[mutter] clutter/stage: Add clutter_stage_is_redraw_queued() API

[Jonas Ådahl <jadahl src gnome org>]

commit 50071303afd47cbb67e6738fc8c0acb767368c3e
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Dec 21 17:28:33 2018 +0100

    clutter/stage: Add clutter_stage_is_redraw_queued() API
    
    This will be used by the screen casting code to check whether it should
    wait for a frame before reading cursor state, or send only the cursor
    update, if no redraw is queued.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/357

 clutter/clutter/clutter-stage.c | 11 +++++++++++
 clutter/clutter/clutter-stage.h |  3 +++
 2 files changed, 14 insertions(+)
---
diff --git a/clutter/clutter/clutter-stage.c b/clutter/clutter/clutter-stage.c
index d1107149e..8dc7ebc4e 100644
--- a/clutter/clutter/clutter-stage.c
+++ b/clutter/clutter/clutter-stage.c
@@ -3731,6 +3731,17 @@ clutter_stage_ensure_redraw (ClutterStage *stage)
   _clutter_master_clock_start_running (master_clock);
 }
 
+/**
+ * clutter_stage_is_redraw_queued: (skip)
+ */
+gboolean
+clutter_stage_is_redraw_queued (ClutterStage *stage)
+{
+  ClutterStagePrivate *priv = stage->priv;
+
+  return priv->redraw_pending;
+}
+
 /**
  * clutter_stage_queue_redraw:
  * @stage: the #ClutterStage
diff --git a/clutter/clutter/clutter-stage.h b/clutter/clutter/clutter-stage.h
index 643f8d7b3..ab1ab92fa 100644
--- a/clutter/clutter/clutter-stage.h
+++ b/clutter/clutter/clutter-stage.h
@@ -250,6 +250,9 @@ void            clutter_stage_ensure_viewport                   (ClutterStage
 CLUTTER_EXPORT
 void            clutter_stage_ensure_redraw                     (ClutterStage          *stage);
 
+CLUTTER_EXPORT
+gboolean        clutter_stage_is_redraw_queued                  (ClutterStage          *stage);
+
 #ifdef CLUTTER_ENABLE_EXPERIMENTAL_API
 CLUTTER_EXPORT
 void            clutter_stage_set_sync_delay                    (ClutterStage          *stage,