let clones share the orginal’s scripts without shallow-copying them

blocks.js

@@ -150,7 +150,7 @@ CustomCommandBlockMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2017-May-12';
+modules.blocks = '2017-May-30';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -570,7 +570,7 @@ SyntaxElementMorph.prototype.revertToDefaultInput = function (arg, noValues) {
             deflt = this.labelPart(this.parseSpec(this.blockSpec)[idx]);
             if (this.isCustomBlock) {
                 def = this.isGlobal ? this.definition
-                        : this.receiver().getMethod(this.blockSpec);
+                        : this.scriptTarget().getMethod(this.blockSpec);
                 if (deflt instanceof InputSlotMorph) {
                     deflt.setChoices.apply(
                         deflt,
@@ -636,7 +636,7 @@ SyntaxElementMorph.prototype.getVarNamesDict = function () {
     if (!block) {
         return {};
     }
-    rcvr = block.receiver();
+    rcvr = block.scriptTarget();
     block.allParents().forEach(function (morph) {
         if (morph instanceof PrototypeHatBlockMorph) {
             tempVars.push.apply(
@@ -1546,7 +1546,7 @@ SyntaxElementMorph.prototype.labelPart = function (spec) {
         // has issues when loading costumes (asynchronously)
         // commented out for now
 
-        var rcvr = this.definition.receiver || this.receiver(),
+        var rcvr = this.definition.receiver || this.scriptTarget(),
             id = spec.slice(1),
             cst;
         if (!rcvr) {return this.labelPart('%stop'); }
@@ -1888,7 +1888,7 @@ SyntaxElementMorph.prototype.showBubble = function (value, exportPic) {
     if ((value === undefined) || !wrrld || !this.receiver) {
         return null;
     }
-    rcvr = this.receiver();
+    rcvr = this.scriptTarget();
     if (value instanceof ListWatcherMorph) {
         morphToShow = value;
         morphToShow.update(true);
@@ -2053,7 +2053,7 @@ SyntaxElementMorph.prototype.endLayout = function () {
     accessors are:
 
     selector        - (string) name of method to be triggered
-    receiver()      - answer the object (sprite) to which I apply
+    scriptTarget()  - answer the object (sprite) to which I apply
     inputs()        - answer an array with my arg slots and nested reporters
     defaults        - an optional Array containing default input values
     topBlock()      - answer the top block of the stack I'm attached to
@@ -2204,16 +2204,23 @@ BlockMorph.prototype.init = function (silently) {
     this.cachedInputs = null;
 };
 
-BlockMorph.prototype.receiver = function () {
+BlockMorph.prototype.scriptTarget = function () {
-    // answer the object to which I apply (whose method I represent)
+    // answer the sprite or stage that this block acts on,
-    var up = this.parent;
+    // if the user clicks on it.
-    while (!!up) {
+    // NOTE: since scripts can be shared by more than a single sprite
-        if (up.owner) {
+    // this method only gives the desired result within the context of
-            return up.owner;
+    // the user actively clicking on a block inside the IDE
-        }
+    // there is no direct relationship between a block and a sprite.
-        up = up.parent;
+    var scripts = this.parentThatIsA(ScriptsMorph),
+        ide;
+    if (scripts) {
+        return scripts.scriptTarget();
     }
-    return null;
+    ide = this.parentThatIsA(IDE_Morph);
+    if (ide) {
+        return ide.currentSprite;
+    }
+    throw new Error('script target cannot be found for orphaned block');
 };
 
 BlockMorph.prototype.toString = function () {
@@ -2461,7 +2468,7 @@ BlockMorph.prototype.userMenu = function () {
 
             // allow toggling inheritable attributes
             if (StageMorph.prototype.enableInheritance) {
-                rcvr = this.receiver();
+                rcvr = this.scriptTarget();
                 field = {
                     xPosition: 'x position',
                     yPosition: 'y position',
@@ -2695,7 +2702,7 @@ BlockMorph.prototype.isInheritedVariable = function () {
             (this.selector === 'reportGetVar') &&
             (this.parent instanceof FrameMorph)) {
         return contains(
-            this.receiver().inheritedVariableNames(),
+            this.scriptTarget().inheritedVariableNames(),
             this.blockSpec
         );
     }
@@ -2704,13 +2711,13 @@ BlockMorph.prototype.isInheritedVariable = function () {
 
 BlockMorph.prototype.isTransientVariable = function () {
     // private - only for variable getter template inside the palette
-    var varFrame = this.receiver().variables.silentFind(this.blockSpec);
+    var varFrame = this.scriptTarget().variables.silentFind(this.blockSpec);
     return varFrame ? varFrame.vars[this.blockSpec].isTransient : false;
 };
 
 BlockMorph.prototype.toggleTransientVariable = function () {
     // private - only for variable getter template inside the palette
-    var varFrame = this.receiver().variables.silentFind(this.blockSpec);
+    var varFrame = this.scriptTarget().variables.silentFind(this.blockSpec);
     if (!varFrame) {return; }
     varFrame.vars[this.blockSpec].isTransient =
         !(varFrame.vars[this.blockSpec].isTransient);
@@ -3212,7 +3219,7 @@ BlockMorph.prototype.refactorThisVar = function (justTheTemplate) {
 
     var myself = this,
         oldName = this.blockSpec,
-        receiver = this.receiver(),
+        receiver = this.scriptTarget(),
         ide = this.parentThatIsA(IDE_Morph),
         stage = ide.stage,
         oldWatcher = receiver.findVariableWatcher(oldName),
@@ -3674,14 +3681,7 @@ BlockMorph.prototype.hasLabels = function () {
 
