[clutter] stage: Maintain the motion event delivery invariants

[Emmanuele Bassi <ebassi src gnome org>]

commit d5ea422c8fcf0fb3422f42f79b9d278b14d6dec5
Author: Emmanuele Bassi <ebassi linux intel com>
Date:   Mon Jun 20 13:53:09 2011 +0100

    stage: Maintain the motion event delivery invariants
    
    It is possible, by calling clutter_set_motion_events_enabled() prior to
    the creation of any stage, to control the per-actor motion event
    delivery flag on each newly created stage. Since we deprecated the
    global accessor functions in favour of the per-Stage ones, we need to
    remove the call to clutter_get_motion_events_enabled() inside the
    ClutterStage instance initialization, and replace it with an internal
    function.
    
    This code will go away when we can finally break API and remove the
    deprecated functions.

 clutter/clutter-main.c    |   12 +++++++++---
 clutter/clutter-private.h |   21 +++++++++++----------
 clutter/clutter-stage.c   |    9 ++++++++-
 3 files changed, 28 insertions(+), 14 deletions(-)
---
diff --git a/clutter/clutter-main.c b/clutter/clutter-main.c
index 972d41d..22bb22f 100644
--- a/clutter/clutter-main.c
+++ b/clutter/clutter-main.c
@@ -303,9 +303,7 @@ clutter_set_motion_events_enabled (gboolean enable)
 gboolean
 clutter_get_motion_events_enabled (void)
 {
-  ClutterMainContext *context = _clutter_context_get_default ();
-
-  return context->motion_events_per_actor;
+  return _clutter_context_get_motion_events_enabled ();
 }
 
 ClutterActor *
@@ -3099,3 +3097,11 @@ _clutter_context_pop_shader_stack (ClutterActor *actor)
 
   return _clutter_context_peek_shader_stack ();
 }
+
+gboolean
+_clutter_context_get_motion_events_enabled (void)
+{
+  ClutterMainContext *context = _clutter_context_get_default ();
+
+  return context->motion_events_per_actor;
+}
diff --git a/clutter/clutter-private.h b/clutter/clutter-private.h
index b75953e..2c3dd6e 100644
--- a/clutter/clutter-private.h
+++ b/clutter/clutter-private.h
@@ -178,16 +178,17 @@ typedef struct
 gboolean _clutter_threads_dispatch      (gpointer data);
 void     _clutter_threads_dispatch_free (gpointer data);
 
-ClutterMainContext *    _clutter_context_get_default            (void);
-gboolean                _clutter_context_is_initialized         (void);
-PangoContext *          _clutter_context_create_pango_context   (void);
-PangoContext *          _clutter_context_get_pango_context      (void);
-ClutterPickMode         _clutter_context_get_pick_mode          (void);
-void                    _clutter_context_push_shader_stack      (ClutterActor *actor);
-ClutterActor *          _clutter_context_pop_shader_stack       (ClutterActor *actor);
-ClutterActor *          _clutter_context_peek_shader_stack      (void);
-guint32                 _clutter_context_acquire_id             (gpointer      key);
-void                    _clutter_context_release_id             (guint32       id_);
+ClutterMainContext *    _clutter_context_get_default                    (void);
+gboolean                _clutter_context_is_initialized                 (void);
+PangoContext *          _clutter_context_create_pango_context           (void);
+PangoContext *          _clutter_context_get_pango_context              (void);
+ClutterPickMode         _clutter_context_get_pick_mode                  (void);
+void                    _clutter_context_push_shader_stack              (ClutterActor *actor);
+ClutterActor *          _clutter_context_pop_shader_stack               (ClutterActor *actor);
+ClutterActor *          _clutter_context_peek_shader_stack              (void);
+guint32                 _clutter_context_acquire_id                     (gpointer      key);
+void                    _clutter_context_release_id                     (guint32       id_);
+gboolean                _clutter_context_get_motion_events_enabled      (void);
 
 const gchar *_clutter_gettext (const gchar *str);
 
diff --git a/clutter/clutter-stage.c b/clutter/clutter-stage.c
index 6c5cf57..10190a9 100644
--- a/clutter/clutter-stage.c
+++ b/clutter/clutter-stage.c
@@ -1998,7 +1998,14 @@ clutter_stage_init (ClutterStage *self)
   priv->use_fog                = FALSE;
   priv->throttle_motion_events = TRUE;
   priv->min_size_changed       = FALSE;
-  priv->motion_events_enabled  = clutter_get_motion_events_enabled ();
+
+  /* XXX - we need to keep the invariant that calling
+   * clutter_set_motion_event_enabled() before the stage creation
+   * will cause motion event delivery to be disabled on any newly
+   * created stage. this can go away when we break API and remove
+   * deprecated functions.
+   */
+  priv->motion_events_enabled = _clutter_context_get_motion_events_enabled ();
 
   priv->color = default_stage_color;