Android应用实践之数独游戏开发

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:background="@color/background" 
  android:layout_height="fill_parent"
  android:layout_width="fill_parent"
  android:padding="30dip" 
  android:orientation="horizontal">
  <LinearLayout
    android:orientation="vertical" 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center">

    <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center"
      android:layout_marginBottom="25dip"
      android:text="@string/main_title"
      android:textSize="24sp" />

    <Button
      android:id="@+id/continue_button"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/continue_label" />

    <Button
      android:id="@+id/new_button"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/new_game_label" />

    <Button
      android:id="@+id/about_button"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/about_label" />

    <Button
      android:id="@+id/exit_button"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/exit_label" />
  </LinearLayout>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/keypad"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:orientation="vertical"
  android:background="@color/puzzle_background"
  android:stretchColumns="*" >

  <TableRow >

    <Button
      android:id="@+id/keypad_1"
      android:text="@string/keypad_1" />

    <Button
      android:id="@+id/keypad_2"
      android:text="@string/keypad_2" />

    <Button
      android:id="@+id/keypad_3"
      android:text="@string/keypad_3" />
  </TableRow>

  <TableRow >

    <Button
      android:id="@+id/keypad_4"
      android:text="@string/keypad_4" />

    <Button
      android:id="@+id/keypad_5"
      android:text="@string/keypad_5" />

    <Button
      android:id="@+id/keypad_6"
      android:text="@string/keypad_6" />
  </TableRow>

  <TableRow >

    <Button
      android:id="@+id/keypad_7"
      android:text="@string/keypad_7" />

    <Button
      android:id="@+id/keypad_8"
      android:text="@string/keypad_8" />

    <Button
      android:id="@+id/keypad_9"
      android:text="@string/keypad_9" />
  </TableRow>

</TableLayout>

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"  
  android:layout_height="fill_parent"  
  android:padding="10dip">
  <TextView 
    android:id="@+id/about_content"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/about_text"/>
</ScrollView>

package com.dw.gamesuduku;

import android.app.Activity;
import android.os.Bundle;
public class About extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.about);
  }
}

package com.dw.gamesuduku;

import android.app.Activity;
import android.app.Dialog;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.widget.Toast;
public class Game extends Activity {
  private static final String TAG="Sudoku";
  private static final String PREF_PUZZLE="puzzle";
  protected static final int DIFFICULTY_CONTINUE=-1;

  public static final String KEY_DIFFICULTY="difficulty";
  public static final int DIFFICULTY_EASY=0;
  public static final int DIFFICULTY_MEDIUM=1;
  public static final int DIFFICULTY_HARD=2;

  private int puzzle[]=new int[9*9];
  private PuzzleView puzzleView;
  //三种游戏模式
  private static final String easyPuzzle="360000000004230800000004200"+
                  "070460003820000014500013010"+
                  "001900000007048300000000045";
  private static final String mediumPuzzle="650000070000506000014000005"+
                       "007009000002314700000700800"+
                       "500000630000201000030000097";
  private static final String hardPuzzle="009000000080605020501078000"+
                      "000000700706040102004000000"+
                      "000720903090301080000000600";

  private final int used[][][]=new int[9][9][];
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    Log.e(TAG, "onCreate");
    int diff=getIntent().getIntExtra(KEY_DIFFICULTY, DIFFICULTY_EASY);
    puzzle=getPuzzle(diff);
    calculateUsedTiles();

    puzzleView=new PuzzleView(this);
    setContentView(puzzleView);
    puzzleView.requestFocus();
    //if the activity is restarted ,do a continue next time
    getIntent().putExtra(KEY_DIFFICULTY, DIFFICULTY_CONTINUE);
  }


  @Override
  protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    Music.stop(this);
    //Save the current puzzle
    getPreferences(MODE_PRIVATE).edit().putString(PREF_PUZZLE, toPuzzleString(puzzle)).commit();
  }

  @Override
  protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    Music.play(this, R.raw.game);
  }

  protected int[] getUsedTiles(int x,int y){
    return used[x][y];
  }

  private void calculateUsedTiles() {
    // TODO Auto-generated method stub
    for (int x = 0; x < 9; x++) {
      for (int y = 0; y < 9; y++) {
        used[x][y]=calculateUsedTiles(x,y);
      }
    }
  }
  private int[] calculateUsedTiles(int x, int y) {
    // TODO Auto-generated method stub
    int c[]=new int[9];
    //horizontal

    for(int i=0;i<9;i++){
      if(i==y)
        continue;
      int t=getTitle(x, i);
      if(t!=0)
        c[t-1]=t;
    }
    //vertical

