Refactor so that layer group is optionally passed into createClone (and initDrawable) instead of isStage property getting stored on a sprite.

src/serialization/sb2.js

@@ -15,6 +15,7 @@ const StringUtil = require('../util/string-util');
 const specMap = require('./sb2_specmap');
 const Variable = require('../engine/variable');
 const MonitorRecord = require('../engine/monitor-record');
+const StageLayering = require('../engine/stage-layering');
 
 const {loadCostume} = require('../import/load-costume.js');
 const {loadSound} = require('../import/load-sound.js');
@@ -327,7 +328,7 @@ const parseScratchObject = function (object, runtime, extensions, topLevel, zip)
     // Blocks container for this object.
     const blocks = new Blocks();
     // @todo: For now, load all Scratch objects (stage/sprites) as a Sprite.
-    const sprite = new Sprite(blocks, runtime, topLevel /* whether this sprite is a stge or not */);
+    const sprite = new Sprite(blocks, runtime);
     // Sprite/stage name from JSON.
     if (object.hasOwnProperty('objName')) {
         sprite.name = topLevel ? 'Stage' : object.objName;
@@ -399,7 +400,7 @@ const parseScratchObject = function (object, runtime, extensions, topLevel, zip)
     }
 
     // Create the first clone, and load its run-state from JSON.
-    const target = sprite.createClone();
+    const target = sprite.createClone(topLevel ? StageLayering.BACKGROUND_LAYER : StageLayering.SPRITE_LAYER);
 
     const getVariableId = generateVariableIdGetter(target.id, topLevel);
 

src/serialization/sb3.js

@@ -8,6 +8,7 @@ const vmPackage = require('../../package.json');
 const Blocks = require('../engine/blocks');
 const Sprite = require('../sprites/sprite');
 const Variable = require('../engine/variable');
+const StageLayering = require('../engine/stage-layering');
 const log = require('../util/log');
 const uid = require('../util/uid');
 
@@ -684,7 +685,7 @@ const parseScratchObject = function (object, runtime, extensions, zip) {
     const blocks = new Blocks();
 
     // @todo: For now, load all Scratch objects (stage/sprites) as a Sprite.
-    const sprite = new Sprite(blocks, runtime, object.isStage);
+    const sprite = new Sprite(blocks, runtime);
 
     // Sprite/stage name from JSON.
     if (object.hasOwnProperty('name')) {
@@ -779,7 +780,7 @@ const parseScratchObject = function (object, runtime, extensions, zip) {
         // process has been completed.
     });
     // Create the first clone, and load its run-state from JSON.
-    const target = sprite.createClone();
+    const target = sprite.createClone(object.isStage ? StageLayering.BACKGROUND_LAYER : StageLayering.SPRITE_LAYER);
     // Load target properties from JSON.
     if (object.hasOwnProperty('tempo')) {
         target.tempo = object.tempo;

src/sprites/rendered-target.js

@@ -156,13 +156,11 @@ class RenderedTarget extends Target {
 
     /**
      * Create a drawable with the this.renderer.
-     * @param {boolean} isStage Whether the drawable should be initialized as
-     * the stage or a sprite
+     * @param {boolean} layerGroup The layer group this drawable should be added to
      */
-    initDrawable (isStage) {
+    initDrawable (layerGroup) {
         if (this.renderer) {
-            this.drawableID = this.renderer.createDrawable(isStage ?
-                StageLayering.BACKGROUND_LAYER : StageLayering.SPRITE_LAYER);
+            this.drawableID = this.renderer.createDrawable(layerGroup);
         }
         // If we're a clone, start the hats.
         if (!this.isOriginal) {
@@ -920,7 +918,7 @@ class RenderedTarget extends Target {
         newClone.effects = JSON.parse(JSON.stringify(this.effects));
         newClone.variables = JSON.parse(JSON.stringify(this.variables));
         newClone.lists = JSON.parse(JSON.stringify(this.lists));
-        newClone.initDrawable(false); // this,sprite is not a stage if we're calling makeClone on it
+        newClone.initDrawable(StageLayering.SPRITE_LAYER); // TODO should sprite clones be in their own layer group?
         newClone.updateAllDrawableProperties();
         // Place behind the current target.
         newClone.goBehindOther(this);

src/sprites/sprite.js

@@ -3,6 +3,7 @@ const Blocks = require('../engine/blocks');
 const {loadSoundFromAsset} = require('../import/load-sound');
 const {loadCostumeFromAsset} = require('../import/load-costume');
 const StringUtil = require('../util/string-util');
+const StageLayering = require('../engine/stage-layering');
 
 class Sprite {
     /**
@@ -10,10 +11,9 @@ class Sprite {
      * All clones of a sprite have shared blocks, shared costumes, shared variables.
      * @param {?Blocks} blocks Shared blocks object for all clones of sprite.
      * @param {Runtime} runtime Reference to the runtime.
-     * @param {boolean=} isStage Whether or not this sprite is a stage
      * @constructor
      */
-    constructor (blocks, runtime, isStage) {
+    constructor (blocks, runtime) {
         this.runtime = runtime;
         if (!blocks) {
             // Shared set of blocks for all clones.
@@ -47,10 +47,6 @@ class Sprite {
          * @type {Array.<!RenderedTarget>}
          */
         this.clones = [];
-
-        // Needed for figuring out whether the associated drawable should
-        // go in the background layer or sprite layer
-        this.isStage = isStage || false;
     }
 
     /**
@@ -100,15 +96,19 @@ class Sprite {
 
     /**
      * Create a clone of this sprite.
+     * @param {string=} optLayerGroup Optional layer group the clone's drawable should be added to
+     * Defaults to the sprite layer group
      * @returns {!RenderedTarget} Newly created clone.
      */
-    createClone () {
+    createClone (optLayerGroup) {
         const newClone = new RenderedTarget(this, this.runtime);
         newClone.isOriginal = this.clones.length === 0;
         this.clones.push(newClone);
         newClone.initAudio();
         if (newClone.isOriginal) {
-            newClone.initDrawable(this.isStage);
+            // Default to the sprite layer group if optLayerGroup is not provided
+            const layerGroup = typeof optLayerGroup === 'string' ? optLayerGroup : StageLayering.SPRITE_LAYER;
+            newClone.initDrawable(layerGroup);
             this.runtime.fireTargetWasCreated(newClone);
         } else {
             this.runtime.fireTargetWasCreated(newClone, this.clones[0]);