Prototypal inheritance of sprite-local variables

(experimental) slotwise inheritance à la Henry Lieberman for
sprite-local variables.

see
http://web.media.mit.edu/~lieber/Lieberary/OOP/Delegation/Delegation.htm
l

Let a sprite inherit another sprite’s local variables by making it the
“parent” in the sprite-icon’s context menu (the button icon in the
sprite corral underneath the stage). The child not only inherits the
variable slot but also - dynamically - the parent variable’s value.
Changing the parent’s variable value also changes it for every child.
If a child uses SET or CHANGE on an inherited variable it automatically
“shadows” it with its own value, thereby stopping dynamic participation
in the parent slot’s value (in effect dis-inheriting that slot).
Deleting a shadowed variable slot once again reinstates its inheritance
status.

inherited variables are shown as “ghosted” both in the child’s
variables palette and in such stage watchers. “Shadowing” them
un-ghosts both the variable blob template in the palette and the
watcher onstage (if any). Deleting a shadowed variable once again
ghosts the watcher and the palette block template.

Delete a (shadowed) variable either via the “Delete a variable” button
in the IDE or using the new “Delete” block in the variables category

1 files changed, 19 insertions, 8 deletions

diff --git a/morphic.js b/morphic.js
index 9616897..359e552 100644
--- a/morphic.js
+++ b/morphic.js
@@ -8,7 +8,7 @@
     written by Jens Mönig
     jens@moenig.org
 
-    Copyright (C) 2014 by Jens Mönig
+    Copyright (C) 2015 by Jens Mönig
 
     This file is part of Snap!.
 
@@ -527,6 +527,12 @@
     a duplicate of the template whose "isDraggable" flag is true and
     whose "isTemplate" flag is false, in other words: a non-template.
 
+    When creating a copy from a template, the copy's
+    
+        reactToTemplateCopy
+
+    is invoked, if it is present.
+
     Dragging is indicated by adding a drop shadow to the morph in hand.
     If a morph follows the hand without displaying a drop shadow it is
     merely being moved about without changing its parent (owner morph),
@@ -1020,9 +1026,10 @@
     programming hero.
 
     I have originally written morphic.js in Florian Balmer's Notepad2
-    editor for Windows and later switched to Apple's Dashcode. I've also
-    come to depend on both Douglas Crockford's JSLint, Mozilla's Firebug
-    and Google's Chrome to get it right.
+    editor for Windows, later switched to Apple's Dashcode and later
+    still to Apple's Xcode. I've also come to depend on both Douglas
+    Crockford's JSLint, Mozilla's Firebug and Google's Chrome to get
+    it right.
 
 
     IX. contributors
@@ -1041,7 +1048,7 @@
 /*global window, HTMLCanvasElement, getMinimumFontHeight, FileReader, Audio,
 FileList, getBlurredShadowSupport*/
 
-var morphicVersion = '2014-December-05';
+var morphicVersion = '2015-March-21';
 var modules = {}; // keep track of additional loaded modules
 var useBlurredShadows = getBlurredShadowSupport(); // check for Chrome-bug
 
@@ -8060,7 +8067,7 @@ TriggerMorph.prototype.init = function (
     this.environment = environment || null;
     this.labelString = labelString || null;
     this.label = null;
-    this.hint = hint || null;
+    this.hint = hint || null; // null, String, or Function
     this.fontSize = fontSize || MorphicPreferences.menuFontSize;
     this.fontStyle = fontStyle || 'sans-serif';
     this.highlightColor = new Color(192, 192, 192);
@@ -8209,10 +8216,11 @@ TriggerMorph.prototype.triggerDoubleClick = function () {
 // TriggerMorph events:
 
 TriggerMorph.prototype.mouseEnter = function () {
+    var contents = this.hint instanceof Function ? this.hint() : this.hint;
     this.image = this.highlightImage;
     this.changed();
-    if (this.hint) {
-        this.bubbleHelp(this.hint);
+    if (contents) {
+        this.bubbleHelp(contents);
     }
 };
 
@@ -9683,6 +9691,9 @@ HandMorph.prototype.processMouseMove = function (event) {
                 morph = this.morphToGrab.fullCopy();
                 morph.isTemplate = false;
                 morph.isDraggable = true;
+                if (morph.reactToTemplateCopy) {
+                    morph.reactToTemplateCopy();
+                }
                 this.grab(morph);
                 this.grabOrigin = this.morphToGrab.situation();
             }