Add support for :dir(ltr/rtl) CSS selector, layout/style part. Bug 562159, r=bz

content/events/public/nsEventStates.h

@@ -248,6 +248,10 @@ private:
 #define NS_EVENT_STATE_VULNERABLE_NO_UPDATE NS_DEFINE_EVENT_STATE_MACRO(41)
 // Platform does not support plugin content (some mobile platforms)
 #define NS_EVENT_STATE_TYPE_UNSUPPORTED_PLATFORM NS_DEFINE_EVENT_STATE_MACRO(42)
+// Element is ltr (for :dir pseudo-class)
+#define NS_EVENT_STATE_LTR NS_DEFINE_EVENT_STATE_MACRO(43)
+// Element is rtl (for :dir pseudo-class)
+#define NS_EVENT_STATE_RTL NS_DEFINE_EVENT_STATE_MACRO(44)
 
 /**
  * NOTE: do not go over 63 without updating nsEventStates::InternalType!

content/html/content/src/nsGenericHTMLElement.h

@@ -49,6 +49,7 @@ public:
   {
     NS_ASSERTION(mNodeInfo->NamespaceID() == kNameSpaceID_XHTML,
                  "Unexpected namespace");
+    AddStatesSilently(NS_EVENT_STATE_LTR);
   }
 
   /** Typesafe, non-refcounting cast from nsIContent.  Cheaper than QI. **/

dom/locales/en-US/chrome/layout/css.properties

@@ -114,6 +114,7 @@ PEMQExpectedFeatureValue=Found invalid value for media feature.
 PEBadFontBlockStart=Expected '{' to begin @font-face rule but found '%1$S'.
 PEBadFontBlockEnd=Expected '}' to end @font-face rule but found '%1$S'.
 PEAnonBoxNotAlone=Did not expect anonymous box.
+PEBadDirValue=Expected 'ltr' or 'rtl' in direction selector but found '%1$S'.
 PESupportsConditionStartEOF='not' or '('
 PESupportsConditionInParensStartEOF='not', '(' or identifier
 PESupportsConditionNotEOF='not'

layout/style/nsCSSParser.cpp

@@ -3595,10 +3595,12 @@ CSSParserImpl::ParsePseudoClassWithIdentArg(nsCSSSelector& aSelector,
     return eSelectorParsingStatus_Error; // our caller calls SkipUntil(')')
   }
 
-  // -moz-locale-dir can only have values of 'ltr' or 'rtl'.
+  // -moz-locale-dir and :dir can only have values of 'ltr' or 'rtl'.
-  if (aType == nsCSSPseudoClasses::ePseudoClass_mozLocaleDir) {
+  if (aType == nsCSSPseudoClasses::ePseudoClass_mozLocaleDir ||
+      aType == nsCSSPseudoClasses::ePseudoClass_dir) {
     if (!mToken.mIdent.EqualsLiteral("ltr") &&
         !mToken.mIdent.EqualsLiteral("rtl")) {
+      REPORT_UNEXPECTED_TOKEN(PEBadDirValue);
       return eSelectorParsingStatus_Error; // our caller calls SkipUntil(')')
     }
   }

layout/style/nsCSSPseudoClassList.h

@@ -9,27 +9,45 @@
  * This file contains the list of nsIAtoms and their values for CSS
  * pseudo-classes.  It is designed to be used as inline input to
  * nsCSSPseudoClasses.cpp *only* through the magic of C preprocessing.
- * All entries must be enclosed in the macros CSS_PSEUDO_CLASS or
+ * All entries must be enclosed in the macros CSS_PSEUDO_CLASS,
- * CSS_STATE_PSEUDO_CLASS which will have cruel and unusual things
+ * CSS_STATE_DEPENDENT_PSEUDO_CLASS, or CSS_STATE_PSEUDO_CLASS which
- * done to it.  The entries should be kept in some sort of logical
+ * will have cruel and unusual things done to them.  The entries should
- * order.  The first argument to CSS_PSEUDO_CLASS is the C++
+ * be kept in some sort of logical order.  The first argument to
- * identifier of the atom.  The second argument is the string value of
+ * CSS_PSEUDO_CLASS is the C++ identifier of the atom.  The second
- * the atom.  CSS_STATE_PSEUDO_CLASS also takes the name of the state
+ * argument is the string value of the atom.
- * bits that the class corresponds to.  Only one of the bits needs to
+ * CSS_STATE_DEPENDENT_PSEUDO_CLASS and CSS_STATE_PSEUDO_CLASS also take
- * match for the pseudo-class to match.  If CSS_STATE_PSEUDO_CLASS is
+ * the name of the state bits that the class corresponds to.  Only one
- * not defined, it'll be automatically defined to CSS_PSEUDO_CLASS.
+ * of the bits needs to match for a CSS_STATE_PSEUDO_CLASS to match;
+ * CSS_STATE_DEPENDENT_PSEUDO_CLASS matching depends on a customized per-class
+ * algorithm which should be defined in SelectorMatches() in
+ * nsCSSRuleProcessor.cpp.
+ *
+ * If CSS_STATE_PSEUDO_CLASS is not defined, it'll be automatically
+ * defined to CSS_STATE_DEPENDENT_PSEUDO_CLASS;
+ * if CSS_STATE_DEPENDENT_PSEUDO_CLASS is not defined, it'll be
+ * automatically defined to CSS_PSEUDO_CLASS.
  */
 
