[mutter] Extend the DBus XRandR protocol to expose cloning restriction

[Giovanni Campagna <gcampagna src gnome org>]

commit dc242e46c2b881780fd67245997aa801213a345b
Author: Giovanni Campagna <gcampagn redhat com>
Date:   Fri Jul 19 18:47:01 2013 +0200

    Extend the DBus XRandR protocol to expose cloning restriction
    
    Turns out that even if two outputs say that they can be controlled
    by a given CRTC, you can't configure them in the same CRTC unless
    they are marked as "possible clones" one of the other.
    This can further restrict the configuration options, so we need
    to expose this limitation in the DBus API.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=705670

 src/core/monitor-private.h |    3 ++
 src/core/monitor.c         |   48 +++++++++++++++++++++++++++++++++++++++++--
 src/xrandr.xml             |    7 +++++-
 3 files changed, 54 insertions(+), 4 deletions(-)
---
diff --git a/src/core/monitor-private.h b/src/core/monitor-private.h
index 98f3101..4385b3e 100644
--- a/src/core/monitor-private.h
+++ b/src/core/monitor-private.h
@@ -70,6 +70,9 @@ struct _MetaOutput
   MetaCRTC **possible_crtcs;
   unsigned int n_possible_crtcs;
 
+  MetaOutput **possible_clones;
+  unsigned int n_possible_clones;
+
   /* The low-level bits used to build the high-level info
      in MetaMonitorInfo
 
diff --git a/src/core/monitor.c b/src/core/monitor.c
index 8ee1a54..8d57696 100644
--- a/src/core/monitor.c
+++ b/src/core/monitor.c
@@ -144,6 +144,8 @@ make_dummy_monitor_config (MetaMonitorManager *manager)
   manager->outputs[0].n_possible_crtcs = 1;
   manager->outputs[0].possible_crtcs = g_new0 (MetaCRTC *, 1);
   manager->outputs[0].possible_crtcs[0] = &manager->crtcs[0];
+  manager->outputs[0].n_possible_clones = 0;
+  manager->outputs[0].possible_clones = g_new0 (MetaOutput *, 0);
 }
 
 #ifdef HAVE_RANDR
@@ -273,6 +275,17 @@ read_monitor_infos_from_xrandr (MetaMonitorManager *manager)
                   }
               }
 
+            meta_output->n_possible_clones = output->nclone;
+            meta_output->possible_clones = g_new0 (MetaOutput *, meta_output->n_possible_clones);
+            /* We can build the list of clones now, because we don't have the list of outputs
+               yet, so temporarily set the pointers to the bare XIDs, and then we'll fix them
+               in a second pass
+            */
+            for (j = 0; j < (unsigned)output->nclone; j++)
+              {
+                meta_output->possible_clones = GINT_TO_POINTER (output->clones[j]);
+              }
+
             meta_output->is_primary = ((XID)meta_output->output_id == primary_output);
             meta_output->is_presentation = FALSE;
 
@@ -284,6 +297,28 @@ read_monitor_infos_from_xrandr (MetaMonitorManager *manager)
 
     manager->n_outputs = n_actual_outputs;
 
+    /* Now fix the clones */
+    for (i = 0; i < manager->n_outputs; i++)
+      {
+        MetaOutput *meta_output;
+
+        meta_output = &manager->outputs[i];
+
+        for (j = 0; j < meta_output->n_possible_clones; j++)
+          {
+            RROutput clone = GPOINTER_TO_INT (meta_output->possible_clones[j]);
+
+            for (k = 0; k < manager->n_outputs; k++)
+              {
+                if (clone == (XID)manager->outputs[k].output_id)
+                  {
+                    meta_output->possible_clones[j] = &manager->outputs[k];
+                    break;
+                  }
+              }
+          }
+      }
+
     XRRFreeScreenResources (resources);
 }
 
