[glom] EggSpreadTableDnd: Replace use of deprecated gtk_style_context_set_background.

[Murray Cumming <murrayc src gnome org>]

commit 4c244aae3f2407cc6dec248a9e68a607a41ebc71
Author: Murray Cumming <murrayc murrayc com>
Date:   Sun Jul 19 20:36:15 2015 +0200

    EggSpreadTableDnd: Replace use of deprecated gtk_style_context_set_background.
    
    Replace use of gtk_style_context_set_background() in the _realize() vfunc
    with use of gtk_render_background() in the _draw() vfunc. This is based
    on the _draw() implementations in similar GTK+ containers such as GtkGrid.

 .../eggspreadtable/eggspreadtablednd.c             |   21 ++++++++++++++++++-
 1 files changed, 19 insertions(+), 2 deletions(-)
---
diff --git a/glom/utility_widgets/eggspreadtable/eggspreadtablednd.c 
b/glom/utility_widgets/eggspreadtable/eggspreadtablednd.c
index 0b7e94b..5704f64 100644
--- a/glom/utility_widgets/eggspreadtable/eggspreadtablednd.c
+++ b/glom/utility_widgets/eggspreadtable/eggspreadtablednd.c
@@ -42,6 +42,8 @@ static void          egg_spread_table_dnd_set_property      (GObject
 
 /* GtkWidgetClass */
 static void          egg_spread_table_dnd_realize            (GtkWidget         *widget);
+static gboolean      egg_spread_table_dnd_draw               (GtkWidget *widget,
+                    cairo_t *cr);
 static void          egg_spread_table_dnd_size_allocate      (GtkWidget         *widget,
                                                              GtkAllocation     *allocation);
 
@@ -183,6 +185,7 @@ egg_spread_table_dnd_class_init (EggSpreadTableDndClass *class)
 
   widget_class->realize                 = egg_spread_table_dnd_realize;
   widget_class->size_allocate           = egg_spread_table_dnd_size_allocate;
+  widget_class->draw                    = egg_spread_table_dnd_draw;
   widget_class->drag_leave              = egg_spread_table_dnd_drag_leave;
   widget_class->drag_motion             = egg_spread_table_dnd_drag_motion;
   widget_class->drag_drop               = egg_spread_table_dnd_drag_drop;
@@ -387,9 +390,23 @@ egg_spread_table_dnd_realize (GtkWidget *widget)
   window = gdk_window_new (gtk_widget_get_parent_window (widget),
                            &attributes, attributes_mask);
   gtk_widget_set_window (widget, window);
-  gdk_window_set_user_data (window, widget);
+  gdk_window_set_user_data (window, widget); 
+}
+
+static gboolean
+egg_spread_table_dnd_draw (GtkWidget *widget,
+  cairo_t *cr)
+{
+  GtkStyleContext *context;
+  GtkAllocation allocation;
+
+  context = gtk_widget_get_style_context (widget);
+  gtk_widget_get_allocation (widget, &allocation);
+
+  gtk_render_background (context, cr, 0, 0, allocation.width, allocation.height);
+  gtk_render_frame (context, cr, 0, 0, allocation.width, allocation.height);
 
-  gtk_style_context_set_background (gtk_widget_get_style_context (widget), window);
+  return GTK_WIDGET_CLASS (egg_spread_table_dnd_parent_class)->draw (widget, cr);
 }
 
 static void