add movement check, score addition

js/game_manager.js

@@ -103,11 +103,15 @@ GameManager.prototype.move = function (direction) {
 
           // Update the score
           self.score += merged.value;
+
+          // Something's moved for sure
         } else {
           self.moveTile(tile, positions.farthest);
         }
 
-        moved = true;
+        if (!self.positionsEqual(cell, tile)) {
+          moved = true; // The tile moved from its original cell!
+        }
       }
     });
   });
@@ -201,3 +205,7 @@ GameManager.prototype.tileMatchesAvailable = function () {
 
   return false;
 };
+
+GameManager.prototype.positionsEqual = function (first, second) {
+  return first.x === second.x && first.y === second.y;
+};

js/html_actuator.js

@@ -2,13 +2,15 @@ function HTMLActuator() {
   this.tileContainer  = document.getElementsByClassName("tile-container")[0];
   this.gameContainer  = document.getElementsByClassName("game-container")[0];
   this.scoreContainer = document.getElementsByClassName("score-container")[0];
+
+  this.score = 0;
 }
 
 HTMLActuator.prototype.actuate = function (grid, metadata) {
   var self = this;
 
   window.requestAnimationFrame(function () {
-    self.clearContainer();
+    self.clearContainer(self.tileContainer);
 
     grid.cells.forEach(function (column) {
       column.forEach(function (cell) {
@@ -26,9 +28,9 @@ HTMLActuator.prototype.actuate = function (grid, metadata) {
   });
 };
 
-HTMLActuator.prototype.clearContainer = function () {
-  while (this.tileContainer.firstChild) {
-    this.tileContainer.removeChild(this.tileContainer.firstChild);
+HTMLActuator.prototype.clearContainer = function (container) {
+  while (container.firstChild) {
+    container.removeChild(container.firstChild);
   }
 };
 
@@ -69,7 +71,20 @@ HTMLActuator.prototype.positionClass = function (position) {
 };
 
 HTMLActuator.prototype.updateScore = function (score) {
-  this.scoreContainer.textContent = score;
+  this.clearContainer(this.scoreContainer);
+
+  var difference = score - this.score;
+  this.score = score;
+
+  this.scoreContainer.textContent = this.score;
+
+  if (difference) {
+    var addition = document.createElement("div");
+    addition.classList.add("score-addition");
+    addition.textContent = "+" + difference;
+
+    this.scoreContainer.appendChild(addition);
+  }
 };
 
 HTMLActuator.prototype.gameOver = function () {