shadow inherited scripts on dragging & dropping blocks and comments

blocks.js

@@ -150,7 +150,7 @@ CustomCommandBlockMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2017-June-20';
+modules.blocks = '2017-June-22';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -3736,6 +3736,23 @@ BlockMorph.prototype.mouseClickLeft = function () {
     }
 };
 
+BlockMorph.prototype.selectForEdit = function () {
+    var rcvr = this.scriptTarget(),
+        selected;
+    if (rcvr.inheritsAttribute('scripts')) {
+        // copy on write:
+        this.selectionID = true;
+        rcvr.shadowAttribute('scripts');
+        selected = detect(rcvr.scripts.allChildren(), function (m) {
+            return m.selectionID;
+        });
+        delete this.selectionID;
+        delete selected.selectionID;
+        return selected;
+    }
+    return this;
+};
+
 BlockMorph.prototype.focus = function () {
     var scripts = this.parentThatIsA(ScriptsMorph),
         world = this.world(),
@@ -6602,6 +6619,17 @@ ScriptsMorph.prototype.mouseClickLeft = function (pos) {
     if (this.focus) {this.focus.stopEditing(); }
 };
 
+ScriptsMorph.prototype.selectForEdit = function () {
+    var rcvr = this.scriptTarget();
+    if (rcvr.inheritsAttribute('scripts')) {
+        // copy on write:
+        this.feedbackMorph.destroy();
+        rcvr.shadowAttribute('scripts');
+        return rcvr.scripts;
+    }
+    return this;
+};
+
 // ScriptsMorph keyboard support
 
 ScriptsMorph.prototype.edit = function (pos) {
@@ -12805,6 +12833,9 @@ CommentMorph.prototype.fullCopy = function () {
     var cpy = new CommentMorph(this.contents.text);
     cpy.isCollapsed = this.isCollapsed;
     cpy.setTextWidth(this.textWidth());
+    if (this.selectionID) { // for copy on write
+        cpy.selectionID = true;
+    }
     return cpy;
 };
 
@@ -12963,6 +12994,24 @@ CommentMorph.prototype.prepareToBeGrabbed = function (hand) {
     }
 };
 
+CommentMorph.prototype.selectForEdit = function () {
+    var scripts = this.parentThatIsA(ScriptsMorph),
+        rcvr = scripts ? scripts.scriptTarget() : null,
+        selected;
+    if (rcvr && rcvr.inheritsAttribute('scripts')) {
+        // copy on write:
+        this.selectionID = true;
+        rcvr.shadowAttribute('scripts');
+        selected = detect(rcvr.scripts.allChildren(), function (m) {
+            return m.selectionID;
+        });
+        delete this.selectionID;
+        delete selected.selectionID;
+        return selected;
+    }
+    return this;
+};
+
 CommentMorph.prototype.snap = function (hand) {
     // passing the hand is optional (for when blocks are dragged & dropped)
     var scripts = this.parent,

history.txt

@@ -3454,6 +3454,11 @@ Fixes:
 ------
 * objects: stop all scripts for a sprite when shadowing or inheriting its scripts
 
+170622
+------
+* Morphic: support for copy-on-write worlds (“selectForEdit”)
+* Blocks, Objects: shadow inherited scripts on dragging & dropping blocks and comments
+
 
 Features:
 * polymorphic sprite-local custom blocks

objects.js

@@ -82,7 +82,7 @@ SpeechBubbleMorph, RingMorph, isNil, FileReader, TableDialogMorph,
 BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph, localize,
 TableMorph, TableFrameMorph, normalizeCanvas, BooleanSlotMorph, HandleMorph*/
 
-modules.objects = '2017-June-21';
+modules.objects = '2017-June-22';
 
 var SpriteMorph;
 var StageMorph;
@@ -5186,7 +5186,8 @@ SpriteMorph.prototype.shadowedAttributes = function () {
 
 SpriteMorph.prototype.shadowAttribute = function (aName) {
     var ide, wardrobe,
-        myself = this;
+        myself = this,
+        pos;
     if (!this.inheritsAttribute(aName)) {
         return;
     }
@@ -5206,11 +5207,14 @@ SpriteMorph.prototype.shadowAttribute = function (aName) {
         this.costumes = wardrobe;
     } else if (aName === 'scripts') {
         ide.stage.threads.stopAllForReceiver(this);
+        pos = this.scripts.position();
         this.scripts = this.exemplar.scripts.fullCopy();
         if (ide && (contains(ide.currentSprite.allExemplars(), this))) {
             ide.createSpriteEditor();
             ide.fixLayout('selectSprite');
             this.scripts.fixMultiArgs();
+            this.scripts.setPosition(pos);
+            ide.spriteEditor.adjustScrollBars();
         }
         this.specimens().forEach(function (obj) {
             if (obj.inheritsAttribute('scripts')) {