    for(int i=0;i<9;i++){
      if(i==x)
        continue;
      int t=getTitle(i, y);
      if(t!=0)
        c[t-1]=t;
    }
    //same cell block
    int startx=(x/3)*3;
    int starty=(y/3)*3;
    for(int i=startx;i<startx+3;i++){
      for(int j=starty;j<starty+3;j++){
        if(i==x&&j==y)
          continue;
        int t=getTitle(i, j);
        if(t!=0)
          c[t-1]=t;
      }
    }
    //compress
    int nused=0;
    for (int t : c) {
      if(t!=0)
      nused++;
    }
    int c1[]=new int[nused];
    nused=0;
    for (int t : c) {
      if(t!=0)
        c1[nused++]=t;
    }
    return c1;
  }
  //give a difficulty level
  private int[] getPuzzle(int diff) {
    // TODO Auto-generated method stub
    String puz = null;
    switch (diff) {
    case DIFFICULTY_CONTINUE:
      puz=getPreferences(MODE_PRIVATE).getString(PREF_PUZZLE, easyPuzzle);
      break;
    case DIFFICULTY_HARD:
      puz=hardPuzzle;
      break;
    case DIFFICULTY_MEDIUM:
      puz=mediumPuzzle;
      break;
    case DIFFICULTY_EASY:
      puz=easyPuzzle;
      break;
    }
    return fromPuzzleString(puz);
  }
  //convert an array into a puzzle string
  static private String toPuzzleString(int[] puz){
    StringBuilder buf=new StringBuilder();
    for (int element : puz) {
      buf.append(element);
    }
    return buf.toString();
  }
  //convert a puzzle string to an array
  static protected int[] fromPuzzleString(String string) {
    // TODO Auto-generated method stub
    int[] puz=new int[string.length()];
    for (int i = 0; i < puz.length; i++) {
    puz[i]=string.charAt(i)-'0';
    }
    return puz;
  } 
  public String getTitleString(int x, int y) {
    // TODO Auto-generated method stub
    int v=getTitle(x,y);
    if(v==0)
      return "";
    else
      return String.valueOf(v);
  }
  private int getTitle(int x, int y) {
    // TODO Auto-generated method stub
    return puzzle[y*9+x];
  }
  private void setTitle(int x,int y,int value){
    puzzle[y*9+x]=value;
  }
  //change the tile only if it's a valid move
  protected boolean setTileIfValid(int x, int y, int value) {
    // TODO Auto-generated method stub
    int tiles[]=getUsedTiles(x, y);
    if(value!=0){
      for (int tile : tiles) {
        if(tile==value)
          return false;
      }
    }
    setTitle(x, y, value);
    calculateUsedTiles();
    return true;

  }
  //open the keypad if there are any valid moves
  protected void showKeypadOrError(int x, int y) {
    // TODO Auto-generated method stub
    int tiles[]=getUsedTiles(x, y);
    if(tiles.length==9){
      Toast toast=Toast.makeText(this, R.string.no_moves_label, Toast.LENGTH_SHORT);
      toast.setGravity(Gravity.BOTTOM, 0, 0);
      toast.show();
    }else{
      Log.d(TAG, "showKeypad:used="+toPuzzleString(tiles));
      Dialog v=new Keypad(this,tiles,puzzleView);
      v.show();
    }
  }
}

package com.dw.gamesuduku;

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;

public class Keypad extends Dialog {

  protected static final String TAG="Sudoku";
  private final View keys[]=new View[9];
  private View keypad;
  private final int useds[];
  private PuzzleView puzzleView;

  public Keypad(Context context,int useds[],PuzzleView puzzleView){
    super(context);
    this.useds=useds;
    this.puzzleView=puzzleView;
  }

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.keypad);
    findViews();
    for (int element : useds) {
      if(element!=0){
        keys[element-1].setVisibility(View.INVISIBLE);
      }
      setListeners();
    }
  }


