new "shown?" predicate

HISTORY.md

@@ -28,6 +28,7 @@
     * new "get graphic effect" reporter
     * new "get pen attribute" reporter
     * new "pen down?" predicate
+    * new "shown?" predicate
     * new "write" command in pen category (used to be "label" in tools)
     * new "numbers", "is empty", "map","keep", "find", "combine" and "for each" primitives in list category
     * new JIT-compiler "blitz-HOF" primitives for "map", "keep", "find" & "combine" via "compile"
@@ -86,6 +87,7 @@
 
 ### 2019-06-01
 * Objects: new "pen down?" predicate
+* Objects: new "shown?" predicate
 
 ### 2019-05-31
 * Threads: optimized FOREACH performance for large linked lists

src/objects.js

@@ -398,6 +398,12 @@ SpriteMorph.prototype.initBlocks = function () {
             category: 'looks',
             spec: 'hide'
         },
+        reportShown: {
+            only: SpriteMorph,
+            type: 'predicate',
+            category: 'looks',
+            spec: 'shown?'
+        },
         goToLayer: {
             only: SpriteMorph,
             type: 'command',
@@ -2193,6 +2199,7 @@ SpriteMorph.prototype.blockTemplates = function (category) {
         blocks.push('-');
         blocks.push(block('show'));
         blocks.push(block('hide'));
+        blocks.push(block('reportShown'));
         blocks.push('-');
         blocks.push(block('goToLayer'));
         blocks.push(block('goBack'));
@@ -4043,6 +4050,10 @@ SpriteMorph.prototype.show = function () {
     this.parts.forEach(function (part) {part.show(); });
 };
 
+SpriteMorph.prototype.reportShown = function () {
+    return this.isVisible;
+};
+
 // SpriteMorph pen color
 
 SpriteMorph.prototype.setColorComponentHSVA = function (idx, num) {