Bug 1563598: Display 'container-live' attribute on descendents of implicitly-live elements. r=Jamie

Differential Revision: https://phabricator.services.mozilla.com/D45609

--HG--
extra : moz-landing-system : lando

accessible/base/nsAccUtils.cpp

@@ -20,6 +20,7 @@
 #include "nsIPersistentProperties2.h"
 #include "mozilla/a11y/PDocAccessibleChild.h"
 #include "mozilla/dom/Element.h"
+#include "nsAccessibilityService.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;
@@ -138,7 +139,11 @@ void nsAccUtils::SetLiveContainerAttributes(
                                        live);
       } else if (role) {
         GetLiveAttrValue(role->liveAttRule, live);
+      } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute(
+                     ancestor, nsGkAtoms::live)) {
+        value->ToString(live);
       }
+
       if (!live.IsEmpty()) {
         SetAccAttr(aAttributes, nsGkAtoms::containerLive, live);
         if (role) {
@@ -488,6 +493,9 @@ bool nsAccUtils::IsARIALive(const Accessible* aAccessible) {
                                        docLive);
       } else if (role) {
         GetLiveAttrValue(role->liveAttRule, docLive);
+      } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute(
+                     ancestor, nsGkAtoms::live)) {
+        value->ToString(docLive);
       }
       if (!docLive.IsEmpty()) {
         live = docLive;

accessible/base/nsAccessibilityService.h

@@ -245,6 +245,25 @@ class nsAccessibilityService final : public mozilla::a11y::DocManager,
     return markupMap ? markupMap->role : mozilla::a11y::roles::NOTHING;
   }
 
+  /**
+   * Return the associated value for a given attribute if
+   * it appears in the MarkupMap. Otherwise, it returns null.
+   */
+  nsStaticAtom* MarkupAttribute(const nsIContent* aContent,
+                                nsStaticAtom* aAtom) const {
+    const mozilla::a11y::HTMLMarkupMapInfo* markupMap =
+        mHTMLMarkupMap.Get(aContent->NodeInfo()->NameAtom());
+    if (markupMap) {
+      for (size_t i = 0; i < mozilla::ArrayLength(markupMap->attrs); i++) {
+        const mozilla::a11y::MarkupAttrInfo* info = markupMap->attrs + i;
+        if (info->name == aAtom) {
+          return info->value;
+        }
+      }
+    }
+    return nullptr;
+  }
+
   /**
    * Set the object attribute defined by markup for the given element.
    */

accessible/tests/mochitest/attributes/test_obj.html

@@ -88,6 +88,9 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=558036
       testAttrs("statusChild", {"container-live": "polite"}, true);
       testAttrs("timerChild", {"container-live": "off"}, true);
       testAbsentAttrs("tablistChild", {"container-live": "polite"});
+      testAttrs("containerLiveOutput", {"container-live": "polite"}, true);
+      testAttrs("containerLiveOutput1", {"container-live": "polite"}, true);
+      testAttrs("containerLiveOutput2", {"container-live": "polite"}, true);
 
       // container-live-role object attribute
       testAttrs("log", {"container-live-role": "log"}, true);
@@ -166,6 +169,9 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=558036
   <pre id="test">
   </pre>
 
+  <!-- container live -->
+  <output id="containerLiveOutput"><div id="containerLiveOutput1"><div id="containerLiveOutput2">Test</div></div></output>
+
   <!-- aria -->
   <div id="atomic" aria-atomic="true">live region</div>
   <div id="atomic_false" aria-atomic="false">live region</div>