Connect4 — 04: אותו משחק אחרי סיבוב ופתיחה מחדש

     }
 }
 
 dependencies {
+    implementation("androidx.lifecycle:lifecycle-viewmodel:2.10.0")
     implementation(libs.activity.ktx)
     implementation(libs.appcompat)
     implementation(libs.constraintlayout)
     implementation(libs.material)

 package com.example.connect4;
 
 import android.os.Bundle;
+import androidx.lifecycle.ViewModelProvider;
 import com.example.connect4.core.GameAction;
 import com.example.connect4.core.GameEngine;
 import com.example.connect4.core.GameState;

 import androidx.core.view.WindowInsetsCompat;
 
 public class MainActivity extends AppCompatActivity {
     private ActivityMainBinding binding;
-    private GameEngine engine = new GameEngine();
+    private GameSession session;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

             Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
             v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
             return insets;
         });
+        session = new ViewModelProvider(this).get(GameSession.class);
+        if (!session.restored) {
+            String moves = getPreferences(MODE_PRIVATE).getString("moves", "");
+            GameEngine restored = new GameEngine();
+            for (int i = 0; i < moves.length(); i++) {
+                if (!restored.apply(new GameAction(moves.charAt(i) - '0'))) break;
+            }
+            session.engine = restored;
+            session.restored = true;
+        }
         binding.board.setColumnListener(column -> {
-            if (engine.apply(new GameAction(column))) render();
+            if (session.engine.apply(new GameAction(column))) { persist(); render(); }
         });
         binding.restart.setOnClickListener(v -> {
-            engine = new GameEngine();
+            session.engine = new GameEngine();
+            persist();
             render();
         });
         render();
     }
     /** Presents the model; drawing does not change the game. */
     private void render() {
-        GameState state = engine.snapshot();
+        GameState state = session.engine.snapshot();
         binding.board.show(state);
         if (state.isDraw()) binding.status.setText("Draw — board full");
         else if (state.isTerminal()) binding.status.setText(state.winner() == GameState.RED ? "Red wins!" : "Yellow wins!");
         else binding.status.setText(state.currentPlayer() == GameState.RED ? "Red to play" : "Yellow to play");
     }
+
+    /** Saves only accepted column history; the engine reconstructs the rest. */
+    private void persist() {
+        getPreferences(MODE_PRIVATE).edit().putString("moves", session.engine.snapshot().moves()).apply();
+    }
+
+    @Override protected void onStop() {
+        persist();
+        super.onStop();
+    }
 }