 // BlockMorph copying
 
-BlockMorph.prototype.fullCopy = function (forClone) {
+BlockMorph.prototype.fullCopy = function () {
-    if (forClone) {
-        if (this.hasBlockVars()) {
-            forClone = false;
-        } else {
-            return copy(this);
-        }
-    }
     var ans = BlockMorph.uber.fullCopy.call(this);
     ans.removeHighlight();
     ans.isDraggable = true;
@@ -3721,7 +3721,7 @@ BlockMorph.prototype.hasBlockVars = function () {
 
 BlockMorph.prototype.mouseClickLeft = function () {
     var top = this.topBlock(),
-        receiver = top.receiver(),
+        receiver = top.scriptTarget(),
         shiftClicked = this.world().currentKey === 16,
         stage;
     if (shiftClicked && !this.isTemplate) {
@@ -3733,7 +3733,7 @@ BlockMorph.prototype.mouseClickLeft = function () {
     if (receiver) {
         stage = receiver.parentThatIsA(StageMorph);
         if (stage) {
-            stage.threads.toggleProcess(top);
+            stage.threads.toggleProcess(top, receiver);
         }
     }
 };
@@ -3755,7 +3755,7 @@ BlockMorph.prototype.focus = function () {
 
 BlockMorph.prototype.activeProcess = function () {
     var top = this.topBlock(),
-        receiver = top.receiver(),
+        receiver = top.scriptTarget(),
         stage;
     if (top instanceof PrototypeHatBlockMorph) {
         return null;
@@ -3763,7 +3763,7 @@ BlockMorph.prototype.activeProcess = function () {
     if (receiver) {
         stage = receiver.parentThatIsA(StageMorph);
         if (stage) {
-            return stage.threads.findProcess(top);
+            return stage.threads.findProcess(top, receiver);
         }
     }
     return null;
@@ -3908,10 +3908,16 @@ BlockMorph.prototype.destroy = function (justThis) {
             comment.destroy();
         });
     }
+
+    /* +++ needs tweaking:
+    // stop active process(es) for this block
+    // for this we need access to the stage...
+
     if ((!this.parent || !this.parent.topBlock)
             && this.activeProcess()) {
         this.activeProcess().stop();
     }
+    */
 
     BlockMorph.uber.destroy.call(this);
 };
@@ -3957,7 +3963,7 @@ BlockMorph.prototype.snap = function () {
     }
     // register generic hat blocks
     if (this.selector === 'receiveCondition') {
-        receiver = top.receiver();
+        receiver = top.scriptTarget();
         if (receiver) {
             stage = receiver.parentThatIsA(StageMorph);
             if (stage) {
@@ -5156,14 +5162,14 @@ ReporterBlockMorph.prototype.mouseClickLeft = function (pos) {
 
 ReporterBlockMorph.prototype.exportResultPic = function () {
     var top = this.topBlock(),
-        receiver = top.receiver(),
+        receiver = top.scriptTarget(),
         stage;
     if (top !== this) {return; }
     if (receiver) {
         stage = receiver.parentThatIsA(StageMorph);
         if (stage) {
             stage.threads.stopProcess(top);
-            stage.threads.startProcess(top, false, true);
+            stage.threads.startProcess(top, receiver, false, true);
         }
     }
 };
@@ -5711,12 +5717,11 @@ ScriptsMorph.prototype.enableNestedAutoWrapping = true;
 
 // ScriptsMorph instance creation:
 
-function ScriptsMorph(owner) {
+function ScriptsMorph() {
-    this.init(owner);
+    this.init();
 }
 
-ScriptsMorph.prototype.init = function (owner) {
+ScriptsMorph.prototype.init = function () {
-    this.owner = owner || null;
     this.feedbackColor = SyntaxElementMorph.prototype.feedbackColor;
     this.feedbackMorph = new BoxMorph();
     this.rejectsHats = false;
@@ -5744,7 +5749,7 @@ ScriptsMorph.prototype.init = function (owner) {
 
 // ScriptsMorph deep copying:
 
-ScriptsMorph.prototype.fullCopy = function (forClone) {
+ScriptsMorph.prototype.fullCopy = function () {
     var cpy = new ScriptsMorph(),
         pos = this.position(),
         child;
@@ -5753,21 +5758,17 @@ ScriptsMorph.prototype.fullCopy = function (forClone) {
     }
     this.children.forEach(function (morph) {
         if (!morph.block) { // omit anchored comments
-            child = morph.fullCopy(forClone);
+            child = morph.fullCopy();
             cpy.add(child);
-            if (!forClone) {
+            child.setPosition(morph.position().subtract(pos));
-                child.setPosition(morph.position().subtract(pos));
+            if (child instanceof BlockMorph) {
-                if (child instanceof BlockMorph) {
+                child.allComments().forEach(function (comment) {
-                    child.allComments().forEach(function (comment) {
+                    comment.align(child);
-                        comment.align(child);
+                });
-                    });
-                }
             }
         }
     });
-    if (!forClone) {
+    cpy.adjustBounds();
-        cpy.adjustBounds();
-    }
     return cpy;
 };
 
