new experimental (hidden) "extract" single command block context menu option

HISTORY.md

@@ -5,6 +5,7 @@
     * added "pie chart" option to PLOT command in the frequency distribution analysis library
     * added getProjectXML() method to the API
     * new noCloud flag that disables cloud access, thanks, Bernat
+    * experimental (hidden) "extract" single command block context menu option
 * **Documentation Updates:**
     * API update
 * **Notable Fixes:**
@@ -17,6 +18,7 @@
 * gui: wait until all costumes have loaded before auto-triggering the green-flag event 
 * gui, objects, store: wait until all sounds have loaded before auto-triggering the green-flag event
 * gui, cloud: added noCloud flag that disables cloud access, thanks, Bernat!
+* blocks: new experimental (hidden) "extract" single command block context menu option
 
 ### 2020-10-20
 * added "pie chart" option to PLOT command in the frequency distribution analysis library

snap.html

@@ -8,7 +8,7 @@
         <script src="src/morphic.js?version=2020-10-20"></script>
         <script src="src/symbols.js?version=2020-10-07"></script>
         <script src="src/widgets.js?version=2020-10-06"></script>
-        <script src="src/blocks.js?version=2020-10-20"></script>
+        <script src="src/blocks.js?version=2020-10-21"></script>
         <script src="src/threads.js?version=2020-10-08"></script>
         <script src="src/objects.js?version=2020-10-21"></script>
         <script src="src/gui.js?version=2020-10-21"></script>

src/blocks.js

@@ -158,7 +158,7 @@ CustomCommandBlockMorph, SymbolMorph, ToggleButtonMorph, DialMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2020-October-20';
+modules.blocks = '2020-October-21';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -3023,6 +3023,15 @@ BlockMorph.prototype.userMenu = function () {
             },
             'only duplicate this block'
         );
+
+        if (shiftClicked) {
+            menu.addItem(
+                'extract',
+                'userExtractJustThis',
+                'EXPERIMENTAL!\nonly grab this block',
+                new Color(100, 0, 0)
+            );
+        }
     }
     menu.addItem(
         "delete",
@@ -5303,6 +5312,57 @@ CommandBlockMorph.prototype.userDestroyJustThis = function () {
     }
 };
 
+CommandBlockMorph.prototype.userExtractJustThis = function () {
+    // extract just this one block, reattach next block to the previous one,
+    // has issue for REDO after UNDO: Next blocks follow
+    // unused for now
+    var scripts = this.parentThatIsA(ScriptsMorph),
+        ide = this.parentThatIsA(IDE_Morph),
+        situation = this.situation(),
+        cs = this.parentThatIsA(CommandSlotMorph, RingReporterSlotMorph),
+        pb,
+        nb = this.nextBlock(),
+        above,
+        parent = this.parentThatIsA(SyntaxElementMorph),
+        cslot = this.parentThatIsA(CSlotMorph, RingReporterSlotMorph);
+
+    this.topBlock().fullChanged();
+    if (this.parent) {
+        pb = this.parent.parentThatIsA(CommandBlockMorph);
+    }
+    if (pb && (pb.nextBlock() === this)) {
+        above = pb;
+    } else if (cs && (cs.nestedBlock() === this)) {
+        above = cs;
+        this.prepareToBeGrabbed(); // restore ring reporter slot, if any
+    }
+    if (ide) {
+        // also stop all active processes hatted by this block
+        ide.removeBlock(this, true); // just this block
+    } else {
+        this.destroy(true); // just this block
+    }
+    if (nb) {
+        if (above instanceof CommandSlotMorph ||
+            above instanceof RingReporterSlotMorph
+        ) {
+            above.nestedBlock(nb);
+        } else if (above instanceof CommandBlockMorph) {
+            above.nextBlock(nb);
+        } else {
+            scripts.add(nb);
+        }
+    } else if (cslot) {
+        cslot.fixLayout();
+    }
+    if (parent) {
+        parent.reactToGrabOf(this); // fix highlight
+    }
+
+    this.pickUp(scripts.world());
+    this.parent.grabOrigin = situation;
+};
+
 // CommandBlockMorph drawing:
 
 CommandBlockMorph.prototype.outlinePath = function(ctx, inset) {