Bug 1870783 part 1: Expose a minimum role of GROUPING for popovers. r=eeejay

Differential Revision: https://phabricator.services.mozilla.com/D196944

Author: jcsteh

accessible/generic/DocAccessible.cpp

@@ -1863,6 +1863,12 @@ bool DocAccessible::UpdateAccessibleOnAttrChange(dom::Element* aElement,
     return true;
   }
 
+  if (aAttribute == nsGkAtoms::popover && aElement->IsHTMLElement()) {
+    // Changing the popover attribute might change the role.
+    RecreateAccessible(aElement);
+    return true;
+  }
+
   return false;
 }
 

accessible/generic/LocalAccessible-inl.h

@@ -22,11 +22,12 @@ namespace a11y {
 
 inline mozilla::a11y::role LocalAccessible::Role() const {
   const nsRoleMapEntry* roleMapEntry = ARIARoleMap();
-  if (!roleMapEntry || roleMapEntry->roleRule != kUseMapRole) {
-    return ARIATransformRole(NativeRole());
-  }
-
-  return ARIATransformRole(roleMapEntry->role);
+  mozilla::a11y::role r =
+      (!roleMapEntry || roleMapEntry->roleRule != kUseMapRole)
+          ? NativeRole()
+          : roleMapEntry->role;
+  r = ARIATransformRole(r);
+  return GetMinimumRole(r);
 }
 
 inline mozilla::a11y::role LocalAccessible::ARIARole() {

accessible/generic/LocalAccessible.cpp

@@ -1897,6 +1897,19 @@ role LocalAccessible::ARIATransformRole(role aRole) const {
   return aRole;
 }
 
+role LocalAccessible::GetMinimumRole(role aRole) const {
+  if (aRole != roles::TEXT && aRole != roles::TEXT_CONTAINER &&
+      aRole != roles::SECTION) {
+    // This isn't a generic role, so aRole is specific enough.
+    return aRole;
+  }
+  dom::Element* el = Elm();
+  if (el && el->IsHTMLElement() && el->HasAttr(nsGkAtoms::popover)) {
+    return roles::GROUPING;
+  }
+  return aRole;
+}
+
 role LocalAccessible::NativeRole() const { return roles::NOTHING; }
 
 uint8_t LocalAccessible::ActionCount() const {

accessible/generic/LocalAccessible.h

@@ -838,6 +838,12 @@ class LocalAccessible : public nsISupports, public Accessible {
    */
   mozilla::a11y::role ARIATransformRole(mozilla::a11y::role aRole) const;
 
+  /**
+   * Return the minimum role that should be used as a last resort if the element
+   * does not have a more specific role.
+   */
+  mozilla::a11y::role GetMinimumRole(mozilla::a11y::role aRole) const;
+
   //////////////////////////////////////////////////////////////////////////////
   // Name helpers
 

accessible/tests/browser/role/browser.toml

@@ -9,3 +9,4 @@ support-files = [
 prefs = ["javascript.options.asyncstack_capture_debuggee_only=false"]
 
 ["browser_computedARIARole.js"]
+["browser_minimumRole.js"]

accessible/tests/browser/role/browser_minimumRole.js

@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* import-globals-from ../../mochitest/role.js */
+loadScripts({ name: "role.js", dir: MOCHITESTS_DIR });
+
+/**
+ * Test that popover gets a minimum role.
+ */
+addAccessibleTask(
+  `
+<div id="generic" popover>generic</div>
+<div id="alert" role="alert" popover>alert</div>
+<blockquote id="blockquote" popover>blockquote</div>
+  `,
+  async function testPopover(browser, docAcc) {
+    let generic = findAccessibleChildByID(docAcc, "generic");
+    ok(!generic, "generic doesn't have an Accessible");
+    info("Showing generic");
+    let shown = waitForEvent(EVENT_SHOW, "generic");
+    await invokeContentTask(browser, [], () => {
+      content.document.getElementById("generic").showPopover();
+    });
+    generic = (await shown).accessible;
+    testRole(generic, ROLE_GROUPING, "generic has minimum role group");
+    info("Setting popover to null on generic");
+    // Setting popover to null causes the Accessible to be recreated.
+    shown = waitForEvent(EVENT_SHOW, "generic");
+    await invokeContentTask(browser, [], () => {
+      content.document.getElementById("generic").popover = null;
+    });
+    generic = (await shown).accessible;
+    testRole(generic, ROLE_SECTION, "generic has generic role");
+
+    let alert = findAccessibleChildByID(docAcc, "alert");
+    ok(!alert, "alert doesn't have an Accessible");
+    info("Showing alert");
+    shown = waitForEvent(EVENT_SHOW, "alert");
+    await invokeContentTask(browser, [], () => {
+      content.document.getElementById("alert").showPopover();
+    });
+    alert = (await shown).accessible;
+    testRole(alert, ROLE_ALERT, "alert has role alert");
+
+    let blockquote = findAccessibleChildByID(docAcc, "blockquote");
+    ok(!blockquote, "blockquote doesn't have an Accessible");
+    info("Showing blockquote");
+    shown = waitForEvent(EVENT_SHOW, "blockquote");
+    await invokeContentTask(browser, [], () => {
+      content.document.getElementById("blockquote").showPopover();
+    });
+    blockquote = (await shown).accessible;
+    testRole(blockquote, ROLE_BLOCKQUOTE, "blockquote has role blockquote");
+  },
+  { chrome: true, topLevel: true }
+);