auto import from //depot/cupcake/@135843
This commit is contained in:
The Android Open Source Project
553
samples/Snake/src/com/example/android/snake/SnakeView.java
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553
samples/Snake/src/com/example/android/snake/SnakeView.java
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@@ -0,0 +1,553 @@
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/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.example.android.snake;
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import java.util.ArrayList;
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import java.util.Random;
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import android.content.Context;
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import android.content.res.Resources;
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import android.os.Handler;
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import android.os.Message;
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import android.util.AttributeSet;
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import android.os.Bundle;
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import android.util.Log;
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import android.view.KeyEvent;
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import android.view.View;
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import android.widget.TextView;
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/**
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* SnakeView: implementation of a simple game of Snake
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*
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*
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*/
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public class SnakeView extends TileView {
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private static final String TAG = "SnakeView";
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/**
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* Current mode of application: READY to run, RUNNING, or you have already
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* lost. static final ints are used instead of an enum for performance
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* reasons.
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*/
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private int mMode = READY;
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public static final int PAUSE = 0;
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public static final int READY = 1;
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public static final int RUNNING = 2;
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public static final int LOSE = 3;
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/**
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* Current direction the snake is headed.
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*/
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private int mDirection = NORTH;
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private int mNextDirection = NORTH;
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private static final int NORTH = 1;
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private static final int SOUTH = 2;
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private static final int EAST = 3;
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private static final int WEST = 4;
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/**
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* Labels for the drawables that will be loaded into the TileView class
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*/
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private static final int RED_STAR = 1;
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private static final int YELLOW_STAR = 2;
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private static final int GREEN_STAR = 3;
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/**
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* mScore: used to track the number of apples captured mMoveDelay: number of
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* milliseconds between snake movements. This will decrease as apples are
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* captured.
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*/
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private long mScore = 0;
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private long mMoveDelay = 600;
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/**
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* mLastMove: tracks the absolute time when the snake last moved, and is used
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* to determine if a move should be made based on mMoveDelay.
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*/
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private long mLastMove;
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/**
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* mStatusText: text shows to the user in some run states
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*/
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private TextView mStatusText;
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/**
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* mSnakeTrail: a list of Coordinates that make up the snake's body
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* mAppleList: the secret location of the juicy apples the snake craves.
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*/
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private ArrayList<Coordinate> mSnakeTrail = new ArrayList<Coordinate>();
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private ArrayList<Coordinate> mAppleList = new ArrayList<Coordinate>();
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/**
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* Everyone needs a little randomness in their life
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*/
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private static final Random RNG = new Random();
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/**
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* Create a simple handler that we can use to cause animation to happen. We
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* set ourselves as a target and we can use the sleep()
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* function to cause an update/invalidate to occur at a later date.
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*/
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private RefreshHandler mRedrawHandler = new RefreshHandler();
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class RefreshHandler extends Handler {
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@Override
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public void handleMessage(Message msg) {
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SnakeView.this.update();
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SnakeView.this.invalidate();
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}
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public void sleep(long delayMillis) {
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this.removeMessages(0);
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sendMessageDelayed(obtainMessage(0), delayMillis);
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}
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};
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/**
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* Constructs a SnakeView based on inflation from XML
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*
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* @param context
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* @param attrs
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*/
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public SnakeView(Context context, AttributeSet attrs) {
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super(context, attrs);
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initSnakeView();
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}
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public SnakeView(Context context, AttributeSet attrs, int defStyle) {
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super(context, attrs, defStyle);
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initSnakeView();
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}
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private void initSnakeView() {
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setFocusable(true);
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Resources r = this.getContext().getResources();
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resetTiles(4);
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loadTile(RED_STAR, r.getDrawable(R.drawable.redstar));
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loadTile(YELLOW_STAR, r.getDrawable(R.drawable.yellowstar));
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loadTile(GREEN_STAR, r.getDrawable(R.drawable.greenstar));
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}
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private void initNewGame() {
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mSnakeTrail.clear();
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mAppleList.clear();
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// For now we're just going to load up a short default eastbound snake
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// that's just turned north
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mSnakeTrail.add(new Coordinate(7, 7));
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mSnakeTrail.add(new Coordinate(6, 7));
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mSnakeTrail.add(new Coordinate(5, 7));
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mSnakeTrail.add(new Coordinate(4, 7));
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mSnakeTrail.add(new Coordinate(3, 7));
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mSnakeTrail.add(new Coordinate(2, 7));
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mNextDirection = NORTH;
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// Two apples to start with
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addRandomApple();
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addRandomApple();
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mMoveDelay = 600;
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mScore = 0;
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}
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/**
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* Given a ArrayList of coordinates, we need to flatten them into an array of
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* ints before we can stuff them into a map for flattening and storage.
