The things related to touch and smooth scrolling were 3.4 additions,
so mark them as such.
https://bugzilla.gnome.org/show_bug.cgi?id=676329
* @GDK_SCROLL_LEFT: the window is scrolled to the left.
* @GDK_SCROLL_RIGHT: the window is scrolled to the right.
* @GDK_SCROLL_SMOOTH: the scrolling is determined by the delta values
- * in #GdkEventScroll. See gdk_event_get_scroll_deltas().
+ * in #GdkEventScroll. See gdk_event_get_scroll_deltas(). Since: 3.4
*
* Specifies the direction for #GdkEventScroll.
*/
* @GDK_SUBSTRUCTURE_MASK: receive events about window configuration changes of
* child windows
* @GDK_SCROLL_MASK: receive scroll events
- * @GDK_TOUCH_MASK: receive touch events
- * @GDK_SMOOTH_SCROLL_MASK: receive smooth scrolling events
+ * @GDK_TOUCH_MASK: receive touch events. Since 3.4
+ * @GDK_SMOOTH_SCROLL_MASK: receive smooth scrolling events. Since 3.4
* @GDK_ALL_EVENTS_MASK: the combination of all the above event masks.
*
* A set of bit-flags to indicate which events a window is to receive.