Bug 1373798 - Move HTML dir attribute state into event state flags

* Stop calling SetHasDirAuto/ClearHasDirAuto in input element code
* Introduce event state flags that track the state of an element's dir attribute
* Rewrite our existing checks for the state of the dir attr on top of the new event state flags
* Add pseudo-classes for matching on the dir attribute states
* Use the new dir attribute pseudoclasses in html.css

Tag #1375

9 files changed, 114 insertions, 65 deletions

diff --git a/dom/base/DirectionalityUtils.cpp b/dom/base/DirectionalityUtils.cpp
index d9a6c4524c..632abb2c8b 100644
--- a/dom/base/DirectionalityUtils.cpp
+++ b/dom/base/DirectionalityUtils.cpp
@@ -728,7 +728,7 @@ WalkDescendantsResetAutoDirection(Element* aElement)
 {
   nsIContent* child = aElement->GetFirstChild();
   while (child) {
-    if (child->HasDirAuto()) {
+    if (child->IsElement() && child->AsElement()->HasDirAuto()) {
       child = child->GetNextNonChildNode(aElement);
       continue;
     }
@@ -791,7 +791,7 @@ WalkDescendantsClearAncestorDirAuto(Element* aElement)
 {
   nsIContent* child = aElement->GetFirstChild();
   while (child) {
-    if (child->HasDirAuto()) {
+    if (child->IsElement() && child->AsElement()->HasDirAuto()) {
       child = child->GetNextNonChildNode(aElement);
       continue;
     }
diff --git a/dom/base/Element.h b/dom/base/Element.h
index df0dbcc45e..76f0767e63 100644
--- a/dom/base/Element.h
+++ b/dom/base/Element.h
@@ -256,6 +256,23 @@ public:
   void ClearStyleStateLocks();
 
   /**
+   * Accessors for the state of our dir attribute.
+   */
+  bool HasDirAuto() const
+  {
+    return State().HasState(NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO);
+  }
+
+  /**
+   * Elements with dir="rtl" or dir="ltr".
+   */
+  bool HasFixedDir() const
+  {
+    return State().HasAtLeastOneOfStates(NS_EVENT_STATE_DIR_ATTR_LTR |
+                                         NS_EVENT_STATE_DIR_ATTR_RTL);
+  }
+
+  /**
    * Get the inline style declaration, if any, for this element.
    */
   virtual DeclarationBlock* GetInlineStyleDeclaration();
@@ -380,15 +397,6 @@ public:
 
   bool GetBindingURL(nsIDocument *aDocument, css::URLValue **aResult);
 
-  // The bdi element defaults to dir=auto if it has no dir attribute set.
-  // Other elements will only have dir=auto if they have an explicit dir=auto,
-  // which will mean that HasValidDir() returns true but HasFixedDir() returns
-  // false
-  inline bool HasDirAuto() const {
-    return (!HasFixedDir() &&
-            (HasValidDir() || IsHTMLElement(nsGkAtoms::bdi)));
-  }
-
   Directionality GetComputedDirectionality() const;
 
   inline Element* GetFlattenedTreeParentElementForStyle() const;
@@ -501,6 +509,16 @@ protected:
     RemoveStatesSilently(aStates);
     NotifyStateChange(aStates);
   }
+  virtual void ToggleStates(EventStates aStates, bool aNotify)
+  {
+    NS_PRECONDITION(!aStates.HasAtLeastOneOfStates(INTRINSIC_STATES),
+                    "Should only be removing externally-managed states here");
+    mState ^= aStates;
+    if (aNotify) {
+      NotifyStateChange(aStates);
+    }
+  }
+
 public:
   virtual void UpdateEditableState(bool aNotify) override;
 
diff --git a/dom/base/nsIContentInlines.h b/dom/base/nsIContentInlines.h
index 6a82f7f652..6a9bd7afa4 100644
--- a/dom/base/nsIContentInlines.h
+++ b/dom/base/nsIContentInlines.h
@@ -87,4 +87,10 @@ nsINode::GetFlattenedTreeParentNodeForStyle() const
   return ::GetFlattenedTreeParentNode<nsIContent::eForStyle>(this);
 }
 
