Add flags to pseudo-elements, and add one that says which ones are expected to contain elements. (Bug 505515) r=bzbarsky

layout/style/nsCSSPseudoElementList.h

@@ -42,45 +42,40 @@
  * This file contains the list of nsIAtoms and their values for CSS
  * pseudo-elements.  It is designed to be used as inline input to
  * nsCSSPseudoElements.cpp *only* through the magic of C preprocessing.  All
- * entries must be enclosed either in the macro CSS_PSEUDO_ELEMENT or in the
- * macro CSS2_PSEUDO_ELEMENT; these macros will have cruel and unusual things
- * done to them.  The difference between the two macros is that the
- * pseudo-elements enclosed in CSS2_PSEUDO_ELEMENT are the pseudo-elements
- * which are allowed to have only a single ':' in stylesheets.  The entries
- * should be kept in some sort of logical order.  The first argument to all the
- * macros is the C++ identifier of the atom.  The second argument is the string
- * value of the atom.
+ * entries must be enclosed either in the macro CSS_PSEUDO_ELEMENT;
+ * these macros will have cruel and unusual things done to them.  The
+ * entries should be kept in some sort of logical order.
  *
- * Code including this file MUST define CSS_PSEUDO_ELEMENT.  If desired, it can
- * also define CSS2_PSEUDO_ELEMENT to perform special handling of the CSS2
- * pseudo-elements.
+ * Code including this file MUST define CSS_PSEUDO_ELEMENT, which takes
+ * three parameters:
+ * name_  : The C++ identifier used for the atom (which will be a member
+ *          of nsCSSPseudoElements)
+ * value_ : The pseudo-element as a string, with single-colon syntax,
+ *          used as the string value of the atom.
+ * flags_ : A bitfield containing flags defined in nsCSSPseudoElements.h
  */
 
 // OUTPUT_CLASS=nsCSSPseudoElements
 // MACRO_NAME=CSS_PSEUDO_ELEMENT
 
-#ifndef CSS2_PSEUDO_ELEMENT
-#define DEFINED_CSS2_PSEUDO_ELEMENT
-#define CSS2_PSEUDO_ELEMENT(name_, value_) CSS_PSEUDO_ELEMENT(name_, value_)
-#endif // CSS2_PSEUDO_ELEMENT
+CSS_PSEUDO_ELEMENT(after, ":after", CSS_PSEUDO_ELEMENT_IS_CSS2)
+CSS_PSEUDO_ELEMENT(before, ":before", CSS_PSEUDO_ELEMENT_IS_CSS2)
 
-CSS2_PSEUDO_ELEMENT(after, ":after")
-CSS2_PSEUDO_ELEMENT(before, ":before")
+CSS_PSEUDO_ELEMENT(firstLetter, ":first-letter",
+                   CSS_PSEUDO_ELEMENT_IS_CSS2 |
+                   CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)
+CSS_PSEUDO_ELEMENT(firstLine, ":first-line",
+                   CSS_PSEUDO_ELEMENT_IS_CSS2 |
+                   CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)
 
-CSS2_PSEUDO_ELEMENT(firstLetter, ":first-letter")
-CSS2_PSEUDO_ELEMENT(firstLine, ":first-line")
+CSS_PSEUDO_ELEMENT(mozSelection, ":-moz-selection",
+                   CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS)
 
-CSS_PSEUDO_ELEMENT(mozSelection, ":-moz-selection")
+CSS_PSEUDO_ELEMENT(mozFocusInner, ":-moz-focus-inner", 0)
+CSS_PSEUDO_ELEMENT(mozFocusOuter, ":-moz-focus-outer", 0)
 
-CSS_PSEUDO_ELEMENT(mozFocusInner, ":-moz-focus-inner")
-CSS_PSEUDO_ELEMENT(mozFocusOuter, ":-moz-focus-outer")
+CSS_PSEUDO_ELEMENT(mozListBullet, ":-moz-list-bullet", 0)
+CSS_PSEUDO_ELEMENT(mozListNumber, ":-moz-list-number", 0)
 
-CSS_PSEUDO_ELEMENT(mozListBullet, ":-moz-list-bullet")
-CSS_PSEUDO_ELEMENT(mozListNumber, ":-moz-list-number")
-
-CSS_PSEUDO_ELEMENT(horizontalFramesetBorder, ":-moz-hframeset-border")
-CSS_PSEUDO_ELEMENT(verticalFramesetBorder, ":-moz-vframeset-border")
-
-#ifdef DEFINED_CSS2_PSEUDO_ELEMENT
-#undef CSS2_PSEUDO_ELEMENT
-#endif
+CSS_PSEUDO_ELEMENT(horizontalFramesetBorder, ":-moz-hframeset-border", 0)
+CSS_PSEUDO_ELEMENT(verticalFramesetBorder, ":-moz-vframeset-border", 0)

layout/style/nsCSSPseudoElements.cpp

@@ -44,18 +44,30 @@
 #include "nsMemory.h"
 
