clean up ids

Author: molly-moen

src/animationsController.js

@@ -267,9 +267,11 @@ module.exports = class AnimationsController {
   /**
    * Schedule the animations for a move from the current position
    * @param {number} endX X coordinate of the target position
-   * @param {number} endY Y coordinate of the target position
+   * @param {number} endY Y coordinate of the target position  
+   * @param {string} id Optional id of pegman. If no id is provided,
+   *   will schedule move for default pegman.
    */
-  scheduleMove(endX, endY, timeForAnimation, id = null) {
+  scheduleMove(endX, endY, timeForAnimation, id) {
     var startX = this.maze.getPegmanX(id);
     var startY = this.maze.getPegmanY(id);
     var direction = this.maze.getPegmanD(id);
@@ -336,9 +338,11 @@ module.exports = class AnimationsController {
 
   /**
    * Schedule the animations for a turn from the current direction
-   * @param {number} endDirection The direction we're turning to
+   * @param {number} endDirection The direction we're turning to  
+   * @param {string} id Optional id of pegman. If no id is provided,
+   *   will schedule turn for default pegman.
    */
-  scheduleTurn(endDirection, id = null) {
+  scheduleTurn(endDirection, id) {
     var numFrames = 4;
     var startDirection = this.maze.getPegmanD(id);
     var deltaDirection = endDirection - startDirection;
@@ -392,7 +396,7 @@ module.exports = class AnimationsController {
     }
   }
 
-  scheduleWallHit(targetX, targetY, deltaX, deltaY, frame, id = null) {
+  scheduleWallHit(targetX, targetY, deltaX, deltaY, frame, id) {
     // Play the animation of hitting the wall
     const pegmanX = this.maze.getPegmanX(id);
     const pegmanY = this.maze.getPegmanY(id);
@@ -463,7 +467,7 @@ module.exports = class AnimationsController {
     }
   }
 
-  scheduleObstacleHit(targetX, targetY, deltaX, deltaY, frame, id = null) {
+  scheduleObstacleHit(targetX, targetY, deltaX, deltaY, frame, id) {
     // Play the animation
     var obsId = targetX + this.maze.map.COLS * targetY;
     var obsIcon = document.getElementById('obstacle' + obsId);
@@ -540,8 +544,10 @@ module.exports = class AnimationsController {
    * @param {boolean} victoryDance This is a victory dance after completing the
    *   puzzle (vs. dancing on load).
    * @param {integer} timeAlloted How much time we have for our animations
+   * @param {string} id Optional id of pegman. If no id is provided, will schedule
+   *   dance for default pegman.
    */
-  scheduleDance(victoryDance, timeAlloted, id = null) {
+  scheduleDance(victoryDance, timeAlloted, id) {
     const finishIcon = document.getElementById('finish');
     const pegmanX = this.maze.getPegmanX(id);
     const pegmanY = this.maze.getPegmanY(id);
@@ -644,9 +650,11 @@ module.exports = class AnimationsController {
    * Display Pegman at the specified location, facing the specified direction.
    * @param {number} x Horizontal grid (or fraction thereof).
    * @param {number} y Vertical grid (or fraction thereof).
-   * @param {number} frame Direction (0 - 15) or dance (16 - 17).
+   * @param {number} frame Direction (0 - 15) or dance (16 - 17). * 
+   * @param {string} id Optional id of pegman. If no id is provided,
+   *   will display default pegman.
    */
-  displayPegman(x, y, frame, id = null) {
+  displayPegman(x, y, frame, id) {
     var pegmanIcon = document.getElementById('pegman');
     var clipRect = document.getElementById('clipRect');
     displayPegman(this.maze.skin, pegmanIcon, clipRect, x, y, frame);

src/mazeController.js

@@ -231,7 +231,7 @@ module.exports = class MazeController {
     this.animationsController.scheduleDance(true, timePerStep);
   }
 
-  animatedMove(direction, timeForMove, id = null) {
+  animatedMove(direction, timeForMove, id) {
     var positionChange = tiles.directionToDxDy(direction);
     var newX = this.getPegmanX(id) + positionChange.dx;
     var newY = this.getPegmanY(id) + positionChange.dy;
@@ -241,13 +241,13 @@ module.exports = class MazeController {
     this.setPegmanY(newY, id);
   }
 