+inline bool
+nsINode::NodeOrAncestorHasDirAuto() const
+{
+  return AncestorHasDirAuto() || (IsElement() && AsElement()->HasDirAuto());
+}
+
 #endif // nsIContentInlines_h
diff --git a/dom/base/nsINode.h b/dom/base/nsINode.h
index 0f882445f7..7c3eb91340 100644
--- a/dom/base/nsINode.h
+++ b/dom/base/nsINode.h
@@ -1608,10 +1608,11 @@ private:
     NodeIsContent,
     // Set if the node has animations or transitions
     ElementHasAnimations,
-    // Set if node has a dir attribute with a valid value (ltr, rtl, or auto)
+    // Set if node has a dir attribute with a valid value (ltr, rtl, or auto).
+    // Note that we cannot compute this from the dir attribute event state
+    // flags, because we can't use those to distinguish
+    // <bdi dir="some-invalid-value"> and <bdi dir="auto">.
     NodeHasValidDirAttribute,
-    // Set if node has a dir attribute with a fixed value (ltr or rtl, NOT auto)
-    NodeHasFixedDir,
     // Set if the node has dir=auto and has a property pointing to the text
     // node that determines its direction
     NodeHasDirAutoSet,
@@ -1619,8 +1620,6 @@ private:
     // and has a TextNodeDirectionalityMap property listing the elements whose
     // direction it determines.
     NodeHasTextNodeDirectionalityMap,
-    // Set if the node has dir=auto.
-    NodeHasDirAuto,
     // Set if a node in the node's parent chain has dir=auto.
     NodeAncestorHasDirAuto,
     // Set if the element is in the scope of a scoped style sheet; this flag is
@@ -1715,17 +1714,6 @@ public:
   void SetHasValidDir() { SetBoolFlag(NodeHasValidDirAttribute); }
   void ClearHasValidDir() { ClearBoolFlag(NodeHasValidDirAttribute); }
   bool HasValidDir() const { return GetBoolFlag(NodeHasValidDirAttribute); }
-  void SetHasFixedDir() {
-    MOZ_ASSERT(NodeType() != nsIDOMNode::TEXT_NODE,
-               "SetHasFixedDir on text node");
-    SetBoolFlag(NodeHasFixedDir);
-  }
-  void ClearHasFixedDir() {
-    MOZ_ASSERT(NodeType() != nsIDOMNode::TEXT_NODE,
-               "ClearHasFixedDir on text node");
-    ClearBoolFlag(NodeHasFixedDir);
-  }
-  bool HasFixedDir() const { return GetBoolFlag(NodeHasFixedDir); }
   void SetHasDirAutoSet() {
     MOZ_ASSERT(NodeType() != nsIDOMNode::TEXT_NODE,
                "SetHasDirAutoSet on text node");
@@ -1754,16 +1742,12 @@ public:
     return GetBoolFlag(NodeHasTextNodeDirectionalityMap);
   }
 
-  void SetHasDirAuto() { SetBoolFlag(NodeHasDirAuto); }
-  void ClearHasDirAuto() { ClearBoolFlag(NodeHasDirAuto); }
-  bool HasDirAuto() const { return GetBoolFlag(NodeHasDirAuto); }
-
   void SetAncestorHasDirAuto() { SetBoolFlag(NodeAncestorHasDirAuto); }
   void ClearAncestorHasDirAuto() { ClearBoolFlag(NodeAncestorHasDirAuto); }
   bool AncestorHasDirAuto() const { return GetBoolFlag(NodeAncestorHasDirAuto); }
 
