Android 贪吃蛇源码分析

package com.example.Android.snake;import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.widget.TextView;/**
* Snake: a simple game that everyone can enjoy.
*
* This is an implementation of the classic Game "Snake", in which you control a
* serpent roaming around the garden looking for apples. Be careful, though,
* because when you catch one, not only will you become longer, but you"ll move
* faster. Running into yourself or the walls will end the game.
*
*/
public class Snake extends Activity {
    private final static String TAG = "****   ***Snake***** *****";    private SnakeView mSnakeView;

    private static String ICICLE_KEY = "snake-view";    /**
     * Called when Activity is first created. Turns off the title bar, sets up
     * the content views, and fires up the SnakeView.
     *
     */
    @Override
    public void onCreate（Bundle savedInstanceState） {
        super.onCreate（savedInstanceState）;        // No Title bar
        requestWindowFeature（Window.FEATURE_NO_TITLE）;        setContentView（R.layout.snake_layout）;        mSnakeView = （SnakeView） findViewById（R.id.snake）;
        mSnakeView.setTextView（（TextView） findViewById（R.id.text））;
        if （savedInstanceState == null） {
            // We were just launched -- set up a new game
            mSnakeView.setMode（SnakeView.READY）;
        } else {
            // We are being restored
            Bundle map = savedInstanceState.getBundle（ICICLE_KEY）;
            if （map ！= null） {
                mSnakeView.restoreState（map）;
            } else {
                mSnakeView.setMode（SnakeView.PAUSE）;
            }
        }
    }    @Override
    protected void onPause（） {
        super.onPause（）;
        // Pause the game along with the activity
        mSnakeView.setMode（SnakeView.PAUSE）;
    }    @Override
    public void onSaveInstanceState（Bundle outState） {
        //Store the game state
        outState.putBundle（ICICLE_KEY, mSnakeView.saveState（））;
    }}/*
* Copyright （C） 2007 The Android Open Source Project
*
* 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.example.android.snake;import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
/**
* 格子的绘画
* TileView: a View-variant designed for handling arrays of "icons" or other
* drawables.
*
*/
public class TileView extends View {    /**
     * Parameters controlling the size of the tiles and their range within view.
     * Width/Height are in pixels, and Drawables will be scaled to fit to these
     * dimensions. X/Y Tile Counts are the number of tiles that will be drawn.
     */    protected static int mTileSize;    /** x轴方向上格子的个数 */
    protected static int mXTileCount;
    /** y轴方向上格子的个数 */
    protected static int mYTileCount;    private static int mXOffset;
    private static int mYOffset;
    /**
     *
     * A hash that maps integer handles specified by the subclasser to the
     * drawable that will be used for that reference
     */
    private Bitmap[] mTileArray;     /**
     * 声明用来存放绘画图像的x，y轴的位置的数组
     * A two-dimensional array of integers in which the number represents the
     * index of the tile that should be drawn at that locations
     */
    private int[][] mTileGrid;    private final Paint mPaint = new Paint（）;    public TileView（Context context, AttributeSet attrs, int defStyle） {
        super（context, attrs, defStyle）;        TypedArray a = context.obtainStyledAttributes（attrs, R.styleable.TileView）;        mTileSize = a.getInt（R.styleable.TileView_tileSize, 12）;

        a.recycle（）;
    }    public TileView（Context context, AttributeSet attrs） {
        super（context, attrs）;        TypedArray a = context.obtainStyledAttributes（attrs, R.styleable.TileView）;        mTileSize = a.getInt（R.styleable.TileView_tileSize, 12）;

        a.recycle（）;
    }

    /**
     * Rests the internal array of Bitmaps used for drawing tiles, and
     * sets the maximum index of tiles to be inserted
     *
     * @param tilecount
     */

    public void resetTiles（int tilecount） {
        mTileArray = new Bitmap[tilecount];
    }
    @Override
    protected void onSizeChanged（int w, int h, int oldw, int oldh） {
        mXTileCount = （int） Math.floor（w / mTileSize）;
        mYTileCount = （int） Math.floor（h / mTileSize）;        mXOffset = （（w - （mTileSize * mXTileCount）） / 2）;
        mYOffset = （（h - （mTileSize * mYTileCount）） / 2）;        mTileGrid = new int[mXTileCount][mYTileCount];
        clearTiles（）;
    }    /**
     * Function to set the specified Drawable as the tile for a particular
     * integer key.
     *
     * @param key
     * @param tile
     */
    public void loadTile（int key, Drawable tile） {
        Bitmap bitmap = Bitmap.createBitmap（mTileSize, mTileSize, Bitmap.Config.ARGB_8888）;
        Canvas canvas = new Canvas（bitmap）;
        //指定矩形的大小
        tile.setBounds（0, 0, mTileSize, mTileSize）;
        tile.draw（canvas）;

        mTileArray[key] = bitmap;
    }    /**
     * Resets all tiles to 0 （empty）
     * 清空
     */
    public void clearTiles（） {
        for （int x = 0; x < mXTileCount; x++） {
            for （int y = 0; y < mYTileCount; y++） {
                setTile（0, x, y）;
            }
        }
    }    /**
     * Used to indicate that a particular tile （set with loadTile and referenced
     * by an integer） should be drawn at the given x/y coordinates during the
     * next invalidate/draw cycle.
     *
     * @param tileindex 图片的索引
     * @param x
     * @param y
     */
    public void setTile（int tileindex, int x, int y） {
        mTileGrid[x][y] = tileindex;
    }    /**
     * 画出主界面图
     */
    @Override
    public void onDraw（Canvas canvas） {
        super.onDraw（canvas）;
        for （int x = 0; x < mXTileCount; x += 1） {
            for （int y = 0; y < mYTileCount; y += 1） {
                if （mTileGrid[x][y] > 0） {
                    canvas.drawBitmap（mTileArray[mTileGrid[x][y]],
                            mXOffset + x * mTileSize,
                            mYOffset + y * mTileSize,
                            mPaint）;
                }
            }
        }    }}