[mutter] compositor: Let MetaDisplay choose the correct compositor type

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 0db38c4999e631c928bb917dd7e6b3ac3aace0b9
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Aug 19 10:24:17 2019 +0200

    compositor: Let MetaDisplay choose the correct compositor type
    
    A base type shouldn't know about sub types, so let MetaDisplay make
    the correct choice of what type of MetaCompositor it should create. No
    other semantical changes introduced.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/727

 src/compositor/compositor.c             | 77 ++++++++++++++++++++++++---------
 src/compositor/meta-compositor-server.c |  8 ++++
 src/compositor/meta-compositor-server.h |  2 +
 src/compositor/meta-compositor-x11.c    |  8 ++++
 src/compositor/meta-compositor-x11.h    |  2 +
 src/core/display.c                      | 14 +++++-
 src/meta/compositor.h                   |  3 --
 7 files changed, 90 insertions(+), 24 deletions(-)
---
diff --git a/src/compositor/compositor.c b/src/compositor/compositor.c
index c8b3e303d..d60865910 100644
--- a/src/compositor/compositor.c
+++ b/src/compositor/compositor.c
@@ -58,7 +58,6 @@
 
 #include "backends/meta-dnd-private.h"
 #include "clutter/clutter-mutter.h"
-#include "compositor/meta-compositor-x11.h"
 #include "compositor/meta-window-actor-x11.h"
 #include "compositor/meta-window-actor-wayland.h"
 #include "compositor/meta-window-actor-private.h"
@@ -80,10 +79,20 @@
 #include "x11/meta-x11-display-private.h"
 
 #ifdef HAVE_WAYLAND
-#include "compositor/meta-compositor-server.h"
 #include "wayland/meta-wayland-private.h"
 #endif
 
+enum
+{
+  PROP_0,
+
+  PROP_DISPLAY,
+
+  N_PROPS
+};
+
+static GParamSpec *obj_props[N_PROPS] = { NULL, };
+
 typedef struct _MetaCompositorPrivate
 {
   GObject parent;
@@ -1140,28 +1149,44 @@ on_shadow_factory_changed (MetaShadowFactory *factory,
     meta_window_actor_invalidate_shadow (l->data);
 }
 
-/**
- * meta_compositor_new: (skip)
- * @display:
- *
- */
-MetaCompositor *
-meta_compositor_new (MetaDisplay *display)
+static void
+meta_compositor_set_property (GObject      *object,
+                              guint         prop_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
 {
-  MetaCompositor *compositor;
-  MetaCompositorPrivate *priv;
+  MetaCompositor *compositor = META_COMPOSITOR (object);
+  MetaCompositorPrivate *priv =
+    meta_compositor_get_instance_private (compositor);
 
-#ifdef HAVE_WAYLAND
-  if (meta_is_wayland_compositor ())
-    compositor = g_object_new (META_TYPE_COMPOSITOR_SERVER, NULL);
-  else
-#endif
-    compositor = g_object_new (META_TYPE_COMPOSITOR_X11, NULL);
+  switch (prop_id)
+    {
+    case PROP_DISPLAY:
+      priv->display = g_value_get_object (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
 
-  priv = meta_compositor_get_instance_private (compositor);
-  priv->display = display;
+static void
+meta_compositor_get_property (GObject    *object,
+                              guint       prop_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  MetaCompositor *compositor = META_COMPOSITOR (object);
+  MetaCompositorPrivate *priv =
+    meta_compositor_get_instance_private (compositor);
 
-  return compositor;
+  switch (prop_id)
+    {
+    case PROP_DISPLAY:
+      g_value_set_object (value, priv->display);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
 }
 
 static void
@@ -1222,11 +1247,23 @@ meta_compositor_class_init (MetaCompositorClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+  object_class->set_property = meta_compositor_set_property;
+  object_class->get_property = meta_compositor_get_property;
   object_class->dispose = meta_compositor_dispose;
 
   klass->remove_window = meta_compositor_real_remove_window;
   klass->pre_paint = meta_compositor_real_pre_paint;
   klass->post_paint = meta_compositor_real_post_paint;
+
+  obj_props[PROP_DISPLAY] =
+    g_param_spec_object ("display",
+                         "display",
+                         "MetaDisplay",
+                         META_TYPE_DISPLAY,
+                         G_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT_ONLY |
+                         G_PARAM_STATIC_STRINGS);
+  g_object_class_install_properties (object_class, N_PROPS, obj_props);
 }
 
 /**
diff --git a/src/compositor/meta-compositor-server.c b/src/compositor/meta-compositor-server.c
index 206586c06..928501f8a 100644
--- a/src/compositor/meta-compositor-server.c
+++ b/src/compositor/meta-compositor-server.c
@@ -39,6 +39,14 @@ meta_compositor_server_unmanage (MetaCompositor *compositor)
 {
 }
 