-  bool NodeOrAncestorHasDirAuto() const
-    { return HasDirAuto() || AncestorHasDirAuto(); }
+  // Implemented in nsIContentInlines.h.
+  inline bool NodeOrAncestorHasDirAuto() const;
 
   void SetIsElementInStyleScope(bool aValue) {
     MOZ_ASSERT(IsElement(), "SetIsInStyleScope on a non-Element node");
diff --git a/dom/events/EventStates.h b/dom/events/EventStates.h
index 2672d2897d..bda36c0408 100644
--- a/dom/events/EventStates.h
+++ b/dom/events/EventStates.h
@@ -292,14 +292,40 @@ private:
 #define NS_EVENT_STATE_RTL NS_DEFINE_EVENT_STATE_MACRO(43)
 // Element is highlighted (devtools inspector)
 #define NS_EVENT_STATE_DEVTOOLS_HIGHLIGHTED NS_DEFINE_EVENT_STATE_MACRO(45)
+// States for tracking the state of the "dir" attribute for HTML elements.  We
+// use these to avoid having to get "dir" attributes all the time during
+// selector matching for some parts of the UA stylesheet.
+//
+// These states are externally managed, because we also don't want to keep
+// getting "dir" attributes in IntrinsicState.
+//
+// Element is HTML and has a "dir" attibute.  This state might go away depending
+// on how https://github.com/whatwg/html/issues/2769 gets resolved.  The value
+// could be anything.
+#define NS_EVENT_STATE_HAS_DIR_ATTR NS_DEFINE_EVENT_STATE_MACRO(46)
+// Element is HTML, has a "dir" attribute, and the attribute's value is
+// case-insensitively equal to "ltr".
+#define NS_EVENT_STATE_DIR_ATTR_LTR NS_DEFINE_EVENT_STATE_MACRO(47)
+// Element is HTML, has a "dir" attribute, and the attribute's value is
+// case-insensitively equal to "rtl".
+#define NS_EVENT_STATE_DIR_ATTR_RTL NS_DEFINE_EVENT_STATE_MACRO(48)
+// Element is HTML, and is either a <bdi> element with no valid-valued "dir"
+// attribute or any HTML element which has a "dir" attribute whose value is
+// "auto".
+#define NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO NS_DEFINE_EVENT_STATE_MACRO(49)
 // Element is an unresolved custom element candidate
-#define NS_EVENT_STATE_UNRESOLVED NS_DEFINE_EVENT_STATE_MACRO(46)
+#define NS_EVENT_STATE_UNRESOLVED NS_DEFINE_EVENT_STATE_MACRO(50)
 // Element is transitioning for rules changed by style editor
-#define NS_EVENT_STATE_STYLEEDITOR_TRANSITIONING NS_DEFINE_EVENT_STATE_MACRO(47)
+#define NS_EVENT_STATE_STYLEEDITOR_TRANSITIONING NS_DEFINE_EVENT_STATE_MACRO(51)
 // Content shows its placeholder
-#define NS_EVENT_STATE_PLACEHOLDERSHOWN NS_DEFINE_EVENT_STATE_MACRO(48)
+#define NS_EVENT_STATE_PLACEHOLDERSHOWN NS_DEFINE_EVENT_STATE_MACRO(52)
 // Element has focus-within.
-#define NS_EVENT_STATE_FOCUS_WITHIN NS_DEFINE_EVENT_STATE_MACRO(49)
+#define NS_EVENT_STATE_FOCUS_WITHIN NS_DEFINE_EVENT_STATE_MACRO(53)
+
+#define DIR_ATTR_STATES (NS_EVENT_STATE_HAS_DIR_ATTR |          \
+                         NS_EVENT_STATE_DIR_ATTR_LTR |          \
+                         NS_EVENT_STATE_DIR_ATTR_RTL |          \
+                         NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO)
 
 // Event state that is used for values that need to be parsed but do nothing.
 #define NS_EVENT_STATE_IGNORE NS_DEFINE_EVENT_STATE_MACRO(63)
@@ -310,7 +336,7 @@ private:
 
 #define DIRECTION_STATES (NS_EVENT_STATE_LTR | NS_EVENT_STATE_RTL)
 
