player.java

这是我编写的第一个J2ME程序

/*
 * Copyright (c) 2002, 2003 Sun Microsystems, Inc. All Rights Reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * - Redistribution of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * - Redistribution in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Sun Microsystems, Inc., 'Java', 'Java'-based
 * names, or the names of contributors may be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * You acknowledge that this software is not designed, licensed or
 * intended for use in the design, construction, operation or maintenance
 * of any nuclear facility. $Id: Player.java,v 1.1 2003/05/16 00:16:01 zull Exp $
 */
package com.sun.j2me.blueprints.slugs.server;

import com.sun.j2me.blueprints.slugs.shared.*;

/**
 * This class represents a player in the game.
 * Players have an (x, y) location, an id, a
 * status, direction, a number of remaining lives,
 * shovels and jetpacks.
 */
public class Player extends Item implements PlayerActions {
    // direction
    public static final int STILL = 0;
    public static final int NORTH = 1;
    public static final int SOUTH = 2;
    public static final int WEST = 3;
    public static final int EAST = 4;
    public static final int MAX_TICKS = 15;
    private Item covered;
    private int direction;
    private int lives;
    private int jetpack_count;
    private int shovel_count;
    private int speed;
    private int fly_ticks;
    private int dig_ticks;
    private int speed_ticks;

    /**
     * Create a new instance with location
     * ('x', 'y') and ID 'id'.
     */
    public Player(int x, int y, int id) {
        super(x, y, RUN | id);

        direction = STILL;
        lives = 0;
        jetpack_count = 0;
        shovel_count = 0;
        speed = 1;
        fly_ticks = 0;
        dig_ticks = 0;
        speed_ticks = 0;
    }

    /**
     * Set the direction for this instance
     */
    public void setDirection(int direction) {
        this.direction = direction;
    } 

    /**
     * Get the direction for this instance
     */
    public int getDirection() {
        return direction;
    } 

    /**
     * Set the number of lives for this instance
     */
    public void setLives(int lives) {
        this.lives = lives;
    } 

    /**
     * Get the number of lives for this instance
     */
    public int getLives() {
        return lives;
    } 

    /**
     * Set the number of jetpacks for this instance
     */
    public void setJetpackCount(int jetpack_count) {
        this.jetpack_count = jetpack_count;
    } 

    /**
     * Get the number of jetpacks for this instance
     */
    public int getJetpackCount() {
        return jetpack_count;
    } 

    /**
     * Set the number of shovels for this instance
     */
    public void setShovelCount(int shovel_count) {
        this.shovel_count = shovel_count;
    } 

    /**
     * Get the number of shovels for this instance
     */
    public int getShovelCount() {
        return shovel_count;
    } 

    /**
     * Track flying, digging and boosting activity
     */
    public void tick() {
        int status = getStatus();

        if (fly_ticks > 0 && (status & FLY) != 0) {
            if (--fly_ticks == 0) {
                clearStatusBit(FLY);
                setStatusBit(RUN);
            } 
        } 

        if (dig_ticks > 0 && (status & BURROW) != 0) {
            if (--dig_ticks == 0) {
                clearStatusBit(BURROW);
                setStatusBit(RUN);
            } 
        } 

        if (speed_ticks > 0) {
            if (--speed_ticks == 0) {
                speed = 1;
            } 
        } 
    } 

    /**
     * Set the item this instance is covering on the field
     */
    public void setCovered(Item item) {
        covered = item;
    } 

    /**
     * Get the item this instance is covering on the field
     */
    public Item getCovered() {
        return covered;
    } 

    /**
     * Returns 'true' if the player is flying, 'false' othewise
     */
    public boolean isFlying() {
        return (getStatus() & FLY) != 0;
    } 

    /**
     * Returns 'true' if the player is digging, 'false' othewise
     */
    public boolean isDigging() {
        return (getStatus() & BURROW) != 0;
    } 

    /**
     * Returns 'true' if the player is on the ground, 'false' othewise
     */
    public boolean isOnGround() {
        return !isFlying() &&!isDigging();
    } 

    /**
     * Get the speed for this instance
     */
    public int getSpeed() {
        return speed;
    } 

    /**
     * Add a status bit for the player
     */
    public void setStatusBit(int bit) {
        if (bit == FLY) {
            fly_ticks = MAX_TICKS;
        } else if (bit == BURROW) {
            dig_ticks = MAX_TICKS;
        } else if (bit == RUN_FAST) {
            speed = 2;
            speed_ticks = MAX_TICKS;

            return;
        } 

        setStatus(getStatus() | bit);
    } 

    /**
     * Remove a status bit for the player
     */
    public void clearStatusBit(int bit) {
        setStatus(getStatus() & ~bit);
    } 

}