stylecontext: add style classes for top/bottom/right/left areas

This is useful to e.g. theme notebook tabs differently according to
their position directly from the CSS sheet.

GtkNotebook support in a separate commit.

https://bugzilla.gnome.org/show_bug.cgi?id=659777

1 files changed, 39 insertions, 0 deletions

diff --git a/gtk/gtkstylecontext.h b/gtk/gtkstylecontext.h
index 3e32c683cb..33cf5560fa 100644
--- a/gtk/gtkstylecontext.h
+++ b/gtk/gtkstylecontext.h
@@ -600,6 +600,45 @@ struct _GtkStyleContextClass
  */
 #define GTK_STYLE_CLASS_VERTICAL "vertical"
 
+/**
+ * GTK_STYLE_CLASS_TOP:
+ *
+ * A CSS class to indicate an area at the top of a widget.
+ *
+ * This is used by widgets that can render an area in different
+ * positions, such as tabs in a #GtkNotebook.
+ */
+#define GTK_STYLE_CLASS_TOP "top"
+
+/**
+ * GTK_STYLE_CLASS_BOTTOM:
+ *
+ * A CSS class to indicate an area at the bottom of a widget.
+ *
+ * This is used by widgets that can render an area in different
+ * positions, such as tabs in a #GtkNotebook.
+ */
+#define GTK_STYLE_CLASS_BOTTOM "bottom"
+
+/**
+ * GTK_STYLE_CLASS_LEFT:
+ *
+ * A CSS class to indicate an area at the left of a widget.
+ *
+ * This is used by widgets that can render an area in different
+ * positions, such as tabs in a #GtkNotebook.
+ */
+#define GTK_STYLE_CLASS_LEFT "left"
+
+/**
+ * GTK_STYLE_CLASS_RIGHT:
+ *
+ * A CSS class to indicate an area at the right of a widget.
+ *
+ * This is used by widgets that can render an area in different
+ * positions, such as tabs in a #GtkNotebook.
+ */
+#define GTK_STYLE_CLASS_RIGHT "right"
 
 /* Predefined set of widget regions */