-#define ESM_MANAGED_STATES (NS_EVENT_STATE_ACTIVE | NS_EVENT_STATE_FOCUS |  \
+#define ESM_MANAGED_STATES (DIR_ATTR_STATES | NS_EVENT_STATE_ACTIVE | NS_EVENT_STATE_FOCUS |  \
                             NS_EVENT_STATE_HOVER | NS_EVENT_STATE_DRAGOVER |   \
                             NS_EVENT_STATE_URLTARGET | NS_EVENT_STATE_FOCUSRING | \
                             NS_EVENT_STATE_FULL_SCREEN | NS_EVENT_STATE_UNRESOLVED | \
diff --git a/dom/html/HTMLInputElement.cpp b/dom/html/HTMLInputElement.cpp
index 7c2688b7ed..7708a60acf 100644
--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -1264,10 +1264,6 @@ HTMLInputElement::BeforeSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
       }
     } else if (aNotify && aName == nsGkAtoms::disabled) {
       mDisabledChanged = true;
-    } else if (aName == nsGkAtoms::dir &&
-               AttrValueIs(kNameSpaceID_None, nsGkAtoms::dir,
-                           nsGkAtoms::_auto, eIgnoreCase)) {
-      SetDirectionIfAuto(false, aNotify);
     } else if (mType == NS_FORM_INPUT_RADIO && aName == nsGkAtoms::required) {
       nsCOMPtr<nsIRadioGroupContainer> container = GetRadioGroupContainer();
 
@@ -1419,7 +1415,7 @@ HTMLInputElement::AfterSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
                  "HTML5 spec does not allow underflow for type=range");
     } else if (aName == nsGkAtoms::dir &&
                aValue && aValue->Equals(nsGkAtoms::_auto, eIgnoreCase)) {
-      SetDirectionIfAuto(true, aNotify);
+      SetDirectionFromValue(aNotify);
     } else if (aName == nsGkAtoms::lang) {
       if (mType == NS_FORM_INPUT_NUMBER) {
         // Update the value that is displayed to the user to the new locale:
@@ -4975,7 +4971,9 @@ HTMLInputElement::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
   }
 
   // Set direction based on value if dir=auto
-  SetDirectionIfAuto(HasDirAuto(), false);
+  if (HasDirAuto()) {
+    SetDirectionFromValue(false);
+  }
 
   // An element can't suffer from value missing if it is not in a document.
   // We have to check if we suffer from that as we are now in a document.
@@ -6693,17 +6691,12 @@ HTMLInputElement::SetDefaultValueAsValue()
 }
 
 void
-HTMLInputElement::SetDirectionIfAuto(bool aAuto, bool aNotify)
+HTMLInputElement::SetDirectionFromValue(bool aNotify)
 {
-  if (aAuto) {
-    SetHasDirAuto();
-    if (IsSingleLineTextControl(true)) {
-      nsAutoString value;
-      GetValue(value);
-      SetDirectionalityFromValue(this, value, aNotify);
-    }
-  } else {
-    ClearHasDirAuto();
+  if (IsSingleLineTextControl(true)) {
+    nsAutoString value;
+    GetValue(value);
+    SetDirectionalityFromValue(this, value, aNotify);
   }
 }
 
@@ -8480,7 +8473,7 @@ HTMLInputElement::OnValueChanged(bool aNotify, bool aWasInteractiveUserChange)
   UpdateAllValidityStates(aNotify);
 
   if (HasDirAuto()) {
-    SetDirectionIfAuto(true, aNotify);
+    SetDirectionFromValue(aNotify);
   }
 
   // :placeholder-shown pseudo-class may change when the value changes.
diff --git a/dom/html/HTMLInputElement.h b/dom/html/HTMLInputElement.h
index 48807f7337..55bb59ec98 100644
--- a/dom/html/HTMLInputElement.h
+++ b/dom/html/HTMLInputElement.h
@@ -1122,7 +1122,7 @@ protected:
    */
   nsresult SetDefaultValueAsValue();
 
