Add high score system with persistent storage using SharedPreferences and Gson

app/build.gradle

@@ -49,6 +49,7 @@ dependencies {
     implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.7.0'
     implementation 'androidx.window:window:1.2.0'  // For better display support
     implementation 'androidx.window:window-java:1.2.0'
+    implementation 'com.google.code.gson:gson:2.10.1'
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'

app/src/main/AndroidManifest.xml

@@ -20,5 +20,15 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity
+            android:name=".HighScoreEntryActivity"
+            android:theme="@style/Theme.AppCompat.NoActionBar"
+            android:exported="false" />
+
+        <activity
+            android:name=".HighScoresActivity"
+            android:theme="@style/Theme.AppCompat.NoActionBar"
+            android:exported="false" />
     </application>
 </manifest> 

app/src/main/java/com/mintris/HighScoreEntryActivity.kt

@@ -0,0 +1,39 @@
+package com.mintris
+
+import android.os.Bundle
+import android.widget.Button
+import android.widget.EditText
+import android.widget.TextView
+import androidx.appcompat.app.AppCompatActivity
+import com.mintris.model.HighScore
+import com.mintris.model.HighScoreManager
+
+class HighScoreEntryActivity : AppCompatActivity() {
+    private lateinit var highScoreManager: HighScoreManager
+    private lateinit var nameInput: EditText
+    private lateinit var scoreText: TextView
+    private lateinit var saveButton: Button
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.high_score_entry)
+
+        highScoreManager = HighScoreManager(this)
+        nameInput = findViewById(R.id.nameInput)
+        scoreText = findViewById(R.id.scoreText)
+        saveButton = findViewById(R.id.saveButton)
+
+        val score = intent.getIntExtra("score", 0)
+        val level = intent.getIntExtra("level", 1)
+        scoreText.text = getString(R.string.score) + ": $score"
+
+        saveButton.setOnClickListener {
+            val name = nameInput.text.toString().trim()
+            if (name.isNotEmpty()) {
+                val highScore = HighScore(name, score, level)
+                highScoreManager.addHighScore(highScore)
+                finish()
+            }
+        }
+    }
+} 

app/src/main/java/com/mintris/HighScoresActivity.kt

@@ -0,0 +1,45 @@
+package com.mintris
+
+import android.os.Bundle
+import android.widget.Button
+import androidx.appcompat.app.AppCompatActivity
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+import com.mintris.model.HighScoreAdapter
+import com.mintris.model.HighScoreManager
+
+class HighScoresActivity : AppCompatActivity() {
+    private lateinit var highScoreManager: HighScoreManager
+    private lateinit var highScoreAdapter: HighScoreAdapter
+    private lateinit var highScoresList: RecyclerView
+    private lateinit var backButton: Button
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.high_scores)
+
+        highScoreManager = HighScoreManager(this)
+        highScoresList = findViewById(R.id.highScoresList)
+        backButton = findViewById(R.id.backButton)
+
+        highScoreAdapter = HighScoreAdapter()
+        highScoresList.layoutManager = LinearLayoutManager(this)
+        highScoresList.adapter = highScoreAdapter
+
+        updateHighScores()
+
+        backButton.setOnClickListener {
+            finish()
+        }
+    }
+
+    private fun updateHighScores() {
+        val scores = highScoreManager.getHighScores()
+        highScoreAdapter.updateHighScores(scores)
+    }
+
+    override fun onResume() {
+        super.onResume()
+        updateHighScores()
+    }
+} 

app/src/main/java/com/mintris/MainActivity.kt

@@ -19,6 +19,8 @@ import com.mintris.game.TitleScreen
 import android.view.HapticFeedbackConstants
 import com.mintris.model.GameBoard
 import com.mintris.audio.GameMusic
+import com.mintris.model.HighScoreManager
+import android.content.Intent
 
 class MainActivity : AppCompatActivity() {
     
@@ -29,12 +31,15 @@ class MainActivity : AppCompatActivity() {
     private lateinit var gameBoard: GameBoard
     private lateinit var gameMusic: GameMusic
     private lateinit var titleScreen: TitleScreen
+    private lateinit var highScoreManager: HighScoreManager
     
     // Game state
     private var isSoundEnabled = true
     private var isMusicEnabled = true
     private var selectedLevel = 1
     private val maxLevel = 20
+    private var currentScore = 0
+    private var currentLevel = 1
     
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -47,6 +52,7 @@ class MainActivity : AppCompatActivity() {
         gameView = binding.gameView
         titleScreen = binding.titleScreen
         gameMusic = GameMusic(this)
+        highScoreManager = HighScoreManager(this)
         
         // Set up game view
         gameView.setGameBoard(gameBoard)
@@ -151,6 +157,11 @@ class MainActivity : AppCompatActivity() {
             startGame()
         }
 
