[mutter/wip/halfline/black-stage-before-dpms-off: 1/2] stage: add new api for making the stage not paint children

[Ray Strode <halfline src gnome org>]

commit e191611da0b70206451c682a07a655f4e9137d50
Author: Ray Strode <rstrode redhat com>
Date:   Sat Oct 17 15:00:44 2015 -0400

    stage: add new api for making the stage not paint children
    
    We want to darken the stage before dpms, so this commit adds
    a way to do that.

 src/backends/meta-stage.c |   17 +++++++++++++++++
 src/backends/meta-stage.h |    2 ++
 2 files changed, 19 insertions(+), 0 deletions(-)
---
diff --git a/src/backends/meta-stage.c b/src/backends/meta-stage.c
index eb270f1..edd9df7 100644
--- a/src/backends/meta-stage.c
+++ b/src/backends/meta-stage.c
@@ -41,6 +41,7 @@ typedef struct {
 struct _MetaStagePrivate {
   MetaOverlay cursor_overlay;
   gboolean is_active;
+  gboolean is_black;
 };
 typedef struct _MetaStagePrivate MetaStagePrivate;
 
@@ -121,6 +122,9 @@ meta_stage_paint (ClutterActor *actor)
   MetaStage *stage = META_STAGE (actor);
   MetaStagePrivate *priv = meta_stage_get_instance_private (stage);
 
+  if (priv->is_black)
+    return;
+
   CLUTTER_ACTOR_CLASS (meta_stage_parent_class)->paint (actor);
 
   meta_overlay_paint (&priv->cursor_overlay);
@@ -261,3 +265,16 @@ meta_stage_set_active (MetaStage *stage,
    */
   clutter_stage_event (CLUTTER_STAGE (stage), &event);
 }
+
+void
+meta_stage_set_black (MetaStage *stage,
+                      gboolean   is_black)
+{
+  MetaStagePrivate *priv = meta_stage_get_instance_private (stage);
+
+  if (priv->is_black != is_black)
+    {
+      priv->is_black = is_black;
+      clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
+    }
+}
diff --git a/src/backends/meta-stage.h b/src/backends/meta-stage.h
index 262d68f..ddc4676 100644
--- a/src/backends/meta-stage.h
+++ b/src/backends/meta-stage.h
@@ -57,6 +57,8 @@ void meta_stage_set_cursor (MetaStage     *stage,
 
 void meta_stage_set_active (MetaStage *stage,
                             gboolean   is_active);
+void meta_stage_set_black (MetaStage *stage,
+                           gboolean   is_black);
 G_END_DECLS
 
 #endif /* META_STAGE_H */