@@ -6073,7 +6074,7 @@ ScriptsMorph.prototype.userMenu = function () {
         shiftClicked = this.world().currentKey === 16,
         blockEditor,
         myself = this,
-        obj = this.owner,
+        obj = this.scriptTarget(),
         hasUndropQueue,
         stage = obj.parentThatIsA(StageMorph);
 
@@ -6594,6 +6595,28 @@ ScriptsMorph.prototype.edit = function (pos) {
     this.focus.getFocus(world);
 };
 
+// ScriptsMorph context - scripts target
+
+ScriptsMorph.prototype.scriptTarget = function () {
+    // answer the sprite or stage that this script editor acts on,
+    // if the user clicks on a block.
+    // NOTE: since scripts can be shared by more than a single sprite
+    // this method only gives the desired result within the context of
+    // the user actively clicking on a block inside the IDE
+    // there is no direct relationship between a block or a scripts editor
+    //  and a sprite.
+    var editor = this.parentThatIsA(IDE_Morph);
+    if (editor) {
+        return editor.currentSprite;
+    }
+    editor = this.parentThatIsA(BlockEditorMorph);
+    if (editor) {
+        return editor.target.currentSprite;
+    }
+    throw new Error('script target bannot be found for orphaned scripts');
+};
+
+
 // ArgMorph //////////////////////////////////////////////////////////
 
 /*
@@ -6644,7 +6667,7 @@ ArgMorph.prototype.reactToSliderEdit = function () {
     block = this.parentThatIsA(BlockMorph);
     if (block) {
         top = block.topBlock();
-        receiver = top.receiver();
+        receiver = top.scriptTarget();
         if (top instanceof PrototypeHatBlockMorph) {
             return;
         }
@@ -6652,7 +6675,7 @@ ArgMorph.prototype.reactToSliderEdit = function () {
             stage = receiver.parentThatIsA(StageMorph);
             if (stage && (stage.isThreadSafe ||
                     Process.prototype.enableSingleStepping)) {
-                stage.threads.startProcess(top, stage.isThreadSafe);
+                stage.threads.startProcess(top, receiver, stage.isThreadSafe);
             } else {
                 top.mouseClickLeft();
             }
@@ -7944,7 +7967,7 @@ InputSlotMorph.prototype.menuFromDict = function (choices, noEmptyOption) {
 
 InputSlotMorph.prototype.messagesMenu = function () {
     var dict = {},
-        rcvr = this.parentThatIsA(BlockMorph).receiver(),
+        rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         myself = this,
         allNames = [];
@@ -7977,7 +8000,7 @@ InputSlotMorph.prototype.messagesMenu = function () {
 
 InputSlotMorph.prototype.messagesReceivedMenu = function () {
     var dict = {'any message': ['any message']},
-        rcvr = this.parentThatIsA(BlockMorph).receiver(),
+        rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         myself = this,
         allNames = [];
@@ -8012,7 +8035,7 @@ InputSlotMorph.prototype.collidablesMenu = function () {
             edge : ['edge'],
             'pen trails' : ['pen trails']
         },
-        rcvr = this.parentThatIsA(BlockMorph).receiver(),
+        rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         allNames = [];
 
@@ -8036,7 +8059,7 @@ InputSlotMorph.prototype.distancesMenu = function () {
     var dict = {
             'mouse-pointer' : ['mouse-pointer']
         },
-        rcvr = this.parentThatIsA(BlockMorph).receiver(),
+        rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         allNames = [];
 
@@ -8058,7 +8081,7 @@ InputSlotMorph.prototype.distancesMenu = function () {
 
 InputSlotMorph.prototype.clonablesMenu = function () {
     var dict = {},
-        rcvr = this.parentThatIsA(BlockMorph).receiver(),
+        rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         allNames = [];
 
@@ -8080,7 +8103,7 @@ InputSlotMorph.prototype.clonablesMenu = function () {
 };
 
 InputSlotMorph.prototype.objectsMenu = function () {
-    var rcvr = this.parentThatIsA(BlockMorph).receiver(),
+    var rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         dict = {},
         allNames = [];
@@ -8146,7 +8169,7 @@ InputSlotMorph.prototype.gettablesMenu = function () {
 InputSlotMorph.prototype.attributesMenu = function () {
     var block = this.parentThatIsA(BlockMorph),
         objName = block.inputs()[1].evaluate(),
-        rcvr = block.receiver(),
+        rcvr = block.scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         obj,
         dict = {},
@@ -8196,7 +8219,7 @@ InputSlotMorph.prototype.attributesMenu = function () {
 };
 
 InputSlotMorph.prototype.costumesMenu = function () {
-    var rcvr = this.parentThatIsA(BlockMorph).receiver(),
+    var rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         dict,
         allNames = [];
     if (rcvr instanceof SpriteMorph) {
@@ -8217,7 +8240,7 @@ InputSlotMorph.prototype.costumesMenu = function () {
 };
 
 InputSlotMorph.prototype.soundsMenu = function () {
-    var rcvr = this.parentThatIsA(BlockMorph).receiver(),
+    var rcvr = this.parentThatIsA(BlockMorph).scriptTarget(),
         allNames = [],
         dict = {};
 
