add options

pxtblocks/polyfills.ts

@@ -1,16 +1,43 @@
+// all options default to true
+interface CheckVisibilityOptions {
+    contentVisibilityAuto?: boolean;
+    opacityProperty?: boolean;
+    visibilityProperty?: boolean;
+    checkOpacity?: boolean;
+    checkVisibilityCSS?: boolean;
+}
+
 export function applyPolyfills() {
     if (!(Element.prototype as any).checkVisibility) {
-        (Element.prototype as any).checkVisibility = function checkVisibility(this: Element): boolean {
+        (Element.prototype as any).checkVisibility = function checkVisibility(this: Element, options: CheckVisibilityOptions = {}): boolean {
+            let checkOpacity = true;
+
+            if (options.opacityProperty != undefined || options.checkOpacity != undefined) {
+                checkOpacity = !!(options.opacityProperty || options.checkOpacity);
+            }
+
+            let checkVisibility = true;
+
+            if (options.visibilityProperty != undefined || options.checkVisibilityCSS != undefined) {
+                checkVisibility = !!(options.visibilityProperty || options.checkVisibilityCSS);
+            }
+
+            let checkContentVisibility = true;
+
+            if (options.contentVisibilityAuto != undefined) {
+                checkContentVisibility = !!options.contentVisibilityAuto;
+            }
+
             const computedStyle = getComputedStyle(this);
 
             // technically, this should also check for contentVisibility === "auto" and then
             // traverse the ancestors of this node to see if any have contentVisibility set
             // to "hidden", but Blockly doesn't use content-visibility AFAIK
             if (
-                computedStyle.opacity === "0" ||
-                computedStyle.visibility === "hidden" ||
                 computedStyle.display === "none" ||
-                (computedStyle as any).contentVisibility === "hidden"
+                (checkOpacity && computedStyle.opacity === "0") ||
+                (checkVisibility && computedStyle.visibility === "hidden") ||
+                (checkContentVisibility && (computedStyle as any).contentVisibility === "hidden")
             ) {
                 return false;
             }