[gnome-flashback] backends: add logical monitor -> monitor -> output -> crtc ref chain

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 57c784bb6d46e931123e970aa91fc7e73a277d4a
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Tue Jul 16 21:05:47 2019 +0300

    backends: add logical monitor -> monitor -> output -> crtc ref chain
    
    Based on mutter commit:
    https://gitlab.gnome.org/GNOME/mutter/commit/768ec15ea072df21dd6c

 backends/gf-logical-monitor.c | 15 ++++++++++-----
 backends/gf-monitor.c         | 22 ++++++++++++++++++++--
 backends/gf-output.c          | 19 +++++++++++++++++--
 3 files changed, 47 insertions(+), 9 deletions(-)
---
diff --git a/backends/gf-logical-monitor.c b/backends/gf-logical-monitor.c
index dceb90e..09f55be 100644
--- a/backends/gf-logical-monitor.c
+++ b/backends/gf-logical-monitor.c
@@ -96,15 +96,19 @@ derive_monitor_transform (GfMonitor *monitor)
 }
 
 static void
-gf_logical_monitor_finalize (GObject *object)
+gf_logical_monitor_dispose (GObject *object)
 {
   GfLogicalMonitor *logical_monitor;
 
   logical_monitor = GF_LOGICAL_MONITOR (object);
 
-  g_list_free (logical_monitor->monitors);
+  if (logical_monitor->monitors)
+    {
+      g_list_free_full (logical_monitor->monitors, g_object_unref);
+      logical_monitor->monitors = NULL;
+    }
 
-  G_OBJECT_CLASS (gf_logical_monitor_parent_class)->finalize (object);
+  G_OBJECT_CLASS (gf_logical_monitor_parent_class)->dispose (object);
 }
 
 static void
@@ -114,7 +118,7 @@ gf_logical_monitor_class_init (GfLogicalMonitorClass *logical_monitor_class)
 
   object_class = G_OBJECT_CLASS (logical_monitor_class);
 
-  object_class->finalize = gf_logical_monitor_finalize;
+  object_class->dispose = gf_logical_monitor_dispose;
 }
 
 static void
@@ -194,7 +198,8 @@ gf_logical_monitor_add_monitor (GfLogicalMonitor *logical_monitor,
   GList *l;
 
   is_presentation = logical_monitor->is_presentation;
-  logical_monitor->monitors = g_list_append (logical_monitor->monitors, monitor);
+  logical_monitor->monitors = g_list_append (logical_monitor->monitors,
+                                             g_object_ref (monitor));
 
   for (l = logical_monitor->monitors; l; l = l->next)
     {
diff --git a/backends/gf-monitor.c b/backends/gf-monitor.c
index 4efb53d..e3ad771 100644
--- a/backends/gf-monitor.c
+++ b/backends/gf-monitor.c
@@ -248,6 +248,24 @@ out:
   return best_scale;
 }
 
+static void
+gf_monitor_dispose (GObject *object)
+{
+  GfMonitor *monitor;
+  GfMonitorPrivate *priv;
+
+  monitor = GF_MONITOR (object);
+  priv = gf_monitor_get_instance_private (monitor);
+
+  if (priv->outputs)
+    {
+      g_list_free_full (priv->outputs, g_object_unref);
+      priv->outputs = NULL;
+    }
+
+  G_OBJECT_CLASS (gf_monitor_parent_class)->dispose (object);
+}
+
 static void
 gf_monitor_finalize (GObject *object)
 {
@@ -259,7 +277,6 @@ gf_monitor_finalize (GObject *object)
 
   g_hash_table_destroy (priv->mode_ids);
   g_list_free_full (priv->modes, (GDestroyNotify) gf_monitor_mode_free);
-  g_clear_pointer (&priv->outputs, g_list_free);
   gf_monitor_spec_free (priv->spec);
 
   G_OBJECT_CLASS (gf_monitor_parent_class)->finalize (object);
@@ -336,6 +353,7 @@ gf_monitor_class_init (GfMonitorClass *monitor_class)
 
   object_class = G_OBJECT_CLASS (monitor_class);
 
+  object_class->dispose = gf_monitor_dispose;
   object_class->finalize = gf_monitor_finalize;
   object_class->get_property = gf_monitor_get_property;
   object_class->set_property = gf_monitor_set_property;
@@ -401,7 +419,7 @@ gf_monitor_append_output (GfMonitor *monitor,
 
   priv = gf_monitor_get_instance_private (monitor);
 
-  priv->outputs = g_list_append (priv->outputs, output);
+  priv->outputs = g_list_append (priv->outputs, g_object_ref (output));
 }
 
 void
diff --git a/backends/gf-output.c b/backends/gf-output.c
index 9627914..f4a05af 100644
--- a/backends/gf-output.c
+++ b/backends/gf-output.c
@@ -38,6 +38,20 @@ typedef struct
 
 G_DEFINE_TYPE_WITH_PRIVATE (GfOutput, gf_output, G_TYPE_OBJECT)
 
+static void
+gf_output_dispose (GObject *object)
+{
+  GfOutput *output;
+  GfOutputPrivate *priv;
+
+  output = GF_OUTPUT (object);
+  priv = gf_output_get_instance_private (output);
+
+  g_clear_object (&priv->crtc);
+
+  G_OBJECT_CLASS (gf_output_parent_class)->dispose (object);
+}
+
 static void
 gf_output_finalize (GObject *object)
 {
@@ -66,6 +80,7 @@ gf_output_class_init (GfOutputClass *output_class)
 
   object_class = G_OBJECT_CLASS (output_class);
 
+  object_class->dispose = gf_output_dispose;
   object_class->finalize = gf_output_finalize;
 }
 
@@ -90,7 +105,7 @@ gf_output_assign_crtc (GfOutput *output,
 
   g_assert (crtc);
 
-  priv->crtc = crtc;
+  g_set_object (&priv->crtc, crtc);
 }
 
 void
@@ -100,7 +115,7 @@ gf_output_unassign_crtc (GfOutput *output)
 
   priv = gf_output_get_instance_private (output);
 
-  priv->crtc = NULL;
+  g_clear_object (&priv->crtc);
 }
 
 GfCrtc *