added hooks for dynamic symbols coloring

HISTORY.md

@@ -5,6 +5,7 @@
 ### 2020-07-20
 * objects: fixed a list-watcher direct-editing offset bug
 * morphic: update the Hand's position on mouse-down - avoid triggering at the origin point
+* symbols: added hooks for dynamic coloring
 
 ### 2020-07-19
 * blocks: blocks-fade-out support for label arrows (under construction)

snap.html

@@ -5,7 +5,7 @@
         <title>Snap! Build Your Own Blocks 6.0.1 - dev -</title>
         <link rel="shortcut icon" href="src/favicon.ico">
         <script src="src/morphic.js?version=2020-07-20"></script>
-        <script src="src/symbols.js?version=2020-07-01"></script>
+        <script src="src/symbols.js?version=2020-07-20"></script>
         <script src="src/widgets.js?version=2020-07-13"></script>
         <script src="src/blocks.js?version=2020-07-20"></script>
         <script src="src/threads.js?version=2020-07-09"></script>

src/symbols.js

@@ -41,7 +41,7 @@
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.symbols = '2020-July-13';
+modules.symbols = '2020-July-20';
 
 var SymbolMorph;
 
@@ -194,6 +194,18 @@ SymbolMorph.prototype.setLabelColor = function (
     this.setColor(textColor);
 };
 
+// SymbolMorph dynamic coloring:
+
+SymbolMorph.prototype.getRenderColor = function () {
+    // answer the rendering color, can be overridden for my children
+    return this.color;
+};
+
+SymbolMorph.prototype.getShadowRenderColor = function () {
+    // answer the shadow rendering color, can be overridden for my children
+    return this.shadowColor;
+};
+
 // SymbolMorph layout:
 
 SymbolMorph.prototype.setExtent = function (aPoint) {
@@ -221,12 +233,12 @@ SymbolMorph.prototype.render = function (ctx) {
     if (this.shadowColor) {
         ctx.save();
         ctx.translate(sx, sy);
-        this.renderShape(ctx, this.shadowColor);
+        this.renderShape(ctx, this.getShadowRenderColor());
         ctx.restore();
     }
     ctx.save();
     ctx.translate(x, y);
-    this.renderShape(ctx, this.color);
+    this.renderShape(ctx, this.getRenderColor());
     ctx.restore();
 };