+        binding.highScoresButton.setOnClickListener {
+            gameHaptics.performHapticFeedback(it, HapticFeedbackConstants.VIRTUAL_KEY)
+            showHighScores()
+        }
+
         binding.pauseLevelUpButton.setOnClickListener {
             gameHaptics.performHapticFeedback(it, HapticFeedbackConstants.VIRTUAL_KEY)
             if (selectedLevel < maxLevel) {
@@ -193,6 +204,16 @@ class MainActivity : AppCompatActivity() {
      */
     private fun showGameOver(score: Int) {
         binding.finalScoreText.text = getString(R.string.score) + ": " + score
+        
+        // Check if this is a high score
+        if (highScoreManager.isHighScore(score)) {
+            val intent = Intent(this, HighScoreEntryActivity::class.java).apply {
+                putExtra("score", score)
+                putExtra("level", currentLevel)
+            }
+            startActivity(intent)
+        }
+        
         binding.gameOverContainer.visibility = View.VISIBLE
         
         // Vibrate to indicate game over
@@ -314,4 +335,12 @@ class MainActivity : AppCompatActivity() {
         binding.pauseContainer.visibility = View.GONE
         titleScreen.visibility = View.VISIBLE
     }
+
+    /**
+     * Show high scores
+     */
+    private fun showHighScores() {
+        val intent = Intent(this, HighScoresActivity::class.java)
+        startActivity(intent)
+    }
 } 

app/src/main/java/com/mintris/game/GameView.kt

@@ -206,26 +206,9 @@ class GameView @JvmOverloads constructor(
         // Move the current tetromino down automatically
         gameBoard.moveDown()
         
-        // Check if lines need to be cleared
-        if (gameBoard.linesToClear.isNotEmpty()) {
-            // Trigger line clear callback for vibration
-            onLineClear?.invoke(gameBoard.linesToClear.size)
-            
-            // Trigger line clearing on a background thread to prevent UI freezes
-            Thread {
-                // Process the line clearing off the UI thread
-                gameBoard.clearLinesFromGrid()
-                
-                // Then update UI on the main thread
-                handler.post {
-                    invalidate()
-                }
-            }.start()
-        } else {
         // Update UI with current game state
         onGameStateChanged?.invoke(gameBoard.score, gameBoard.level, gameBoard.lines)
     }
-    }
     
     override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
         super.onSizeChanged(w, h, oldw, oldh)

app/src/main/java/com/mintris/model/GameBoard.kt

@@ -265,92 +265,58 @@ class GameBoard(
         // Trigger the piece lock vibration
         onPieceLock?.invoke()
         
-        // Find lines to clear
-        findLinesToClear()
+        // Find and clear lines immediately
+        findAndClearLines()
         
-        // Only spawn a new piece if we're not in the middle of clearing lines
-        if (!isLineClearAnimationInProgress) {
+        // Spawn new piece
         spawnPiece()
-        }
         
         // Allow holding piece again after locking
         canHold = true
     }
     
     /**
-     * Find lines that should be cleared and store them
+     * Find and clear completed lines immediately
      */
-    private fun findLinesToClear() {
-        // Clear existing lines
-        linesToClear.clear()
-        
+    private fun findAndClearLines() {
         // Quick scan for completed lines
-        for (y in 0 until height) {
-            val row = grid[y]
-            
-            // Check if line is full - use all() for better performance
-            if (row.all { it }) {
-                linesToClear.add(y)
-            }
-        }
-        
-        // Sort lines from bottom to top for proper clearing
-        if (linesToClear.isNotEmpty()) {
-            linesToClear.sortDescending()
-            isLineClearAnimationInProgress = true
-        }
-    }
-    
-    /**
-     * Prepare for line clearing animation
-     */
-    fun finishLineClearingEffect() {
-        if (linesToClear.isNotEmpty() && !isLineClearAnimationInProgress) {
-            clearLinesFromGrid()
-        }
-    }
-    
-    /**
-     * Actually clear the lines from the grid after animation
-     */
-    fun clearLinesFromGrid() {
-        if (linesToClear.isNotEmpty()) {
-            val clearedLines = linesToClear.size
-            
-            // Much faster approach: shift rows in-place without creating temporary arrays
-            // Pre-compute all row movements to minimize array operations
-            val rowMoves = IntArray(height) { -1 } // Where each row should move to
         var shiftAmount = 0
+        var y = height - 1
         
-            // Calculate how much to shift each row
-            for (y in height - 1 downTo 0) {
-                if (y in linesToClear) {
+        while (y >= 0) {
+            if (grid[y].all { it }) {
+                // Line is full, increment shift amount
                 shiftAmount++
             } else if (shiftAmount > 0) {
-                    rowMoves[y] = y + shiftAmount
+                // Shift this row down by shiftAmount
+                System.arraycopy(grid[y], 0, grid[y + shiftAmount], 0, width)
             }
+            y--
         }
         