@@ -8257,7 +8280,7 @@ InputSlotMorph.prototype.shadowedVariablesMenu = function () {
         dict = {};
 
     if (!block) {return dict; }
-    rcvr = block.receiver();
+    rcvr = block.scriptTarget();
     if (rcvr && rcvr.exemplar) {
         vars = rcvr.inheritedVariableNames(true);
         vars.forEach(function (name) {
@@ -13237,7 +13260,7 @@ ScriptFocusMorph.prototype.deleteLastElement = function () {
 };
 
 ScriptFocusMorph.prototype.insertBlock = function (block) {
-    var pb, stage, ide;
+    var pb, stage, ide, rcvr;
     block.isTemplate = false;
     block.isDraggable = true;
 
@@ -13303,8 +13326,9 @@ ScriptFocusMorph.prototype.insertBlock = function (block) {
 
     // register generic hat blocks
     if (block.selector === 'receiveCondition') {
-        if (this.editor.owner) {
+        rcvr = this.editor.scriptTarget();
-            stage = this.editor.owner.parentThatIsA(StageMorph);
+        if (rcvr) {
+            stage = rcvr.parentThatIsA(StageMorph);
             if (stage) {
                 stage.enableCustomHatBlocks = true;
                 stage.threads.pauseCustomHatBlocks = false;
@@ -13752,7 +13776,7 @@ ScriptFocusMorph.prototype.reactToKeyEvent = function (key) {
             delete this.fps;
             delete this.step;
             this.show();
-            this.editor.owner.searchBlocks(
+            this.editor.scriptTarget().searchBlocks(
                 key,
                 types,
                 vNames,

byob.js

@@ -108,7 +108,7 @@ BooleanSlotMorph, XML_Serializer*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.byob = '2017-April-10';
+modules.byob = '2017-May-30';
 
 // Declarations
 
@@ -799,7 +799,7 @@ CustomCommandBlockMorph.prototype.edit = function () {
         );
     } else {
         // check for local custom block inheritance
-        rcvr = this.receiver();
+        rcvr = this.scriptTarget();
         if (!this.isGlobal) {
             if (contains(
                     Object.keys(rcvr.inheritedBlocks()),
@@ -860,8 +860,12 @@ CustomCommandBlockMorph.prototype.attachTargets = function () {
 CustomCommandBlockMorph.prototype.isInUse = function () {
     // answer true if an instance of my definition is found
     // in any of my receiver's scripts or block definitions
+    // NOTE: for sprite-local blocks only to be used in a situation
+    // where the user actively clicks on a block in the IDE,
+    // e.g. to edit it (and change its type)
     var def = this.definition,
-        ide = this.receiver().parentThatIsA(IDE_Morph);
+        rcvr = this.scriptTarget(),
+        ide = rcvr.parentThatIsA(IDE_Morph);
     if (def.isGlobal && ide) {
         return ide.sprites.asArray().concat([ide.stage]).some(
             function (any, idx) {
@@ -869,15 +873,14 @@ CustomCommandBlockMorph.prototype.isInUse = function () {
             }
         );
     }
-    // return this.receiver().usesBlockInstance(def);
+    return rcvr.allDependentInvocationsOf(this.blockSpec).length > 0;
-    return this.receiver().allDependentInvocationsOf(this.blockSpec).length > 0;
 };
 
 // CustomCommandBlockMorph menu:
 
 CustomCommandBlockMorph.prototype.userMenu = function () {
     var hat = this.parentThatIsA(PrototypeHatBlockMorph),
-        rcvr = this.receiver(),
+        rcvr = this.scriptTarget(),
         myself = this,
         shiftClicked = this.world().currentKey === 16,
         menu;
@@ -999,7 +1002,7 @@ CustomCommandBlockMorph.prototype.exportBlockDefinition = function () {
 };
 
 CustomCommandBlockMorph.prototype.duplicateBlockDefinition = function () {
-    var rcvr = this.receiver(),
+    var rcvr = this.scriptTarget(),
         ide = this.parentThatIsA(IDE_Morph),
         def = this.isGlobal ? this.definition : rcvr.getMethod(this.blockSpec),
         dup = def.copyAndBindTo(rcvr);
@@ -1015,7 +1018,7 @@ CustomCommandBlockMorph.prototype.duplicateBlockDefinition = function () {
 
 CustomCommandBlockMorph.prototype.deleteBlockDefinition = function () {
     var idx, stage, ide, method, block,
-        rcvr = this.receiver(),
+        rcvr = this.scriptTarget(),
         myself = this;
     if (this.isPrototype) {
         return null; // under construction...
@@ -1093,7 +1096,7 @@ CustomCommandBlockMorph.prototype.relabel = function (alternatives) {
 };
 
 CustomCommandBlockMorph.prototype.alternatives = function () {
-    var rcvr = this.receiver(),
+    var rcvr = this.scriptTarget(),
         stage = rcvr.parentThatIsA(StageMorph),
         allDefs = rcvr.customBlocks.concat(stage.globalBlocks),
         type = this instanceof CommandBlockMorph ? 'command'
@@ -1894,7 +1897,7 @@ BlockEditorMorph.prototype.init = function (definition, target) {
     this.createLabel();
 
     // create scripting area
-    scripts = new ScriptsMorph(target);
+    scripts = new ScriptsMorph();
     scripts.rejectsHats = true;
     scripts.isDraggable = false;
     scripts.color = IDE_Morph.prototype.groupColor;

gui.js

@@ -74,7 +74,7 @@ isRetinaSupported, SliderMorph, Animation*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.gui = '2017-May-12';
+modules.gui = '2017-May-30';
 
