[gimp/gtk3-port: 123/227] app: port GimpComponentEditor to GtkStyleContext

[Michael Natterer <mitch src gnome org>]

commit c5dbdf0dfbc979741cc5bd6fb0eef23392020b30
Author: Michael Natterer <mitch gimp org>
Date:   Sun Dec 19 13:16:31 2010 +0100

    app: port GimpComponentEditor to GtkStyleContext

 app/widgets/gimpcomponenteditor.c |   22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)
---
diff --git a/app/widgets/gimpcomponenteditor.c b/app/widgets/gimpcomponenteditor.c
index d6e5a2b..3e184fe 100644
--- a/app/widgets/gimpcomponenteditor.c
+++ b/app/widgets/gimpcomponenteditor.c
@@ -285,26 +285,32 @@ void
 gimp_component_editor_set_view_size (GimpComponentEditor *editor,
                                      gint                 view_size)
 {
-  GtkWidget   *tree_widget;
-  GtkStyle    *tree_style;
-  GtkIconSize  icon_size;
-  GtkTreeIter  iter;
-  gboolean     iter_valid;
+  GtkWidget       *tree_widget;
+  GtkStyleContext *tree_style;
+  GtkBorder        border;
+  GtkIconSize      icon_size;
+  GtkTreeIter      iter;
+  gboolean         iter_valid;
 
   g_return_if_fail (GIMP_IS_COMPONENT_EDITOR (editor));
   g_return_if_fail (view_size >  0 &&
                     view_size <= GIMP_VIEWABLE_MAX_PREVIEW_SIZE);
 
   tree_widget = GTK_WIDGET (editor->view);
-  tree_style  = gtk_widget_get_style (tree_widget);
+  tree_style  = gtk_widget_get_style_context (tree_widget);
+
+  gtk_style_context_save (tree_style);
+  gtk_style_context_add_class (tree_style, GTK_STYLE_CLASS_BUTTON);
+  gtk_style_context_get_border (tree_style, 0, &border);
+  gtk_style_context_restore (tree_style);
 
   icon_size = gimp_get_icon_size (tree_widget,
                                   GIMP_STOCK_VISIBLE,
                                   GTK_ICON_SIZE_BUTTON,
                                   view_size -
-                                  2 * tree_style->xthickness,
+                                  (border.left + border.right),
                                   view_size -
-                                  2 * tree_style->ythickness);
+                                  (border.top + border.bottom));
 
   g_object_set (editor->eye_cell,
                 "stock-size", icon_size,