[epiphany/wip/exalm/dark: 3/3] Follow the system dark preference for reader mode

[Alexander Mikhaylenko <alexm src gnome org>]

commit 96413d0943f3111f0820f93919170d45f68fd349
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sun Nov 21 18:13:11 2021 +0500

    Follow the system dark preference for reader mode
    
    When it's available, hide the reader color scheme preference and follow the
    system.
    
    Fixes https://gitlab.gnome.org/GNOME/epiphany/-/issues/1546

 embed/ephy-reader-handler.c             | 13 ++++++++++---
 embed/ephy-web-view.c                   | 33 ++++++++++++++++++++++++---------
 src/preferences/prefs-appearance-page.c |  4 ++++
 3 files changed, 38 insertions(+), 12 deletions(-)
---
diff --git a/embed/ephy-reader-handler.c b/embed/ephy-reader-handler.c
index 707497bdb..fb53436e6 100644
--- a/embed/ephy-reader-handler.c
+++ b/embed/ephy-reader-handler.c
@@ -163,6 +163,7 @@ readability_js_finish_cb (GObject      *object,
   const gchar *title;
   const gchar *font_style;
   const gchar *color_scheme;
+  HdyStyleManager *style_manager;
 
   js_result = webkit_web_view_run_javascript_finish (web_view, result, &error);
   if (!js_result) {
@@ -181,9 +182,15 @@ readability_js_finish_cb (GObject      *object,
   font_style = enum_nick (EPHY_TYPE_PREFS_READER_FONT_STYLE,
                           g_settings_get_enum (EPHY_SETTINGS_READER,
                                                EPHY_PREFS_READER_FONT_STYLE));
-  color_scheme = enum_nick (EPHY_TYPE_PREFS_READER_COLOR_SCHEME,
-                            g_settings_get_enum (EPHY_SETTINGS_READER,
-                                                 EPHY_PREFS_READER_COLOR_SCHEME));
+
+  style_manager = hdy_style_manager_get_default ();
+
+  if (hdy_style_manager_get_system_supports_color_schemes (style_manager))
+    color_scheme = hdy_style_manager_get_dark (style_manager) ? "dark" : "light";
+  else
+    color_scheme = enum_nick (EPHY_TYPE_PREFS_READER_COLOR_SCHEME,
+                              g_settings_get_enum (EPHY_SETTINGS_READER,
+                                                   EPHY_PREFS_READER_COLOR_SCHEME));
 
   g_string_append_printf (html, "<style>%s</style>"
                           "<title>%s</title>"
diff --git a/embed/ephy-web-view.c b/embed/ephy-web-view.c
index 27bff9a12..b40c05157 100644
--- a/embed/ephy-web-view.c
+++ b/embed/ephy-web-view.c
@@ -2576,10 +2576,9 @@ enum_nick (GType enum_type,
 }
 
 static void
-reader_setting_changed_cb (GSettings   *settings,
-                           gchar       *key,
-                           EphyWebView *web_view)
+reader_setting_changed_cb (EphyWebView *web_view)
 {
+  HdyStyleManager *style_manager;
   const gchar *font_style;
   const gchar *color_scheme;
   gchar *js_snippet;
@@ -2588,11 +2587,17 @@ reader_setting_changed_cb (GSettings   *settings,
     return;
 
   font_style = enum_nick (EPHY_TYPE_PREFS_READER_FONT_STYLE,
-                          g_settings_get_enum (settings,
+                          g_settings_get_enum (EPHY_SETTINGS_READER,
                                                EPHY_PREFS_READER_FONT_STYLE));
-  color_scheme = enum_nick (EPHY_TYPE_PREFS_READER_COLOR_SCHEME,
-                            g_settings_get_enum (settings,
-                                                 EPHY_PREFS_READER_COLOR_SCHEME));
+
+  style_manager = hdy_style_manager_get_default ();
+
+  if (hdy_style_manager_get_system_supports_color_schemes (style_manager))
+    color_scheme = hdy_style_manager_get_dark (style_manager) ? "dark" : "light";
+  else
+    color_scheme = enum_nick (EPHY_TYPE_PREFS_READER_COLOR_SCHEME,
+                              g_settings_get_enum (EPHY_SETTINGS_READER,
+                                                   EPHY_PREFS_READER_COLOR_SCHEME));
 
   js_snippet = g_strdup_printf ("document.body.className = '%s %s'",
                                 font_style,
@@ -3979,11 +3984,21 @@ ephy_web_view_init (EphyWebView *web_view)
 
   g_signal_connect_object (EPHY_SETTINGS_READER, "changed::" EPHY_PREFS_READER_FONT_STYLE,
                            G_CALLBACK (reader_setting_changed_cb),
-                           web_view, 0);
+                           web_view, G_CONNECT_SWAPPED);
 
   g_signal_connect_object (EPHY_SETTINGS_READER, "changed::" EPHY_PREFS_READER_COLOR_SCHEME,
                            G_CALLBACK (reader_setting_changed_cb),
-                           web_view, 0);
+                           web_view, G_CONNECT_SWAPPED);
+
+  g_signal_connect_object (hdy_style_manager_get_default (),
+                           "notify::system-supports-color-schemes",
+                           G_CALLBACK (reader_setting_changed_cb),
+                           web_view, G_CONNECT_SWAPPED);
+
+  g_signal_connect_object (hdy_style_manager_get_default (),
+                           "notify::dark",
+                           G_CALLBACK (reader_setting_changed_cb),
+                           web_view, G_CONNECT_SWAPPED);
 
   g_signal_connect (web_view, "decide-policy",
                     G_CALLBACK (decide_policy_cb),
diff --git a/src/preferences/prefs-appearance-page.c b/src/preferences/prefs-appearance-page.c
index 7b65ee54f..42193af00 100644
--- a/src/preferences/prefs-appearance-page.c
+++ b/src/preferences/prefs-appearance-page.c
@@ -348,6 +348,10 @@ setup_appearance_page (PrefsAppearancePage *appearance_page)
                                 reader_font_style_set_mapping,
                                 NULL, NULL);
 
+  g_object_bind_property (hdy_style_manager_get_default (), "system-supports-color-schemes",
+                          appearance_page->reader_mode_color_scheme, "visible",
+                          G_BINDING_SYNC_CREATE | G_BINDING_INVERT_BOOLEAN);
+
   hdy_combo_row_set_for_enum (HDY_COMBO_ROW (appearance_page->reader_mode_color_scheme),
                               EPHY_TYPE_PREFS_READER_COLOR_SCHEME,
                               reader_color_scheme_get_name, NULL, NULL);