 // OUTPUT_CLASS=nsCSSPseudoClasses
 // MACRO_NAME=CSS_PSEUDO_CLASS
 
+#ifdef DEFINED_CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#error "CSS_STATE_DEPENDENT_PSEUDO_CLASS shouldn't be defined"
+#endif
+
+#ifndef CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#define CSS_STATE_DEPENDENT_PSEUDO_CLASS(_name, _value, _bit) \
+  CSS_PSEUDO_CLASS(_name, _value)
+#define DEFINED_CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#endif
+
 #ifdef DEFINED_CSS_STATE_PSEUDO_CLASS
-#error "This shouldn't be defined"
+#error "CSS_STATE_PSEUDO_CLASS shouldn't be defined"
 #endif
 
 #ifndef CSS_STATE_PSEUDO_CLASS
 #define CSS_STATE_PSEUDO_CLASS(_name, _value, _bit) \
-  CSS_PSEUDO_CLASS(_name, _value)
+  CSS_STATE_DEPENDENT_PSEUDO_CLASS(_name, _value, _bit)
 #define DEFINED_CSS_STATE_PSEUDO_CLASS
 #endif
 
@@ -90,6 +108,11 @@ CSS_PSEUDO_CLASS(mozTableBorderNonzero, ":-moz-table-border-nonzero")
 // it doesn't actually get directly matched on in SelectorMatches.
 CSS_PSEUDO_CLASS(notPseudo, ":not")
 
+// :dir(ltr) and :dir(rtl) match elements whose resolved directionality
+// in the markup language is ltr or rtl respectively
+CSS_STATE_DEPENDENT_PSEUDO_CLASS(dir, ":dir",
+                                 NS_EVENT_STATE_LTR | NS_EVENT_STATE_RTL)
+
 CSS_STATE_PSEUDO_CLASS(link, ":link", NS_EVENT_STATE_UNVISITED)
 // what matches :link or :visited
 CSS_STATE_PSEUDO_CLASS(mozAnyLink, ":-moz-any-link",
@@ -178,3 +201,8 @@ CSS_STATE_PSEUDO_CLASS(mozMeterSubSubOptimum, ":-moz-meter-sub-sub-optimum",
 #undef DEFINED_CSS_STATE_PSEUDO_CLASS
 #undef CSS_STATE_PSEUDO_CLASS
 #endif
+
+#ifdef DEFINED_CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#undef DEFINED_CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#undef CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#endif

layout/style/nsCSSPseudoClasses.cpp

@@ -42,7 +42,8 @@ nsCSSPseudoClasses::HasStringArg(Type aType)
   return aType == ePseudoClass_lang ||
          aType == ePseudoClass_mozEmptyExceptChildrenWithLocalname ||
          aType == ePseudoClass_mozSystemMetric ||
-         aType == ePseudoClass_mozLocaleDir;
+         aType == ePseudoClass_mozLocaleDir ||
+         aType == ePseudoClass_dir;
 }
 
 bool

layout/style/nsCSSRuleProcessor.cpp

@@ -1308,7 +1308,7 @@ struct NodeMatchContext {
   // event-state-dependent selector for any value of that event state.
   // So mStateMask contains the states that should NOT be tested.
   //
-  // NOTE: For |aStateMask| to work correctly, it's important that any
+  // NOTE: For |mStateMask| to work correctly, it's important that any
   // change that changes multiple state bits include all those state
   // bits in the notification.  Otherwise, if multiple states change but
   // we do separate notifications then we might determine the style is
@@ -1533,7 +1533,21 @@ checkGenericEmptyMatches(Element* aElement,
   return (child == nullptr);
 }
 