-  virtual void SetDirectionIfAuto(bool aAuto, bool aNotify);
+  void SetDirectionFromValue(bool aNotify);
 
   /**
    * Return if an element should have a specific validity UI
diff --git a/dom/html/HTMLUnknownElement.h b/dom/html/HTMLUnknownElement.h
index c77fba919e..6390cc5761 100644
--- a/dom/html/HTMLUnknownElement.h
+++ b/dom/html/HTMLUnknownElement.h
@@ -7,6 +7,7 @@
 #define mozilla_dom_HTMLUnknownElement_h
 
 #include "mozilla/Attributes.h"
+#include "mozilla/EventStates.h"
 #include "nsGenericHTMLElement.h"
 
 namespace mozilla {
@@ -27,7 +28,7 @@ public:
     : nsGenericHTMLElement(aNodeInfo)
   {
     if (NodeInfo()->Equals(nsGkAtoms::bdi)) {
-      SetHasDirAuto();
+      AddStatesSilently(NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO);
     }
   }
 
diff --git a/dom/html/nsGenericHTMLElement.cpp b/dom/html/nsGenericHTMLElement.cpp
index be78dc1cf0..3cf19ea8f9 100644
--- a/dom/html/nsGenericHTMLElement.cpp
+++ b/dom/html/nsGenericHTMLElement.cpp
@@ -708,28 +708,49 @@ nsGenericHTMLElement::AfterSetAttr(int32_t aNamespaceID, nsIAtom* aName,
     }
     else if (aName == nsGkAtoms::dir) {
       Directionality dir = eDir_LTR;
+      // A boolean tracking whether we need to recompute our directionality.
+      // This needs to happen after we update our internal "dir" attribute
+      // state but before we call SetDirectionalityOnDescendants.
+      bool recomputeDirectionality = false;
+      // We don't want to have to keep getting the "dir" attribute in
+      // IntrinsicState, so we manually recompute our dir-related event states
+      // here and send the relevant update notifications.
+      EventStates dirStates;
       if (aValue && aValue->Type() == nsAttrValue::eEnum) {
         SetHasValidDir();
+        dirStates |= NS_EVENT_STATE_HAS_DIR_ATTR;
         Directionality dirValue = (Directionality)aValue->GetEnumValue();
         if (dirValue == eDir_Auto) {
-          SetHasDirAuto();
-          ClearHasFixedDir();
+          dirStates |= NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO;
         } else {
           dir = dirValue;
           SetDirectionality(dir, aNotify);
-          ClearHasDirAuto();
-          SetHasFixedDir();
+          if (dirValue == eDir_LTR) {
+            dirStates |= NS_EVENT_STATE_DIR_ATTR_LTR;
+          } else {
+            MOZ_ASSERT(dirValue == eDir_RTL);
+            dirStates |= NS_EVENT_STATE_DIR_ATTR_RTL;
+          }
         }
       } else {
+        if (aValue) {
+          // We have a value, just not a valid one.
+          dirStates |= NS_EVENT_STATE_HAS_DIR_ATTR;
+        }
         ClearHasValidDir();
-        ClearHasFixedDir();
         if (NodeInfo()->Equals(nsGkAtoms::bdi)) {
-          SetHasDirAuto();
+          dirStates |= NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO;
         } else {
-          ClearHasDirAuto();
-          dir = RecomputeDirectionality(this, aNotify);
+          recomputeDirectionality = true;
         }
       }
+      // Now figure out what's changed about our dir states.
+      EventStates oldDirStates = State() & DIR_ATTR_STATES;
+      EventStates changedStates = dirStates ^ oldDirStates;
+      ToggleStates(changedStates, aNotify);
+      if (recomputeDirectionality) {
+        dir = RecomputeDirectionality(this, aNotify);
+      }
       SetDirectionalityOnDescendants(this, dir, aNotify);
     } else if (aName == nsGkAtoms::contenteditable) {
       int32_t editableCountDelta = 0;