 // define storage for all atoms
-#define CSS_PSEUDO_ELEMENT(_name, _value) \
-  nsICSSPseudoElement* nsCSSPseudoElements::_name;
+#define CSS_PSEUDO_ELEMENT(name_, value_, flags_) \
+  nsICSSPseudoElement* nsCSSPseudoElements::name_;
 #include "nsCSSPseudoElementList.h"
 #undef CSS_PSEUDO_ELEMENT
 
 static const nsStaticAtom CSSPseudoElements_info[] = {
-#define CSS_PSEUDO_ELEMENT(name_, value_) \
+#define CSS_PSEUDO_ELEMENT(name_, value_, flags_) \
     { value_, (nsIAtom**)&nsCSSPseudoElements::name_ },
 #include "nsCSSPseudoElementList.h"
 #undef CSS_PSEUDO_ELEMENT
 };
 
+// Separate from the array above so that we can have an array of
+// nsStaticAtom (to pass to NS_RegisterStaticAtoms and
+// nsAtomListUtils::IsMember), but with corresponding indices (so the
+// i-th element of this array is the flags for the i-th pseudo-element
+// in the previous array).
+static const PRUint32 CSSPseudoElements_flags[] = {
+#define CSS_PSEUDO_ELEMENT(name_, value_, flags_) \
+  flags_,
+#include "nsCSSPseudoElementList.h"
+#undef CSS_PSEUDO_ELEMENT
+};
+
 void nsCSSPseudoElements::AddRefAtoms()
 {
   NS_RegisterStaticAtoms(CSSPseudoElements_info,
@@ -68,14 +80,16 @@ PRBool nsCSSPseudoElements::IsPseudoElement(nsIAtom *aAtom)
                                    NS_ARRAY_LENGTH(CSSPseudoElements_info));
 }
 
-PRBool nsCSSPseudoElements::IsCSS2PseudoElement(nsIAtom *aAtom)
+/* static */ PRUint32
+nsCSSPseudoElements::FlagsForPseudoElement(nsIAtom *aAtom)
 {
-#define CSS2_PSEUDO_ELEMENT(name_, value_) \
-   nsCSSPseudoElements::name_ == aAtom ||
-#define CSS_PSEUDO_ELEMENT(name_, value_)
-  return
-#include "nsCSSPseudoElementList.h"
-    PR_FALSE;
-#undef CSS_PSEUDO_ELEMENT
-#undef CSS2_PSEUDO_ELEMENT
+  PRUint32 i;
+  for (i = 0; i < NS_ARRAY_LENGTH(CSSPseudoElements_info); ++i) {
+    if (*CSSPseudoElements_info[i].mAtom == aAtom) {
+      break;
+    }
+  }
+  NS_ASSERTION(i < NS_ARRAY_LENGTH(CSSPseudoElements_info),
+               "argument must be a pseudo-element");
+  return CSSPseudoElements_flags[i];
 }

layout/style/nsCSSPseudoElements.h

@@ -43,6 +43,20 @@
 
 #include "nsIAtom.h"
 
+// Is this pseudo-element a CSS2 pseudo-element that can be specified
+// with the single colon syntax (in addition to the double-colon syntax,
+// which can be used for all pseudo-elements)?
+#define CSS_PSEUDO_ELEMENT_IS_CSS2                (1<<0)
+// Is this pseudo-element a pseudo-element that can contain other
+// elements?
+// (Currently pseudo-elements are either leaves of the tree (relative to
+// real elements) or they contain other elements in a non-tree-like
+// manner (i.e., like incorrectly-nested start and end tags).  It's
+// possible that in the future there might be container pseudo-elements
+// that form a properly nested tree structure.  If that happens, we
+// should probably split this flag into two.)
+#define CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS      (1<<1)
+
 // Empty class derived from nsIAtom so that function signatures can
 // require an atom from this atom list.
 class nsICSSPseudoElement : public nsIAtom {};
@@ -54,11 +68,27 @@ public:
 
   static PRBool IsPseudoElement(nsIAtom *aAtom);
 
-  static PRBool IsCSS2PseudoElement(nsIAtom *aAtom);
+  static PRBool IsCSS2PseudoElement(nsIAtom *aAtom) {
+    return PseudoElementHasFlags(aAtom, CSS_PSEUDO_ELEMENT_IS_CSS2);
+  }
 
-#define CSS_PSEUDO_ELEMENT(_name, _value) static nsICSSPseudoElement* _name;
+  static PRBool PseudoElementContainsElements(nsIAtom *aAtom) {
+    return PseudoElementHasFlags(aAtom, CSS_PSEUDO_ELEMENT_CONTAINS_ELEMENTS);
+  }
+
+#define CSS_PSEUDO_ELEMENT(_name, _value, _flags) \
+  static nsICSSPseudoElement* _name;
 #include "nsCSSPseudoElementList.h"
 #undef CSS_PSEUDO_ELEMENT
+
+private:
+  static PRUint32 FlagsForPseudoElement(nsIAtom *aAtom);
+
+  // Does the given pseudo-element have all of the flags given?
+  static PRBool PseudoElementHasFlags(nsIAtom *aAtom, PRUint32 aFlags)
+  {
+    return (FlagsForPseudoElement(aAtom) & aFlags) == aFlags;
+  }
 };
 
 #endif /* nsCSSPseudoElements_h___ */