  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    int tile=0;
    switch (keyCode) {
    case KeyEvent.KEYCODE_0:
    case KeyEvent.KEYCODE_SPACE:tile=0;break;
    case KeyEvent.KEYCODE_1:tile=1;break;
    case KeyEvent.KEYCODE_2:tile=2;break;
    case KeyEvent.KEYCODE_3:tile=3;break;
    case KeyEvent.KEYCODE_4:tile=4;break;
    case KeyEvent.KEYCODE_5:tile=5;break;
    case KeyEvent.KEYCODE_6:tile=6;break;
    case KeyEvent.KEYCODE_7:tile=7;break;
    case KeyEvent.KEYCODE_8:tile=8;break;
    case KeyEvent.KEYCODE_9:tile=9;break;
    default:
      return super.onKeyDown(keyCode, event);
    }
    if(isValid(tile)){
      returnResult(tile);
    }
    return true;
  }

  private boolean isValid(int tile) {
    // TODO Auto-generated method stub
    for (int t : useds) {
      if(tile==t)
        return false;
    }
    return true;
  }

  private void findViews() {
    // TODO Auto-generated method stub
    keypad=findViewById(R.id.keypad);
    keys[0]=findViewById(R.id.keypad_1);
    keys[1]=findViewById(R.id.keypad_2);
    keys[2]=findViewById(R.id.keypad_3);
    keys[3]=findViewById(R.id.keypad_4);
    keys[4]=findViewById(R.id.keypad_5);
    keys[5]=findViewById(R.id.keypad_6);
    keys[6]=findViewById(R.id.keypad_7);
    keys[7]=findViewById(R.id.keypad_8);
    keys[8]=findViewById(R.id.keypad_9);
  }
  private void setListeners(){
    for(int i=0;i<keys.length;i++){
      final int t=i+1;
      keys[i].setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
          // TODO Auto-generated method stub
          returnResult(t);
        }
      });
    }
    keypad.setOnClickListener(new View.OnClickListener() {
      public void onClick(View arg0) {
        // TODO Auto-generated method stub
        returnResult(0);
      }
    });
  }
  private void returnResult(int tile) {
    // TODO Auto-generated method stub
    puzzleView.setSelectedTile(tile);
    dismiss();
  }

}

package com.dw.gamesuduku;

import android.content.Context;
import android.media.MediaPlayer;

public class Music {
  private static MediaPlayer mp=null;
  //stop old song and start a new song
  public static void play(Context context,int resource){
    stop(context);
    if(Settings.getMusic(context)){
    mp=MediaPlayer.create(context, resource);
    mp.setLooping(true);
    mp.start();
    }
  }
  //stop the music
  public static void stop(Context context) {
    // TODO Auto-generated method stub
    if(mp!=null){
      mp.stop();
      mp.release();
      mp=null;
    }
  }
}

package com.dw.gamesuduku;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.FontMetrics;
import android.graphics.Paint.Style;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AnimationUtils;

@SuppressLint("DrawAllocation")
public class PuzzleView extends View {
  private static final String TAG = "Sudoku";
  private final Game game;

  private float width;
  private float height;
  private int selX;
  private int selY;
  private final Rect selRect = new Rect();

  private static final String SELX="selX";
  private static final String SELY="selY";
  private static final String VIEW_STATE="viewState";
  private static final int ID=42;//any positive int num

  public PuzzleView(Context context) {
    super(context);
    this.game = (Game) context;
    setFocusable(true);
    setFocusableInTouchMode(true);
    setId(ID);
  }

  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    // TODO Auto-generated method stub
    width = w / 9f;
    height = h / 9f;
    getRect(selX, selY, selRect);
    Log.d(TAG, "onSizeChanged:width" + width + ",height" + height);
    super.onSizeChanged(w, h, oldw, oldh);
  }

  //实例状态保存在bundle中，保存当前游戏状态
  @Override
  protected Parcelable onSaveInstanceState() {
    // TODO Auto-generated method stub
    Parcelable p=super.onSaveInstanceState();
    Log.d(TAG, "onSavedInstanceState");
    Bundle bundle=new Bundle();
    bundle.putInt(SELX, selX);
    bundle.putInt(SELY, selY);
    bundle.putParcelable(VIEW_STATE, p);
    return bundle;
  }
   //恢复已经保存的信息
  @Override
  protected void onRestoreInstanceState(Parcelable state) {
    // TODO Auto-generated method stub
    Log.d(TAG, "onRestoreInstanceState");
    Bundle bundle=(Bundle) state;
    select(bundle.getInt(SELX),bundle.getInt(SELY));
    super.onRestoreInstanceState(bundle.getParcelable(VIEW_STATE));
    return;
  }

  @Override
  protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    // draw background
    Paint background = new Paint();
    background.setColor(getResources().getColor(R.color.puzzle_background));
    canvas.drawRect(0, 0, getWidth(), getHeight(), background);

    // draw board
    Paint dark = new Paint();
    dark.setColor(getResources().getColor(R.color.puzzle_dark));

    Paint hilite = new Paint();
    hilite.setColor(getResources().getColor(R.color.puzzle_hilite));

    Paint light = new Paint();
    light.setColor(getResources().getColor(R.color.puzzle_light));