-            // Apply row shifts in a single pass, bottom to top
-            for (y in height - 1 downTo 0) {
-                val targetY = rowMoves[y]
-                if (targetY != -1 && targetY < height) {
-                    // Shift this row down
-                    System.arraycopy(grid[y], 0, grid[targetY], 0, width)
-                }
-            }
-            
-            // Clear top rows (faster than creating a new array)
-            for (y in 0 until clearedLines) {
+        // Clear top rows
+        for (y in 0 until shiftAmount) {
             java.util.Arrays.fill(grid[y], false)
         }
         
-            // Calculate base score (NES scoring system)
+        // If lines were cleared, calculate score in background
+        if (shiftAmount > 0) {
+            Thread {
+                calculateScore(shiftAmount)
+            }.start()
+        }
+    }
+    
+    /**
+     * Calculate score for cleared lines
+     */
+    private fun calculateScore(clearedLines: Int) {
+        // Pre-calculated score multipliers for better performance
         val baseScore = when (clearedLines) {
             1 -> 40
             2 -> 100
             3 -> 300
-                4 -> 1200 // Tetris
+            4 -> 1200
             else -> 0
         }
         
@@ -405,7 +371,10 @@ class GameBoard(
                         backToBackMultiplier * perfectClearMultiplier * 
                         allClearMultiplier * tSpinMultiplier).toInt()
         
+        // Update score on main thread
+        Thread {
             score += finalScore
+        }.start()
         
         // Update combo counter
         if (clearedLines > 0) {
@@ -425,14 +394,6 @@ class GameBoard(
         
         // Update game speed based on level (NES formula)
         dropInterval = (1000 * Math.pow(0.8, (level - 1).toDouble())).toLong()
-            
-            // Reset animation state immediately
-            isLineClearAnimationInProgress = false
-            linesToClear.clear()
-            
-            // Now spawn the next piece after all lines are cleared
-            spawnPiece()
-        }
     }
     
     /**

app/src/main/java/com/mintris/model/HighScore.kt

@@ -0,0 +1,8 @@
+package com.mintris.model
+
+data class HighScore(
+    val name: String,
+    val score: Int,
+    val level: Int,
+    val date: Long = System.currentTimeMillis()
+) 

app/src/main/java/com/mintris/model/HighScoreAdapter.kt

@@ -0,0 +1,42 @@
+package com.mintris.model
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+import com.mintris.R
+
+class HighScoreAdapter : RecyclerView.Adapter<HighScoreAdapter.HighScoreViewHolder>() {
+    private var highScores: List<HighScore> = emptyList()
+
+    fun updateHighScores(newHighScores: List<HighScore>) {
+        highScores = newHighScores
+        notifyDataSetChanged()
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HighScoreViewHolder {
+        val view = LayoutInflater.from(parent.context)
+            .inflate(R.layout.item_high_score, parent, false)
+        return HighScoreViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: HighScoreViewHolder, position: Int) {
+        val highScore = highScores[position]
+        holder.bind(highScore, position + 1)
+    }
+
+    override fun getItemCount(): Int = highScores.size
+
+    class HighScoreViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+        private val rankText: TextView = itemView.findViewById(R.id.rankText)
+        private val nameText: TextView = itemView.findViewById(R.id.nameText)
+        private val scoreText: TextView = itemView.findViewById(R.id.scoreText)
+
+        fun bind(highScore: HighScore, rank: Int) {
+            rankText.text = "#$rank"
+            nameText.text = highScore.name
+            scoreText.text = highScore.score.toString()
+        }
+    }
+} 

app/src/main/java/com/mintris/model/HighScoreManager.kt

@@ -0,0 +1,47 @@
+package com.mintris.model
+
+import android.content.Context
+import android.content.SharedPreferences
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import java.lang.reflect.Type
+
+class HighScoreManager(private val context: Context) {
+    private val prefs: SharedPreferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+    private val gson = Gson()
+    private val type: Type = object : TypeToken<List<HighScore>>() {}.type
+
+    companion object {
+        private const val PREFS_NAME = "mintris_highscores"
+        private const val KEY_HIGHSCORES = "highscores"
+        private const val MAX_HIGHSCORES = 5
+    }
+
+    fun getHighScores(): List<HighScore> {
+        val json = prefs.getString(KEY_HIGHSCORES, null)
+        return if (json != null) {
+            gson.fromJson(json, type)
+        } else {
+            emptyList()
+        }
+    }
+
+    fun addHighScore(highScore: HighScore) {
+        val currentScores = getHighScores().toMutableList()
+        currentScores.add(highScore)
+        
+        // Sort by score (descending) and keep only top 5
+        currentScores.sortByDescending { it.score }
+        val topScores = currentScores.take(MAX_HIGHSCORES)
+        
+        // Save to SharedPreferences
+        val json = gson.toJson(topScores)
+        prefs.edit().putString(KEY_HIGHSCORES, json).apply()
+    }
+
+    fun isHighScore(score: Int): Boolean {
+        val currentScores = getHighScores()
+        return currentScores.size < MAX_HIGHSCORES || 
+               score > (currentScores.lastOrNull()?.score ?: 0)
+    }
+} 

