[clutter: 4/11] stage: Add state tracking

[Emmanuele Bassi <ebassi src gnome org>]

commit 19ff11ac933cbfcc1f87c5914d36a85ee014f8e9
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Jan 25 21:24:47 2012 +0000

    stage: Add state tracking
    
    State changes on the Stage are currently deferred to the windowing
    system backends, but the code is generally the same, and it should
    be abstracted neatly inside the Stage class itself.
    
    There's also the extra caveat for backends that state changes on a
    Stage must also emit a ClutterEvent of type CLUTTER_STAGE_STATE, a
    requirement that needlessly complicates the backend code.

 clutter/clutter-stage-private.h |    7 ++
 clutter/clutter-stage.c         |  121 +++++++++++++++++++++++++++++++++------
 2 files changed, 111 insertions(+), 17 deletions(-)
---
diff --git a/clutter/clutter-stage-private.h b/clutter/clutter-stage-private.h
index a4f9ef5..d2c7f78 100644
--- a/clutter/clutter-stage-private.h
+++ b/clutter/clutter-stage-private.h
@@ -109,6 +109,13 @@ ClutterActor *  _clutter_stage_get_drag_actor           (ClutterStage       *sta
 void            _clutter_stage_remove_drag_actor        (ClutterStage       *stage,
                                                          ClutterInputDevice *device);
 
+ClutterStageState       _clutter_stage_get_state        (ClutterStage      *stage);
+gboolean                _clutter_stage_is_activated     (ClutterStage      *stage);
+gboolean                _clutter_stage_is_fullscreen    (ClutterStage      *stage);
+gboolean                _clutter_stage_update_state     (ClutterStage      *stage,
+                                                         ClutterStageState  unset_state,
+                                                         ClutterStageState  set_state);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_STAGE_PRIVATE_H__ */
diff --git a/clutter/clutter-stage.c b/clutter/clutter-stage.c
index 85fe3da..8cd091b 100644
--- a/clutter/clutter-stage.c
+++ b/clutter/clutter-stage.c
@@ -121,32 +121,33 @@ struct _ClutterStagePrivate
   /* the stage implementation */
   ClutterStageWindow *impl;
 
-  ClutterColor        color;
-  ClutterPerspective  perspective;
-  CoglMatrix          projection;
-  CoglMatrix          inverse_projection;
-  CoglMatrix          view;
-  float               viewport[4];
-  ClutterFog          fog;
+  ClutterColor color;
+  ClutterPerspective perspective;
+  CoglMatrix projection;
+  CoglMatrix inverse_projection;
+  CoglMatrix view;
+  float viewport[4];
 
-  gchar              *title;
-  ClutterActor       *key_focused_actor;
+  ClutterFog fog;
 
-  GQueue             *event_queue;
+  gchar *title;
+  ClutterActor *key_focused_actor;
 
-  ClutterStageHint    stage_hints;
+  GQueue *event_queue;
 
-  gint                picks_per_frame;
+  ClutterStageHint stage_hints;
 
-  GArray             *paint_volume_stack;
+  gint picks_per_frame;
 
-  ClutterPlane        current_clip_planes[4];
+  GArray *paint_volume_stack;
 
-  GList              *pending_queue_redraws;
+  ClutterPlane current_clip_planes[4];
 
-  ClutterPickMode     pick_buffer_mode;
+  GList *pending_queue_redraws;
 
-  CoglFramebuffer    *active_framebuffer;
+  ClutterPickMode pick_buffer_mode;
+
+  CoglFramebuffer *active_framebuffer;
 
   GHashTable *devices;
 
@@ -159,6 +160,8 @@ struct _ClutterStagePrivate
   gulong redraw_count;
 #endif /* CLUTTER_ENABLE_DEBUG */
 
+  ClutterStageState current_state;
+
   guint relayout_pending       : 1;
   guint redraw_pending         : 1;
   guint is_fullscreen          : 1;
@@ -4397,3 +4400,87 @@ _clutter_stage_remove_drag_actor (ClutterStage       *stage,
   if (g_hash_table_size (drag_actors) == 0)
     g_object_set_data (G_OBJECT (stage), "__clutter_stage_drag_actors", NULL);
 }
+
+/*< private >
+ * _clutter_stage_get_state:
+ * @stage: a #ClutterStage
+ *
+ * Retrieves the current #ClutterStageState flags associated to the @stage.
+ *
+ * Return value: a bitwise OR of #ClutterStageState flags
+ */
+ClutterStageState
+_clutter_stage_get_state (ClutterStage *stage)
+{
+  return stage->priv->current_state;
+}
+
+/*< private >
+ * _clutter_stage_is_activated:
+ * @stage: a #ClutterStage
+ *
+ * Checks whether the @stage state includes %CLUTTER_STAGE_STATE_ACTIVATED.
+ *
+ * Return value: %TRUE if the @stage is active
+ */
+gboolean
+_clutter_stage_is_activated (ClutterStage *stage)
+{
+  return (stage->priv->current_state & CLUTTER_STAGE_STATE_ACTIVATED) != 0;
+}
+
+/*< private >
+ * _clutter_stage_is_fullscreen:
+ * @stage: a #ClutterStage
+ *
+ * Checks whether the @stage state includes %CLUTTER_STAGE_STATE_FULLSCREEN.
+ *
+ * Return value: %TRUE if the @stage is fullscreen
+ */
+gboolean
+_clutter_stage_is_fullscreen (ClutterStage *stage)
+{
+  return (stage->priv->current_state & CLUTTER_STAGE_STATE_FULLSCREEN) != 0;
+}
+
+/*< private >
+ * _clutter_stage_update_state:
+ * @stage: a #ClutterStage
+ * @unset_flags: flags to unset
+ * @set_flags: flags to set
+ *
+ * Updates the state of @stage, by unsetting the @unset_flags and setting
+ * the @set_flags.
+ *
+ * If the stage state has been changed, this function will queue a
+ * #ClutterEvent of type %CLUTTER_STAGE_STATE.
+ *
+ * Return value: %TRUE if the state was updated, and %FALSE otherwise
+ */
+gboolean
+_clutter_stage_update_state (ClutterStage      *stage,
+                             ClutterStageState  unset_flags,
+                             ClutterStageState  set_flags)
+{
+  ClutterStageState new_state;
+  ClutterEvent *event;
+
+  new_state = stage->priv->current_state;
+  new_state |= set_flags;
+  new_state &= ~unset_flags;
+
+  if (new_state == stage->priv->current_state)
+    return FALSE;
+
+  event = clutter_event_new (CLUTTER_STAGE_STATE);
+  clutter_event_set_stage (event, stage);
+
+  event->stage_state.new_state = new_state;
+  event->stage_state.changed_mask = new_state ^ stage->priv->current_state;
+
+  stage->priv->current_state = new_state;
+
+  _clutter_event_push (event, FALSE);
+
+  return TRUE;
+}