 // Declarations
 

history.txt

@@ -3428,6 +3428,10 @@ Fixes:
 * added inheritance support for the wardrobe (‘costumes’)
 * added inheritance support for ‘costume #’
 
+170530
+------
+* let clones share the orginal’s scripts without shallow-copying them
+
 
 Features:
 * polymorphic sprite-local custom blocks
@@ -3441,6 +3445,7 @@ Features:
 * support for codification of String, Number and Boolean value types
 * costume icons indicate svg costumes
 * sprites’s rotation centers can be adjusted onstage
+* clones share their original sprite’s scripts, not a shallow-copy of them
 
 Fixes:
 * changed keyboard shortcut indicator for “find blocks” to “^”

objects.js

@@ -82,7 +82,7 @@ SpeechBubbleMorph, RingMorph, isNil, FileReader, TableDialogMorph,
 BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph, localize,
 TableMorph, TableFrameMorph, normalizeCanvas, BooleanSlotMorph, HandleMorph*/
 
-modules.objects = '2017-May-15';
+modules.objects = '2017-May-30';
 
 var SpriteMorph;
 var StageMorph;
@@ -1343,7 +1343,7 @@ function SpriteMorph(globals) {
 SpriteMorph.prototype.init = function (globals) {
     this.name = localize('Sprite');
     this.variables = new VariableFrame(globals || null, this);
-    this.scripts = new ScriptsMorph(this);
+    this.scripts = new ScriptsMorph();
     this.customBlocks = [];
     this.costumes = new List();
     this.costume = null;
@@ -1388,7 +1388,7 @@ SpriteMorph.prototype.init = function (globals) {
 
     // sprite inheritance
     this.exemplar = null;
-    this.cachedSpecimens = null; // temporary for morphic animations
+    this.cachedSpecimens = null; // not to be persisted
     this.inheritedAttributes = []; // 'x position', 'direction', 'size' etc...
 
     SpriteMorph.uber.init.call(this);
@@ -1413,11 +1413,10 @@ SpriteMorph.prototype.fullCopy = function (forClone) {
     c.color = this.color.copy();
     c.blocksCache = {};
     c.paletteCache = {};
-    c.scripts = this.scripts.fullCopy(forClone);
-    c.scripts.owner = c;
     c.variables = this.variables.copy();
     c.variables.owner = c;
     if (!forClone) {
+        c.scripts = this.scripts.fullCopy();
         c.customBlocks = [];
         this.customBlocks.forEach(function (def) {
             cb = def.copyAndBindTo(c);
@@ -3159,7 +3158,8 @@ SpriteMorph.prototype.createClone = function (immediately) {
 };
 
 SpriteMorph.prototype.clonify = function (stage, immediately) {
-    var hats;
+    var hats,
+        myself = this;
     this.parts.forEach(function (part) {
         part.clonify(stage);
     });
@@ -3173,6 +3173,7 @@ SpriteMorph.prototype.clonify = function (stage, immediately) {
     hats.forEach(function (block) {
         stage.threads.startProcess(
             block,
+            myself,
             stage.isThreadSafe,
             null, // export result
             null, // callback
@@ -3899,7 +3900,7 @@ SpriteMorph.prototype.prepareToBeGrabbed = function (hand) {
     this.recordLayers();
     this.shadowAttribute('x position');
     this.shadowAttribute('y position');
-    this.cachedSpecimens = this.specimens();
+    this.specimens(); // make sure specimens are cached
     if (!this.bounds.containsPoint(hand.position()) &&
             this.isCorrectingOutsideDrag()) {
         this.setCenter(hand.position());
@@ -3920,7 +3921,6 @@ SpriteMorph.prototype.justDropped = function () {
     if (stage) {
         stage.enableCustomHatBlocks = true;
     }
-    this.cachedSpecimens = null;
     if (this.exemplar) {
         this.inheritedAttributes.forEach(function (att) {
             myself.refreshInheritedAttribute(att);
@@ -4111,17 +4111,17 @@ SpriteMorph.prototype.slideBackTo = function (
     var myself = this;
 
     // caching specimens
-    this.cachedSpecimens = situation.origin.children.filter(function (m) {
+    if (isNil(this.cachedSpecimens)) {
-        return m instanceof SpriteMorph && (m.exemplar === myself);
+        this.cachedSpecimens = situation.origin.children.filter(function (m) {
-    });
+            return m instanceof SpriteMorph && (m.exemplar === myself);
+        });
+    }
 
     SpriteMorph.uber.slideBackTo.call(
         this,
         situation,
         msecs,
         function () {
-            // make sure to flush cached specimens
-            myself.cachedSpecimens = null;
             if (onBeforeDrop) {onBeforeDrop(); }
         },
         onBeforeDrop,
@@ -4548,11 +4548,16 @@ SpriteMorph.prototype.mouseDownLeft = function () {
 SpriteMorph.prototype.receiveUserInteraction = function (interaction) {
     var stage = this.parentThatIsA(StageMorph),
         procs = [],
+        myself = this,
         hats;
     if (!stage) {return; } // currently dragged
     hats = this.allHatBlocksForInteraction(interaction);
     hats.forEach(function (block) {
-        procs.push(stage.threads.startProcess(block, stage.isThreadSafe));
+        procs.push(stage.threads.startProcess(
+            block,
+            myself,
+            stage.isThreadSafe
+        ));
     });
     return procs;
 };
@@ -5129,6 +5134,7 @@ SpriteMorph.prototype.setExemplar = function (another) {
         ide.flushBlocksCache('variables');
         ide.refreshPalette();
     }
+    another.cachedSpecimens = null;
 };
 
