Android程序源码--贪吃蛇

/** * <p>Title: Snake</p> * <p>Copyright: (C) 2007 The Android Open Source Project. Licensed under the Apache License, Version 2.0 (the "License")</p> * @author Gavin 标注 */ package com.deaboway.snake; import java.util.ArrayList; import java.util.Random; import android.content.Context; import android.content.res.Resources; import android.os.Handler; import android.os.Message; import android.util.AttributeSet; import android.os.Bundle; import android.util.Log; import android.view.KeyEvent; import android.view.View; import android.widget.TextView; /** * SnakeView: implementation of a simple game of Snake * * */ public class SnakeView extends TileView { private static final String TAG = "Deaboway"; /** * Current mode of application: READY to run, RUNNING, or you have already * lost. static final ints are used instead of an enum for performance * reasons. */ // 游戏状态，默认值是准备状态 private int mMode = READY; // 游戏的四个状态 暂停 准备 运行 和 失败 public static final int PAUSE = 0; public static final int READY = 1; public static final int RUNNING = 2; public static final int LOSE = 3; // 游戏中蛇的前进方向，默认值北方 private int mDirection = NORTH; // 下一步的移动方向，默认值北方 private int mNextDirection = NORTH; // 游戏方向设定 北 南 东 西 private static final int NORTH = 1; private static final int SOUTH = 2; private static final int EAST = 3; private static final int WEST = 4; /** * Labels for the drawables that will be loaded into the TileView class */ // 三种游戏元 private static final int RED_STAR = 1; private static final int YELLOW_STAR = 2; private static final int GREEN_STAR = 3; /** * mScore: used to track the number of apples captured mMoveDelay: number of * milliseconds between snake movements. This will decrease as apples are * captured. */ // 游戏得分 private long mScore = 0; // 移动延迟 private long mMoveDelay = 600; /** * mLastMove: tracks the absolute time when the snake last moved, and is * used to determine if a move should be made based on mMoveDelay. */ // 最后一次移动时的毫秒时刻 private long mLastMove; /** * mStatusText: text shows to the user in some run states */ // 显示游戏状态的文本组件 private TextView mStatusText; /** * mSnakeTrail: a list of Coordinates that make up the snake's body * mAppleList: the secret location of the juicy apples the snake craves. */ // 蛇身数组(数组以坐标对象为元素) private ArrayList<Coordinate> mSnakeTrail = new ArrayList<Coordinate>(); // 苹果数组(数组以坐标对象为元素) private ArrayList<Coordinate> mAppleList = new ArrayList<Coordinate>(); /** * Everyone needs a little randomness in their life */ // 随机数 private static final Random RNG = new Random(); /** * Create a simple handler that we can use to cause animation to happen. We * set ourselves as a target and we can use the sleep() function to cause an * update/invalidate to occur at a later date. */ // 创建一个Refresh Handler来产生动画： 通过sleep()来实现 private RefreshHandler mRedrawHandler = new RefreshHandler(); // 一个Handler class RefreshHandler extends Handler { // 处理消息队列 @Override public void handleMessage(Message msg) { // 更新View对象 SnakeView.this.update(); // 强制重绘 SnakeView.this.invalidate(); } // 延迟发送消息 public void sleep(long delayMillis) { this.removeMessages(0); sendMessageDelayed(obtainMessage(0), delayMillis); } }; /** * Constructs a SnakeView based on inflation from XML * * @param context * @param attrs */ // 构造函数 public SnakeView(Context context, AttributeSet attrs) { super(context, attrs); // 构造时初始化 initSnakeView(); } public SnakeView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initSnakeView(); } // 初始化 private void initSnakeView() { // 可选焦点 setFocusable(true); Resources r = this.getContext().getResources(); // 设置贴片图片数组 resetTiles(4); // 把三种图片存到Bitmap对象数组 loadTile(RED_STAR, r.getDrawable(R.drawable.redstar)); loadTile(YELLOW_STAR, r.getDrawable(R.drawable.yellowstar)); loadTile(GREEN_STAR, r.getDrawable(R.drawable.greenstar)); } // 开始新的游戏——初始化 private void initNewGame() { // 清空ArrayList列表 mSnakeTrail.clear(); mAppleList.clear(); // For now we're just going to load up a short default eastbound snake // that's just turned north // 创建蛇身 mSnakeTrail.add(new Coordinate(7, 7)); mSnakeTrail.add(new Coordinate(6, 7)); mSnakeTrail.add(new Coordinate(5, 7)); mSnakeTrail.add(new Coordinate(4, 7)); mSnakeTrail.add(new Coordinate(3, 7)); mSnakeTrail.add(new Coordinate(2, 7)); // 新的方向 ：北方 mNextDirection = NORTH; // 2个随机位置的苹果 addRandomApple(); addRandomApple(); // 移动延迟 mMoveDelay = 600; // 初始得分0 mScore = 0; } /** * Given a ArrayList of coordinates, we need to flatten them into an array * of ints before we can stuff them into a map for flattening and storage. * * @param cvec * : a ArrayList of Coordinate objects * @return : a simple array containing the x/y values of the coordinates as * [x1,y1,x2,y2,x3,y3...] */ // 坐标数组转整数数组，把Coordinate对象的x y放到一个int数组中——用来保存状态 private int[] coordArrayListToArray(ArrayList<Coordinate> cvec) { int count = cvec.size(); int[] rawArray = new int[count * 2]; for (int index = 0; index < count; index++) { Coordinate c = cvec.get(index); rawArray[2 * index] = c.x; rawArray[2 * index + 1] = c.y; } return rawArray; } /** * Save game state so that the user does not lose anything if the game * process is killed while we are in the background. * * @return a Bundle with this view's state */ // 保存状态 public Bundle saveState() { Bundle map = new Bundle(); map.putIntArray("mAppleList", coordArrayListToArray(mAppleList)); map.putInt("mDirection", Integer.valueOf(mDirection)); map.putInt("mNextDirection", Integer.valueOf(mNextDirection)); map.putLong("mMoveDelay", Long.valueOf(mMoveDelay)); map.putLong("mScore", Long.valueOf(mScore)); map.putIntArray("mSnakeTrail", coordArrayListToArray(mSnakeTrail)); return map; } /** * Given a flattened array of ordinate pairs, we reconstitute them into a * ArrayList of Coordinate objects * * @param rawArray * : [x1,y1,x2,y2,...] * @return a ArrayList of Coordinates */ // 整数数组转坐标数组，把一个int数组中的x y放到Coordinate对象数组中——用来恢复状态 private ArrayList<Coordinate> coordArrayToArrayList(int[] rawArray) { ArrayList<Coordinate> coordArrayList = new ArrayList<Coordinate>(); int coordCount = rawArray.length; for (int index = 0; index < coordCount; index += 2) { Coordinate c = new Coordinate(rawArray[index], rawArray[index + 1]); coordArrayList.add(c); } return coordArrayList; } /** * Restore game state if our process is being relaunched * * @param icicle * a Bundle containing the game state */ // 恢复状态 public void restoreState(Bundle icicle) { setMode(PAUSE); mAppleList = coordArrayToArrayList(icicle.getIntArray("mAppleList")); mDirection = icicle.getInt("mDirection"); mNextDirection = icicle.getInt("mNextDirection"); mMoveDelay = icicle.getLong("mMoveDelay"); mScore = icicle.getLong("mScore"); mSnakeTrail = coordArrayToArrayList(icicle.getIntArray("mSnakeTrail")); } /* * handles key events in the game. Update the direction our snake is * traveling based on the DPAD. Ignore events that would cause the snake to * immediately turn back on itself. * * (non-Javadoc)