Disable diagonal inputs and prevent accidental hard drops. Block back swipe gesture to prevent accidental app exits.

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.VIBRATE" />
+    <!-- Add permission to handle system gestures if needed on some devices -->
+    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
 
     <application
         android:allowBackup="true"
@@ -14,7 +16,10 @@
             android:name=".MainActivity"
             android:exported="true"
             android:screenOrientation="portrait"
-            android:theme="@style/Theme.Mintris.NoActionBar">
+            android:theme="@style/Theme.Mintris.NoActionBar"
+            android:immersive="true"
+            android:resizeableActivity="false"
+            android:excludeFromRecents="false">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />

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

@@ -32,6 +32,8 @@ import java.util.*
 import android.graphics.Color
 import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.result.contract.ActivityResultContracts
+import android.graphics.Rect
+import android.view.KeyEvent
 
 class MainActivity : AppCompatActivity() {
     
@@ -73,6 +75,9 @@ class MainActivity : AppCompatActivity() {
         binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
         
+        // Disable Android back gesture to prevent accidental app exits
+        disableAndroidBackGesture()
+        
         // Initialize game components
         gameBoard = GameBoard()
         gameHaptics = GameHaptics(this)
@@ -646,4 +651,83 @@ class MainActivity : AppCompatActivity() {
             else -> Color.WHITE
         }
     }
+
+    /**
+     * Disables the Android system back gesture to prevent accidental exits
+     */
+    private fun disableAndroidBackGesture() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            // Set the entire window to be excluded from the system gesture areas
+            window.decorView.post {
+                // Create a list of rectangles representing the edges of the screen to exclude from system gestures
+                val gestureInsets = window.decorView.rootWindowInsets?.systemGestureInsets
+                if (gestureInsets != null) {
+                    val leftEdge = Rect(0, 0, 50, window.decorView.height)
+                    val rightEdge = Rect(window.decorView.width - 50, 0, window.decorView.width, window.decorView.height)
+                    val bottomEdge = Rect(0, window.decorView.height - 50, window.decorView.width, window.decorView.height)
+                    
+                    window.decorView.systemGestureExclusionRects = listOf(leftEdge, rightEdge, bottomEdge)
+                }
+            }
+        }
+        
+        // Add an on back pressed callback to handle back button/gesture
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            onBackPressedDispatcher.addCallback(this, object : androidx.activity.OnBackPressedCallback(true) {
+                override fun handleOnBackPressed() {
+                    // If we're playing the game, handle it as a pause action instead of exiting
+                    if (gameView.visibility == View.VISIBLE && !gameView.isPaused && !gameView.isGameOver()) {
+                        gameView.pause()
+                        gameMusic.pause()
+                        showPauseMenu()
+                        binding.pauseStartButton.visibility = View.GONE
+                        binding.resumeButton.visibility = View.VISIBLE
+                    } else if (binding.pauseContainer.visibility == View.VISIBLE) {
+                        // If pause menu is showing, handle as a resume
+                        resumeGame()
+                    } else if (binding.gameOverContainer.visibility == View.VISIBLE) {
+                        // If game over is showing, go back to title
+                        hideGameOver()
+                        showTitleScreen()
+                    } else if (titleScreen.visibility == View.VISIBLE) {
+                        // If title screen is showing, allow normal back behavior (exit app)
+                        isEnabled = false
+                        onBackPressedDispatcher.onBackPressed()
+                    }
+                }
+            })
+        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            // For Android 11 (R) to Android 12 (S), use the WindowInsetsController to disable gestures
+            window.insetsController?.systemBarsBehavior = 
+                android.view.WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+        }
+    }
+    
+    /**
+     * Completely block the hardware back button during gameplay
+     */
+    override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
+        // If back button is pressed
+        if (keyCode == KeyEvent.KEYCODE_BACK) {
+            // Handle back button press as a pause action during gameplay
+            if (gameView.visibility == View.VISIBLE && !gameView.isPaused && !gameView.isGameOver()) {
+                gameView.pause()
+                gameMusic.pause()
+                showPauseMenu()
+                binding.pauseStartButton.visibility = View.GONE
+                binding.resumeButton.visibility = View.VISIBLE
+                return true // Consume the event
+            } else if (binding.pauseContainer.visibility == View.VISIBLE) {
+                // If pause menu is showing, handle as a resume
+                resumeGame()
+                return true // Consume the event
+            } else if (binding.gameOverContainer.visibility == View.VISIBLE) {
+                // If game over is showing, go back to title
+                hideGameOver()
+                showTitleScreen()
+                return true // Consume the event
+            }
+        }
+        return super.onKeyDown(keyCode, event)
+    }
 } 

