[clutter] evdev: Implement the ClutterEventExtender interface

[Carlos Garnacho <carlosg src gnome org>]

commit dfc749e576584c9ea6ad0aac739683e8ac64ea84
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Nov 17 17:40:30 2015 +0100

    evdev: Implement the ClutterEventExtender interface
    
    This will allow the ClutterDeviceManagerEvdev to define evdev-specific
    event data.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=758238

 clutter/evdev/clutter-device-manager-evdev.c |   31 +++++++++++++++++++++++--
 1 files changed, 28 insertions(+), 3 deletions(-)
---
diff --git a/clutter/evdev/clutter-device-manager-evdev.c b/clutter/evdev/clutter-device-manager-evdev.c
index ac5ea93..50df6f5 100644
--- a/clutter/evdev/clutter-device-manager-evdev.c
+++ b/clutter/evdev/clutter-device-manager-evdev.c
@@ -144,9 +144,14 @@ struct _ClutterDeviceManagerEvdevPrivate
   GSList *event_filters;
 };
 
-G_DEFINE_TYPE_WITH_PRIVATE (ClutterDeviceManagerEvdev,
-                            clutter_device_manager_evdev,
-                            CLUTTER_TYPE_DEVICE_MANAGER)
+static void clutter_device_manager_evdev_event_extender_init (ClutterEventExtenderInterface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (ClutterDeviceManagerEvdev,
+                         clutter_device_manager_evdev,
+                         CLUTTER_TYPE_DEVICE_MANAGER,
+                         G_ADD_PRIVATE (ClutterDeviceManagerEvdev)
+                         G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_EVENT_EXTENDER,
+                                                clutter_device_manager_evdev_event_extender_init))
 
 static ClutterOpenDeviceCallback  device_open_callback;
 static ClutterCloseDeviceCallback device_close_callback;
@@ -178,6 +183,26 @@ static const char *option_xkb_layout = "us";
 static const char *option_xkb_variant = "";
 static const char *option_xkb_options = "";
 
+static void
+clutter_device_manager_evdev_copy_event_data (ClutterEventExtender *event_extender,
+                                              const ClutterEvent   *src,
+                                              ClutterEvent         *dest)
+{
+}
+
+static void
+clutter_device_manager_evdev_free_event_data (ClutterEventExtender *event_extender,
+                                              ClutterEvent         *event)
+{
+}
+
+static void
+clutter_device_manager_evdev_event_extender_init (ClutterEventExtenderInterface *iface)
+{
+  iface->copy_event_data = clutter_device_manager_evdev_copy_event_data;
+  iface->free_event_data = clutter_device_manager_evdev_free_event_data;
+}
+
 /*
  * ClutterEventSource for reading input devices
  */