[clutter] device-manager: Add private interface to manipulate platform event data

[Carlos Garnacho <carlosg src gnome org>]

commit 5ea70bd102b25ca4c85ce06921d17b0eff15e673
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Nov 17 17:35:55 2015 +0100

    device-manager: Add private interface to manipulate platform event data
    
    This normally belonged to the ClutterBackend, however there's device
    managers (eg. evdev) that are somewhat detached from the backend, so
    need to bridge this somehow.
    
    This allows device managers to implement these bits that were usually
    responsibility of the ClutterBackend.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=758238

 clutter/clutter-device-manager-private.h |   20 ++++++++++++++++++++
 clutter/clutter-device-manager.c         |    9 +++++++++
 2 files changed, 29 insertions(+), 0 deletions(-)
---
diff --git a/clutter/clutter-device-manager-private.h b/clutter/clutter-device-manager-private.h
index 3e09288..9c42450 100644
--- a/clutter/clutter-device-manager-private.h
+++ b/clutter/clutter-device-manager-private.h
@@ -145,6 +145,26 @@ struct _ClutterInputDeviceClass
                                  guint              *evdev_keycode);
 };
 
+/* Platform-dependent interface */
+typedef struct _ClutterEventExtender ClutterEventExtender;
+typedef struct _ClutterEventExtenderInterface ClutterEventExtenderInterface;
+
+#define CLUTTER_TYPE_EVENT_EXTENDER         (clutter_event_extender_get_type ())
+#define CLUTTER_EVENT_EXTENDER(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), CLUTTER_TYPE_EVENT_EXTENDER, 
ClutterEventExtender))
+#define CLUTTER_IS_EVENT_EXTENDER(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), CLUTTER_TYPE_EVENT_EXTENDER))
+#define CLUTTER_EVENT_EXTENDER_GET_IFACE(o) (G_TYPE_INSTANCE_GET_INTERFACE ((o), 
CLUTTER_TYPE_EVENT_EXTENDER, ClutterEventExtenderInterface))
+
+struct _ClutterEventExtenderInterface
+{
+  void (* copy_event_data) (ClutterEventExtender *event_extender,
+                            const ClutterEvent   *src,
+                            ClutterEvent         *dest);
+  void (* free_event_data) (ClutterEventExtender *event_extender,
+                            ClutterEvent         *event);
+};
+
+GType           clutter_event_extender_get_type        (void) G_GNUC_CONST;
+
 /* device manager */
 void            _clutter_device_manager_add_device              (ClutterDeviceManager *device_manager,
                                                                  ClutterInputDevice   *device);
diff --git a/clutter/clutter-device-manager.c b/clutter/clutter-device-manager.c
index 32a6e8a..597b0d1 100644
--- a/clutter/clutter-device-manager.c
+++ b/clutter/clutter-device-manager.c
@@ -79,6 +79,15 @@ G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (ClutterDeviceManager,
                                      clutter_device_manager,
                                      G_TYPE_OBJECT)
 
+G_DEFINE_INTERFACE (ClutterEventExtender,
+                    clutter_event_extender,
+                    CLUTTER_TYPE_DEVICE_MANAGER)
+
+static void
+clutter_event_extender_default_init (ClutterEventExtenderInterface *iface)
+{
+}
+
 static void
 clutter_device_manager_set_property (GObject      *gobject,
                                      guint         prop_id,