[gtk+/wip/cssnode3: 58/88] cssnode: Change get_style_provider() vfunc

[Benjamin Otte <otte src gnome org>]

commit ffcd01ae34c07618e9a51b11f9ec86222951ce9f
Author: Benjamin Otte <otte redhat com>
Date:   Tue Feb 17 15:18:32 2015 +0100

    cssnode: Change get_style_provider() vfunc
    
    Instead of always returning a provider, allow the vfunc to return NULL
    to mane "use same provider as parent". This allows a bunch of
    optimizations.

 gtk/gtkcssnode.c        |   26 ++++++++++++++++++++------
 gtk/gtkcssnodeprivate.h |    1 +
 gtk/gtkcsspathnode.c    |    2 +-
 gtk/gtkcsswidgetnode.c  |    2 +-
 4 files changed, 23 insertions(+), 8 deletions(-)
---
diff --git a/gtk/gtkcssnode.c b/gtk/gtkcssnode.c
index 877dd18..d81f061 100644
--- a/gtk/gtkcssnode.c
+++ b/gtk/gtkcssnode.c
@@ -29,6 +29,12 @@
 
 G_DEFINE_TYPE (GtkCssNode, gtk_css_node, G_TYPE_OBJECT)
 
+static GtkStyleProviderPrivate *
+gtk_css_node_get_style_provider_or_null (GtkCssNode *cssnode)
+{
+  return GTK_CSS_NODE_GET_CLASS (cssnode)->get_style_provider (cssnode);
+}
+
 void
 gtk_css_node_set_invalid (GtkCssNode *node,
                           gboolean    invalid)
@@ -82,13 +88,15 @@ gtk_css_node_finalize (GObject *object)
 static gboolean
 may_use_global_parent_cache (GtkCssNode *node)
 {
+  GtkStyleProviderPrivate *provider;
   GtkCssNode *parent;
   
   parent = gtk_css_node_get_parent (node);
   if (parent == NULL)
     return FALSE;
 
-  if (gtk_css_node_get_style_provider (node) != gtk_css_node_get_style_provider (parent))
+  provider = gtk_css_node_get_style_provider_or_null (node);
+  if (provider != NULL && provider != gtk_css_node_get_style_provider (parent))
     return FALSE;
 
   return TRUE;
@@ -275,10 +283,7 @@ gtk_css_node_real_get_widget_path (GtkCssNode *cssnode)
 static GtkStyleProviderPrivate *
 gtk_css_node_real_get_style_provider (GtkCssNode *cssnode)
 {
-  if (cssnode->parent)
-    return gtk_css_node_get_style_provider (cssnode->parent);
-
-  return GTK_STYLE_PROVIDER_PRIVATE (_gtk_settings_get_style_cascade (gtk_settings_get_default (), 1));
+  return NULL;
 }
 
 static void
@@ -821,5 +826,14 @@ gtk_css_node_get_widget_path (GtkCssNode *cssnode)
 GtkStyleProviderPrivate *
 gtk_css_node_get_style_provider (GtkCssNode *cssnode)
 {
-  return GTK_CSS_NODE_GET_CLASS (cssnode)->get_style_provider (cssnode);
+  GtkStyleProviderPrivate *result;
+  
+  result = gtk_css_node_get_style_provider_or_null (cssnode);
+  if (result)
+    return result;
+
+  if (cssnode->parent)
+    return gtk_css_node_get_style_provider (cssnode->parent);
+
+  return GTK_STYLE_PROVIDER_PRIVATE (_gtk_settings_get_style_cascade (gtk_settings_get_default (), 1));
 }
diff --git a/gtk/gtkcssnodeprivate.h b/gtk/gtkcssnodeprivate.h
index 32f938f..8cfcd2a 100644
--- a/gtk/gtkcssnodeprivate.h
+++ b/gtk/gtkcssnodeprivate.h
@@ -68,6 +68,7 @@ struct _GtkCssNodeClass
                                                          GtkCssMatcher         *matcher);
   GtkWidgetPath *       (* create_widget_path)          (GtkCssNode            *cssnode);
   const GtkWidgetPath * (* get_widget_path)             (GtkCssNode            *cssnode);
+  /* get style provider to use or NULL to use parent's */
   GtkStyleProviderPrivate *(* get_style_provider)       (GtkCssNode            *cssnode);
   GtkCssStyle *         (* update_style)                (GtkCssNode            *cssnode,
                                                          GtkCssChange           pending_changes,
diff --git a/gtk/gtkcsspathnode.c b/gtk/gtkcsspathnode.c
index 1fc702e..50a1cc3 100644
--- a/gtk/gtkcsspathnode.c
+++ b/gtk/gtkcsspathnode.c
@@ -107,7 +107,7 @@ gtk_css_path_node_get_style_provider (GtkCssNode *node)
   GtkCssPathNode *path_node = GTK_CSS_PATH_NODE (node);
 
   if (path_node->context == NULL)
-    return GTK_CSS_NODE_CLASS (gtk_css_path_node_parent_class)->get_style_provider (node);
+    return NULL;
 
   return gtk_style_context_get_style_provider (path_node->context);
 }
diff --git a/gtk/gtkcsswidgetnode.c b/gtk/gtkcsswidgetnode.c
index 12e346b..10d0334 100644
--- a/gtk/gtkcsswidgetnode.c
+++ b/gtk/gtkcsswidgetnode.c
@@ -262,7 +262,7 @@ gtk_css_widget_node_get_style_provider (GtkCssNode *node)
   GtkCssWidgetNode *widget_node = GTK_CSS_WIDGET_NODE (node);
 
   if (widget_node->widget == NULL)
-    return GTK_CSS_NODE_CLASS (gtk_css_widget_node_parent_class)->get_style_provider (node);
+    return NULL;
 
   return gtk_style_context_get_style_provider (gtk_widget_get_style_context (widget_node->widget));
 }