 SpriteMorph.prototype.allExemplars = function () {
@@ -5145,9 +5151,12 @@ SpriteMorph.prototype.allExemplars = function () {
 SpriteMorph.prototype.specimens = function () {
     // without myself
     var myself = this;
-    return this.cachedSpecimens || this.siblings().filter(function (m) {
+    if (isNil(this.cachedSpecimens)) {
-        return m instanceof SpriteMorph && (m.exemplar === myself);
+        this.cachedSpecimens = this.siblings().filter(function (m) {
-    });
+            return m instanceof SpriteMorph && (m.exemplar === myself);
+        });
+    }
+    return this.cachedSpecimens;
 };
 
 SpriteMorph.prototype.allSpecimens = function () {
@@ -5536,6 +5545,16 @@ SpriteMorph.prototype.restoreLayers = function () {
     this.layers = null;
 };
 
+// SpriteMorph destroying
+
+SpriteMorph.prototype.destroy = function () {
+    // make sure to invalidate the specimens cache
+    if (this.exemplar) {
+        this.exemplar.cachedSpecimens = null;
+    }
+    SpriteMorph.uber.destroy.call(this);
+};
+
 // SpriteMorph highlighting
 
 SpriteMorph.prototype.addHighlight = function (oldHighlight) {
@@ -5768,7 +5787,7 @@ StageMorph.prototype.init = function (globals) {
     this.name = localize('Stage');
     this.threads = new ThreadManager();
     this.variables = new VariableFrame(globals || null, this);
-    this.scripts = new ScriptsMorph(this);
+    this.scripts = new ScriptsMorph();
     this.customBlocks = [];
     this.globalBlocks = [];
     this.costumes = new List();
@@ -6174,25 +6193,24 @@ StageMorph.prototype.step = function () {
 };
 
 StageMorph.prototype.stepGenericConditions = function (stopAll) {
-    var hats = [],
+    var hatCount = 0,
         myself = this,
         ide;
     this.children.concat(this).forEach(function (morph) {
-        if (morph instanceof SpriteMorph || morph instanceof StageMorph) {
+        if (isSnapObject(morph)) {
-            hats = hats.concat(morph.allGenericHatBlocks());
+            morph.allGenericHatBlocks().forEach(function (block) {
+                hatCount += 1;
+                myself.threads.doWhen(block, morph, stopAll);
+            });
         }
     });
-    if (!hats.length) {
+    if (!hatCount) {
         this.enableCustomHatBlocks = false;
         ide = this.parentThatIsA(IDE_Morph);
         if (ide) {
             ide.controlBar.stopButton.refresh();
         }
-        return;
     }
-    hats.forEach(function (block) {
-        myself.threads.doWhen(block, stopAll);
-    });
 };
 
 StageMorph.prototype.developersMenu = function () {
@@ -6266,7 +6284,6 @@ StageMorph.prototype.processKeyEvent = function (event, action) {
 
 StageMorph.prototype.fireKeyEvent = function (key) {
     var evt = key.toLowerCase(),
-        hats = [],
         procs = [],
         ide = this.parentThatIsA(IDE_Morph),
         myself = this;
@@ -6311,12 +6328,15 @@ StageMorph.prototype.fireKeyEvent = function (key) {
     }
     this.children.concat(this).forEach(function (morph) {
         if (isSnapObject(morph)) {
-            hats = hats.concat(morph.allHatBlocksForKey(evt));
+            morph.allHatBlocksForKey(evt).forEach(function (block) {
+                procs.push(myself.threads.startProcess(
+                    block,
+                    morph,
+                    myself.isThreadSafe
+                ));
+            });
         }
     });
-    hats.forEach(function (block) {
-        procs.push(myself.threads.startProcess(block, myself.isThreadSafe));
-    });
     return procs;
 };
 
@@ -6333,21 +6353,20 @@ StageMorph.prototype.inspectKeyEvent
 
 StageMorph.prototype.fireGreenFlagEvent = function () {
     var procs = [],
-        hats = [],
         ide = this.parentThatIsA(IDE_Morph),
         myself = this;
 
     this.children.concat(this).forEach(function (morph) {
         if (isSnapObject(morph)) {
-            hats = hats.concat(morph.allHatBlocksFor('__shout__go__'));
+            morph.allHatBlocksFor('__shout__go__').forEach(function (block) {
+                procs.push(myself.threads.startProcess(
+                    block,
+                    morph,
+                    myself.isThreadSafe
+                ));
+            });
         }
     });
-    hats.forEach(function (block) {
-        procs.push(myself.threads.startProcess(
-            block,
-            myself.isThreadSafe
-        ));
-    });
     if (ide) {
         ide.controlBar.pauseButton.refresh();
     }
@@ -7210,6 +7229,12 @@ StageMorph.prototype.allSpecimens = function () {
 
 StageMorph.prototype.shadowAttribute = nop;
 