+MetaCompositorServer *
+meta_compositor_server_new (MetaDisplay *display)
+{
+  return g_object_new (META_TYPE_COMPOSITOR_SERVER,
+                       "display", display,
+                       NULL);
+}
+
 static void
 meta_compositor_server_init (MetaCompositorServer *compositor_server)
 {
diff --git a/src/compositor/meta-compositor-server.h b/src/compositor/meta-compositor-server.h
index b16971ae3..8bff05e7b 100644
--- a/src/compositor/meta-compositor-server.h
+++ b/src/compositor/meta-compositor-server.h
@@ -27,4 +27,6 @@
 G_DECLARE_FINAL_TYPE (MetaCompositorServer, meta_compositor_server,
                       META, COMPOSITOR_SERVER, MetaCompositor)
 
+MetaCompositorServer * meta_compositor_server_new (MetaDisplay *display);
+
 #endif /* META_COMPOSITOR_SERVER_H */
diff --git a/src/compositor/meta-compositor-x11.c b/src/compositor/meta-compositor-x11.c
index 15534ccd3..15be1169c 100644
--- a/src/compositor/meta-compositor-x11.c
+++ b/src/compositor/meta-compositor-x11.c
@@ -322,6 +322,14 @@ meta_compositor_x11_get_output_xwindow (MetaCompositorX11 *compositor_x11)
   return compositor_x11->output;
 }
 
+MetaCompositorX11 *
+meta_compositor_x11_new (MetaDisplay *display)
+{
+  return g_object_new (META_TYPE_COMPOSITOR_X11,
+                       "display", display,
+                       NULL);
+}
+
 static void
 meta_compositor_x11_dispose (GObject *object)
 {
diff --git a/src/compositor/meta-compositor-x11.h b/src/compositor/meta-compositor-x11.h
index f577f73e0..7165493cd 100644
--- a/src/compositor/meta-compositor-x11.h
+++ b/src/compositor/meta-compositor-x11.h
@@ -27,6 +27,8 @@
 G_DECLARE_FINAL_TYPE (MetaCompositorX11, meta_compositor_x11,
                       META, COMPOSITOR_X11, MetaCompositor)
 
+MetaCompositorX11 * meta_compositor_x11_new (MetaDisplay *display);
+
 void meta_compositor_x11_process_xevent (MetaCompositorX11 *compositor_x11,
                                          XEvent            *xevent,
                                          MetaWindow        *window);
diff --git a/src/core/display.c b/src/core/display.c
index 3d1e33429..71b0fb49d 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -50,6 +50,7 @@
 #include "backends/x11/cm/meta-backend-x11-cm.h"
 #include "clutter/x11/clutter-x11.h"
 #include "compositor/compositor-private.h"
+#include "compositor/meta-compositor-x11.h"
 #include "core/bell.h"
 #include "core/boxes-private.h"
 #include "core/display-private.h"
@@ -76,6 +77,7 @@
 #include "x11/xprops.h"
 
 #ifdef HAVE_WAYLAND
+#include "compositor/meta-compositor-server.h"
 #include "wayland/meta-xwayland-private.h"
 #include "wayland/meta-wayland-tablet-seat.h"
 #include "wayland/meta-wayland-tablet-pad.h"
@@ -538,6 +540,16 @@ meta_display_remove_pending_pings_for_window (MetaDisplay *display,
   g_slist_free (dead);
 }
 
+static MetaCompositor *
+create_compositor (MetaDisplay *display)
+{
+#ifdef HAVE_WAYLAND
+  if (meta_is_wayland_compositor ())
+    return META_COMPOSITOR (meta_compositor_server_new (display));
+  else
+#endif
+    return META_COMPOSITOR (meta_compositor_x11_new (display));
+}
 
 static void
 enable_compositor (MetaDisplay *display)
@@ -567,7 +579,7 @@ enable_compositor (MetaDisplay *display)
     }
 
   if (!display->compositor)
-      display->compositor = meta_compositor_new (display);
+    display->compositor = create_compositor (display);
 
   meta_compositor_manage (display->compositor);
 }
diff --git a/src/meta/compositor.h b/src/meta/compositor.h
index 1a028b90e..1ccae70d7 100644
--- a/src/meta/compositor.h
+++ b/src/meta/compositor.h
@@ -66,9 +66,6 @@ typedef enum
   META_SIZE_CHANGE_UNFULLSCREEN,
 } MetaSizeChange;
 
-META_EXPORT
-MetaCompositor *meta_compositor_new     (MetaDisplay    *display);
-
 META_EXPORT
 void            meta_compositor_destroy (MetaCompositor *compositor);