-// An array of the states that are relevant for various pseudoclasses.
+// Arrays of the states that are relevant for various pseudoclasses.
+static const nsEventStates sPseudoClassStateDependences[] = {
+#define CSS_PSEUDO_CLASS(_name, _value) \
+  nsEventStates(),
+#define CSS_STATE_DEPENDENT_PSEUDO_CLASS(_name, _value, _states)  \
+  _states,
+#include "nsCSSPseudoClassList.h"
+#undef CSS_STATE_DEPENDENT_PSEUDO_CLASS
+#undef CSS_PSEUDO_CLASS
+  // Add more entries for our fake values to make sure we can't
+  // index out of bounds into this array no matter what.
+  nsEventStates(),
+  nsEventStates()
+};
+
 static const nsEventStates sPseudoClassStates[] = {
 #define CSS_PSEUDO_CLASS(_name, _value)         \
   nsEventStates(),
@@ -1556,7 +1570,7 @@ MOZ_STATIC_ASSERT(NS_ARRAY_LENGTH(sPseudoClassStates) ==
 //  * when non-null, it indicates that we're processing a negation,
 //    which is done only when SelectorMatches calls itself recursively
 //  * what it points to should be set to true whenever a test is skipped
-//    because of aStateMask
+//    because of aNodeMatchContent.mStateMask
 static bool SelectorMatches(Element* aElement,
                               nsCSSSelector* aSelector,
                               NodeMatchContext& aNodeMatchContext,
@@ -1997,6 +2011,38 @@ static bool SelectorMatches(Element* aElement,
         }
         break;
 
+      case nsCSSPseudoClasses::ePseudoClass_dir:
+        {
+          if (aDependence) {
+            nsEventStates states
+              = sPseudoClassStateDependences[pseudoClass->mType];
+            if (aNodeMatchContext.mStateMask.HasAtLeastOneOfStates(states)) {
+              *aDependence = true;
+              return false;
+            }
+          }
+
+          // if we only had to consider HTML, directionality would be exclusively
+          // LTR or RTL, and this could be just
+          //
+          //  if (dirString.EqualsLiteral("rtl") !=
+          //    aElement->StyleState().HasState(NS_EVENT_STATE_RTL)
+          //
+          // However, in markup languages where there is no direction attribute
+          // we have to consider the possibility that neither dir(rtl) nor
+          // dir(ltr) matches.
+          nsEventStates state = aElement->StyleState();
+          bool elementIsRTL = state.HasState(NS_EVENT_STATE_RTL);
+          bool elementIsLTR = state.HasState(NS_EVENT_STATE_LTR);
+          nsDependentString dirString(pseudoClass->u.mString);
+
+          if ((dirString.EqualsLiteral("rtl") && !elementIsRTL) ||
+              (dirString.EqualsLiteral("ltr") && !elementIsLTR)) {
+            return false;
+          }
+        }
+        break;
+
       default:
         NS_ABORT_IF_FALSE(false, "How did that happen?");
       }
@@ -2128,10 +2174,10 @@ static bool SelectorMatches(Element* aElement,
       bool dependence = false;
       result = !SelectorMatches(aElement, negation, aNodeMatchContext,
                                 aTreeMatchContext, &dependence);
-      // If the selector does match due to the dependence on aStateMask,
+      // If the selector does match due to the dependence on
-      // then we want to keep result true so that the final result of
+      // aNodeMatchContext.mStateMask, then we want to keep result true
-      // SelectorMatches is true.  Doing so tells StateEnumFunc that
+      // so that the final result of SelectorMatches is true.  Doing so
-      // there is a dependence on the state.
+      // tells StateEnumFunc that there is a dependence on the state.
       result = result || dependence;
     }
   }
@@ -2665,7 +2711,7 @@ nsEventStates ComputeSelectorStateDependence(nsCSSSelector& aSelector)
     if (pseudoClass->mType >= nsCSSPseudoClasses::ePseudoClass_Count) {
       continue;
     }
-    states |= sPseudoClassStates[pseudoClass->mType];
+    states |= sPseudoClassStateDependences[pseudoClass->mType];
   }
   return states;
 }