Bug 1748749 - P2: Cache has long desc. r=Jamie

We only need to cache the existance of a longdesc in an image.
This increments the action count.

Differential Revision: https://phabricator.services.mozilla.com/D135906

accessible/generic/ImageAccessible.cpp

@@ -11,6 +11,7 @@
 #include "Role.h"
 #include "AccAttributes.h"
 #include "AccIterator.h"
+#include "CacheConstants.h"
 #include "States.h"
 
 #include "imgIContainer.h"
@@ -18,6 +19,7 @@
 #include "nsGenericHTMLElement.h"
 #include "mozilla/dom/BrowsingContext.h"
 #include "mozilla/dom/Document.h"
+#include "mozilla/dom/MutationEventBinding.h"
 #include "nsContentUtils.h"
 #include "nsIImageLoadingContent.h"
 #include "nsPIDOMWindow.h"
@@ -105,6 +107,20 @@ ENameValueFlag ImageAccessible::NativeName(nsString& aName) const {
 
 role ImageAccessible::NativeRole() const { return roles::GRAPHIC; }
 
+void ImageAccessible::DOMAttributeChanged(int32_t aNameSpaceID,
+                                          nsAtom* aAttribute, int32_t aModType,
+                                          const nsAttrValue* aOldValue,
+                                          uint64_t aOldState) {
+  LinkableAccessible::DOMAttributeChanged(aNameSpaceID, aAttribute, aModType,
+                                          aOldValue, aOldState);
+
+  if (aAttribute == nsGkAtoms::longdesc &&
+      (aModType == dom::MutationEvent_Binding::ADDITION ||
+       aModType == dom::MutationEvent_Binding::REMOVAL)) {
+    SendCache(CacheDomain::Actions, CacheUpdateType::Update);
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // LocalAccessible
 

accessible/generic/ImageAccessible.h

@@ -40,13 +40,6 @@ class ImageAccessible : public LinkableAccessible,
   LayoutDeviceIntPoint Position(uint32_t aCoordType);
   LayoutDeviceIntSize Size();
 
- protected:
-  virtual ~ImageAccessible();
-
-  // LocalAccessible
-  virtual ENameValueFlag NativeName(nsString& aName) const override;
-
- private:
   /**
    * Return whether the element has a longdesc URI.
    */
@@ -55,6 +48,18 @@ class ImageAccessible : public LinkableAccessible,
     return uri;
   }
 
+ protected:
+  virtual ~ImageAccessible();
+
+  // LocalAccessible
+  virtual ENameValueFlag NativeName(nsString& aName) const override;
+
+  virtual void DOMAttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,
+                                   int32_t aModType,
+                                   const nsAttrValue* aOldValue,
+                                   uint64_t aOldState) override;
+
+ private:
   /**
    * Return an URI for showlongdesc action if any.
    */

accessible/generic/LocalAccessible.cpp

@@ -33,6 +33,7 @@
 #include "TableCellAccessible.h"
 #include "TreeWalker.h"
 #include "HTMLElementAccessibles.h"
+#include "ImageAccessible.h"
 
 #include "nsIDOMXULButtonElement.h"
 #include "nsIDOMXULSelectCntrlEl.h"
@@ -3282,8 +3283,12 @@ already_AddRefed<AccAttributes> LocalAccessible::BundleFieldsForCache(
   }
 
   if (aCacheDomain & CacheDomain::Actions) {
-    if (ActionCount()) {
-      // We only cache the first action.
+    uint8_t actionCount = ActionCount();
+    ImageAccessible* imgAcc = AsImage();
+    bool hasLongDesc = imgAcc && imgAcc->HasLongDesc();
+
+    if (actionCount && !(actionCount == 1 && hasLongDesc)) {
+      // We only cache the first action that is not showlongdesc.
       nsAutoString actionName;
       ActionNameAt(0, actionName);
       RefPtr<nsAtom> actionAtom = NS_Atomize(actionName);
@@ -3291,6 +3296,14 @@ already_AddRefed<AccAttributes> LocalAccessible::BundleFieldsForCache(
     } else if (aUpdateType == CacheUpdateType::Update) {
       fields->SetAttribute(nsGkAtoms::action, DeleteEntry());
     }
+
+    if (imgAcc) {
+      if (hasLongDesc) {
+        fields->SetAttribute(nsGkAtoms::longdesc, true);
+      } else if (aUpdateType == CacheUpdateType::Update) {
+        fields->SetAttribute(nsGkAtoms::longdesc, DeleteEntry());
+      }
+    }
   }
 
   if (aUpdateType == CacheUpdateType::Initial) {