css: Make the 'currentColor' keyword a symbolic color

This is the first step on a quest to ensure that there is only ever one
GType in use for GValues in every stage of the CSS resolving process.

gtk/gtkcssshorthandpropertyimpl.c

@@ -30,6 +30,7 @@
 #include "gtkcsstypesprivate.h"
 #include "gtkprivatetypebuiltins.h"
 #include "gtkstylepropertiesprivate.h"
+#include "gtksymboliccolorprivate.h"
 #include "gtktypebuiltins.h"
 
 /* this is in case round() is not provided by the compiler, 
@@ -161,19 +162,18 @@ parse_border_color (GtkCssShorthandProperty *shorthand,
     {
       if (_gtk_css_parser_try (parser, "currentcolor", TRUE))
         {
-          g_value_init (&values[i], GTK_TYPE_CSS_SPECIAL_VALUE);
+          symbolic = gtk_symbolic_color_ref (_gtk_symbolic_color_get_current_color ());
-          g_value_set_enum (&values[i], GTK_CSS_CURRENT_COLOR);
         }
       else
         {
           symbolic = _gtk_css_parser_read_symbolic_color (parser);
           if (symbolic == NULL)
             return FALSE;
-
-          g_value_init (&values[i], GTK_TYPE_SYMBOLIC_COLOR);
-          g_value_set_boxed (&values[i], symbolic);
         }
 
+      g_value_init (&values[i], GTK_TYPE_SYMBOLIC_COLOR);
+      g_value_set_boxed (&values[i], symbolic);
+
       if (value_is_done_parsing (parser))
         break;
     }

gtk/gtkcssstylefuncs.c

@@ -37,6 +37,7 @@
 #include "gtkprivatetypebuiltins.h"
 #include "gtkshadowprivate.h"
 #include "gtkstylecontextprivate.h"
+#include "gtksymboliccolorprivate.h"
 #include "gtkthemingengine.h"
 #include "gtktypebuiltins.h"
 #include "gtkwin32themeprivate.h"
@@ -173,15 +174,14 @@ rgba_value_parse (GtkCssParser *parser,
 
   if (_gtk_css_parser_try (parser, "currentcolor", TRUE))
     {
-      g_value_unset (value);
+      symbolic = gtk_symbolic_color_ref (_gtk_symbolic_color_get_current_color ());
-      g_value_init (value, GTK_TYPE_CSS_SPECIAL_VALUE);
+    }
-      g_value_set_enum (value, GTK_CSS_CURRENT_COLOR);
+  else
-      return TRUE;
+    {
+      symbolic = _gtk_css_parser_read_symbolic_color (parser);
+      if (symbolic == NULL)
+        return FALSE;
     }
-
-  symbolic = _gtk_css_parser_read_symbolic_color (parser);
-  if (symbolic == NULL)
-    return FALSE;
 
   if (gtk_symbolic_color_resolve (symbolic, NULL, &rgba))
     {
@@ -223,14 +223,16 @@ rgba_value_compute (GValue          *computed,
 
   if (G_VALUE_HOLDS (specified, GTK_TYPE_CSS_SPECIAL_VALUE))
     {
-      g_assert (g_value_get_enum (specified) == GTK_CSS_CURRENT_COLOR);
-      g_value_copy (_gtk_style_context_peek_property (context, "color"), computed);
     }
   else if (G_VALUE_HOLDS (specified, GTK_TYPE_SYMBOLIC_COLOR))
     {
-      if (_gtk_style_context_resolve_color (context,
+      GtkSymbolicColor *symbolic = g_value_get_boxed (specified);
-                                            g_value_get_boxed (specified),
+      
-                                            &rgba))
+      if (symbolic == _gtk_symbolic_color_get_current_color ())
+        g_value_copy (_gtk_style_context_peek_property (context, "color"), computed);
+      else if (_gtk_style_context_resolve_color (context,
+                                                 symbolic,
+                                                 &rgba))
         g_value_set_boxed (computed, &rgba);
       else
         g_value_set_boxed (computed, &white);

gtk/gtkcssstylepropertyimpl.c

@@ -39,6 +39,7 @@
 #include "gtkcssimageprivate.h"
 #include "gtkgradient.h"
 #include "gtkshadowprivate.h"
+#include "gtksymboliccolorprivate.h"
 #include "gtkthemingengine.h"
 #include "gtktypebuiltins.h"
 #include "gtkwin32themeprivate.h"
@@ -56,43 +57,45 @@ color_compute (GtkCssStyleProperty    *property,
   /* for when resolvage fails */
 restart:
 
-  if (G_VALUE_HOLDS (specified, GTK_TYPE_CSS_SPECIAL_VALUE))
+  if (G_VALUE_HOLDS (specified, GTK_TYPE_SYMBOLIC_COLOR))
-    {
-      g_assert (g_value_get_enum (specified) == GTK_CSS_CURRENT_COLOR);
-
-      /* The computed value of the ‘currentColor’ keyword is the computed
-       * value of the ‘color’ property. If the ‘currentColor’ keyword is
-       * set on the ‘color’ property itself, it is treated as ‘color: inherit’. 
-       */
-      if (g_str_equal (_gtk_style_property_get_name (GTK_STYLE_PROPERTY (property)), "color"))
-        {
-          GtkStyleContext *parent = gtk_style_context_get_parent (context);
-
-          if (parent)
-            g_value_copy (_gtk_style_context_peek_property (parent, "color"), computed);
-          else
-            _gtk_css_style_compute_value (computed,
-                                          context,
-                                          _gtk_css_style_property_get_initial_value (property));
-        }
-      else
-        {
-          g_value_copy (_gtk_style_context_peek_property (context, "color"), computed);
-        }
-    }
-  else if (G_VALUE_HOLDS (specified, GTK_TYPE_SYMBOLIC_COLOR))
     {
+      GtkSymbolicColor *symbolic = g_value_get_boxed (specified);
       GdkRGBA rgba;
 
