cssselector: Make specificity handling a vfunc

The new region selector tracks more than just one soimple selector, so
it requires some more advanced specificity tracking.

Technically, this is still not correct, because it will report the same
specificity for
  tab:sorted
and
  tab:sorted:sorted
(and the second selector will be printed as the first) but this is
regions, so meh.

gtk/gtkcssselector.c

@@ -52,13 +52,14 @@ struct _GtkCssSelectorClass {
 				     GtkCssChange                previous_change);
   GtkCssChange      (* tree_get_change)  (const GtkCssSelectorTree *tree,
 					  const GtkCssMatcher      *matcher);
+  void              (* add_specificity)  (const GtkCssSelector  *selector,
+                                          guint                 *ids,
+                                          guint                 *classes,
+                                          guint                 *elements);
   guint             (* hash_one)    (const GtkCssSelector       *selector);
   int               (* compare_one) (const GtkCssSelector       *a,
 				     const GtkCssSelector       *b);
 
-  guint         increase_id_specificity :1;
-  guint         increase_class_specificity :1;
-  guint         increase_element_specificity :1;
   guint         is_simple :1;
 };
 
@@ -261,6 +262,17 @@ gtk_css_selector_tree_get_previous_change (const GtkCssSelectorTree *tree,
   return previous_change;
 }
 
+/* DEFAULTS */
+
+static void
+gtk_css_selector_default_add_specificity (const GtkCssSelector *selector,
+                                          guint                *ids,
+                                          guint                *classes,
+                                          guint                *elements)
+{
+  /* no specificity changes */
+}
+ 
 /* DESCENDANT */
 
 static void
@@ -360,9 +372,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_DESCENDANT = {
   gtk_css_selector_descendant_tree_match,
   gtk_css_selector_descendant_get_change,
   gtk_css_selector_descendant_tree_get_change,
+  gtk_css_selector_default_add_specificity,
   gtk_css_selector_descendant_hash_one,
   gtk_css_selector_descendant_compare_one,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE
 };
 
 /* DESCENDANT FOR REGION */
@@ -475,9 +488,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_DESCENDANT_FOR_REGION = {
   gtk_css_selector_descendant_for_region_tree_match,
   gtk_css_selector_descendant_for_region_get_change,
   gtk_css_selector_descendant_for_region_tree_get_change,
+  gtk_css_selector_default_add_specificity,
   gtk_css_selector_descendant_for_region_hash_one,
   gtk_css_selector_descendant_for_region_compare_one,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE
 };
 
 /* CHILD */
@@ -561,9 +575,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_CHILD = {
   gtk_css_selector_child_tree_match,
   gtk_css_selector_child_get_change,
   gtk_css_selector_child_tree_get_change,
+  gtk_css_selector_default_add_specificity,
   gtk_css_selector_child_hash_one,
   gtk_css_selector_child_compare_one,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE
 };
 
 /* SIBLING */
@@ -667,9 +682,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_SIBLING = {
   gtk_css_selector_sibling_tree_match,
   gtk_css_selector_sibling_get_change,
   gtk_css_selector_sibling_tree_get_change,
+  gtk_css_selector_default_add_specificity,
   gtk_css_selector_sibling_hash_one,
   gtk_css_selector_sibling_compare_one,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE
 };
 
 /* ADJACENT */
@@ -754,9 +770,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_ADJACENT = {
   gtk_css_selector_adjacent_tree_match,
   gtk_css_selector_adjacent_get_change,
   gtk_css_selector_adjacent_tree_get_change,
+  gtk_css_selector_default_add_specificity,
   gtk_css_selector_adjacent_hash_one,
   gtk_css_selector_adjacent_compare_one,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE
 };
 
 /* SIMPLE SELECTOR DEFINE */
@@ -860,6 +877,20 @@ gtk_css_selector_ ## n ## _get_change (const GtkCssSelector *selector, GtkCssCha
   return previous_change | GTK_CSS_CHANGE_ ## c; \
 } \
 \
+static void \
+gtk_css_selector_ ## n ## _add_specificity (const GtkCssSelector *selector, \
+                                            guint                *ids, \
+                                            guint                *classes, \
+                                            guint                *elements) \
+{ \
+  if (increase_id_specificity) \
+    (*ids)++; \
+  if (increase_class_specificity) \
+    (*classes)++; \
+  if (increase_element_specificity) \
+    (*elements)++; \
+} \
+\
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_ ## c = { \
   G_STRINGIFY(n), \
   gtk_css_selector_ ## n ## _print, \
@@ -867,9 +898,9 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_ ## c = { \
   gtk_css_selector_ ## n ## _tree_match, \
   gtk_css_selector_ ## n ## _get_change, \
   gtk_css_selector_ ## n ## _tree_get_change, \
+  gtk_css_selector_ ## n ## _add_specificity, \
   hash_func, \
   comp_func, \
-  increase_id_specificity, increase_class_specificity, increase_element_specificity, \
   TRUE \
 };\
 \
@@ -880,9 +911,9 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_NOT_ ## c = { \
   gtk_css_selector_not_ ## n ## _tree_match, \
   gtk_css_selector_ ## n ## _get_change, \
   gtk_css_selector_ ## n ## _tree_get_change, \
+  gtk_css_selector_ ## n ## _add_specificity, \
   hash_func, \
   comp_func, \
-  increase_id_specificity, increase_class_specificity, increase_element_specificity, \
   TRUE \
 };
 
@@ -1085,6 +1116,28 @@ gtk_css_selector_region_get_change (const GtkCssSelector *selector, GtkCssChange
   return previous_change | GTK_CSS_CHANGE_REGION;
 }
 
+static guint
+count_bits (guint n)
+{
+  guint result = 0;
+
+  for (result = 0; n != 0; result++)
+    n &= n - 1;
+
+  return result;
+}
+
+static void
+gtk_css_selector_region_add_specificity (const GtkCssSelector *selector,
+                                         guint                *ids,
+                                         guint                *classes,
+                                         guint                *elements)
+{
+  (*elements)++;
+
+  (*classes) += count_bits (selector->region.flags);
+}
+ 
 static guint
 gtk_css_selector_region_hash_one (const GtkCssSelector *a)
 {
@@ -1111,9 +1164,10 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_REGION = {
   gtk_css_selector_region_tree_match,
   gtk_css_selector_region_get_change,
   gtk_css_selector_region_tree_get_change,
+  gtk_css_selector_region_add_specificity,
   gtk_css_selector_region_hash_one,
   gtk_css_selector_region_compare_one,
-  FALSE, FALSE, TRUE, TRUE
+  TRUE
 };
 
 /* CLASS */
@@ -1922,14 +1976,7 @@ _gtk_css_selector_get_specificity (const GtkCssSelector *selector,
 {
   for (; selector; selector = gtk_css_selector_previous (selector))
     {
-      const GtkCssSelectorClass *klass = selector->class;
+      selector->class->add_specificity (selector, ids, classes, elements);
-
-      if (klass->increase_id_specificity)
-        (*ids)++;
-      if (klass->increase_class_specificity)
-        (*classes)++;
-      if (klass->increase_element_specificity)
-        (*elements)++;
     }
 }