Bug 1899960 - P2: Imply an unavailable state if focusable is in unavailable subtree. r=Jamie

I decided not to use aria-disabled directly because we currently don't
cache it in the parent, and I don't think the benefit would be great
enough.

Differential Revision: https://phabricator.services.mozilla.com/D250357

accessible/basetypes/Accessible.cpp

@@ -716,6 +716,21 @@ void Accessible::ApplyImplicitState(uint64_t& aState) const {
   if (aState & kExpandCollapseStates) {
     aState |= states::EXPANDABLE;
   }
+
+  if (aState & states::FOCUSABLE && !(aState & states::UNAVAILABLE)) {
+    // Propagate UNAVAILABLE state from ancestors down to any focusable
+    // descendant.
+    for (auto ancestor = Parent(); ancestor; ancestor = ancestor->Parent()) {
+      if (ancestor->IsDoc()) {
+        break;
+      }
+
+      if (ancestor->State() & states::UNAVAILABLE) {
+        aState |= states::UNAVAILABLE;
+        break;
+      }
+    }
+  }
 }
 
 bool Accessible::NameIsEmpty() const {

accessible/generic/LocalAccessible.cpp

@@ -1665,18 +1665,7 @@ void LocalAccessible::ApplyARIAState(uint64_t* aState) const {
     }
   }
 
-  if (*aState & states::FOCUSABLE) {
-    // Propogate aria-disabled from ancestors down to any focusable descendant.
-    const LocalAccessible* ancestor = this;
-    while ((ancestor = ancestor->LocalParent()) && !ancestor->IsDoc()) {
-      dom::Element* el = ancestor->Elm();
-      if (el && nsAccUtils::ARIAAttrValueIs(el, nsGkAtoms::aria_disabled,
-                                            nsGkAtoms::_true, eCaseMatters)) {
-        *aState |= states::UNAVAILABLE;
-        break;
-      }
-    }
-  } else {
+  if (!(*aState & states::FOCUSABLE)) {
     // Sometimes, we use aria-activedescendant targeting something which isn't
     // actually a descendant. This is technically a spec violation, but it's a
     // useful hack which makes certain things much easier. For example, we use

accessible/tests/browser/e10s/browser_caching_states.js

@@ -778,6 +778,7 @@ addAccessibleTask(
 </fieldset>
 <div id="ariaDisabled" aria-disabled="true" role="button">ariaDisabled</div>
 <input id="enabled">
+<div id="ariaDisabledGroup" aria-disabled="true"><input id="inAriaDisabledGroup"></div>
   `,
   async function testUnavailable(browser, docAcc) {
     const input = findAccessibleChildByID(docAcc, "input");
@@ -840,6 +841,28 @@ addAccessibleTask(
     // Test a control that is initially enabled.
     const enabled = findAccessibleChildByID(docAcc, "enabled");
     testStates(enabled, 0, 0, STATE_UNAVAILABLE);
+
+    const ariaDisabledGroup = findAccessibleChildByID(
+      docAcc,
+      "ariaDisabledGroup"
+    );
+    const inAriaDisabledGroup = findAccessibleChildByID(
+      docAcc,
+      "inAriaDisabledGroup"
+    );
+    testStates(ariaDisabledGroup, STATE_UNAVAILABLE);
+    testStates(inAriaDisabledGroup, STATE_UNAVAILABLE);
+    info("Enabling ariaDisabledGroup");
+    changed = waitForStateChange(ariaDisabledGroup, STATE_UNAVAILABLE, false);
+    await invokeSetAttribute(
+      browser,
+      "ariaDisabledGroup",
+      "aria-disabled",
+      null
+    );
+    await changed;
+    testStates(ariaDisabledGroup, 0, 0, STATE_UNAVAILABLE);
+    testStates(inAriaDisabledGroup, 0, 0, STATE_UNAVAILABLE);
   },
   { chrome: true, topLevel: true }
 );