[cssom-view-1] Specify the check* options for isVisible(). w3c#6850

Author: tabatkins

cssom-view-1/Overview.bs

@@ -41,12 +41,14 @@ urlPrefix: https://drafts.csswg.org/cssom/
 urlPrefix: https://www.w3.org/TR/CSS21/visuren.html
     type: dfn; text: anonymous block box; url: #anonymous-block-level
 url: https://drafts.csswg.org/mediaqueries-4/#mf-colors; type: dfn; text: color media query
+url: https://www.w3.org/TR/wai-aria-1.1/#dfn-hidden; type: dfn; text: hidden; spec: wai-aria-1
 </pre>
 
 <pre class='link-defaults'>
 spec:css-display-3; type:value; for:display; text:table
 spec:css-position-3; type:property; text:position
 spec:dom; type:interface; text:Document
+spec:html; type:dfn; text: inert
 </pre>
 
 <style>
@@ -1040,7 +1042,10 @@ dictionary ScrollIntoViewOptions : ScrollOptions {
 };
 
 dictionary IsVisibleOptions {
-
+    bool checkAriaHidden = false;
+    bool checkInert = false;
+    bool checkOpacity = false;
+    bool checkVisibilityCSS = false;
 };
 
 partial interface Element {
@@ -1109,10 +1114,26 @@ Note: The {{DOMRect}} object returned by {{Element/getBoundingClientRect()}} is
 
     1. If |this| does not have an associated [=layout box=],
         return false.
-    2. If |this|, or a [=shadow-inclusive ancestor=] of |this|,
+    1. If |this|, or a [=shadow-inclusive ancestor=] of |this|,
         has ''content-visibility: hidden'',
         return false.
-    3. Return true.
+    1. If the {{IsVisibleOptions/checkAriaHidden}} dictionary member of |options|
+        is true,
+        and |this| is [=hidden=] (in the ARIA sense),
+        return false.
+    1. If the {{IsVisibleOptions/checkInert}} dictionary member of |options|
+        is true,
+        and |this| is [=inert=],
+        return false.
+    1. If the {{IsVisibleOptions/checkOpacity}} dictionary member of |options|
+        is true,
+        and the computed value of 'opacity' on |this| is ''0'',
+        return false.
+    1. If the {{IsVisibleOptions/checkVisibilityCSS}} dictionary member of |options|
+        is true,
+        and |this| is [=invisible=],
+        return false.
+    1. Return true.
 </div>
 
 The <dfn method for=Element caniuse=scrollintoview>scrollIntoView(<var>arg</var>)</dfn> method must run these steps: