Bug 1875629 - Add AXContents to outer docs (scroll areas). r=morgan

Without this attribute VoiceOver gets into an unstable state when the cursor or focus
leaves the document.

Differential Revision: https://phabricator.services.mozilla.com/D211617

accessible/mac/AccessibleWrap.mm

@@ -18,6 +18,7 @@
 
 #import "MOXLandmarkAccessibles.h"
 #import "MOXMathAccessibles.h"
+#import "MOXOuterDoc.h"
 #import "MOXTextMarkerDelegate.h"
 #import "MOXWebAreaAccessible.h"
 #import "mozAccessible.h"
@@ -118,6 +119,10 @@ Class AccessibleWrap::GetNativeType() {
     return [MOXWebAreaAccessible class];
   }
 
+  if (IsOuterDoc()) {
+    return [MOXOuterDoc class];
+  }
+
   return GetTypeFromRole(Role());
 
   NS_OBJC_END_TRY_BLOCK_RETURN(nil);

accessible/mac/MOXOuterDoc.h

@@ -0,0 +1,16 @@
+/* -*- Mode: Objective-C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset:
+ * 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* 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/. */
+
+#import "mozAccessible.h"
+
+@interface MOXOuterDoc : mozAccessible
+
+// overrides
+- (NSString*)moxContents;
+
+@end

accessible/mac/MOXOuterDoc.mm

@@ -0,0 +1,15 @@
+/* -*- (Mode: Objective-C++; tab-width: 2; indent-tabs-mode: nil;
+ * c-basic-offset:) 2 -*- */
+/* 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/. */
+
+#import "MOXOuterDoc.h"
+
+@implementation MOXOuterDoc
+
+- (NSArray* _Nullable)moxContents {
+  return [self moxUnignoredChildren];
+}
+
+@end

accessible/mac/Platform.mm

@@ -14,6 +14,7 @@
 #include "DocAccessibleParent.h"
 #include "mozTableAccessible.h"
 #include "mozTextAccessible.h"
+#include "MOXOuterDoc.h"
 #include "MOXWebAreaAccessible.h"
 #include "nsAccUtils.h"
 #include "TextRange.h"
@@ -65,6 +66,8 @@ void ProxyCreated(RemoteAccessible* aProxy) {
     type = [mozTableCellAccessible class];
   } else if (aProxy->IsDoc()) {
     type = [MOXWebAreaAccessible class];
+  } else if (aProxy->IsOuterDoc()) {
+    type = [MOXOuterDoc class];
   } else {
     type = GetTypeFromRole(aProxy->Role());
   }

accessible/mac/moz.build

@@ -21,6 +21,7 @@ UNIFIED_SOURCES += [
     "MOXAccessibleBase.mm",
     "MOXLandmarkAccessibles.mm",
     "MOXMathAccessibles.mm",
+    "MOXOuterDoc.mm",
     "MOXSearchInfo.mm",
     "MOXTextMarkerDelegate.mm",
     "MOXWebAreaAccessible.mm",

accessible/tests/browser/mac/browser_webarea.js

@@ -75,3 +75,34 @@ addAccessibleTask(`<title>webarea test</title>`, async browser => {
     "iframe document has finished loading"
   );
 });
+
+// Test AXContents in outer doc (AXScrollArea)
+addAccessibleTask(
+  `<p id="p">Hello</p>`,
+  async (browser, accDoc) => {
+    const doc = accDoc.nativeInterface.QueryInterface(
+      Ci.nsIAccessibleMacInterface
+    );
+
+    const outerDoc = doc.getAttributeValue("AXParent");
+    const p = getNativeInterface(accDoc, "p");
+
+    let contents = outerDoc.getAttributeValue("AXContents");
+    is(contents.length, 1, "outer doc has single AXContents member");
+    is(
+      contents[0].getAttributeValue("AXRole"),
+      "AXWebArea",
+      "AXContents member is a web area"
+    );
+
+    ok(
+      !doc.attributeNames.includes("AXContents"),
+      "Web area does not have XContents"
+    );
+    ok(
+      !p.attributeNames.includes("AXContents"),
+      "Web content does not hace XContents"
+    );
+  },
+  { iframe: true, remoteIframe: true }
+);