Bug 1520611 - Consolidate ProxyAccessible::MustPruneChildren into nsAccUtils. r=Jamie

Differential Revision: https://phabricator.services.mozilla.com/D16997

--HG--
extra : moz-landing-system : lando

accessible/atk/AccessibleWrap.cpp

@@ -726,7 +726,7 @@ gint getChildCountCB(AtkObject* aAtkObj) {
   }
 
   ProxyAccessible* proxy = GetProxy(aAtkObj);
-  if (proxy && !proxy->MustPruneChildren()) {
+  if (proxy && !nsAccUtils::MustPrune(proxy)) {
     return proxy->EmbeddedChildCount();
   }
 
@@ -757,7 +757,9 @@ AtkObject* refChildCB(AtkObject* aAtkObj, gint aChildIndex) {
       }
     }
   } else if (ProxyAccessible* proxy = GetProxy(aAtkObj)) {
-    if (proxy->MustPruneChildren()) return nullptr;
+    if (nsAccUtils::MustPrune(proxy)) {
+      return nullptr;
+    }
 
     ProxyAccessible* child = proxy->EmbeddedChildAt(aChildIndex);
     if (child) childAtkObj = GetWrapperFor(child);

accessible/base/nsAccUtils.cpp

@@ -389,23 +389,34 @@ uint32_t nsAccUtils::TextLength(Accessible* aAccessible) {
   return text.Length();
 }
 
-bool nsAccUtils::MustPrune(Accessible* aAccessible) {
-  roles::Role role = aAccessible->Role();
+bool nsAccUtils::MustPrune(AccessibleOrProxy aAccessible) {
+  MOZ_ASSERT(!aAccessible.IsNull());
+  roles::Role role = aAccessible.Role();
 
-  return
-      // Always prune the tree for sliders, as it doesn't make sense for a
-      // slider to have descendants and this confuses NVDA.
-      role == roles::SLIDER ||
-      // Don't prune the tree for certain roles if the tree is more complex than
-      // a single text leaf.
-      ((role == roles::MENUITEM || role == roles::COMBOBOX_OPTION ||
-        role == roles::OPTION || role == roles::ENTRY ||
-        role == roles::FLAT_EQUATION || role == roles::PASSWORD_TEXT ||
-        role == roles::PUSHBUTTON || role == roles::TOGGLE_BUTTON ||
-        role == roles::GRAPHIC || role == roles::PROGRESSBAR ||
-        role == roles::SEPARATOR) &&
-       aAccessible->ContentChildCount() == 1 &&
-       aAccessible->ContentChildAt(0)->IsTextLeaf());
+  if (role == roles::SLIDER) {
+    // Always prune the tree for sliders, as it doesn't make sense for a
+    // slider to have descendants and this confuses NVDA.
+    return true;
+  }
+
+  if (role != roles::MENUITEM && role != roles::COMBOBOX_OPTION &&
+      role != roles::OPTION && role != roles::ENTRY &&
+      role != roles::FLAT_EQUATION && role != roles::PASSWORD_TEXT &&
+      role != roles::PUSHBUTTON && role != roles::TOGGLE_BUTTON &&
+      role != roles::GRAPHIC && role != roles::PROGRESSBAR &&
+      role != roles::SEPARATOR) {
+    // If it doesn't match any of these roles, don't prune its children.
+    return false;
+  }
+
+  if (aAccessible.ChildCount() != 1) {
+    // If the accessible has more than one child, don't prune it.
+    return false;
+  }
+
+  roles::Role childRole = aAccessible.FirstChild().Role();
+  // If the accessible's child is a text leaf, prune the accessible.
+  return childRole == roles::TEXT_LEAF || childRole == roles::STATICTEXT;
 }
 
 bool nsAccUtils::PersistentPropertiesToArray(nsIPersistentProperties* aProps,

accessible/base/nsAccUtils.h

@@ -9,6 +9,7 @@
 #include "mozilla/a11y/Accessible.h"
 #include "mozilla/a11y/DocManager.h"
 
+#include "AccessibleOrProxy.h"
 #include "nsAccessibilityService.h"
 #include "nsCoreUtils.h"
 
@@ -251,7 +252,7 @@ class nsAccUtils {
    * Return true if the given accessible can't have children. Used when exposing
    * to platform accessibility APIs, should the children be pruned off?
    */
-  static bool MustPrune(Accessible* aAccessible);
+  static bool MustPrune(AccessibleOrProxy aAccessible);
 
   static bool PersistentPropertiesToArray(nsIPersistentProperties* aProps,
                                           nsTArray<Attribute>* aAttributes);

accessible/ipc/ProxyAccessibleBase.cpp

@@ -67,24 +67,6 @@ void ProxyAccessibleBase<Derived>::ClearChildDoc(
   mChildren.RemoveElement(aChildDoc);
 }
 
-template <class Derived>
-bool ProxyAccessibleBase<Derived>::MustPruneChildren() const {
-  // this is the equivalent to nsAccUtils::MustPrune for proxies and should be
-  // kept in sync with that.
-  if (mRole != roles::MENUITEM && mRole != roles::COMBOBOX_OPTION &&
-      mRole != roles::OPTION && mRole != roles::ENTRY &&
-      mRole != roles::FLAT_EQUATION && mRole != roles::PASSWORD_TEXT &&
-      mRole != roles::PUSHBUTTON && mRole != roles::TOGGLE_BUTTON &&
-      mRole != roles::GRAPHIC && mRole != roles::SLIDER &&
-      mRole != roles::PROGRESSBAR && mRole != roles::SEPARATOR)
-    return false;
-
-  if (mChildren.Length() != 1) return false;
-
-  return mChildren[0]->Role() == roles::TEXT_LEAF ||
-         mChildren[0]->Role() == roles::STATICTEXT;
-}
-
 template <class Derived>
 uint32_t ProxyAccessibleBase<Derived>::EmbeddedChildCount() const {
   size_t count = 0, kids = mChildren.Length();

accessible/ipc/ProxyAccessibleBase.h

@@ -71,7 +71,6 @@ class ProxyAccessibleBase {
   uint32_t EmbeddedChildCount() const;
   int32_t IndexOfEmbeddedChild(const Derived* aChild);
   Derived* EmbeddedChildAt(size_t aChildIdx);
-  bool MustPruneChildren() const;
 
   void Shutdown();
 

accessible/windows/msaa/AccessibleWrap.cpp

@@ -903,7 +903,7 @@ AccessibleWrap::accNavigate(
   switch (navDir) {
     case NAVDIR_FIRSTCHILD:
       if (IsProxy()) {
-        if (!Proxy()->MustPruneChildren()) {
+        if (!nsAccUtils::MustPrune(Proxy())) {
           navAccessible = WrapperFor(Proxy()->FirstChild());
         }
       } else {
@@ -912,7 +912,7 @@ AccessibleWrap::accNavigate(
       break;
     case NAVDIR_LASTCHILD:
       if (IsProxy()) {
-        if (!Proxy()->MustPruneChildren()) {
+        if (!nsAccUtils::MustPrune(Proxy())) {
           navAccessible = WrapperFor(Proxy()->LastChild());
         }
       } else {
@@ -1387,7 +1387,7 @@ already_AddRefed<IAccessible> AccessibleWrap::GetIAccessibleFor(
   }
 
   if (varChild.ulVal != GetExistingID() &&
-      (IsProxy() ? Proxy()->MustPruneChildren()
+      (IsProxy() ? nsAccUtils::MustPrune(Proxy())
                  : nsAccUtils::MustPrune(this))) {
     // This accessible should have no subtree in platform, return null for its
     // children.