-  animatedTurn(direction, id = null) {
+  animatedTurn(direction, id) {
     var newDirection = this.getPegmanD(id) + direction;
     this.animationsController.scheduleTurn(newDirection, id);
     this.setPegmanD(tiles.constrainDirection4(newDirection), id);
   }
 
-  animatedFail(forward, id = null) {
+  animatedFail(forward, id) {
     var dxDy = tiles.directionToDxDy(this.getPegmanD(id));
     var deltaX = dxDy.dx;
     var deltaY = dxDy.dy;
@@ -303,7 +303,7 @@ module.exports = class MazeController {
    * in the specified direction.
    * @param {!Direction} direction Direction (0 - 3).
    */
-  animatedLook(direction, id = null) {
+  animatedLook(direction, id) {
     var x = this.getPegmanX(id);
     var y = this.getPegmanY(id);
     switch (direction) {
@@ -361,32 +361,32 @@ module.exports = class MazeController {
     });
   }
 
-  getPegmanX(id = null) {
+  getPegmanX(id) {
     const pegman = this.pegmanController.getPegman(id);
     return pegman && pegman.getX();
   }
 
-  getPegmanY(id = null) {
+  getPegmanY(id) {
     const pegman = this.pegmanController.getPegman(id);
     return pegman && pegman.getY();
   }
 
-  getPegmanD(id = null) {
+  getPegmanD(id) {
     const pegman = this.pegmanController.getPegman(id);
     return pegman && pegman.getDirection();
   }
 
-  setPegmanX(x, id = null) {
+  setPegmanX(x, id) {
     const pegman = this.pegmanController.getOrCreatePegman(id);
     pegman.setX(x);
   }
 
-  setPegmanY(y, id = null) {
+  setPegmanY(y, id) {
     const pegman = this.pegmanController.getOrCreatePegman(id);
     pegman.setY(y);
   }
 
-  setPegmanD(d, id = null) {
+  setPegmanD(d, id) {
     const pegman = this.pegmanController.getOrCreatePegman(id);
     pegman.setDirection(d);
   }

src/pegman.js

@@ -1,5 +1,8 @@
 module.exports = class Pegman {
-  constructor(x = null, y = null, direction = null, id = null, isVisible = true) {
+  constructor(id, x = null, y = null, direction = null, isVisible = true) {
+    if (id == null) {
+      throw new Error('Pegman id cannot be null or undefined');
+    }
     this.x = x;
     this.y = y;
     this.direction = direction;

src/pegmanController.js

@@ -1,37 +1,42 @@
 const Pegman = require('./pegman');
 
+const DEFAULT_ID = 'defaultPegman';
+
 module.exports =  class PegmanController {
+
   constructor() {
     this.pegmen = {};
-    this.firstPegman = null;
   }
 
-  getOrCreatePegman(id = null) {
+  getOrCreatePegman(id) {
+    // if id is null or undefined, set to default value.
+    if(id == undefined) {
+      id = DEFAULT_ID;
+    }
     let pegman = this.getPegman(id);
     if (!pegman) {
-      pegman = new Pegman(null, null, null, id);
+      pegman = new Pegman(id);
       this.addPegman(pegman);
     }
     return pegman;
   }
 
-  getPegman(id = null) {
-    if (id == null) {
-      return this.firstPegman;
-    } else {
-      return this.pegmen[id];
+  getPegman(id) {
+    // if id is null or undefined, set to default value.
+    if(id == undefined) {
+      id = DEFAULT_ID;
     }
+    return this.pegmen[id];
   }
 
   addPegman(pegman) {
-    // if this is the first pegman added, store as firstPegman
-    if (this.firstPegman === null) {
-      this.firstPegman = pegman;
-    }
-    // if the pegman has an id, put it in this.pegmen
-    // pegmen without ids cannot be accessed via this.pegmen.
-    if (pegman.id != null) {
-      this.pegmen[pegman.id] = pegman;
+    if (this.pegmen[pegman.id]) {
+      throw new Error(`Pegman with id ${pegman.id} already exists.`);
     }
+    this.pegmen[pegman.id] = pegman;
+  }
+
+  isDefaultPegman(id) {
+    return id == undefined || id === DEFAULT_ID;
   }
 }