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, 14 insertions, 4 deletions

diff --git a/gui.js b/gui.js
index 50f3cb2..4cd2a9b 100644
--- a/gui.js
+++ b/gui.js
@@ -69,7 +69,7 @@ SpeechBubbleMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.gui = '2015-March-15';
+modules.gui = '2015-March-21';
 
 // Declarations
 
@@ -2598,7 +2598,7 @@ IDE_Morph.prototype.aboutSnap = function () {
         module, btn1, btn2, btn3, btn4, licenseBtn, translatorsBtn,
         world = this.world();
 
-    aboutTxt = 'Snap! 4.0\nBuild Your Own Blocks\n\n--- rc ---\n\n'
+    aboutTxt = 'Snap! 4.1 (OOP)\nBuild Your Own Blocks\n\n--- dev ---\n\n'
         + 'Copyright \u24B8 2015 Jens M\u00F6nig and '
         + 'Brian Harvey\n'
         + 'jens@moenig.org, bh@cs.berkeley.edu\n\n'
@@ -5182,7 +5182,7 @@ function SpriteIconMorph(aSprite, aTemplate) {
 }
 
 SpriteIconMorph.prototype.init = function (aSprite, aTemplate) {
-    var colors, action, query, myself = this;
+    var colors, action, query, hover, myself = this;
 
     if (!aTemplate) {
         colors = [
@@ -5212,6 +5212,11 @@ SpriteIconMorph.prototype.init = function (aSprite, aTemplate) {
         return false;
     };
 
+    hover = function () {
+        if (!aSprite.exemplar) {return null; }
+        return (localize('parent' + ':\n' + aSprite.exemplar.name));
+    };
+
     // additional properties:
     this.object = aSprite || new SpriteMorph(); // mandatory, actually
     this.version = this.object.version;
@@ -5227,7 +5232,7 @@ SpriteIconMorph.prototype.init = function (aSprite, aTemplate) {
         this.object.name, // label string
         query, // predicate/selector
         null, // environment
-        null, // hint
+        hover, // hint
         aTemplate // optional, for cached background images
     );
 
@@ -5398,6 +5403,7 @@ SpriteIconMorph.prototype.userMenu = function () {
     menu.addItem("duplicate", 'duplicateSprite');
     menu.addItem("delete", 'removeSprite');
     menu.addLine();
+    menu.addItem("parent...", 'chooseExemplar');
     if (this.object.anchor) {
         menu.addItem(
             localize('detach from') + ' ' + this.object.anchor.name,
@@ -5432,6 +5438,10 @@ SpriteIconMorph.prototype.exportSprite = function () {
     this.object.exportSprite();
 };
 
+SpriteIconMorph.prototype.chooseExemplar = function () {
+    this.object.chooseExemplar();
+};
+
 SpriteIconMorph.prototype.showSpriteOnStage = function () {
     this.object.showOnStage();
 };