icon-view: add back gtk_style_context_set_background()

Commit da09447914c0919362533182261a2c862ac8de81 removed the call to
gtk_style_context_set_background() in favour of always rendering it with
gtk_render_background() during the draw vfunc.
This has the side effect of making the backing window always
transparent, which blocks GTK from applying some optimizations during
the paint cycle. The result is that, especially in clutter-gtk
applications, scrolling performance gets really bad.

This commit partially reverts da09447914c0919362533182261a2c862ac8de81
and changes the code so that both gtk_style_context_set_background() and
gtk_render_background() are called.

1 files changed, 43 insertions, 0 deletions

diff --git a/gtk/gtkiconview.c b/gtk/gtkiconview.c
index 19d4f66c05..c6f41d30d0 100644
--- a/gtk/gtkiconview.c
+++ b/gtk/gtkiconview.c
@@ -132,6 +132,9 @@ static void             gtk_icon_view_get_property              (GObject
 static void             gtk_icon_view_destroy                   (GtkWidget          *widget);
 static void             gtk_icon_view_realize                   (GtkWidget          *widget);
 static void             gtk_icon_view_unrealize                 (GtkWidget          *widget);
+static void             gtk_icon_view_style_updated             (GtkWidget          *widget);
+static void             gtk_icon_view_state_flags_changed       (GtkWidget          *widget,
+			                                         GtkStateFlags       previous_state);
 static GtkSizeRequestMode gtk_icon_view_get_request_mode        (GtkWidget          *widget);
 static void             gtk_icon_view_get_preferred_width       (GtkWidget          *widget,
 								 gint               *minimum,
@@ -348,6 +351,7 @@ gtk_icon_view_class_init (GtkIconViewClass *klass)
   widget_class->destroy = gtk_icon_view_destroy;
   widget_class->realize = gtk_icon_view_realize;
   widget_class->unrealize = gtk_icon_view_unrealize;
+  widget_class->style_updated = gtk_icon_view_style_updated;
   widget_class->get_request_mode = gtk_icon_view_get_request_mode;
   widget_class->get_preferred_width = gtk_icon_view_get_preferred_width;
   widget_class->get_preferred_height = gtk_icon_view_get_preferred_height;
@@ -368,6 +372,7 @@ gtk_icon_view_class_init (GtkIconViewClass *klass)
   widget_class->drag_motion = gtk_icon_view_drag_motion;
   widget_class->drag_drop = gtk_icon_view_drag_drop;
   widget_class->drag_data_received = gtk_icon_view_drag_data_received;
+  widget_class->state_flags_changed = gtk_icon_view_state_flags_changed;
 
   container_class->remove = gtk_icon_view_remove;
   container_class->forall = gtk_icon_view_forall;
@@ -1275,6 +1280,7 @@ gtk_icon_view_realize (GtkWidget *widget)
   GdkWindow *window;
   GdkWindowAttr attributes;
   gint attributes_mask;
+  GtkStyleContext *context;
 
   gtk_widget_set_realized (widget, TRUE);
 
@@ -1317,6 +1323,11 @@ gtk_icon_view_realize (GtkWidget *widget)
   icon_view->priv->bin_window = gdk_window_new (window,
 						&attributes, attributes_mask);
   gdk_window_set_user_data (icon_view->priv->bin_window, widget);
+
+  context = gtk_widget_get_style_context (widget);
+  gtk_style_context_set_background (context, icon_view->priv->bin_window);
+  gtk_style_context_set_background (context, window);
+
   gdk_window_show (icon_view->priv->bin_window);
 }
 
@@ -1334,6 +1345,38 @@ gtk_icon_view_unrealize (GtkWidget *widget)
   GTK_WIDGET_CLASS (gtk_icon_view_parent_class)->unrealize (widget);
 }
 
+static void
+_gtk_icon_view_update_background (GtkIconView *icon_view)
+{
+  GtkWidget *widget = GTK_WIDGET (icon_view);
+
+  if (gtk_widget_get_realized (widget))
+    {
+      GtkStyleContext *context;
+
+      context = gtk_widget_get_style_context (widget);
+      gtk_style_context_set_background (context, gtk_widget_get_window (widget));
+      gtk_style_context_set_background (context, icon_view->priv->bin_window);
+    }
+}
+
+static void
+gtk_icon_view_state_flags_changed (GtkWidget     *widget,
+                                   GtkStateFlags  previous_state)
+{
+  _gtk_icon_view_update_background (GTK_ICON_VIEW (widget));
+  gtk_widget_queue_draw (widget);
+}
+
+static void
+gtk_icon_view_style_updated (GtkWidget *widget)
+{
+  GTK_WIDGET_CLASS (gtk_icon_view_parent_class)->style_updated (widget);
+
+  _gtk_icon_view_update_background (GTK_ICON_VIEW (widget));
+  gtk_widget_queue_resize (widget);
+}
+
 static gint
 gtk_icon_view_get_n_items (GtkIconView *icon_view)
 {