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*
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* @param cvec : a ArrayList of Coordinate objects
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* @return : a simple array containing the x/y values of the coordinates
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* as [x1,y1,x2,y2,x3,y3...]
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*/
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private int[] coordArrayListToArray(ArrayList<Coordinate> cvec) {
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int count = cvec.size();
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int[] rawArray = new int[count * 2];
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for (int index = 0; index < count; index++) {
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Coordinate c = cvec.get(index);
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rawArray[2 * index] = c.x;
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rawArray[2 * index + 1] = c.y;
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}
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return rawArray;
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}
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/**
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* Save game state so that the user does not lose anything
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* if the game process is killed while we are in the
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* background.
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*
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* @return a Bundle with this view's state
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*/
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public Bundle saveState() {
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Bundle map = new Bundle();
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map.putIntArray("mAppleList", coordArrayListToArray(mAppleList));
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map.putInt("mDirection", Integer.valueOf(mDirection));
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map.putInt("mNextDirection", Integer.valueOf(mNextDirection));
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map.putLong("mMoveDelay", Long.valueOf(mMoveDelay));
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map.putLong("mScore", Long.valueOf(mScore));
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map.putIntArray("mSnakeTrail", coordArrayListToArray(mSnakeTrail));
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return map;
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}
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/**
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* Given a flattened array of ordinate pairs, we reconstitute them into a
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* ArrayList of Coordinate objects
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*
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* @param rawArray : [x1,y1,x2,y2,...]
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* @return a ArrayList of Coordinates
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*/
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private ArrayList<Coordinate> coordArrayToArrayList(int[] rawArray) {
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ArrayList<Coordinate> coordArrayList = new ArrayList<Coordinate>();
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int coordCount = rawArray.length;
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for (int index = 0; index < coordCount; index += 2) {
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Coordinate c = new Coordinate(rawArray[index], rawArray[index + 1]);
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coordArrayList.add(c);
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}
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return coordArrayList;
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}
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/**
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* Restore game state if our process is being relaunched
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*
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* @param icicle a Bundle containing the game state
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*/
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public void restoreState(Bundle icicle) {
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setMode(PAUSE);
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mAppleList = coordArrayToArrayList(icicle.getIntArray("mAppleList"));
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mDirection = icicle.getInt("mDirection");
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mNextDirection = icicle.getInt("mNextDirection");
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mMoveDelay = icicle.getLong("mMoveDelay");
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mScore = icicle.getLong("mScore");
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mSnakeTrail = coordArrayToArrayList(icicle.getIntArray("mSnakeTrail"));
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}
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/*
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* handles key events in the game. Update the direction our snake is traveling
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* based on the DPAD. Ignore events that would cause the snake to immediately
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* turn back on itself.
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*
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* (non-Javadoc)
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*
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* @see android.view.View#onKeyDown(int, android.os.KeyEvent)
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*/
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@Override
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public boolean onKeyDown(int keyCode, KeyEvent msg) {
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if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
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if (mMode == READY | mMode == LOSE) {
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/*
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* At the beginning of the game, or the end of a previous one,
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* we should start a new game.
