cssshadowvalue: Treat one shadow like multiple shadows

If we create a GtkCssShadowsValue for just one shadow, just return that
show value instead and allow calls on GtkCssShadowsValue API on one
shadow. That saves us around 480 GtkCssShadowsValue instances in the
widget factory.

css value stats before:

GtkCssColorValue: 1452
GtkCssFilterValue: 3
GtkCssRgbaValue: 1092
GtkCssShadowValue: 708
GtkCssEaseValue: 33
GtkCssBorderValue: 2
GtkCssTransformValue: 11
GtkCssDimensionValue: 882
GtkCssShadowsValue: 584
GtkCssBgSizeValue: 23
GtkCssIdentValue: 25
GtkCssPositionValue: 81
GtkCssArrayValue: 143
GtkCssStringValue: 33
GtkCssPaletteValue: 29
GtkCssImageValue: 2765
SUM: 7872

and after:

GtkCssShadowsValue: 107
GtkCssBgSizeValue: 23
GtkCssIdentValue: 25
GtkCssPositionValue: 81
GtkCssArrayValue: 143
GtkCssStringValue: 33
GtkCssPaletteValue: 29
GtkCssImageValue: 2764
GtkCssColorValue: 1452
GtkCssFilterValue: 3
GtkCssRgbaValue: 1092
GtkCssShadowValue: 708
GtkCssEaseValue: 33
GtkCssBorderValue: 2
GtkCssTransformValue: 11
GtkCssDimensionValue: 883
SUM: 7395

7872 to 7395 is a 477 reduction (6.0%)

gtk/gtkcssshadowsvalue.c

@@ -223,14 +223,17 @@ gtk_css_shadows_value_new (GtkCssValue **values,
                            guint         len)
 {
   GtkCssValue *result;
-           
+
   g_return_val_if_fail (values != NULL, NULL);
   g_return_val_if_fail (len > 0, NULL);
-         
+
+  if (len == 1)
+    return values[0];
+
   result = _gtk_css_value_alloc (&GTK_CSS_VALUE_SHADOWS, sizeof (GtkCssValue) + sizeof (GtkCssValue *) * (len - 1));
   result->len = len;
   memcpy (&result->values[0], values, sizeof (GtkCssValue *) * len);
-            
+
   return result;
 }
 
@@ -267,6 +270,9 @@ _gtk_css_shadows_value_parse (GtkCssParser *parser,
 gboolean
 _gtk_css_shadows_value_is_none (const GtkCssValue *shadows)
 {
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    return FALSE;
+
   g_return_val_if_fail (shadows->class == &GTK_CSS_VALUE_SHADOWS, TRUE);
 
   return shadows->len == 0;
@@ -275,6 +281,9 @@ _gtk_css_shadows_value_is_none (const GtkCssValue *shadows)
 gsize
 gtk_css_shadows_value_get_n_shadows (const GtkCssValue *shadows)
 {
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    return 1;
+
   return shadows->len;
 }
 
@@ -284,6 +293,12 @@ gtk_css_shadows_value_get_shadows (const GtkCssValue  *shadows,
 {
   guint i;
 
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    {
+      gtk_css_shadow_value_get_shadow (shadows, &out_shadows[0]);
+      return;
+    }
+
   for (i = 0; i < shadows->len; i++)
     gtk_css_shadow_value_get_shadow (shadows->values[i], &out_shadows[i]);
 }
@@ -295,6 +310,14 @@ gtk_css_shadows_value_snapshot_outset (const GtkCssValue   *shadows,
 {
   guint i;
 
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    {
+      if (!_gtk_css_shadow_value_get_inset (shadows))
+        gtk_css_shadow_value_snapshot_outset (shadows, snapshot, border_box);
+
+      return;
+    }
+
   g_return_if_fail (shadows->class == &GTK_CSS_VALUE_SHADOWS);
 
   for (i = 0; i < shadows->len; i++)
@@ -313,6 +336,14 @@ gtk_css_shadows_value_snapshot_inset (const GtkCssValue   *shadows,
 {
   guint i;
 
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    {
+      if (_gtk_css_shadow_value_get_inset (shadows))
+        gtk_css_shadow_value_snapshot_outset (shadows, snapshot, padding_box);
+
+      return;
+    }
+
   g_return_if_fail (shadows->class == &GTK_CSS_VALUE_SHADOWS);
 
   for (i = 0; i < shadows->len; i++)
@@ -332,6 +363,15 @@ _gtk_css_shadows_value_get_extents (const GtkCssValue *shadows,
   GtkBorder b = { 0 }, sb;
   const GtkCssValue *shadow;
 
+  if (gtk_css_shadow_value_is_shadow (shadows))
+    {
+      if (!_gtk_css_shadow_value_get_inset (shadows))
+        gtk_css_shadow_value_get_extents (shadows, &b);
+
+      *border = b;
+      return;
+    }
+
   g_return_if_fail (shadows->class == &GTK_CSS_VALUE_SHADOWS);
 
   for (i = 0; i < shadows->len; i++)
@@ -356,9 +396,22 @@ gboolean
 gtk_css_shadows_value_push_snapshot (const GtkCssValue *value,
                                      GtkSnapshot       *snapshot)
 {
-  gboolean need_shadow = FALSE;
+  gboolean need_shadow;
   int i;
 
+  if (gtk_css_shadow_value_is_shadow (value))
+    {
+      GskShadow shadow;
+
+      if (!gtk_css_shadow_value_is_clear (value))
+        return FALSE;
+
+      gtk_css_shadow_value_get_shadow (value, &shadow);
+      gtk_snapshot_push_shadow (snapshot, &shadow, 1);
+      return TRUE;
+    }
+
+  need_shadow = FALSE;
   for (i = 0; i < value->len; i++)
     {
       if (!gtk_css_shadow_value_is_clear (value->values[i]))

gtk/gtkcssshadowvalue.c

@@ -473,3 +473,8 @@ gtk_css_shadow_value_is_clear (const GtkCssValue *shadow)
   return gdk_rgba_is_clear (_gtk_css_rgba_value_get_rgba (shadow->color));
 }
 
+gboolean
+gtk_css_shadow_value_is_shadow (const GtkCssValue *maybe_shadow)
+{
+  return maybe_shadow->class == &GTK_CSS_VALUE_SHADOW;
+}

gtk/gtkcssshadowvalueprivate.h

@@ -52,6 +52,8 @@ void            gtk_css_shadow_value_snapshot_inset   (const GtkCssValue
 
 gboolean        gtk_css_shadow_value_is_clear         (const GtkCssValue        *shadow);
 
+gboolean        gtk_css_shadow_value_is_shadow        (const GtkCssValue        *maybe_shadow);
+
 G_END_DECLS
 
 #endif /* __GTK_SHADOW_H__ */