Bug 1680277 - 1/3: Add editable and focusable ancestor getters. r=morgan

For focusable ancestor, just use editable ancestor since the IPC toll
on finding closest focusable ancestor isn't worth it.

Differential Revision: https://phabricator.services.mozilla.com/D99311

accessible/mac/MOXAccessibleProtocol.h

@@ -284,6 +284,12 @@
 // AXEditableAncestor
 - (id _Nullable)moxEditableAncestor;
 
+// AXHighestEditableAncestor
+- (id _Nullable)moxHighestEditableAncestor;
+
+// AXFocusableAncestor
+- (id _Nullable)moxFocusableAncestor;
+
 // AXARIAAtomic
 - (NSNumber* _Nullable)moxARIAAtomic;
 

accessible/mac/mozAccessible.h

@@ -208,6 +208,12 @@ inline mozAccessible* GetNativeFromGeckoAccessible(
 // override
 - (id)moxEditableAncestor;
 
+// override
+- (id)moxHighestEditableAncestor;
+
+// override
+- (id)moxFocusableAncestor;
+
 #ifndef RELEASE_OR_BETA
 // override
 - (NSString*)moxMozDebugDescription;

accessible/mac/mozAccessible.mm

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #import "mozAccessible.h"
+#include "MOXAccessibleBase.h"
 
 #import "MacUtils.h"
 #import "mozView.h"
@@ -831,6 +832,33 @@ struct RoleDescrComparator {
   return nil;
 }
 
+- (id)moxHighestEditableAncestor {
+  id highestAncestor = [self moxEditableAncestor];
+  while ([highestAncestor conformsToProtocol:@protocol(MOXAccessible)]) {
+    id ancestorParent = [highestAncestor moxUnignoredParent];
+    if (![ancestorParent conformsToProtocol:@protocol(MOXAccessible)]) {
+      break;
+    }
+
+    id higherAncestor = [ancestorParent moxEditableAncestor];
+
+    if (!higherAncestor) {
+      break;
+    }
+
+    highestAncestor = higherAncestor;
+  }
+
+  return highestAncestor;
+}
+
+- (id)moxFocusableAncestor {
+  // XXX: Checking focusable state up the chain can be expensive. For now,
+  // we can just return AXEditableAncestor since the main use case for this
+  // is rich text editing with links.
+  return [self moxEditableAncestor];
+}
+
 #ifndef RELEASE_OR_BETA
 - (NSString*)moxMozDebugDescription {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;

accessible/tests/browser/mac/browser_input.js

@@ -178,3 +178,34 @@ addAccessibleTask(
     );
   }
 );
+
+/**
+ * test nested content editables and their ancestor getters.
+ */
+addAccessibleTask(
+  `<div id="outer" role="textbox" contenteditable="true">
+     <p id="p">Bob <a href="#" id="link">Loblaw's</a></p>
+     <div id="inner" role="textbox" contenteditable="true">
+       Law <a href="#" id="inner_link">Blog</a>
+     </div>
+   </div>`,
+  (browser, accDoc) => {
+    let link = getNativeInterface(accDoc, "link");
+    let innerLink = getNativeInterface(accDoc, "inner_link");
+
+    let idmatches = (elem, id) => {
+      is(elem.getAttributeValue("AXDOMIdentifier"), id, "Matches ID");
+    };
+
+    idmatches(link.getAttributeValue("AXEditableAncestor"), "outer");
+    idmatches(link.getAttributeValue("AXFocusableAncestor"), "outer");
+    idmatches(link.getAttributeValue("AXHighestEditableAncestor"), "outer");
+
+    idmatches(innerLink.getAttributeValue("AXEditableAncestor"), "inner");
+    idmatches(innerLink.getAttributeValue("AXFocusableAncestor"), "inner");
+    idmatches(
+      innerLink.getAttributeValue("AXHighestEditableAncestor"),
+      "outer"
+    );
+  }
+);