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*/
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initNewGame();
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setMode(RUNNING);
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update();
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return (true);
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}
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if (mMode == PAUSE) {
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/*
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* If the game is merely paused, we should just continue where
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* we left off.
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*/
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setMode(RUNNING);
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update();
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return (true);
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}
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if (mDirection != SOUTH) {
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mNextDirection = NORTH;
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}
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return (true);
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}
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if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
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if (mDirection != NORTH) {
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mNextDirection = SOUTH;
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}
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return (true);
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}
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if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) {
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if (mDirection != EAST) {
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mNextDirection = WEST;
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}
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return (true);
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}
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if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
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if (mDirection != WEST) {
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mNextDirection = EAST;
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}
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return (true);
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}
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return super.onKeyDown(keyCode, msg);
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}
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/**
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* Sets the TextView that will be used to give information (such as "Game
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* Over" to the user.
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*
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* @param newView
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*/
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public void setTextView(TextView newView) {
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mStatusText = newView;
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}
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/**
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* Updates the current mode of the application (RUNNING or PAUSED or the like)
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* as well as sets the visibility of textview for notification
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*
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* @param newMode
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*/
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public void setMode(int newMode) {
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int oldMode = mMode;
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mMode = newMode;
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if (newMode == RUNNING & oldMode != RUNNING) {
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mStatusText.setVisibility(View.INVISIBLE);
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update();
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return;
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}
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Resources res = getContext().getResources();
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CharSequence str = "";
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if (newMode == PAUSE) {
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str = res.getText(R.string.mode_pause);
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}
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if (newMode == READY) {
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str = res.getText(R.string.mode_ready);
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}
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if (newMode == LOSE) {
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str = res.getString(R.string.mode_lose_prefix) + mScore
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+ res.getString(R.string.mode_lose_suffix);
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}
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mStatusText.setText(str);
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mStatusText.setVisibility(View.VISIBLE);
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}
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/**
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* Selects a random location within the garden that is not currently covered
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* by the snake. Currently _could_ go into an infinite loop if the snake
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* currently fills the garden, but we'll leave discovery of this prize to a
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* truly excellent snake-player.
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*
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*/
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private void addRandomApple() {
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Coordinate newCoord = null;
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boolean found = false;
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while (!found) {
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// Choose a new location for our apple
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int newX = 1 + RNG.nextInt(mXTileCount - 2);
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int newY = 1 + RNG.nextInt(mYTileCount - 2);
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newCoord = new Coordinate(newX, newY);
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// Make sure it's not already under the snake
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boolean collision = false;
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int snakelength = mSnakeTrail.size();
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for (int index = 0; index < snakelength; index++) {
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if (mSnakeTrail.get(index).equals(newCoord)) {
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collision = true;
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}
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}
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// if we're here and there's been no collision, then we have
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// a good location for an apple. Otherwise, we'll circle back
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// and try again
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found = !collision;
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}
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if (newCoord == null) {
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Log.e(TAG, "Somehow ended up with a null newCoord!");
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}
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mAppleList.add(newCoord);
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}
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/**
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* Handles the basic update loop, checking to see if we are in the running
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* state, determining if a move should be made, updating the snake's location.
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*/
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public void update() {
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if (mMode == RUNNING) {
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long now = System.currentTimeMillis();
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if (now - mLastMove > mMoveDelay) {
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clearTiles();
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updateWalls();
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updateSnake();
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updateApples();
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mLastMove = now;
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}
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mRedrawHandler.sleep(mMoveDelay);
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}
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}
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/**
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* Draws some walls.
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*
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*/
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private void updateWalls() {
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for (int x = 0; x < mXTileCount; x++) {
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setTile(GREEN_STAR, x, 0);
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setTile(GREEN_STAR, x, mYTileCount - 1);
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}
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for (int y = 1; y < mYTileCount - 1; y++) {
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setTile(GREEN_STAR, 0, y);
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setTile(GREEN_STAR, mXTileCount - 1, y);
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}
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}
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||||
/**
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* Draws some apples.
