[gtk+/wip/garnacho/touchpad-gestures: 7/14] eventcontroller: Add private ::filter method

[Carlos Garnacho <carlosg src gnome org>]

commit 8acf84ac406d7110c4de8321dc8cf506ef1b6781
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Jul 9 18:55:32 2015 +0200

    eventcontroller: Add private ::filter method
    
    This will be used right before handle_event() in order to filter
    out events, useful to make the previous "no touchpad events" behavior
    the default, and have gesture subclasses include manually the touchpad
    events they handle.

 gtk/gtkeventcontroller.c        |    4 ++++
 gtk/gtkeventcontrollerprivate.h |    3 +++
 2 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkeventcontroller.c b/gtk/gtkeventcontroller.c
index a5cfde1..5449846 100644
--- a/gtk/gtkeventcontroller.c
+++ b/gtk/gtkeventcontroller.c
@@ -145,6 +145,7 @@ gtk_event_controller_class_init (GtkEventControllerClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+  klass->filter_event = gtk_event_controller_handle_event_default;
   klass->handle_event = gtk_event_controller_handle_event_default;
 
   object_class->set_property = gtk_event_controller_set_property;
@@ -218,6 +219,9 @@ gtk_event_controller_handle_event (GtkEventController *controller,
 
   controller_class = GTK_EVENT_CONTROLLER_GET_CLASS (controller);
 
+  if (controller_class->filter_event (controller, event))
+    return retval;
+
   if (controller_class->handle_event)
     {
       g_object_ref (controller);
diff --git a/gtk/gtkeventcontrollerprivate.h b/gtk/gtkeventcontrollerprivate.h
index 603da71..2f66ecc 100644
--- a/gtk/gtkeventcontrollerprivate.h
+++ b/gtk/gtkeventcontrollerprivate.h
@@ -36,6 +36,9 @@ struct _GtkEventControllerClass
   void     (* reset)        (GtkEventController *controller);
 
   /*<private>*/
+
+  gboolean (* filter_event) (GtkEventController *controller,
+                             const GdkEvent     *event);
   gpointer padding[10];
 };