    // draw minor grid lines
    for (int i = 0; i < 9; i++) {
      canvas.drawLine(0, i * height, getWidth(), i * height, light);
      canvas.drawLine(0, i * height + 1, getWidth(), i * height + 1,
          hilite);
      canvas.drawLine(i * width, 0, i * width, getHeight(), dark);
      canvas.drawLine(i * width + 1, 0, i * width + 1, getHeight(),
          hilite);
    }
    // draw major grid lines
    for (int i = 0; i < 9; i++) {
      if (i % 3 != 0)
        continue;
      canvas.drawLine(0, i * height, getWidth(), i * height, dark);
      canvas.drawLine(0, i * height + 1, getWidth(), i * height + 1,
          hilite);
      canvas.drawLine(i * width, 0, i * width, getHeight(), dark);
      canvas.drawLine(i * width + 1, 0, i * width + 1, getHeight(),
          hilite);
    }
    // draw numbers
    Paint foreground = new Paint(Paint.ANTI_ALIAS_FLAG);
    foreground.setColor(getResources().getColor(R.color.puzzle_foregroud));
    foreground.setStyle(Style.FILL);
    foreground.setTextSize(height * 0.75f);
    foreground.setTextScaleX(width / height);
    foreground.setTextAlign(Paint.Align.CENTER);
    // draw num in the center of the tile
    FontMetrics fm = foreground.getFontMetrics();
    float x = width / 2;
    float y = height / 2 - (fm.ascent + fm.descent) / 2;
    for (int i = 0; i < 9; i++) {
      for (int j = 0; j < 9; j++) {
        canvas.drawText(this.game.getTitleString(i, j), i * width + x,
            j * height + y, foreground);
      }
    }
    // draw the selection
    Log.e(TAG, "selRect=" + selRect);
    Paint selected = new Paint();
    selected.setColor(getResources().getColor(R.color.puzzle_selected));
    canvas.drawRect(selRect, selected);

    //draw the hints pick a hint color based on moves left
    //根据每个单元格可填的数目给出不同颜色的提示
    if(Settings.getHints(getContext())){
    Paint hint=new Paint();
    int c[]={getResources().getColor(R.color.puzzle_hint_0),
        getResources().getColor(R.color.puzzle_hint_1),
        getResources().getColor(R.color.puzzle_hint_2),};
    Rect r=new Rect();
    for (int i = 0; i < 9; i++) {
      for (int j = 0; j < 9; j++) {
        int movesleft=9-game.getUsedTiles(i, j).length;
        if(movesleft<c.length){
          getRect(i, j, r);
          hint.setColor(c[movesleft]);
          canvas.drawRect(r, hint);
        }
      }
    }
  }
  }
  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    Log.d(TAG, "onKeyDown:keycode=" + keyCode + ",event=" + event);
    switch (keyCode) {
    case KeyEvent.KEYCODE_DPAD_UP:
      select(selX, selY - 1);
      break;
    case KeyEvent.KEYCODE_DPAD_DOWN:
      select(selX, selY + 1);
      break;
    case KeyEvent.KEYCODE_DPAD_LEFT:
      select(selX - 1, selY);
      break;
    case KeyEvent.KEYCODE_DPAD_RIGHT:
      select(selX + 1, selY);
      break;
    case KeyEvent.KEYCODE_0:
    case KeyEvent.KEYCODE_SPACE:
      setSelectedTile(0);
      break;
    case KeyEvent.KEYCODE_1:
      setSelectedTile(1);
      break;
    case KeyEvent.KEYCODE_2:
      setSelectedTile(2);
      break;
    case KeyEvent.KEYCODE_3:
      setSelectedTile(3);
      break;
    case KeyEvent.KEYCODE_4:
      setSelectedTile(4);
      break;
    case KeyEvent.KEYCODE_5:
      setSelectedTile(5);
      break;
    case KeyEvent.KEYCODE_6:
      setSelectedTile(6);
      break;
    case KeyEvent.KEYCODE_7:
      setSelectedTile(7);
      break;
    case KeyEvent.KEYCODE_8:
      setSelectedTile(8);
      break;
    case KeyEvent.KEYCODE_9:
      setSelectedTile(9);
      break;
    case KeyEvent.KEYCODE_ENTER:
    case KeyEvent.KEYCODE_DPAD_CENTER:
      game.showKeypadOrError(selX, selY);
    default:
      return super.onKeyDown(keyCode, event);
    }
    return true;
  }

