[gnome-flashback] monitor-manager: connect assigned CRTCs to their outputs both ways

[Alberts Muktupāvels <muktupavels src gnome org>]

commit f4a9e95353196fb09be09423eaaf7c507bba6f74
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Jan 31 18:47:15 2021 +0200

    monitor-manager: connect assigned CRTCs to their outputs both ways
    
    We had a pointer from the output to the assigned CRTC, but had no way
    to get the outputs an CRTC was assigned to. Add that connection.
    
    Based on mutter commit:
    https://gitlab.gnome.org/GNOME/mutter/-/commit/5edc118d62a73c5acc

 backends/gf-crtc-private.h |  8 ++++++++
 backends/gf-crtc.c         | 37 +++++++++++++++++++++++++++++++++++++
 backends/gf-output.c       | 14 ++++++++++++--
 3 files changed, 57 insertions(+), 2 deletions(-)
---
diff --git a/backends/gf-crtc-private.h b/backends/gf-crtc-private.h
index 0961048..816a7b7 100644
--- a/backends/gf-crtc-private.h
+++ b/backends/gf-crtc-private.h
@@ -67,6 +67,14 @@ GfGpu              *gf_crtc_get_gpu            (GfCrtc             *self);
 
 GfMonitorTransform  gf_crtc_get_all_transforms (GfCrtc             *self);
 
+const GList        *gf_crtc_get_outputs        (GfCrtc             *self);
+
+void                gf_crtc_assign_output      (GfCrtc             *self,
+                                                GfOutput           *output);
+
+void                gf_crtc_unassign_output    (GfCrtc             *self,
+                                                GfOutput           *output);
+
 void                gf_crtc_set_config         (GfCrtc             *self,
                                                 GfRectangle        *layout,
                                                 GfCrtcMode         *mode,
diff --git a/backends/gf-crtc.c b/backends/gf-crtc.c
index 464c98e..1fc9d62 100644
--- a/backends/gf-crtc.c
+++ b/backends/gf-crtc.c
@@ -29,6 +29,8 @@ typedef struct
 
   GfMonitorTransform  all_transforms;
 
+  GList              *outputs;
+
   GfCrtcConfig       *config;
 } GfCrtcPrivate;
 
@@ -57,6 +59,7 @@ gf_crtc_finalize (GObject *object)
   priv = gf_crtc_get_instance_private (crtc);
 
   g_clear_pointer (&priv->config, g_free);
+  g_clear_pointer (&priv->outputs, g_list_free);
 
   G_OBJECT_CLASS (gf_crtc_parent_class)->finalize (object);
 }
@@ -211,6 +214,40 @@ gf_crtc_get_all_transforms (GfCrtc *self)
   return priv->all_transforms;
 }
 
+const GList *
+gf_crtc_get_outputs (GfCrtc *self)
+{
+  GfCrtcPrivate *priv;
+
+  priv = gf_crtc_get_instance_private (self);
+
+  return priv->outputs;
+}
+
+void
+gf_crtc_assign_output (GfCrtc   *self,
+                       GfOutput *output)
+{
+  GfCrtcPrivate *priv;
+
+  priv = gf_crtc_get_instance_private (self);
+
+  priv->outputs = g_list_append (priv->outputs, output);
+}
+
+void
+gf_crtc_unassign_output (GfCrtc   *self,
+                         GfOutput *output)
+{
+  GfCrtcPrivate *priv;
+
+  priv = gf_crtc_get_instance_private (self);
+
+  g_return_if_fail (g_list_find (priv->outputs, output));
+
+  priv->outputs = g_list_remove (priv->outputs, output);
+}
+
 void
 gf_crtc_set_config (GfCrtc             *self,
                     GfRectangle        *layout,
diff --git a/backends/gf-output.c b/backends/gf-output.c
index 86097db..b5c659b 100644
--- a/backends/gf-output.c
+++ b/backends/gf-output.c
@@ -29,6 +29,8 @@
 #include "config.h"
 #include "gf-output-private.h"
 
+#include "gf-crtc-private.h"
+
 typedef struct
 {
   uint64_t      id;
@@ -278,7 +280,7 @@ gf_output_get_name (GfOutput *self)
 }
 
 void
-gf_output_assign_crtc (GfOutput                *self,
+gf_output_assign_crtc (GfOutput                 *self,
                        GfCrtc                   *crtc,
                        const GfOutputAssignment *output_assignment)
 {
@@ -288,8 +290,12 @@ gf_output_assign_crtc (GfOutput                *self,
 
   g_assert (crtc);
 
+  gf_output_unassign_crtc (self);
+
   g_set_object (&priv->crtc, crtc);
 
+  gf_crtc_assign_output (crtc, self);
+
   priv->is_primary = output_assignment->is_primary;
   priv->is_presentation = output_assignment->is_presentation;
   priv->is_underscanning = output_assignment->is_underscanning;
@@ -302,7 +308,11 @@ gf_output_unassign_crtc (GfOutput *output)
 
   priv = gf_output_get_instance_private (output);
 
-  g_clear_object (&priv->crtc);
+  if (priv->crtc != NULL)
+    {
+      gf_crtc_unassign_output (priv->crtc, output);
+      g_clear_object (&priv->crtc);
+    }
 
   priv->is_primary = FALSE;
   priv->is_presentation = FALSE;