@@ -463,6 +498,7 @@ free_output_array (MetaOutput *old_outputs,
       g_free (old_outputs[i].serial);
       g_free (old_outputs[i].modes);
       g_free (old_outputs[i].possible_crtcs);
+      g_free (old_outputs[i].possible_clones);
     }
 
   g_free (old_outputs);
@@ -567,7 +603,7 @@ handle_get_resources (MetaDBusDisplayConfig *skeleton,
   unsigned int i, j;
 
   g_variant_builder_init (&crtc_builder, G_VARIANT_TYPE ("a(uxiiiiiuaua{sv})"));
-  g_variant_builder_init (&output_builder, G_VARIANT_TYPE ("a(uxiausaua{sv})"));
+  g_variant_builder_init (&output_builder, G_VARIANT_TYPE ("a(uxiausauaua{sv})"));
   g_variant_builder_init (&mode_builder, G_VARIANT_TYPE ("a(uxuud)"));
 
   for (i = 0; i < manager->n_crtcs; i++)
@@ -594,7 +630,7 @@ handle_get_resources (MetaDBusDisplayConfig *skeleton,
   for (i = 0; i < manager->n_outputs; i++)
     {
       MetaOutput *output = &manager->outputs[i];
-      GVariantBuilder crtcs, modes, properties;
+      GVariantBuilder crtcs, modes, clones, properties;
 
       g_variant_builder_init (&crtcs, G_VARIANT_TYPE ("au"));
       for (j = 0; j < output->n_possible_crtcs; j++)
@@ -606,6 +642,11 @@ handle_get_resources (MetaDBusDisplayConfig *skeleton,
         g_variant_builder_add (&modes, "u",
                                (unsigned)(output->modes[j] - manager->modes));
 
+      g_variant_builder_init (&clones, G_VARIANT_TYPE ("au"));
+      for (j = 0; j < output->n_possible_clones; j++)
+        g_variant_builder_add (&clones, "u",
+                               (unsigned)(output->possible_clones[j] - manager->outputs));
+
       g_variant_builder_init (&properties, G_VARIANT_TYPE ("a{sv}"));
       g_variant_builder_add (&properties, "{sv}", "vendor",
                              g_variant_new_string (output->vendor));
@@ -620,13 +661,14 @@ handle_get_resources (MetaDBusDisplayConfig *skeleton,
       g_variant_builder_add (&properties, "{sv}", "presentation",
                              g_variant_new_boolean (output->is_presentation));
 
-      g_variant_builder_add (&output_builder, "(uxiausaua{sv})",
+      g_variant_builder_add (&output_builder, "(uxiausauaua{sv})",
                              i, /* ID */
                              output->output_id,
                              (int)(output->crtc ? output->crtc - manager->crtcs : -1),
                              &crtcs,
                              output->name,
                              &modes,
+                             &clones,
                              &properties);
     }
 
diff --git a/src/xrandr.xml b/src/xrandr.xml
index 8b5aa72..408bc3c 100644
--- a/src/xrandr.xml
+++ b/src/xrandr.xml
@@ -76,6 +76,11 @@
        * s name: the name of the connector to which the output is attached
                  (like VGA1 or HDMI)
        * au modes: valid modes for this output
+       * au clones: valid clones for this output, ie other outputs that
+                    can be assigned the same CRTC as this one; if you
+                    want to mirror two outputs that don't have each other
+                    in the clone list, you must configure two different
+                    CRTCs for the same geometry
        * a{sv} properties: other high-level properties that affect this
                            output; they are not necessarily reflected in
                            the hardware.
@@ -123,7 +128,7 @@
     <method name="GetResources">
       <arg name="serial" direction="out" type="u" />
       <arg name="crtcs" direction="out" type="a(uxiiiiiuaua{sv})" />
-      <arg name="outputs" direction="out" type="a(uxiausaua{sv})" />
+      <arg name="outputs" direction="out" type="a(uxiausauaua{sv})" />
       <arg name="modes" direction="out" type="a(uxuud)" />
     </method>