dynamic extension dropdown menu support

HISTORY.md

@@ -15,6 +15,7 @@
 * tweaked strings library
 * extensions: added color library dropdown menu
 * blocks, threads, extensions: separated extension primitives from extension dropdown menus
+* blocks, byob: dynamic extension dropdown menu support
 
 ### 2021-06-17
 * extensions: added APL extension primitives

snap.html

@@ -14,7 +14,7 @@
         <script src="src/gui.js?version=2021-06-14"></script>
         <script src="src/paint.js?version=2020-05-17"></script>
         <script src="src/lists.js?version=2021-03-15"></script>
-        <script src="src/byob.js?version=2021-06-11"></script>
+        <script src="src/byob.js?version=2021-06-18"></script>
         <script src="src/tables.js?version=2021-03-05"></script>
         <script src="src/sketch.js?version=2020-07-13"></script>
         <script src="src/video.js?version=2019-06-27"></script>

src/blocks.js

@@ -9082,6 +9082,7 @@ InputSlotMorph.prototype.menuFromDict = function (
 {
     var key, dial, flag,
     	myself = this,
+        selector,
         block = this.parentThatIsA(BlockMorph),
         ide = this.parentThatIsA(IDE_Morph),
         menu = new MenuMorph(
@@ -9110,7 +9111,18 @@ InputSlotMorph.prototype.menuFromDict = function (
         }
         choices = choices.call(this);
     } else if (isString(choices)) {
-        choices = this[choices]();
+        if (choices.indexOf('ext_') === 0) {
+            selector = choices.slice(4);
+            choices = SnapExtensions.menus.get(selector);
+            if (choices) {
+                choices = choices.call(this);
+            } else {
+                menu.addItem('cannot find extension menu "' + selector + '"');
+                return menu;
+            }
+        } else {
+            choices = this[choices]();
+        }
         if (!choices) { // menu has already happened
             return;
         }

src/byob.js

@@ -102,11 +102,11 @@ nop, radians, BoxMorph, ArrowMorph, PushButtonMorph, contains, InputSlotMorph,
 ToggleButtonMorph, IDE_Morph, MenuMorph, ToggleElementMorph, fontHeight, isNil,
 StageMorph, SyntaxElementMorph, CommentMorph, localize, CSlotMorph, Variable,
 MorphicPreferences, SymbolMorph, CursorMorph, VariableFrame, BooleanSlotMorph,
-WatcherMorph, XML_Serializer, SnapTranslator*/
+WatcherMorph, XML_Serializer, SnapTranslator, SnapExtensions*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.byob = '2021-June-11';
+modules.byob = '2021-June-18';
 
 // Declarations
 
@@ -331,7 +331,7 @@ CustomBlockDefinition.prototype.dropDownMenuOf = function (inputName) {
                     'directionDialMenu'
                 ],
                 fname
-            )) {
+            ) || fname.indexOf('ext_') === 0) {
                 return fname;
             }
         }
@@ -2749,6 +2749,13 @@ BlockLabelFragment.prototype.hasSpecialMenu = function () {
     );
 };
 
+BlockLabelFragment.prototype.hasExtensionMenu = function () {
+    return contains(
+        Array.from(SnapExtensions.menus.keys()).map(str => '§_ext_' + str),
+        this.options
+    );
+};
+
 // arity
 
 BlockLabelFragment.prototype.isSingleInput = function () {
@@ -3741,6 +3748,13 @@ InputSlotDialogMorph.prototype.addSlotsMenu = function () {
                 localize('special'),
                 this.specialSlotsMenu()
             );
+            if (this.world().currentKey === 16) { // shift-key down
+                menu.addMenu(
+                    (this.fragment.hasExtensionMenu() ? on : off) +
+                    localize('extension'),
+                    this.extensionOptionsMenu()
+                );
+            }
             return menu;
         }
         return this.specialSlotsMenu();
@@ -3808,6 +3822,27 @@ InputSlotDialogMorph.prototype.specialOptionsMenu = function () {
     return menu;
 };
 
+InputSlotDialogMorph.prototype.extensionOptionsMenu = function () {
+    var menu = new MenuMorph(this.setSlotOptions, null, this),
+        myself = this,
+        selectors = Array.from(SnapExtensions.menus.keys()),
+        on = '\u26AB ',
+        off = '\u26AA ';
+
+    function addSpecialOptions(label, selector) {
+        menu.addItem(
+            (myself.fragment.options === selector ?
+                    on : off) + localize(label),
+            selector
+        );
+    }
+
+    selectors.forEach(sel => {
+        addSpecialOptions(sel.slice(4), '§_ext_' + sel);
+    });
+    return menu;
+};
+
 // InputSlotDialogMorph hiding and showing:
 
 /*