[metacity] compositor: add composited property

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 9949f5be1a170e6b158ba76a57554fb96d702242
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Aug 22 16:21:39 2019 +0300

    compositor: add composited property

 src/compositor/meta-compositor-none.c    |  1 +
 src/compositor/meta-compositor-private.h |  3 +++
 src/compositor/meta-compositor-vulkan.c  |  1 +
 src/compositor/meta-compositor-xrender.c |  1 +
 src/compositor/meta-compositor.c         | 39 +++++++++++++++++++++++++++++++-
 5 files changed, 44 insertions(+), 1 deletion(-)
---
diff --git a/src/compositor/meta-compositor-none.c b/src/compositor/meta-compositor-none.c
index 658c13df..e60dba5a 100644
--- a/src/compositor/meta-compositor-none.c
+++ b/src/compositor/meta-compositor-none.c
@@ -161,4 +161,5 @@ meta_compositor_none_class_init (MetaCompositorNoneClass *none_class)
 static void
 meta_compositor_none_init (MetaCompositorNone *none)
 {
+  meta_compositor_set_composited (META_COMPOSITOR (none), FALSE);
 }
diff --git a/src/compositor/meta-compositor-private.h b/src/compositor/meta-compositor-private.h
index c6dea493..87247b81 100644
--- a/src/compositor/meta-compositor-private.h
+++ b/src/compositor/meta-compositor-private.h
@@ -81,6 +81,9 @@ struct _MetaCompositorClass
   void              (* redraw)                       (MetaCompositor     *compositor);
 };
 
+void         meta_compositor_set_composited          (MetaCompositor  *compositor,
+                                                      gboolean         composited);
+
 gboolean     meta_compositor_check_common_extensions (MetaCompositor  *compositor,
                                                       GError         **error);
 
diff --git a/src/compositor/meta-compositor-vulkan.c b/src/compositor/meta-compositor-vulkan.c
index 62fd840c..09883afa 100644
--- a/src/compositor/meta-compositor-vulkan.c
+++ b/src/compositor/meta-compositor-vulkan.c
@@ -1409,4 +1409,5 @@ meta_compositor_vulkan_class_init (MetaCompositorVulkanClass *vulkan_class)
 static void
 meta_compositor_vulkan_init (MetaCompositorVulkan *vulkan)
 {
+  meta_compositor_set_composited (META_COMPOSITOR (vulkan), TRUE);
 }
diff --git a/src/compositor/meta-compositor-xrender.c b/src/compositor/meta-compositor-xrender.c
index 542d5d52..284dbdcf 100644
--- a/src/compositor/meta-compositor-xrender.c
+++ b/src/compositor/meta-compositor-xrender.c
@@ -3146,4 +3146,5 @@ meta_compositor_xrender_class_init (MetaCompositorXRenderClass *xrender_class)
 static void
 meta_compositor_xrender_init (MetaCompositorXRender *xrender)
 {
+  meta_compositor_set_composited (META_COMPOSITOR (xrender), TRUE);
 }
diff --git a/src/compositor/meta-compositor.c b/src/compositor/meta-compositor.c
index a83c3ae7..be518911 100644
--- a/src/compositor/meta-compositor.c
+++ b/src/compositor/meta-compositor.c
@@ -33,6 +33,8 @@ typedef struct
 {
   MetaDisplay *display;
 
+  gboolean     composited;
+
   /* _NET_WM_CM_Sn */
   Atom         cm_atom;
   Window       cm_window;
@@ -54,6 +56,8 @@ enum
 
   PROP_DISPLAY,
 
+  PROP_COMPOSITED,
+
   LAST_PROP
 };
 
@@ -171,6 +175,10 @@ meta_compositor_get_property (GObject    *object,
         g_value_set_pointer (value, priv->display);
         break;
 
+      case PROP_COMPOSITED:
+        g_value_set_boolean (value, priv->composited);
+        break;
+
       default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
         break;
@@ -195,6 +203,10 @@ meta_compositor_set_property (GObject      *object,
         priv->display = g_value_get_pointer (value);
         break;
 
+      case PROP_COMPOSITED:
+        g_assert_not_reached ();
+        break;
+
       default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
         break;
@@ -209,6 +221,11 @@ install_properties (GObjectClass *object_class)
                          G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE |
                          G_PARAM_STATIC_STRINGS);
 
+  properties[PROP_COMPOSITED] =
+    g_param_spec_boolean ("composited", "composited", "composited",
+                          FALSE,
+                          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
+
   g_object_class_install_properties (object_class, LAST_PROP, properties);
 }
 
@@ -463,7 +480,27 @@ meta_compositor_is_our_xwindow (MetaCompositor *compositor,
 gboolean
 meta_compositor_is_composited (MetaCompositor *compositor)
 {
-  return !META_IS_COMPOSITOR_NONE (compositor);
+  MetaCompositorPrivate *priv;
+
+  priv = meta_compositor_get_instance_private (compositor);
+
+  return priv->composited;
+}
+
+void
+meta_compositor_set_composited (MetaCompositor *compositor,
+                                gboolean        composited)
+{
+  MetaCompositorPrivate *priv;
+
+  priv = meta_compositor_get_instance_private (compositor);
+
+  if (priv->composited == composited)
+    return;
+
+  priv->composited = composited;
+
+  g_object_notify_by_pspec (G_OBJECT (compositor), properties[PROP_COMPOSITED]);
 }
 
 gboolean