Bug 1625864 - Fire state change event on LINKED change. r=Jamie,morgan

Also stop recreating any accessible that has href modified.

Differential Revision: https://phabricator.services.mozilla.com/D71258

accessible/base/AccTypes.h

@@ -50,6 +50,7 @@ enum AccType {
    * Other accessible types.
    */
   eApplicationType,
+  eHTMLLinkType,
   eHTMLOptGroupType,
   eImageMapType,
   eMenuPopupType,

accessible/base/nsAccessibilityService.cpp

@@ -285,16 +285,23 @@ nsAccessibilityService::ListenersChanged(nsIArray* aEventChanges) {
     change->GetCountOfEventListenerChangesAffectingAccessibility(&changeCount);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    for (uint32_t i = 0; i < changeCount; i++) {
+    if (changeCount) {
       Document* ownerDoc = node->OwnerDoc();
       DocAccessible* document = GetExistingDocAccessible(ownerDoc);
 
-      // Create an accessible for a inaccessible element having click event
-      // handler.
-      if (document && !document->HasAccessible(node) &&
-          nsCoreUtils::HasClickListener(node)) {
-        document->ContentInserted(node, node->GetNextSibling());
-        break;
+      if (document) {
+        Accessible* acc = document->GetAccessible(node);
+        if (!acc && nsCoreUtils::HasClickListener(node)) {
+          // Create an accessible for a inaccessible element having click event
+          // handler.
+          document->ContentInserted(node, node->GetNextSibling());
+        } else if (acc && acc->IsHTMLLink() && !acc->AsHTMLLink()->IsLinked()) {
+          // Notify of a LINKED state change if an HTML link gets a click
+          // listener but does not have an href attribute.
+          RefPtr<AccEvent> linkedChangeEvent =
+              new AccStateChangeEvent(acc, states::LINKED);
+          document->FireDelayedEvent(linkedChangeEvent);
+        }
       }
     }
   }

accessible/generic/Accessible.h

@@ -39,6 +39,7 @@ class EmbeddedObjCollector;
 class EventTree;
 class HTMLImageMapAccessible;
 class HTMLLIAccessible;
+class HTMLLinkAccessible;
 class HyperTextAccessible;
 class ImageAccessible;
 class KeyBinding;
@@ -576,6 +577,9 @@ class Accessible : public nsISupports {
   bool IsHTMLListItem() const { return mType == eHTMLLiType; }
   HTMLLIAccessible* AsHTMLListItem();
 
+  bool IsHTMLLink() const { return mType == eHTMLLinkType; }
+  HTMLLinkAccessible* AsHTMLLink();
+
   bool IsHTMLOptGroup() const { return mType == eHTMLOptGroupType; }
 
   bool IsHTMLTable() const { return mType == eHTMLTableType; }

accessible/generic/DocAccessible.cpp

@@ -671,7 +671,7 @@ void DocAccessible::AttributeWillChange(dom::Element* aElement,
     return;
   }
 
-  if (aAttribute == nsGkAtoms::aria_disabled ||
+  if (aAttribute == nsGkAtoms::aria_disabled || aAttribute == nsGkAtoms::href ||
       aAttribute == nsGkAtoms::disabled || aAttribute == nsGkAtoms::tabindex ||
       aAttribute == nsGkAtoms::contenteditable) {
     mPrevStateBits = accessible->State();
@@ -732,7 +732,7 @@ void DocAccessible::AttributeChanged(dom::Element* aElement,
 
   // Fire accessible events iff there's an accessible, otherwise we consider
   // the accessible state wasn't changed, i.e. its state is initial state.
-  AttributeChangedImpl(accessible, aNameSpaceID, aAttribute);
+  AttributeChangedImpl(accessible, aNameSpaceID, aAttribute, aModType);
 
   // Update dependent IDs cache. Take care of accessible elements because no
   // accessible element means either the element is not accessible at all or
@@ -748,7 +748,7 @@ void DocAccessible::AttributeChanged(dom::Element* aElement,
 // DocAccessible protected member
 void DocAccessible::AttributeChangedImpl(Accessible* aAccessible,
                                          int32_t aNameSpaceID,
-                                         nsAtom* aAttribute) {
+                                         nsAtom* aAttribute, int32_t aModType) {
   // Fire accessible event after short timer, because we need to wait for
   // DOM attribute & resulting layout to actually change. Otherwise,
   // assistive technology will retrieve the wrong state/value/selection info.
@@ -921,6 +921,23 @@ void DocAccessible::AttributeChangedImpl(Accessible* aAccessible,
   if (aAttribute == nsGkAtoms::value) {
     if (aAccessible->IsProgress())
       FireDelayedEvent(nsIAccessibleEvent::EVENT_VALUE_CHANGE, aAccessible);
+    return;
+  }
+
+  if (aModType == dom::MutationEvent_Binding::REMOVAL ||
+      aModType == dom::MutationEvent_Binding::ADDITION) {
+    if (aAttribute == nsGkAtoms::href) {
+      if (aAccessible->IsHTMLLink() &&
+          !nsCoreUtils::HasClickListener(aAccessible->GetContent())) {
+        RefPtr<AccEvent> linkedChangeEvent =
+            new AccStateChangeEvent(aAccessible, states::LINKED);
+        FireDelayedEvent(linkedChangeEvent);
+        // Fire a focusable state change event if the previous state was
+        // different. It may be the same if there is tabindex on this link.
+        aAccessible->MaybeFireFocusableStateChange(
+            (mPrevStateBits & states::FOCUSABLE));
+      }
+    }
   }
 }
 
