added the ability to only show items in block drop-down menus if the shift-key is pressed

snap.html

@@ -7,7 +7,7 @@
         <script src="src/morphic.js?version=2020-06-13"></script>
         <script src="src/symbols.js?version=2020-06-17"></script>
         <script src="src/widgets.js?version=2020-05-06"></script>
-        <script src="src/blocks.js?version=2020-06-20"></script>
+        <script src="src/blocks.js?version=2020-06-24"></script>
         <script src="src/threads.js?version=2020-06-22"></script>
         <script src="src/objects.js?version=2020-06-20"></script>
         <script src="src/gui.js?version=2020-06-22"></script>

src/blocks.js

@@ -148,7 +148,7 @@ CustomCommandBlockMorph, SymbolMorph, ToggleButtonMorph, DialMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2020-June-20';
+modules.blocks = '2020-June-24';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -8717,6 +8717,25 @@ InputSlotMorph.prototype.menuFromDict = function (
        			menu.addLine();
 			    menu.items.push(dial);
             	menu.addLine();
+            } else if (key.indexOf('§_') === 0) {
+                // prefixing a key with '§_' only makes the menu item
+                // appear when the user holds down the shift-key
+                // use with care because mobile devices might only
+                // have a "soft" keyboard that isn't always there
+                if (this.world().currentKey === 16) { // shift
+                    menu.addItem(
+                        key.slice(2),
+                        choices[key],
+                        null, // hint
+                        null, // color
+                        null, // bold
+                        true, // italic
+                        null, // doubleClickAction
+                        null, // shortcut
+                        !(choices[key] instanceof Array) &&
+                            typeof choices[key] !== 'function' // verbatim?
+                    );
+                }
             } else if (key === '__shout__go__') {
                 // show the green flag symbol
                 flag = new SymbolMorph('flag');