recycle cached Canvasses in the slot editor

HISTORY.md

@@ -13,6 +13,7 @@
 * objects: recycle cached Canvasses
 * blocks: recycle cached Canvasses
 * widgets: recycle cached Canvasses
+* byob: recycle cached Canvasses
 
 ## 5.4.0:
 * **New Features:**

snap.html

@@ -12,7 +12,7 @@
         <script type="text/javascript" src="src/gui.js?version=2020-01-03"></script>
         <script type="text/javascript" src="src/paint.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/lists.js?version=2019-12-08"></script>
-        <script type="text/javascript" src="src/byob.js?version=2019-07-12"></script>
+        <script type="text/javascript" src="src/byob.js?version=2020-01-03"></script>
         <script type="text/javascript" src="src/tables.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/symbols.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/sketch.js?version=2019-10-09"></script>

src/byob.js

@@ -9,7 +9,7 @@
     written by Jens Mönig
     jens@moenig.org
 
-    Copyright (C) 2018 by Jens Mönig
+    Copyright (C) 2020 by Jens Mönig
 
     This file is part of Snap!.
 
@@ -108,7 +108,7 @@ BooleanSlotMorph, XML_Serializer, SnapTranslator*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.byob = '2019-November-12';
+modules.byob = '2020-January-03';
 
 // Declarations
 
@@ -1489,7 +1489,7 @@ JaggedBlockMorph.prototype.drawNew = function () {
     this.cachedClr = this.color.toString();
     this.cachedClrBright = this.bright();
     this.cachedClrDark = this.dark();
-    this.image = newCanvas(this.extent());
+    this.image = newCanvas(this.extent(), false, this.image);
     context = this.image.getContext('2d');
     context.fillStyle = this.cachedClr;