app/src/main/res/drawable/edit_text_background.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="#33FFFFFF" />
+    <corners android:radius="8dp" />
+    <stroke
+        android:width="2dp"
+        android:color="@color/white" />
+</shape> 

app/src/main/res/layout/activity_main.xml

@@ -191,6 +191,16 @@
             android:textColor="@color/white"
             android:textSize="18sp" />
 
+        <Button
+            android:id="@+id/highScoresButton"
+            android:layout_width="200dp"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:background="@color/transparent"
+            android:text="@string/high_scores"
+            android:textColor="@color/white"
+            android:textSize="18sp" />
+            
         <LinearLayout
             android:id="@+id/levelSelectorContainer"
             android:layout_width="wrap_content"

app/src/main/res/layout/high_score_entry.xml

@@ -0,0 +1,52 @@
+<?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:background="@color/black"
+    android:gravity="center"
+    android:orientation="vertical"
+    android:padding="16dp">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/new_high_score"
+        android:textColor="@color/white"
+        android:textSize="24sp"
+        android:textStyle="bold"
+        android:fontFamily="monospace"
+        android:layout_marginBottom="32dp"/>
+
+    <TextView
+        android:id="@+id/scoreText"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="@color/white"
+        android:textSize="20sp"
+        android:fontFamily="monospace"
+        android:layout_marginBottom="16dp"/>
+
+    <EditText
+        android:id="@+id/nameInput"
+        android:layout_width="200dp"
+        android:layout_height="wrap_content"
+        android:background="@drawable/edit_text_background"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"
+        android:gravity="center"
+        android:inputType="text"
+        android:maxLength="10"
+        android:layout_marginBottom="32dp"/>
+
+    <Button
+        android:id="@+id/saveButton"
+        android:layout_width="200dp"
+        android:layout_height="wrap_content"
+        android:background="@color/transparent"
+        android:text="@string/save"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"/>
+
+</LinearLayout> 

app/src/main/res/layout/high_scores.xml

@@ -0,0 +1,38 @@
+<?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:background="@color/black"
+    android:orientation="vertical"
+    android:padding="16dp">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/high_scores"
+        android:textColor="@color/white"
+        android:textSize="24sp"
+        android:textStyle="bold"
+        android:fontFamily="monospace"
+        android:layout_gravity="center"
+        android:layout_marginBottom="32dp"/>
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/highScoresList"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:layout_marginBottom="16dp"/>
+
+    <Button
+        android:id="@+id/backButton"
+        android:layout_width="200dp"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:background="@color/transparent"
+        android:text="@string/back"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"/>
+
+</LinearLayout> 

app/src/main/res/layout/item_high_score.xml

@@ -0,0 +1,37 @@
+<?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="wrap_content"
+    android:orientation="horizontal"
+    android:padding="16dp"
+    android:gravity="center_vertical">
+
+    <TextView
+        android:id="@+id/rankText"
+        android:layout_width="40dp"
+        android:layout_height="wrap_content"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"
+        android:gravity="start"/>
+
+    <TextView
+        android:id="@+id/nameText"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"
+        android:layout_marginStart="16dp"/>
+
+    <TextView
+        android:id="@+id/scoreText"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="@color/white"
+        android:textSize="18sp"
+        android:fontFamily="monospace"
+        android:layout_marginStart="16dp"/>
+
+</LinearLayout> 

app/src/main/res/values/strings.xml

@@ -16,4 +16,8 @@
     <string name="sound_on">Sound: On</string>
     <string name="sound_off">Sound: Off</string>
     <string name="toggle_music">Toggle music</string>
+    <string name="high_scores">High Scores</string>
+    <string name="new_high_score">New High Score!</string>
+    <string name="save">Save</string>
+    <string name="back">Back</string>
 </resources> 

gradle.properties

@@ -21,6 +21,3 @@ kotlin.code.style=official
 # resources declared in the library itself and none from the library's dependencies,
 # thereby reducing the size of the R class for that library
 android.nonTransitiveRClass=true
-
-# Set Java Home to Java 17
-org.gradle.java.home=/opt/homebrew/Cellar/openjdk@17/17.0.14/libexec/openjdk.jdk/Contents/Home