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*
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*/
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||||
private void updateApples() {
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||||
for (Coordinate c : mAppleList) {
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setTile(YELLOW_STAR, c.x, c.y);
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}
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}
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/**
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* Figure out which way the snake is going, see if he's run into anything (the
|
||||
* walls, himself, or an apple). If he's not going to die, we then add to the
|
||||
* front and subtract from the rear in order to simulate motion. If we want to
|
||||
* grow him, we don't subtract from the rear.
|
||||
*
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||||
*/
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||||
private void updateSnake() {
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boolean growSnake = false;
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||||
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||||
// grab the snake by the head
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||||
Coordinate head = mSnakeTrail.get(0);
|
||||
Coordinate newHead = new Coordinate(1, 1);
|
||||
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||||
mDirection = mNextDirection;
|
||||
|
||||
switch (mDirection) {
|
||||
case EAST: {
|
||||
newHead = new Coordinate(head.x + 1, head.y);
|
||||
break;
|
||||
}
|
||||
case WEST: {
|
||||
newHead = new Coordinate(head.x - 1, head.y);
|
||||
break;
|
||||
}
|
||||
case NORTH: {
|
||||
newHead = new Coordinate(head.x, head.y - 1);
|
||||
break;
|
||||
}
|
||||
case SOUTH: {
|
||||
newHead = new Coordinate(head.x, head.y + 1);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
// Collision detection
|
||||
// For now we have a 1-square wall around the entire arena
|
||||
if ((newHead.x < 1) || (newHead.y < 1) || (newHead.x > mXTileCount - 2)
|
||||
|| (newHead.y > mYTileCount - 2)) {
|
||||
setMode(LOSE);
|
||||
return;
|
||||
|
||||
}
|
||||
|
||||
// Look for collisions with itself
|
||||
int snakelength = mSnakeTrail.size();
|
||||
for (int snakeindex = 0; snakeindex < snakelength; snakeindex++) {
|
||||
Coordinate c = mSnakeTrail.get(snakeindex);
|
||||
if (c.equals(newHead)) {
|
||||
setMode(LOSE);
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
// Look for apples
|
||||
int applecount = mAppleList.size();
|
||||
for (int appleindex = 0; appleindex < applecount; appleindex++) {
|
||||
Coordinate c = mAppleList.get(appleindex);
|
||||
if (c.equals(newHead)) {
|
||||
mAppleList.remove(c);
|
||||
addRandomApple();
|
||||
|
||||
mScore++;
|
||||
mMoveDelay *= 0.9;
|
||||
|
||||
growSnake = true;
|
||||
}
|
||||
}
|
||||
|
||||
// push a new head onto the ArrayList and pull off the tail
|
||||
mSnakeTrail.add(0, newHead);
|
||||
// except if we want the snake to grow
|
||||
if (!growSnake) {
|
||||
mSnakeTrail.remove(mSnakeTrail.size() - 1);
|
||||
}
|
||||
|
||||
int index = 0;
|
||||
for (Coordinate c : mSnakeTrail) {
|
||||
if (index == 0) {
|
||||
setTile(YELLOW_STAR, c.x, c.y);
|
||||
} else {
|
||||
setTile(RED_STAR, c.x, c.y);
|
||||
}
|
||||
index++;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* Simple class containing two integer values and a comparison function.
|
||||
* There's probably something I should use instead, but this was quick and
|
||||
* easy to build.
|
||||
*
|
||||
*/
|
||||
private class Coordinate {
|
||||
public int x;
|
||||
public int y;
|
||||
|
||||
public Coordinate(int newX, int newY) {
|
||||
x = newX;
|
||||
y = newY;
|
||||
}
|
||||
|
||||
public boolean equals(Coordinate other) {
|
||||
if (x == other.x && y == other.y) {
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return "Coordinate: [" + x + "," + y + "]";
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
Reference in New Issue
Block a user