 2012 Google Inc.  All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.tv.blackjack.service;

/**
 * This class represents an ordinary deck of 52 playing cards. The deck can be
 * shuffled, and cards can be dealt from the deck.
 */
public class Deck {

    private Card[] deck; // An array of 52 Cards, representing the deck.
    private int cardsUsed; // How many cards have been dealt from the deck.

    public Deck() {
        // Create an unshuffled deck of cards.
        deck = new Card[52];
        int cardCt = 0; // How many cards have been created so far.
        for (int suit = 0; suit <= 3; suit++) {
            for (int value = 1; value <= 13; value++) {
                deck[cardCt] = new Card(value, suit);
                cardCt++;
            }
        }
        cardsUsed = 0;
    }

    public void shuffle() {
        // Put all the used cards back into the deck, and shuffle it into
        // a random order.
        for (int i = 51; i > 0; i--) {
            int rand = (int) (Math.random() * (i + 1));
            Card temp = deck[i];
            deck[i] = deck[rand];
            deck[rand] = temp;
        }
        cardsUsed = 0;
    }

    public int cardsLeft() {
        // As cards are dealt from the deck, the number of cards left
        // decreases. This function returns the number of cards that
        // are still left in the deck.
        return 52 - cardsUsed;
    }

    public Card dealCard() {
        // Deals one card from the deck and returns it.
        if (cardsUsed == 52)
            shuffle();
        cardsUsed++;
        return deck[cardsUsed - 1];
    }
}