[gtk+] Frame—Clarify relationship of :shadow-type & .flat

[Daniel Boles <dboles src gnome org>]

commit b106c5e4d56c88c32ba3d2940171e71cbfc77627
Author: Daniel Boles <dboles src gnome org>
Date:   Tue Feb 21 21:13:43 2017 +0000

    Frame—Clarify relationship of :shadow-type & .flat

 gtk/gtkframe.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkframe.c b/gtk/gtkframe.c
index 3b3ba30..7095c57 100644
--- a/gtk/gtkframe.c
+++ b/gtk/gtkframe.c
@@ -79,7 +79,8 @@
  * ]|
  *
  * GtkFrame has a main CSS node with name frame. This node can be given the
- * style class .flat, which disables drawing of the border.
+ * style class .flat, which disables drawing of the border, equivalent to
+ * calling gtk_frame_set_shadow_type() with GTK_SHADOW_NONE.
  */
 
 struct _GtkFramePrivate
@@ -615,7 +616,10 @@ gtk_frame_get_label_align (GtkFrame *frame,
  * @frame: a #GtkFrame
  * @type: the new #GtkShadowType
  * 
- * Sets the shadow type for @frame.
+ * Sets the #GtkFrame:shadow-type for @frame, i.e. whether it is drawn without
+ * (GTK_SHADOW_NONE) or with (other values) a visible border. Values other than
+ * GTK_SHADOW_NONE are treated identically by #GtkFrame. The chosen type is
+ * applied by removing or adding the .flat class to the main CSS node, frame.
  **/
 void
 gtk_frame_set_shadow_type (GtkFrame      *frame,