Bug 1468110 - add AccessibleNode boolean attributes, r=yzen, qdot

based on ARIA and AOM's ARIA reflection specs (https://wicg.github.io/aom/spec/aria-reflection.html)

accessible/aom/AccessibleNode.cpp

@@ -42,7 +42,9 @@ NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(AccessibleNode)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(AccessibleNode)
 
-AccessibleNode::AccessibleNode(nsINode* aNode) : mDOMNode(aNode)
+AccessibleNode::AccessibleNode(nsINode* aNode) :
+    mBooleanProperties(0),
+    mDOMNode(aNode)
 {
   nsAccessibilityService* accService = GetOrCreateAccService();
   if (!accService) {

accessible/aom/AccessibleNode.h

@@ -10,6 +10,7 @@
 #include "nsWrapperCache.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/Nullable.h"
 
 class nsINode;
 
@@ -24,6 +25,26 @@ namespace dom {
 class DOMStringList;
 struct ParentObject;
 
+#define ANODE_ENUM(name) \
+    e##name,
+
+#define ANODE_FUNC(typeName, type, name)                    \
+  dom::Nullable<type> Get##name()                           \
+  {                                                         \
+    return GetProperty(AOM##typeName##Property::e##name);   \
+  }                                                         \
+                                                            \
+  void Set##name(const dom::Nullable<type>& a##name)        \
+  {                                                         \
+    SetProperty(AOM##typeName##Property::e##name, a##name); \
+  }                                                         \
+
+#define ANODE_PROPS(typeName, type, ...)                     \
+  enum class AOM##typeName##Property {                       \
+    MOZ_FOR_EACH(ANODE_ENUM, (), (__VA_ARGS__))              \
+  };                                                         \
+  MOZ_FOR_EACH(ANODE_FUNC, (typeName, type,), (__VA_ARGS__)) \
+
 class AccessibleNode : public nsISupports,
                        public nsWrapperCache
 {
@@ -49,11 +70,52 @@ public:
 
   static bool IsAOMEnabled(JSContext*, JSObject*);
 
+  ANODE_PROPS(Boolean, bool,
+    Atomic,
+    Busy,
+    Disabled,
+    Expanded,
+    Hidden,
+    Modal,
+    Multiline,
+    Multiselectable,
+    ReadOnly,
+    Required,
+    Selected
+  )
+
 protected:
   AccessibleNode(const AccessibleNode& aCopy) = delete;
   AccessibleNode& operator=(const AccessibleNode& aCopy) = delete;
   virtual ~AccessibleNode();
 
+  dom::Nullable<bool> GetProperty(AOMBooleanProperty aProperty)
+  {
+    int num = static_cast<int>(aProperty);
+    if (mBooleanProperties & (1U << (2 * num))) {
+      bool data = static_cast<bool>(mBooleanProperties & (1U << (2 * num + 1)));
+      return dom::Nullable<bool>(data);
+    }
+    return dom::Nullable<bool>();
+  }
+
+  void SetProperty(AOMBooleanProperty aProperty,
+                   const dom::Nullable<bool>& aValue)
+  {
+    int num = static_cast<int>(aProperty);
+    if (aValue.IsNull()) {
+      mBooleanProperties &= ~(1U << (2 * num));
+    } else {
+      mBooleanProperties |= (1U << (2 * num));
+      mBooleanProperties = (aValue.Value() ? mBooleanProperties | (1U << (2 * num + 1))
+                                           : mBooleanProperties & ~(1U << (2 * num + 1)));
+    }
+  }
+
+  // The 2k'th bit indicates whether the k'th boolean property is used(1) or not(0)
+  // and 2k+1'th bit contains the property's value(1:true, 0:false)
+  uint32_t mBooleanProperties;
+
   RefPtr<a11y::Accessible> mIntl;
   RefPtr<nsINode> mDOMNode;
   RefPtr<dom::DOMStringList> mStates;

accessible/tests/mochitest/aom/test_general.html

@@ -41,6 +41,16 @@
     });
   }
 
+  function testBoolProp(anode, prop) {
+    is(anode[prop], null, `anode.${prop} should be null`);
+    anode[prop] = true;
+    is(anode[prop], true, `anode.${prop} was assigned true`);
+    anode[prop] = false;
+    is(anode[prop], false, `anode.${prop} was assigned false`);
+    anode[prop] = null;
+    is(anode[prop], null, `anode.${prop} was assigned null`);
+  }
+
   // Check that the WebIDL is as expected.
   function checkImplementation(ifrDoc) {
     let anode = ifrDoc.accessibleNode;
@@ -101,6 +111,13 @@
          `${anode.attributes[i]} attribute is expected and found`);
     }
 
+    const boolProps = ["atomic", "busy", "disabled", "expanded", "hidden", "modal",
+                       "multiline", "multiselectable", "readOnly", "required", "selected"];
+
+    for (const boolProp of boolProps) {
+      testBoolProp(anode, boolProp);
+    }
+
     // Check if an AccessibleNode is properly cached.
     let node = ifrDoc.createElement("div");
     anode = node.accessibleNode;

dom/webidl/AccessibleNode.webidl

@@ -17,4 +17,21 @@ interface AccessibleNode {
   boolean has(DOMString... attributes);
   [Throws]
   any get(DOMString attribute);
+
+  // Accessible properties
+  attribute boolean? modal;
+  attribute boolean? multiline;
+  attribute boolean? multiselectable;
+  attribute boolean? readOnly;
+  attribute boolean? required;
+
+  // Accessible states
+  attribute boolean? disabled;
+  attribute boolean? expanded;
+  attribute boolean? hidden;
+  attribute boolean? selected;
+
+  // Live regions
+  attribute boolean? atomic;
+  attribute boolean? busy;
 };