+// StageMorph inheritance support - attributes
+
+StageMorph.prototype.inheritsAttribute = function () {
+    return false;
+};
+
 // StageMorph inheritance support - variables
 
 StageMorph.prototype.isVariableNameInUse

threads.js

@@ -61,7 +61,7 @@ StageMorph, SpriteMorph, StagePrompterMorph, Note, modules, isString, copy,
 isNil, WatcherMorph, List, ListWatcherMorph, alert, console, TableMorph,
 TableFrameMorph, ColorSlotMorph, isSnapObject*/
 
-modules.threads = '2017-May-12';
+modules.threads = '2017-May-30';
 
 var ThreadManager;
 var Process;
@@ -109,7 +109,7 @@ function snapEquals(a, b) {
 function invoke(
     action, // a BlockMorph or a Context, a reified ("ringified") block
     contextArgs, // optional List of arguments for the context, or null
-    receiver, // optional sprite or environment
+    receiver, // sprite or environment, optional for contexts
     timeout, // msecs
     timeoutErrorMsg, // string
     suppressErrors // bool
@@ -126,23 +126,23 @@ function invoke(
     // Use ThreadManager::startProcess with a callback instead
 
     var proc = new Process(),
-        deadline = (timeout ? Date.now() + timeout : null),
+        deadline = (timeout ? Date.now() + timeout : null);
-        rcvr;
 
     if (action instanceof Context) {
-        if (receiver) {
+        if (receiver) { // optional
             action = proc.reportContextFor(receiver);
         }
         proc.initializeFor(action, contextArgs || new List());
     } else if (action instanceof BlockMorph) {
         proc.topBlock = action;
-        rcvr = receiver || action.receiver();
+        if (receiver) {
-        if (rcvr) {
             proc.homeContext = new Context();
-            proc.homeContext.receiver = rcvr;
+            proc.homeContext.receiver = receiver;
-            if (rcvr.variables) {
+            if (receiver.variables) {
-                proc.homeContext.variables.parentFrame = rcvr.variables;
+                proc.homeContext.variables.parentFrame = receiver.variables;
             }
+        } else {
+            throw new Error('expecting a receiver but getting ' + receiver);
         }
         proc.context = new Context(
             null,
@@ -180,25 +180,26 @@ function ThreadManager() {
 
 ThreadManager.prototype.pauseCustomHatBlocks = false;
 
-ThreadManager.prototype.toggleProcess = function (block) {
+ThreadManager.prototype.toggleProcess = function (block, receiver) {
-    var active = this.findProcess(block);
+    var active = this.findProcess(block, receiver);
     if (active) {
         active.stop();
     } else {
-        return this.startProcess(block, null, null, null, true);
+        return this.startProcess(block, receiver, null, null, null, true);
     }
 };
 
 ThreadManager.prototype.startProcess = function (
     block,
+    receiver,
     isThreadSafe,
-    exportResult,
+    exportResult, // bool
     callback,
     isClicked,
     rightAway
 ) {
-    var active = this.findProcess(block),
+    var top = block.topBlock(),
-        top = block.topBlock(),
+        active = this.findProcess(top, receiver),
         newProc;
     if (active) {
         if (isThreadSafe) {
@@ -207,7 +208,7 @@ ThreadManager.prototype.startProcess = function (
         active.stop();
         this.removeTerminatedProcesses();
     }
-    newProc = new Process(block.topBlock(), callback, rightAway);
+    newProc = new Process(top, receiver, callback, rightAway);
     newProc.exportResult = exportResult;
     newProc.isClicked = isClicked || false;
     if (!newProc.homeContext.receiver.isClone) {
@@ -241,8 +242,8 @@ ThreadManager.prototype.stopAllForReceiver = function (rcvr, excpt) {
     });
 };
 
-ThreadManager.prototype.stopProcess = function (block) {
+ThreadManager.prototype.stopProcess = function (block, receiver) {
-    var active = this.findProcess(block);
+    var active = this.findProcess(block, receiver);
     if (active) {
         active.stop();
     }
@@ -309,7 +310,8 @@ ThreadManager.prototype.removeTerminatedProcesses = function () {
     this.processes.forEach(function (proc) {
         var result;
         if ((!proc.isRunning() && !proc.errorFlag) || proc.isDead) {
-            if (proc.topBlock instanceof BlockMorph) {
+            if (proc.topBlock instanceof BlockMorph
+                    && (!proc.receiver.isClone)) {
                 proc.unflash();
                 proc.topBlock.removeHighlight();
             }
@@ -349,19 +351,19 @@ ThreadManager.prototype.removeTerminatedProcesses = function () {
     this.processes = remaining;
 };
 
-ThreadManager.prototype.findProcess = function (block) {
+ThreadManager.prototype.findProcess = function (block, receiver) {
     var top = block.topBlock();
     return detect(
         this.processes,
         function (each) {
-            return each.topBlock === top;
+            return each.topBlock === top && (each.receiver === receiver);
         }
     );
 };
 