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

@@ -39,7 +39,8 @@ class GameView @JvmOverloads constructor(
     
     // Game state
     private var isRunning = false
-    private var isPaused = false
+    var isPaused = false  // Changed from private to public to allow access from MainActivity
+    private var score = 0
     
     // Callbacks
     var onNextPieceChanged: (() -> Unit)? = null
@@ -128,14 +129,16 @@ class GameView @JvmOverloads constructor(
     private var lastTapTime = 0L
     private var lastRotationTime = 0L
     private var lastMoveTime = 0L
-    private var minSwipeVelocity = 800  // Minimum velocity for swipe to be considered a hard drop
+    private var minSwipeVelocity = 1200  // Increased from 800 to require more deliberate swipes
     private val maxTapMovement = 20f    // Maximum movement allowed for a tap (in pixels)
     private val minTapTime = 100L       // Minimum time for a tap (in milliseconds)
     private val rotationCooldown = 150L // Minimum time between rotations (in milliseconds)
     private val moveCooldown = 50L      // Minimum time between move haptics (in milliseconds)
     private var lockedDirection: Direction? = null  // Track the locked movement direction
     private val minMovementThreshold = 0.75f  // Minimum movement threshold relative to block size
-    private val directionLockThreshold = 1.5f  // Threshold for direction lock relative to block size
+    private val directionLockThreshold = 2.5f  // Increased from 1.5f to make direction locking more aggressive
+    private val isStrictDirectionLock = true   // Enable strict direction locking to prevent diagonal inputs
+    private val minHardDropDistance = 1.5f     // Minimum distance (in blocks) for hard drop gesture
 
     private enum class Direction {
         HORIZONTAL, VERTICAL
@@ -612,12 +615,14 @@ class GameView @JvmOverloads constructor(
                     
                     // Check if movement exceeds threshold
                     if (absDeltaX > blockSize * minMovementThreshold || absDeltaY > blockSize * minMovementThreshold) {
-                        // Determine dominant direction
+                        // Determine dominant direction with stricter criteria
                         if (absDeltaX > absDeltaY * directionLockThreshold) {
                             lockedDirection = Direction.HORIZONTAL
                         } else if (absDeltaY > absDeltaX * directionLockThreshold) {
                             lockedDirection = Direction.VERTICAL
                         }
+                        // If strict direction lock is enabled and we couldn't determine a clear direction, don't set one
+                        // This prevents diagonal movements from being recognized
                     }
                 }
                 
@@ -661,8 +666,12 @@ class GameView @JvmOverloads constructor(
                 val deltaY = event.y - startY
                 val deltaX = event.x - startX
                 
-                // If the movement was fast and downward, treat as hard drop
+                // Only allow hard drops with a deliberate downward swipe
-                if (moveTime > 0 && deltaY > blockSize * 0.5f && (deltaY / moveTime) * 1000 > minSwipeVelocity) {
+                // Requires: predominantly vertical movement, minimum distance, and minimum velocity
+                if (moveTime > 0 && 
+                    deltaY > blockSize * minHardDropDistance && // Require longer swipe for hard drop
+                    (deltaY / moveTime) * 1000 > minSwipeVelocity && 
+                    abs(deltaX) < abs(deltaY) * 0.3f) { // Require more purely vertical movement (reduced from 0.5f to 0.3f)
                     gameBoard.hardDrop()
                     invalidate()
                 } else if (moveTime < minTapTime &&