-      if (!_gtk_style_context_resolve_color (context,
+      if (symbolic == _gtk_symbolic_color_get_current_color ())
-                                             g_value_get_boxed (specified),
+        {
-                                             &rgba))
+          /* The computed value of the ‘currentColor’ keyword is the computed
+           * value of the ‘color’ property. If the ‘currentColor’ keyword is
+           * set on the ‘color’ property itself, it is treated as ‘color: inherit’. 
+           */
+          if (g_str_equal (_gtk_style_property_get_name (GTK_STYLE_PROPERTY (property)), "color"))
+            {
+              GtkStyleContext *parent = gtk_style_context_get_parent (context);
+
+              if (parent)
+                g_value_copy (_gtk_style_context_peek_property (parent, "color"), computed);
+              else
+                _gtk_css_style_compute_value (computed,
+                                              context,
+                                              _gtk_css_style_property_get_initial_value (property));
+            }
+          else
+            {
+              g_value_copy (_gtk_style_context_peek_property (context, "color"), computed);
+            }
+        }
+      else if (_gtk_style_context_resolve_color (context,
+                                                 symbolic,
+                                                 &rgba))
+        {
+          g_value_set_boxed (computed, &rgba);
+        }
+      else
         {
           specified = _gtk_css_style_property_get_initial_value (property);
           goto restart;
         }
 
-      g_value_set_boxed (computed, &rgba);
     }
   else
     g_value_copy (specified, computed);
@@ -819,8 +822,8 @@ _gtk_css_style_property_init_properties (void)
                                           NULL,
                                           GTK_CSS_AREA_PADDING_BOX);
 
-  g_value_init (&value, GTK_TYPE_CSS_SPECIAL_VALUE);
+  g_value_init (&value, GTK_TYPE_SYMBOLIC_COLOR);
-  g_value_set_enum (&value, GTK_CSS_CURRENT_COLOR);
+  g_value_set_boxed (&value, _gtk_symbolic_color_get_current_color ());
   _gtk_style_property_register           ("border-top-color",
                                           GDK_TYPE_RGBA,
                                           0,

gtk/gtkcsstypesprivate.h

@@ -26,8 +26,7 @@ G_BEGIN_DECLS
 
 typedef enum {
   GTK_CSS_INHERIT,
-  GTK_CSS_INITIAL,
+  GTK_CSS_INITIAL
-  GTK_CSS_CURRENT_COLOR /*< nick=currentColor >*/
 } GtkCssSpecialValue;
 
 /* We encode horizontal and vertical repeat in one enum value.

gtk/gtksymboliccolor.c

@@ -52,7 +52,8 @@ typedef enum {
   COLOR_TYPE_SHADE,
   COLOR_TYPE_ALPHA,
   COLOR_TYPE_MIX,
-  COLOR_TYPE_WIN32
+  COLOR_TYPE_WIN32,
+  COLOR_TYPE_CURRENT_COLOR
 } ColorType;
 
 struct _GtkSymbolicColor
@@ -267,6 +268,30 @@ gtk_symbolic_color_new_win32 (const gchar *theme_class,
   return symbolic_color;
 }
 
+/**
+ * _gtk_symbolic_color_get_current_color:
+ *
+ * Gets the color representing the CSS 'currentColor' keyword.
+ * This color will resolve to the color set for the color property.
+ *
+ * Returns: (transfer none): The singleton representing the
+ *     'currentColor' keyword
+ **/
+GtkSymbolicColor *
+_gtk_symbolic_color_get_current_color (void)
+{
+  static GtkSymbolicColor *current_color = NULL;
+
+  if (G_UNLIKELY (current_color == NULL))
+    {
+      current_color = g_slice_new0 (GtkSymbolicColor);
+      current_color->type = COLOR_TYPE_CURRENT_COLOR;
+      current_color->ref_count = 1;
+    }
+
+  return current_color;
+}
+
 /**
  * gtk_symbolic_color_ref:
  * @color: a #GtkSymbolicColor
@@ -628,6 +653,9 @@ _gtk_symbolic_color_resolve_full (GtkSymbolicColor           *color,
 					     color->win32.id,
 					     resolved_color);
 
+      break;
+    case COLOR_TYPE_CURRENT_COLOR:
+      return FALSE;
       break;
     default:
       g_assert_not_reached ();
@@ -701,6 +729,9 @@ gtk_symbolic_color_to_string (GtkSymbolicColor *color)
 			     color->win32.theme_class, color->win32.id);
       }
       break;
+    case COLOR_TYPE_CURRENT_COLOR:
+      s = g_strdup ("currentColor");
+      break;
     default:
       g_assert_not_reached ();
     }

gtk/gtksymboliccolorprivate.h

@@ -31,6 +31,8 @@ gboolean           _gtk_symbolic_color_resolve_full       (GtkSymbolicColor
                                                            gpointer                    data,
                                                            GdkRGBA                    *resolved_color);
 
+GtkSymbolicColor * _gtk_symbolic_color_get_current_color  (void);
+
 G_END_DECLS
 
 #endif /* __GTK_SYMBOLIC_COLOR_PRIVATE_H__ */