[gnome-flashback] monitor-conifig-manager: generate primary monitor config with others

[Alberts Muktupāvels <muktupavels src gnome org>]

commit fe9018bdcac5b1b0865d0b0c86deb517d129c889
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Mon Sep 13 20:34:29 2021 +0300

    monitor-conifig-manager: generate primary monitor config with others
    
    Based on mutter commit:
    https://gitlab.gnome.org/GNOME/mutter/-/commit/e59da5ad83f3

 backends/gf-monitor-config-manager.c | 50 +++++++++++-------------------------
 1 file changed, 15 insertions(+), 35 deletions(-)
---
diff --git a/backends/gf-monitor-config-manager.c b/backends/gf-monitor-config-manager.c
index c6d548f..f047dbd 100644
--- a/backends/gf-monitor-config-manager.c
+++ b/backends/gf-monitor-config-manager.c
@@ -146,7 +146,8 @@ monitor_matches_rule (GfMonitor        *monitor,
 
 static GList *
 find_monitors (GfMonitorManager *monitor_manager,
-               MonitorMatchRule  match_rule)
+               MonitorMatchRule  match_rule,
+               GfMonitor        *not_this_one)
 {
   GList *result;
   GList *monitors;
@@ -159,6 +160,9 @@ find_monitors (GfMonitorManager *monitor_manager,
     {
       GfMonitor *monitor = l->data;
 
+      if (not_this_one != NULL && monitor == not_this_one)
+        continue;
+
       if (monitor_matches_rule (monitor, monitor_manager, match_rule))
         result = g_list_prepend (result, monitor);
     }
@@ -175,7 +179,7 @@ find_monitor_with_highest_preferred_resolution (GfMonitorManager *monitor_manage
   int largest_area = 0;
   GfMonitor *largest_monitor = NULL;
 
-  monitors = find_monitors (monitor_manager, match_rule);
+  monitors = find_monitors (monitor_manager, match_rule, NULL);
 
   for (l = monitors; l; l = l->next)
     {
@@ -519,10 +523,8 @@ create_monitors_config (GfMonitorConfigManager *config_manager,
                         GfMonitorsConfigFlag    config_flags)
 {
   GfMonitorManager *monitor_manager = config_manager->monitor_manager;
-  GfLogicalMonitorConfig *primary_logical_monitor_config = NULL;
   GfMonitor *primary_monitor;
   GfLogicalMonitorLayoutMode layout_mode;
-  gboolean has_suggested_position;
   GList *logical_monitor_configs;
   float scale;
   int x, y;
@@ -535,47 +537,24 @@ create_monitors_config (GfMonitorConfigManager *config_manager,
   if (!primary_monitor)
     return NULL;
 
+  x = y = 0;
   layout_mode = gf_monitor_manager_get_default_layout_mode (monitor_manager);
 
-  switch (positioning)
-    {
-      case MONITOR_POSITIONING_SUGGESTED:
-        has_suggested_position = gf_monitor_get_suggested_position (primary_monitor,
-                                                                    &x,
-                                                                    &y);
-        g_assert (has_suggested_position);
-        break;
-
-      case MONITOR_POSITIONING_LINEAR:
-      default:
-        x = y = 0;
-        break;
-    }
-
-  scale = compute_scale_for_monitor (monitor_manager, primary_monitor, NULL);
-  primary_logical_monitor_config = create_preferred_logical_monitor_config (monitor_manager,
-                                                                            primary_monitor,
-                                                                            x,
-                                                                            y,
-                                                                            scale,
-                                                                            layout_mode);
-
-  primary_logical_monitor_config->is_primary = TRUE;
-  logical_monitor_configs = g_list_append (NULL, primary_logical_monitor_config);
-
   monitors = NULL;
   if (!(match_rule & MONITOR_MATCH_PRIMARY))
-    monitors = find_monitors (monitor_manager, match_rule);
+    monitors = find_monitors (monitor_manager, match_rule, primary_monitor);
 
-  x = primary_logical_monitor_config->layout.width;
+  /*
+   * The primary monitor needs to be at the head of the list for the
+   * linear positioning to be correct.
+   */
+  monitors = g_list_prepend (monitors, primary_monitor);
 
   for (l = monitors; l; l = l->next)
     {
       GfMonitor *monitor = l->data;
       GfLogicalMonitorConfig *logical_monitor_config;
-
-      if (monitor == primary_monitor)
-        continue;
+      gboolean has_suggested_position;
 
       switch (positioning)
         {
@@ -602,6 +581,7 @@ create_monitors_config (GfMonitorConfigManager *config_manager,
                                                                         scale,
                                                                         layout_mode);
 
+      logical_monitor_config->is_primary = (monitor == primary_monitor);
       logical_monitor_configs = g_list_append (logical_monitor_configs, logical_monitor_config);
 
       x += logical_monitor_config->layout.width;