st/settings: Expose system color scheme

This is the same interface setting that backs AdwStyleManager.

https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/5545

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2324>

src/st/meson.build

@@ -183,7 +183,7 @@ st_cflags = [
 libst = shared_library('st-' + mutter_api_version,
   sources: st_gir_sources + st_nogir_sources + croco_sources,
   c_args: st_cflags,
-  dependencies: [clutter_dep, mutter_dep, libxml_dep, gdk_pixbuf_dep, m_dep],
+  dependencies: [clutter_dep, mutter_dep, libxml_dep, gdk_pixbuf_dep, m_dep, schemas_dep],
   build_rpath: mutter_typelibdir,
   install_rpath: mutter_typelibdir,
   install_dir: pkglibdir,

src/st/st-settings.c

@@ -26,11 +26,13 @@
 
 #include "st-private.h"
 #include "st-settings.h"
+#include "st-enum-types.h"
 
 #define KEY_ENABLE_ANIMATIONS     "enable-animations"
 #define KEY_PRIMARY_PASTE         "gtk-enable-primary-paste"
 #define KEY_DRAG_THRESHOLD        "drag-threshold"
 #define KEY_FONT_NAME             "font-name"
+#define KEY_COLOR_SCHEME          "color-scheme"
 #define KEY_HIGH_CONTRAST         "high-contrast"
 #define KEY_GTK_ICON_THEME        "icon-theme"
 #define KEY_MAGNIFIER_ACTIVE      "screen-magnifier-enabled"
@@ -42,6 +44,7 @@ enum {
   PROP_PRIMARY_PASTE,
   PROP_DRAG_THRESHOLD,
   PROP_FONT_NAME,
+  PROP_COLOR_SCHEME,
   PROP_HIGH_CONTRAST,
   PROP_GTK_ICON_THEME,
   PROP_MAGNIFIER_ACTIVE,
@@ -71,6 +74,7 @@ struct _StSettings
   gboolean disable_show_password;
   gint drag_threshold;
   double slow_down_factor;
+  StSystemColorScheme color_scheme;
 };
 
 G_DEFINE_TYPE (StSettings, st_settings, G_TYPE_OBJECT)
@@ -185,6 +189,9 @@ st_settings_get_property (GObject    *object,
     case PROP_GTK_ICON_THEME:
       g_value_set_string (value, settings->gtk_icon_theme);
       break;
+    case PROP_COLOR_SCHEME:
+      g_value_set_enum (value, settings->color_scheme);
+      break;
     case PROP_MAGNIFIER_ACTIVE:
       g_value_set_boolean (value, settings->magnifier_active);
       break;
@@ -275,6 +282,18 @@ st_settings_class_init (StSettingsClass *klass)
                                                     "",
                                                     ST_PARAM_READABLE);
 
+  /**
+   * StSettings:color-scheme:
+   *
+   * The preferred color-scheme
+   */
+  props[PROP_COLOR_SCHEME] = g_param_spec_enum ("color-scheme",
+                                                "Color scheme",
+                                                "Color scheme",
+                                                ST_TYPE_SYSTEM_COLOR_SCHEME,
+                                                ST_SYSTEM_COLOR_SCHEME_DEFAULT,
+                                                ST_PARAM_READABLE);
+
   /**
    * StSettings:magnifier-active:
    *
@@ -339,6 +358,12 @@ on_interface_settings_changed (GSettings   *g_settings,
       g_object_notify_by_pspec (G_OBJECT (settings),
                                 props[PROP_GTK_ICON_THEME]);
     }
+  else if (g_str_equal (key, KEY_COLOR_SCHEME))
+    {
+      settings->color_scheme = g_settings_get_enum (g_settings, key);
+      g_object_notify_by_pspec (G_OBJECT (settings),
+                                props[PROP_COLOR_SCHEME]);
+    }
 }
 
 static void
@@ -422,6 +447,8 @@ st_settings_init (StSettings *settings)
                                                KEY_FONT_NAME);
   settings->gtk_icon_theme = g_settings_get_string (settings->interface_settings,
                                                     KEY_GTK_ICON_THEME);
+  settings->color_scheme = g_settings_get_enum (settings->interface_settings,
+                                                KEY_COLOR_SCHEME);
   settings->drag_threshold = g_settings_get_int (settings->mouse_settings,
                                                  KEY_DRAG_THRESHOLD);
   settings->magnifier_active = g_settings_get_boolean (settings->a11y_applications_settings,

src/st/st-settings.h

@@ -25,9 +25,16 @@
 #define __ST_SETTINGS_H__
 
 #include <glib-object.h>
+#include <gdesktop-enums.h>
 
 G_BEGIN_DECLS
 
+typedef enum {
+  ST_SYSTEM_COLOR_SCHEME_DEFAULT = G_DESKTOP_COLOR_SCHEME_DEFAULT,
+  ST_SYSTEM_COLOR_SCHEME_PREFER_DARK = G_DESKTOP_COLOR_SCHEME_PREFER_DARK,
+  ST_SYSTEM_COLOR_SCHEME_PREFER_LIGHT = G_DESKTOP_COLOR_SCHEME_PREFER_LIGHT,
+} StSystemColorScheme;
+
 #define ST_TYPE_SETTINGS (st_settings_get_type ())
 G_DECLARE_FINAL_TYPE (StSettings, st_settings, ST, SETTINGS, GObject)