Added persistence of game state to localstorage after each move

Added rebuilding of game state from localstoage on page load
Added New Game button to allow game restarts now that refreshes resume the game

js/game_manager.js

@@ -1,7 +1,7 @@
-function GameManager(size, InputManager, Actuator, ScoreManager) {
+function GameManager(size, InputManager, Actuator, StorageManager) {
   this.size         = size; // Size of the grid
   this.inputManager = new InputManager;
-  this.scoreManager = new ScoreManager;
+  this.storageManager = new StorageManager;
   this.actuator     = new Actuator;
 
   this.startTiles   = 2;
@@ -15,6 +15,7 @@ function GameManager(size, InputManager, Actuator, ScoreManager) {
 
 // Restart the game
 GameManager.prototype.restart = function () {
+  this.storageManager.clearGameState();
   this.actuator.continue();
   this.setup();
 };
@@ -35,15 +36,24 @@ GameManager.prototype.isGameTerminated = function () {
 
 // Set up the game
 GameManager.prototype.setup = function () {
-  this.grid        = new Grid(this.size);
+  var previousGameState = this.storageManager.getGameState();
 
-  this.score       = 0;
-  this.over        = false;
-  this.won         = false;
-  this.keepPlaying = false;
+  if (previousGameState) {
+      this.grid        = new Grid(previousGameState.grid.size, previousGameState.grid.cells);
+      this.score       = previousGameState.score;
+      this.over        = previousGameState.over;
+      this.won         = previousGameState.won;
+      this.keepPlaying = previousGameState.keepPlaying;
+  } else {
+      this.grid        = new Grid(this.size);
+      this.score       = 0;
+      this.over        = false;
+      this.won         = false;
+      this.keepPlaying = false;
 
-  // Add the initial tiles
-  this.addStartTiles();
+      // Add the initial tiles
+      this.addStartTiles();
+  }
 
   // Update the actuator
   this.actuate();
@@ -68,20 +78,33 @@ GameManager.prototype.addRandomTile = function () {
 
 // Sends the updated grid to the actuator
 GameManager.prototype.actuate = function () {
-  if (this.scoreManager.get() < this.score) {
-    this.scoreManager.set(this.score);
+  if (this.storageManager.getBestScore() < this.score) {
+    this.storageManager.setBestScore(this.score);
   }
 
+  this.storageManager.setGameState(this.serializeGameState());
+
   this.actuator.actuate(this.grid, {
     score:      this.score,
     over:       this.over,
     won:        this.won,
-    bestScore:  this.scoreManager.get(),
+    bestScore:  this.storageManager.getBestScore(),
     terminated: this.isGameTerminated()
   });
 
 };
 
+GameManager.prototype.serializeGameState = function () {
+    return {
+        size:        this.size,
+        grid:        this.grid.gridState(),
+        score:       this.score,
+        over:        this.over,
+        won:         this.won,
+        keepPlaying: this.keepPlaying
+    };
+}
+
 // Save all tile positions and remove merger info
 GameManager.prototype.prepareTiles = function () {
   this.grid.eachCell(function (x, y, tile) {

js/grid.js

@@ -1,20 +1,32 @@
-function Grid(size) {
+function Grid(size, previousCellState) {
   this.size = size;
-
-  this.cells = [];
-
-  this.build();
+  this.cells = previousCellState ? this.buildFromPreviousState(previousCellState) : this.buildNew();
 }
 
 // Build a grid of the specified size
-Grid.prototype.build = function () {
+Grid.prototype.buildNew = function () {
+  var cells = [];
   for (var x = 0; x < this.size; x++) {
-    var row = this.cells[x] = [];
+    var row = cells[x] = [];
 
     for (var y = 0; y < this.size; y++) {
       row.push(null);
     }
   }
+  return cells;
+};
+
+Grid.prototype.buildFromPreviousState = function (state) {
+    var cells = [];
+    for (var x = 0; x < this.size; x++) {
+        var row = cells[x] = [];
+
+        for (var y = 0; y < this.size; y++) {
+            var tileState = state[x][y];
+            row.push(tileState ? new Tile(tileState.position, tileState.value) : null);
+        }
+    }
+    return cells;
 };
 
 // Find the first available random position
@@ -82,3 +94,19 @@ Grid.prototype.withinBounds = function (position) {
   return position.x >= 0 && position.x < this.size &&
          position.y >= 0 && position.y < this.size;
 };
+
+Grid.prototype.gridState = function () {
+  var cellState = [];
+  for (var x = 0; x < this.size; x++) {
+    var row = cellState[x] = [];
+
+    for (var y = 0; y < this.size; y++) {
+        row.push(this.cells[x][y] ? this.cells[x][y].tileState() : null);
+    }
+  }
+
+  return {
+      size: this.size,
+      cells: cellState
+  }
+};

js/keyboard_input_manager.js

@@ -57,6 +57,10 @@ KeyboardInputManager.prototype.listen = function () {
   retry.addEventListener("click", this.restart.bind(this));
   retry.addEventListener("touchend", this.restart.bind(this));
 
+  var restart = document.querySelector(".restart-button");
+  restart.addEventListener("click", this.restart.bind(this));
+  restart.addEventListener("touchend", this.restart.bind(this));
+
   var keepPlaying = document.querySelector(".keep-playing-button");
   keepPlaying.addEventListener("click", this.keepPlaying.bind(this));
   keepPlaying.addEventListener("touchend", this.keepPlaying.bind(this));

js/local_score_manager.js

@@ -19,7 +19,8 @@ window.fakeStorage = {
 };
 
 function LocalScoreManager() {
-  this.key     = "bestScore";
+  this.bestScoreKey     = "bestScore";
+  this.gameStateKey     = "gameState";
 
   var supported = this.localStorageSupported();
   this.storage = supported ? window.localStorage : window.fakeStorage;
@@ -38,11 +39,23 @@ LocalScoreManager.prototype.localStorageSupported = function () {
   }
 };
 
-LocalScoreManager.prototype.get = function () {
-  return this.storage.getItem(this.key) || 0;
+LocalScoreManager.prototype.getBestScore = function () {
+  return this.storage.getItem(this.bestScoreKey) || 0;
 };
 
-LocalScoreManager.prototype.set = function (score) {
-  this.storage.setItem(this.key, score);
+LocalScoreManager.prototype.setBestScore = function (score) {
+  this.storage.setItem(this.bestScoreKey, score);
 };
 
+LocalScoreManager.prototype.getGameState = function () {
+    var stateJSON = this.storage.getItem(this.gameStateKey);
+    return stateJSON ? JSON.parse(stateJSON) : null;
+};
+
+LocalScoreManager.prototype.setGameState = function (gameState) {
+    this.storage.setItem(this.gameStateKey, JSON.stringify(gameState));
+};
+
+LocalScoreManager.prototype.clearGameState = function () {
+    this.storage.removeItem(this.gameStateKey);
+};

js/tile.js

@@ -15,3 +15,13 @@ Tile.prototype.updatePosition = function (position) {
   this.x = position.x;
   this.y = position.y;
 };
+
+Tile.prototype.tileState = function () {
+    return {
+        position: {
+            x: this.x,
+            y: this.y
+        },
+        value: this.value
+    };
+}