Classic Sudoku Puzzle Offline Games (Android Studio – Admob – GDPR)

Introduction

In this tutorial, we will create a classic Sudoku puzzle offline game using Android Studio, AdMob for monetization, and comply with the General Data Protection Regulation (GDPR). The game will have a user-friendly interface, allow users to play in offline mode, and earn rewards through AdMob interstitial ads.

Table of Contents

1. Setting up the project structure
2. Creating the game logic
3. Implementing AdMob interstitial ads
4. Adding GDPR compliance
5. Designing the game UI
6. Implementing game features
7. Testing and debugging

Step 1: Setting up the project structure

1. Open Android Studio and create a new project.
2. Name the project "Sudoku Offline Game" and set the package name to "com.example.sudoku".
3. Choose the Minimum SDK as API 16: Android 4.1 (Jelly Bean) and the Target SDK as API 29: Android 10 (Q).
4. Create a new folder called "resources" inside the project folder and add the following subfolders:
   • layouts
   • values
   • drawables
   • raw
   • res
5. Create a new Java file called "SudokuActivity.java" inside the src/main/java folder.

Step 2: Creating the game logic

1. In the SudokuActivity.java file, create a Sudoku game class that inherits from Activity:

   public class SudokuGame extends AppCompatActivity {
   // game logic goes here
   }

2. Add the necessary variables and methods to the SudokuGame class:

   
   private int[][] board = new int[9][9]; // Sudoku board
   private int[] row = new int[9]; // row indices
   private int[] col = new int[9]; // column indices
   private int[] block = new int[3]; // block indices
   private boolean isSolved = false;

public void generateBoard() { // generate a random Sudoku board }

public void solveBoard() { // solve the Sudoku board using a backtracking algorithm }

public boolean isValidMove(int row, int col, int value) { // check if the move is valid (i.e., the value is not already present in the row, column, or block) }

public void makeMove(int row, int col, int value) { // make the move and update the board }

public void undoMove(int row, int col, int value) { // undo the move and update the board }

public void checkWin() { // check if the game is won }

public void checkLoss() { // check if the game is lost (i.e., the player has made an invalid move) }

3. Implement the generateBoard(), solveBoard(), and isValidMove() methods using a random number generator, a backtracking algorithm, and a validation algorithm respectively.

**Step 3: Implementing AdMob interstitial ads**

1. Create a new AdMob account and get a new ad unit ID.
2. Add the following dependencies to the build.gradle file:
```groovy
implementation 'com.google.android.gms:play-services-ads:20.2.0'
implementation 'com.google.android.gms:play-services-ads-api:20.2.0'

1. In the SudokuActivity.java file, add the following code to display interstitial ads:

   
   import com.google.android.gms.ads.AdRequest;
   import com.google.android.gms.ads.InterstitialAd;

private InterstitialAd interstitialAd;

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); interstitialAd = new InterstitialAd(this); interstitialAd.setAdUnitId("YOUR_AD_UNIT_ID"); interstitialAd.loadAd(new AdRequest.Builder().build()); }

@Override public void onBackPressed() { if (interstitialAd.isLoaded()) { interstitialAd.show(); } else { super.onBackPressed(); } }

4. Add a new layout file called "ad_layout.xml" with the following code:
```xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.gms.ads.AdView
            android:id="@+id/adView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            ads:adSize="BANNER"
            ads:adUnitId="YOUR_AD_UNIT_ID" />

    </FrameLayout>

</LinearLayout>

Step 4: Adding GDPR compliance

1. Add the following dependencies to the build.gradle file:

   implementation 'org.apache.commons:commons-collections4:4.4'
   implementation 'org.apache.commons:commons-lang3:3.12.0'

2. In the SudokuActivity.java file, add the following code to handle GDPR consent:

   
   import org.apache.commons.collections4.CollectionUtils;
   import org.apache.commons.lang3.StringUtils;

private boolean isGDPRConsentGiven = false;

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); isGDPRConsentGiven = getSharedPreferences("GDPR_CONSENT", MODE_PRIVATE).getBoolean("GDPR_CONSENT", false); }

public void requestGDPRConsent() { // display a consent dialog to the user if (isGDPRConsentGiven) { // user has given consent, proceed with the game } else { // user has not given consent, exit the game finish(); } }

3. Create a new layout file called "gdpr_layout.xml" with the following code:
```xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/consent_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="16sp" />

    <Button
        android:id="@+id/accept_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Accept" />

    <Button
        android:id="@+id/decline_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Decline" />

</LinearLayout>

Step 5: Designing the game UI

1. Create a new layout file called "main_layout.xml" with the following code:

   
   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical">
   
   <TextView
       android:id="@+id/game_header"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:textSize="24sp" />
   
   <FrameLayout
       android:layout_width="match_parent"
       android:layout_height="match_parent">
   
       <TableLayout
           android:layout_width="match_parent"
           android:layout_height="match_parent">
   
           <TableRow
               android:layout_width="match_parent"
               android:layout_height="wrap_content">
   
               <TextView
                   android:id="@+id/cell_11"
                   android:layout_width="0dp"
                   android:layout_height="wrap_content"
                   android:layout_weight="1"
                   android:textSize="24sp" />
   
               <TextView
                   android:id="@+id/cell_12"
                   android:layout_width="0dp"
                   android:layout_height="wrap_content"
                   android:layout_weight="1"
                   android:textSize="24sp" />
   
               <!--... (add 80 more cell TextViews)... -->
   
           </TableRow>
   
           <!--... (add 8 more TableRow elements)... -->
   
       </TableLayout>
   
   </FrameLayout>
   
   <Button
       android:id="@+id/solve_button"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Solve" />
   
   <Button
       android:id="@+id/undo_button"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Undo" />
   
   <Button
       android:id="@+id/redo_button"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Redo" />

2. Create a new layout file called "menu_layout.xml" with the following code:
```xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/new_game_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Game" />

    <Button
        android:id="@+id/quit_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Quit" />

</LinearLayout>

Step 6: Implementing game features

1. In the SudokuActivity.java file, add the following code to implement the game features:

   
   import android.view.View;
   import android.widget.Button;
   import android.widget.TableLayout;
   import android.widget.TextView;

public class SudokuActivity extends AppCompatActivity { //...

private Button solveButton;
private Button undoButton;
private Button redoButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_layout);

    solveButton = findViewById(R.id.solve_button);
    undoButton = findViewById(R.id.undo_button);
    redoButton = findViewById(R.id.redo_button);

    solveButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            solveBoard();
        }
    });

    undoButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            undoMove();
        }
    });

    redoButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            redoMove();
        }
    });
}

public void solveBoard() {
    // solve the Sudoku board
}

public void undoMove() {
    // undo the last move
}

public void redoMove() {
    // redo the last move
}

}

2. In the SudokuActivity.java file, add the following code to implement the game logic:
```java
import android.widget.TableLayout;

public class SudokuActivity extends AppCompatActivity {
    //...

    private TableLayout boardLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);

        boardLayout = findViewById(R.id.board_table);

        // generate a random Sudoku board
        generateBoard();

        // display the board
        displayBoard();
    }

    public void generateBoard() {
        // generate a random Sudoku board
    }

    public void displayBoard() {
        // display the Sudoku board
    }
}

Step 7: Testing and debugging

1. Run the game on a physical device or emulator and test the features.
2. Debug the game by using the Android Studio debugger and checking for any errors or exceptions.

By following these steps, you should be able to create a classic Sudoku puzzle offline game using Android Studio, AdMob for monetization, and comply with the General Data Protection Regulation (GDPR).