From 679644180338527648d7856640c2021b4f4daf30 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Thu, 28 Jan 2016 15:26:33 +0100
Subject: [PATCH] monitor-manager: Consider external layout before default
 linear config

In case of no existing configuration, we use a default layout of
aligning attached displays horizontally. This sidesteps any layout
configuration that is done externally, for instance via xorg.conf,
which is not desirable. Instead, base the initial configuration on
the existing layout if it passes some sanity checks before falling
back to the default linear config.
---
 src/backends/meta-monitor-config-manager.c | 71 ++++++++++++++++++++++++++++++
 src/backends/meta-monitor-config-manager.h |  1 +
 src/backends/meta-monitor-manager.c        | 19 ++++++++
 3 files changed, 91 insertions(+)

diff --git a/src/backends/meta-monitor-config-manager.c b/src/backends/meta-monitor-config-manager.c
index cdc9fb775..2fe620767 100644
--- a/src/backends/meta-monitor-config-manager.c
+++ b/src/backends/meta-monitor-config-manager.c
@@ -558,6 +558,77 @@ create_preferred_logical_monitor_config (MetaMonitorManager          *monitor_ma
   return logical_monitor_config;
 }
 
+static MetaLogicalMonitorConfig *
+create_logical_monitor_config_from_output (MetaMonitorManager           *monitor_manager,
+                                           MetaMonitor                  *monitor,
+                                           MetaLogicalMonitorConfig     *primary_logical_monitor_config,
+                                           MetaLogicalMonitorLayoutMode  layout_mode)
+{
+    MetaOutput *output;
+
+    output = meta_monitor_get_main_output (monitor);
+    return create_preferred_logical_monitor_config (monitor_manager,
+                                                    monitor,
+                                                    output->crtc->rect.x,
+                                                    output->crtc->rect.y,
+                                                    primary_logical_monitor_config,
+                                                    layout_mode);
+}
+
+MetaMonitorsConfig *
+meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_manager)
+{
+  MetaMonitorManager *monitor_manager = config_manager->monitor_manager;
+  GList *logical_monitor_configs;
+  MetaMonitor *primary_monitor;
+  MetaLogicalMonitorLayoutMode layout_mode;
+  MetaLogicalMonitorConfig *primary_logical_monitor_config;
+  GList *monitors;
+  GList *l;
+
+  if (meta_monitor_config_store_get_config_count (config_manager->config_store) > 0)
+    return NULL;
+
+  primary_monitor = find_primary_monitor (monitor_manager);
+  if (!primary_monitor || !meta_monitor_is_active (primary_monitor))
+    return NULL;
+
+  layout_mode = meta_monitor_manager_get_default_layout_mode (monitor_manager);
+
+  primary_logical_monitor_config =
+    create_logical_monitor_config_from_output (monitor_manager,
+                                               primary_monitor,
+                                               NULL,
+                                               layout_mode);
+
+  primary_logical_monitor_config->is_primary = TRUE;
+  logical_monitor_configs = g_list_append (NULL,
+                                           primary_logical_monitor_config);
+
+  monitors = meta_monitor_manager_get_monitors (monitor_manager);
+  for (l = monitors; l; l = l->next)
+    {
+      MetaMonitor *monitor = l->data;
+      MetaLogicalMonitorConfig *logical_monitor_config;
+
+      if (monitor == primary_monitor)
+        continue;
+
+      if (!meta_monitor_is_active (monitor))
+        continue;
+
+      logical_monitor_config =
+        create_logical_monitor_config_from_output (monitor_manager,
+                                                   monitor,
+                                                   primary_logical_monitor_config,
+                                                   layout_mode);
+
+      logical_monitor_configs = g_list_append (logical_monitor_configs,
+                                               logical_monitor_config);
+    }
+  return NULL;
+}
+
 MetaMonitorsConfig *
 meta_monitor_config_manager_create_linear (MetaMonitorConfigManager *config_manager)
 {
diff --git a/src/backends/meta-monitor-config-manager.h b/src/backends/meta-monitor-config-manager.h
index b99cdaba2..516909dd7 100644
--- a/src/backends/meta-monitor-config-manager.h
+++ b/src/backends/meta-monitor-config-manager.h
@@ -87,6 +87,7 @@ gboolean meta_monitor_config_manager_assign (MetaMonitorManager *manager,
 
 MetaMonitorsConfig * meta_monitor_config_manager_get_stored (MetaMonitorConfigManager *config_manager);
 
+MetaMonitorsConfig * meta_monitor_config_manager_create_current (MetaMonitorConfigManager *config_manager);
 MetaMonitorsConfig * meta_monitor_config_manager_create_linear (MetaMonitorConfigManager *config_manager);
 
 MetaMonitorsConfig * meta_monitor_config_manager_create_fallback (MetaMonitorConfigManager *config_manager);
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index f2ad3f3d0..8b548fd68 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -553,6 +553,25 @@ meta_monitor_manager_ensure_configured (MetaMonitorManager *manager)
       g_clear_object (&config);
     }
 
+  config = meta_monitor_config_manager_create_current (manager->config_manager);
+  if (config)
+    {
+      if (!meta_monitor_manager_apply_monitors_config (manager,
+                                                       config,
+                                                       method,
+                                                       &error))
+        {
+          g_clear_object (&config);
+          g_warning ("Failed to use current monitor configuration: %s",
+                     error->message);
+          g_clear_error (&error);
+        }
+      else
+        {
+          goto done;
+        }
+    }
+
   config = meta_monitor_config_manager_create_linear (manager->config_manager);
   if (config)
     {
-- 
2.14.2