Bug 819273 - ARIA combobox should have accessible value, r=tbsaunde

accessible/src/base/nsARIAMap.cpp

@@ -249,7 +249,7 @@ static nsRoleMapEntry sWAIRoleMaps[] =
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    eSelect,
+    eListControl | eSelect,
     kNoReqStates,
     eARIAMultiSelectable,
     eARIAReadonly

accessible/src/base/nsAccessibilityService.cpp

@@ -804,7 +804,7 @@ nsAccessibilityService::GetOrCreateAccessible(nsINode* aNode,
           newAcc = new ARIAGridCellAccessibleWrap(content, document);
         }
 
-      } else if ((roleMapEntry->accTypes & eTable) &&
+      } else if ((roleMapEntry->IsOfType(eTable)) &&
                  frame->AccessibleType() != eHTMLTableType) {
         newAcc = new ARIAGridAccessibleWrap(content, document);
       }
@@ -824,7 +824,7 @@ nsAccessibilityService::GetOrCreateAccessible(nsINode* aNode,
       if (!roleMapEntry && newAcc) {
         if (frame->AccessibleType() == eHTMLTableRowType) {
           nsRoleMapEntry* contextRoleMap = aContext->ARIARoleMap();
-          if (contextRoleMap && !(contextRoleMap->accTypes & eTable))
+          if (contextRoleMap && !(contextRoleMap->IsOfType(eTable)))
             roleMapEntry = &nsARIAMap::gEmptyRoleMap;
 
         } else if (frame->AccessibleType() == eHTMLTableCellType &&
@@ -836,7 +836,7 @@ nsAccessibilityService::GetOrCreateAccessible(nsINode* aNode,
                    content->Tag() == nsGkAtoms::dd ||
                    frame->AccessibleType() == eHTMLLiType) {
           nsRoleMapEntry* contextRoleMap = aContext->ARIARoleMap();
-          if (contextRoleMap && !(contextRoleMap->accTypes & eList))
+          if (contextRoleMap && !(contextRoleMap->IsOfType(eList)))
             roleMapEntry = &nsARIAMap::gEmptyRoleMap;
         }
       }

accessible/src/generic/Accessible.cpp

@@ -1589,17 +1589,44 @@ Accessible::GetValue(nsAString& aValue)
 void
 Accessible::Value(nsString& aValue)
 {
-  if (mRoleMapEntry) {
-    if (mRoleMapEntry->valueRule == eNoValue)
-      return;
+  if (!mRoleMapEntry)
+    return;
 
-    // aria-valuenow is a number, and aria-valuetext is the optional text equivalent
-    // For the string value, we will try the optional text equivalent first
+  if (mRoleMapEntry->valueRule != eNoValue) {
+    // aria-valuenow is a number, and aria-valuetext is the optional text
+    // equivalent. For the string value, we will try the optional text
+    // equivalent first.
     if (!mContent->GetAttr(kNameSpaceID_None,
                            nsGkAtoms::aria_valuetext, aValue)) {
       mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_valuenow,
                         aValue);
     }
+    return;
+  }
+
+  // Value of combobox is a text of current or selected item.
+  if (mRoleMapEntry->Is(nsGkAtoms::combobox)) {
+    Accessible* option = CurrentItem();
+    if (!option) {
+      Accessible* listbox = nullptr;
+      IDRefsIterator iter(mDoc, mContent, nsGkAtoms::aria_owns);
+      while ((listbox = iter.Next()) && !listbox->IsListControl());
+
+      if (!listbox) {
+        uint32_t childCount = ChildCount();
+        for (uint32_t idx = 0; idx < childCount; idx++) {
+          Accessible* child = mChildren.ElementAt(idx);
+          if (child->IsListControl())
+            listbox = child;
+        }
+      }
+
+      if (listbox)
+        option = listbox->GetSelectedItem(0);
+    }
+
+    if (option)
+      nsTextEquivUtils::GetNameFromSubtree(option, aValue);
   }
 }
 

accessible/src/html/HTMLFormControlAccessible.cpp

@@ -358,7 +358,7 @@ HTMLTextFieldAccessible::Value(nsString& aValue)
     textArea->GetValue(aValue);
     return;
   }
-  
+
   nsHTMLInputElement* input = nsHTMLInputElement::FromContent(mContent);
   if (input)
     input->GetValue(aValue);

accessible/tests/mochitest/value/test_general.html

@@ -50,6 +50,21 @@
       testValue("aria_main_link", href);
       testValue("aria_navigation_link", href);
 
+      //////////////////////////////////////////////////////////////////////////
+      // ARIA comboboxes
+
+      // aria-activedescendant defines a current item the value is computed from
+      testValue("aria_combobox1", kDiscBulletText + "Zoom");
+
+      // aria-selected defines a selected item the value is computed from,
+      // list control is pointed by aria-owns relation.
+      testValue("aria_combobox2", kDiscBulletText + "Zoom");
+
+      // aria-selected defines a selected item the value is computed from,
+      // list control is a child of combobox.
+      testValue("aria_combobox3", kDiscBulletText + "2");
+
+      //////////////////////////////////////////////////////////////////////////
       // HTML controls
       testValue("combobox1", "item1");
       testValue("combobox2", "item2");
@@ -69,7 +84,12 @@
      href="https://bugzilla.mozilla.org/show_bug.cgi?id=494807"
      title="Do not expose a11y info specific to hyperlinks when role is overridden using ARIA">
     Mozilla Bug 494807
-  </a><br />
+  </a>
+  <a target="_blank"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=819273"
+     title=" ARIA combobox should have accessible value">
+    Mozilla Bug 819273
+  </a>
   <p id="display"></p>
   <div id="content" style="display: none">
   </div>
@@ -88,6 +108,32 @@
   <!-- strange edge case: please don't do this in the wild -->
   <a id="aria_link_link" role="link" href="foo">link</a>
 
+  <div id="aria_combobox1" role="combobox"
+       aria-owns="aria_combobox1_owned_listbox"
+       aria-activedescendant="aria_combobox1_selected_option">
+  </div>
+  <ul role="listbox" id="aria_combobox1_owned_listbox">
+    <li role="option">Zebra</li>
+    <li role="option" id="aria_combobox1_selected_option">Zoom</li>
+  </ul>
+
+  <div id="aria_combobox2" role="combobox"
+       aria-owns="aria_combobox2_owned_listbox">
+  </div>
+  <ul role="listbox" id="aria_combobox2_owned_listbox">
+    <li role="option">Zebra</li>
+    <li role="option" aria-selected="true">Zoom</li>
+  </ul>
+
+  <div id="aria_combobox3" role="combobox">
+    <div role="textbox"></div>
+    <ul role="listbox">
+      <li role="option">1</li>
+      <li role="option" aria-selected="true">2</li>
+      <li role="option">3</li>
+    </ul>
+  </div>
+
   <select id="combobox1">
     <option id="cb1_item1">item1</option>
     <option id="cb1_item2">item2</option>