-ThreadManager.prototype.doWhen = function (block, stopIt) {
+ThreadManager.prototype.doWhen = function (block, receiver, stopIt) {
     if (this.pauseCustomHatBlocks) {return; }
-    if ((!block) || this.findProcess(block)) {
+    if ((!block) || this.findProcess(block, receiver)) {
         return;
     }
     var pred = block.inputs()[0], world;
@@ -376,12 +378,20 @@ ThreadManager.prototype.doWhen = function (block, stopIt) {
         if (invoke(
             pred,
             null,
-            block.receiver(), // needed for shallow copied clones - was null
+            receiver,
             50,
             'the predicate takes\ntoo long for a\ncustom hat block',
             true // suppress errors => handle them right here instead
         ) === true) {
-            this.startProcess(block, null, null, null, null, true); // atomic
+            this.startProcess(
+                block,
+                receiver,
+                null,
+                null,
+                null,
+                null,
+                true // atomic
+            );
         }
     } catch (error) {
         block.addErrorHighlight();
@@ -476,9 +486,9 @@ Process.prototype.enableSingleStepping = false; // experimental
 Process.prototype.flashTime = 0; // experimental
 // Process.prototype.enableJS = false;
 
-function Process(topBlock, onComplete, rightAway) {
+function Process(topBlock, receiver, onComplete, rightAway) {
     this.topBlock = topBlock || null;
-
+    this.receiver = receiver;
     this.readyToYield = false;
     this.readyToTerminate = false;
     this.isDead = false;
@@ -486,7 +496,7 @@ function Process(topBlock, onComplete, rightAway) {
     this.isShowingResult = false;
     this.errorFlag = false;
     this.context = null;
-    this.homeContext = new Context();
+    this.homeContext = new Context(null, null, null, receiver);
     this.lastYield =  Date.now();
     this.isFirstStep = true;
     this.isAtomic = false;
@@ -502,7 +512,6 @@ function Process(topBlock, onComplete, rightAway) {
     this.isInterrupted = false; // experimental, for single-stepping
 
     if (topBlock) {
-        this.homeContext.receiver = topBlock.receiver();
         this.homeContext.variables.parentFrame =
             this.homeContext.receiver.variables;
         this.context = new Context(
@@ -651,7 +660,7 @@ Process.prototype.evaluateBlock = function (block, argCount) {
     }
 
     // first evaluate all inputs, then apply the primitive
-    var rcvr = this.context.receiver || this.topBlock.receiver(),
+    var rcvr = this.context.receiver || this.receiver,
         inputs = this.context.inputs;
 
     if (argCount > inputs.length) {
@@ -963,7 +972,7 @@ Process.prototype.reify = function (topBlock, parameterNames, isCustomBlock) {
 
     context.inputs = parameterNames.asArray();
     context.receiver
-        = this.context ? this.context.receiver : topBlock.receiver();
+        = this.context ? this.context.receiver : this.receiver;
     context.origin = context.receiver; // for serialization
 
     return context;
@@ -1137,6 +1146,9 @@ Process.prototype.initializeFor = function (context, args) {
         value,
         exit;
 
+    // remember the receiver
+    this.context = context.receiver;
+
     // assign parameters if any were passed
     if (parms.length > 0) {
 
@@ -1557,7 +1569,7 @@ Process.prototype.doDeleteAttr = function (attrName) {
             if (!isNil(name)) {
                 rcvr.inheritAttribute(name);
             }
-            return; // +++ error: cannot delete attribute...
+            return; // error: cannot delete attribute...
         }
     }
     if (name instanceof Array) {
@@ -2063,7 +2075,7 @@ Process.prototype.doThinkFor = function (data, secs) {
 
 Process.prototype.blockReceiver = function () {
     return this.context ? this.context.receiver || this.homeContext.receiver
-            : this.homeContext.receiver;
+            : this.homeContext.receiver || this.receiver;
 };
 
 // Process sound primitives (interpolated)
@@ -2180,7 +2192,6 @@ Process.prototype.doBroadcast = function (message) {
         trg,
         rcvrs,
         myself = this,
-        hats = [],
         procs = [];
 
     if (message instanceof List && (message.length() === 2)) {
@@ -2211,40 +2222,19 @@ Process.prototype.doBroadcast = function (message) {
         stage.lastMessage = message; // the actual data structure
         rcvrs.forEach(function (morph) {
             if (isSnapObject(morph)) {
-                hats = hats.concat(morph.allHatBlocksFor(msg));
+                morph.allHatBlocksFor(msg).forEach(function (block) {
+                    procs.push(stage.threads.startProcess(
+                        block,
+                        morph,
+                        stage.isThreadSafe
+                    ));
+                });
             }
         });
-        hats.forEach(function (block) {
-            procs.push(stage.threads.startProcess(block, stage.isThreadSafe));
-        });
     }
     return procs;
 };
 
-// old purely global broadcast code, commented out and retained in case
-// we need to revert
-
-/*
-Process.prototype.doBroadcast = function (message) {
-    var stage = this.homeContext.receiver.parentThatIsA(StageMorph),
-        hats = [],
-        procs = [];
-
-    if (message !== '') {
-        stage.lastMessage = message;
-        stage.children.concat(stage).forEach(function (morph) {
-            if (isSnapObject(morph)) {
-                hats = hats.concat(morph.allHatBlocksFor(message));
-            }
-        });
-        hats.forEach(function (block) {
-            procs.push(stage.threads.startProcess(block, stage.isThreadSafe));
-        });
-    }
-    return procs;
-};
-*/
-
 Process.prototype.doBroadcastAndWait = function (message) {
     if (!this.context.activeSends) {
         this.context.activeSends = this.doBroadcast(message);