@@ -1789,17 +1806,6 @@ bool DocAccessible::UpdateAccessibleOnAttrChange(dom::Element* aElement,
     return true;
   }
 
-  if (aAttribute == nsGkAtoms::href) {
-    // Not worth the expense to ensure which namespace these are in. It doesn't
-    // kill use to recreate the accessible even if the attribute was used in
-    // the wrong namespace or an element that doesn't support it.
-
-    // Make sure the accessible is recreated asynchronously to allow the content
-    // to handle the attribute change.
-    RecreateAccessible(aElement);
-    return true;
-  }
-
   if (aAttribute == nsGkAtoms::aria_multiselectable &&
       aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::role)) {
     // This affects whether the accessible supports SelectAccessible.

accessible/generic/DocAccessible.h

@@ -472,9 +472,10 @@ class DocAccessible : public HyperTextAccessibleWrap,
    * @param aAccessible   [in] accessible the DOM attribute is changed for
    * @param aNameSpaceID  [in] namespace of changed attribute
    * @param aAttribute    [in] changed attribute
+   * @param aModType      [in] modification type (changed/added/removed)
    */
   void AttributeChangedImpl(Accessible* aAccessible, int32_t aNameSpaceID,
-                            nsAtom* aAttribute);
+                            nsAtom* aAttribute, int32_t aModType);
 
   /**
    * Fire accessible events when ARIA attribute is changed.

accessible/html/HTMLLinkAccessible.cpp

@@ -23,7 +23,9 @@ using namespace mozilla::a11y;
 
 HTMLLinkAccessible::HTMLLinkAccessible(nsIContent* aContent,
                                        DocAccessible* aDoc)
-    : HyperTextAccessibleWrap(aContent, aDoc) {}
+    : HyperTextAccessibleWrap(aContent, aDoc) {
+  mType = eHTMLLinkType;
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // nsIAccessible
@@ -107,7 +109,7 @@ already_AddRefed<nsIURI> HTMLLinkAccessible::AnchorURIAt(
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// Protected members
+// HTMLLinkAccessible
 
 bool HTMLLinkAccessible::IsLinked() const {
   EventStates state = mContent->AsElement()->State();

accessible/html/HTMLLinkAccessible.h

@@ -35,17 +35,21 @@ class HTMLLinkAccessible : public HyperTextAccessibleWrap {
   virtual already_AddRefed<nsIURI> AnchorURIAt(
       uint32_t aAnchorIndex) const override;
 
- protected:
-  virtual ~HTMLLinkAccessible() {}
-
-  enum { eAction_Jump = 0 };
-
   /**
    * Returns true if the link has href attribute.
    */
   bool IsLinked() const;
+
+ protected:
+  virtual ~HTMLLinkAccessible() {}
+
+  enum { eAction_Jump = 0 };
 };
 
+inline HTMLLinkAccessible* Accessible::AsHTMLLink() {
+  return IsHTMLLink() ? static_cast<HTMLLinkAccessible*>(this) : nullptr;
+}
+
 }  // namespace a11y
 }  // namespace mozilla
 

accessible/tests/mochitest/events/test_focusable_statechange.html

@@ -122,6 +122,10 @@
       getNode("scrollable2").setAttribute("disabled", "true");
       await p;
 
+      p = waitForEvent(...focusableStateChange("link", false));
+      getNode("link").removeAttribute("href");
+      await p;
+
       SimpleTest.finish();
     }
 
@@ -152,5 +156,7 @@
 
   <textarea id="textarea" rows="3" cols="30"></textarea>
 
+  <a id="link" href="#">A link</a>
+
 </body>
 </html>

accessible/tests/mochitest/events/test_statechange.html

@@ -117,6 +117,20 @@
       await p;
     }
 
+    async function testLinked() {
+      let p = waitForEvent(...stateChange(STATE_LINKED, false, false, "link1"));
+      getNode("link1").removeAttribute("href");
+      await p;
+
+      p = waitForEvent(...stateChange(STATE_LINKED, false, false, "link2"));
+      getNode("link2").removeAttribute("onclick");
+      await p;
+
+      p = waitForEvent(...stateChange(STATE_LINKED, false, true, "link3"));
+      getNode("link3").setAttribute("href", "http://example.com");
+      await p;
+    }
+
     async function doTests() {
       // Test opening details objects
       await openNode("detailsOpen", "summaryOpen", true);
@@ -159,6 +173,8 @@
       await echoingStateChange("text1", "aria-disabled", "disabled", null,
                                EXT_STATE_ENABLED, true, true);
 
+      await testLinked();
+
       SimpleTest.finish();
     }
 
@@ -245,6 +261,10 @@
 
   <input id="text1">
 
+  <a id="link1" href="#">I am a link link</a>
+  <a id="link2" onclick="console.log('hi')">I am a link-ish link</a>
+  <a id="link3">I am a non-link link</a>
+
   <div id="eventdump"></div>
 </body>
 </html>