[gtk+] gdkdevice: Add GDK_SOURCE_TABLET_PAD input source type for GdkDevices

[Carlos Garnacho <carlosg src gnome org>]

commit 3f56af373891bf6e3e01079c07521928613bdb1b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Aug 4 19:01:38 2016 +0200

    gdkdevice: Add GDK_SOURCE_TABLET_PAD input source type for GdkDevices
    
    This will represent a tablet pad.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=770026

 gdk/gdkdevice.h |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/gdk/gdkdevice.h b/gdk/gdkdevice.h
index b345e9d..07720b2 100644
--- a/gdk/gdkdevice.h
+++ b/gdk/gdkdevice.h
@@ -49,6 +49,9 @@ typedef struct _GdkTimeCoord GdkTimeCoord;
  *     as a touchpad. This device type has been added in 3.4.
  * @GDK_SOURCE_TRACKPOINT: the device is a trackpoint. This device type has been
  *     added in 3.22
+ * @GDK_SOURCE_TABLET_PAD: the device is a "pad", a collection of buttons,
+ *     rings and strips found in drawing tablets. This device type has been
+ *     added in 3.22.
  *
  * An enumeration describing the type of an input device in general terms.
  */
@@ -61,7 +64,8 @@ typedef enum
   GDK_SOURCE_KEYBOARD,
   GDK_SOURCE_TOUCHSCREEN,
   GDK_SOURCE_TOUCHPAD,
-  GDK_SOURCE_TRACKPOINT
+  GDK_SOURCE_TRACKPOINT,
+  GDK_SOURCE_TABLET_PAD
 } GdkInputSource;
 
 /**