  //显示软键盘
  @Override
  public boolean onTouchEvent(MotionEvent event) {
    // TODO Auto-generated method stub
    if(event.getAction()!=MotionEvent.ACTION_DOWN)
    return super.onTouchEvent(event);

    select((int)(event.getX()/width),(int)(event.getY()/height));
    game.showKeypadOrError(selX, selY);
    Log.d(TAG, "onTouchEvent:x"+selX+",y"+selY);
    return true;
  }

  public void setSelectedTile(int tile) {
    // TODO Auto-generated method stub
    //num is not valid for this tile
    Log.d(TAG, "selectedTile:invalid:"+tile);
//   startAnimation(AnimationUtils.loadAnimation(game, R.aims.shake));
    if (game.setTileIfValid(selX, selY, tile)) {
      invalidate();
    } else {
      // num is not invalid for this tile
      Log.d(TAG, "setSelectedTile:invalid " + tile);
    }

  }
  // 首先计算选定区域的x，y坐标，然后再次调用getRect方法计算新的选择矩形
  private void select(int x, int y) {
    // TODO Auto-generated method stub
    invalidate(selRect);// 第一次调用通知原选择的区域需要重绘
    selX = Math.min(Math.max(x, 0), 8);
    selY = Math.min(Math.max(y, 0), 8);
    getRect(selX, selY, selRect);
    invalidate(selRect);// 第二次调用通知新选择的区域也需要重绘
  }

  private void getRect(int x, int y, Rect rect) {
    // TODO Auto-generated method stub
    rect.set((int) (x * width), (int) (y * height),
        (int) (x * width + width), (int) (y * height + height));

  }

}

package com.dw.gamesuduku;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;

public class Settings extends Activity {
  private static final String OPT_MUSIC="music";
  private static final boolean OPT_MUSIC_DEF=true;
  private static final String OPT_HINTS="hints";
  private static final boolean OPT_HINTS_DEF=true;
  @Override
  public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    getFragmentManager().beginTransaction().replace(android.R.id.content, new PrefsFragement()).commit();
  }
  public static class PrefsFragement extends PreferenceFragment{ 
    public void onCreate(Bundle savedInstanceState) { 
      // TODO Auto-generated method stub 
      super.onCreate(savedInstanceState); 
      addPreferencesFromResource(R.xml.settings);
    } 
  } 
  //get the current music option
  public static boolean getMusic(Context context){
    return PreferenceManager.getDefaultSharedPreferences(context).getBoolean(OPT_MUSIC,OPT_MUSIC_DEF);
  }
  //get the current music option
  public static boolean getHints(Context context){
    return PreferenceManager.getDefaultSharedPreferences(context).getBoolean(OPT_HINTS,OPT_HINTS_DEF);
  }
}

package com.dw.gamesuduku;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;

public class Sudoku extends Activity implements OnClickListener {
  private static final String TAG = "Sudoku";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    View continueButton = this.findViewById(R.id.continue_button);
    continueButton.setOnClickListener(this);

    View newButton = this.findViewById(R.id.new_button);
    newButton.setOnClickListener(this);

    View aboutButton = this.findViewById(R.id.about_button);
    aboutButton.setOnClickListener(this);

    View exitButton = this.findViewById(R.id.exit_button);
    exitButton.setOnClickListener(this);
  }

  @Override
  public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case R.id.continue_button:
      startGame(Game.DIFFICULTY_CONTINUE);
    case R.id.about_button:
      Intent i = new Intent(this, About.class);
      startActivity(i);
      break;
    case R.id.new_button:
      openNewGameDialog();
      break;
    case R.id.exit_button:
      finish();
      break;
    }
  }
  @Override
  protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    Music.play(this, R.raw.welcome);
  }
  @Override
  protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    Music.stop(this);
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // TODO Auto-generated method stub

    super.onCreateOptionsMenu(menu);
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    switch (item.getItemId()) {
    case R.id.settings:
      startActivity(new Intent(this, Settings.class));
      return true;
    }
    return false;
  }

  private void openNewGameDialog() {
    // TODO Auto-generated method stub
    new AlertDialog.Builder(this).setTitle(R.string.new_game_title)
        .setItems(R.array.difficulty,
            new DialogInterface.OnClickListener() {

              @Override
              public void onClick(
                  DialogInterface dialoginterface, int i) {
                // TODO Auto-generated method stub
                startGame(i);
              }
            }).show();
  }
  protected void startGame(int i) {
    // TODO Auto-generated method stub
    Log.i(TAG, "clicked on"+i);
    Intent intent=new Intent(Sudoku.this,Game.class);
    intent.putExtra(Game.KEY_DIFFICULTY, i);
    startActivity(intent); 
  }
}