[gtk/theme-redux: 5/7] Drop the prefer-dark setting

[Matthias Clasen <matthiasc src gnome org>]

commit b5b3dbb649edcf00a40f10d0af19400d021a124f
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Apr 11 15:53:53 2020 -0400

    Drop the prefer-dark setting
    
    There is no way to win with this setting, so instead
    of trying to add yet more override knobs for application
    developers, do away with theme variants altogether.
    
    As a user, just pick your favorite theme, and if it
    is dark, so be it.
    
    As an app developer, you can inspect the gtk-theme-name
    property and match that against your supported themes.
    If that is not good enough for you, you can volunteer
    to implement a theme property API that would let themes
    declare whether they are dark or light.

 gtk/gtksettings.c | 75 +++++++++----------------------------------------------
 1 file changed, 12 insertions(+), 63 deletions(-)
---
diff --git a/gtk/gtksettings.c b/gtk/gtksettings.c
index 6ce91b34b1..802ca328b9 100644
--- a/gtk/gtksettings.c
+++ b/gtk/gtksettings.c
@@ -170,7 +170,6 @@ enum {
   PROP_ENABLE_INPUT_FEEDBACK_SOUNDS,
   PROP_ENABLE_EVENT_SOUNDS,
   PROP_PRIMARY_BUTTON_WARPS_SLIDER,
-  PROP_APPLICATION_PREFER_DARK_THEME,
   PROP_ENTRY_SELECT_ON_FOCUS,
   PROP_ENTRY_PASSWORD_HINT_TIMEOUT,
   PROP_LABEL_SELECT_ON_FOCUS,
@@ -715,29 +714,6 @@ gtk_settings_class_init (GtkSettingsClass *class)
                                                                    GTK_PARAM_READWRITE));
   g_assert (result == PROP_PRIMARY_BUTTON_WARPS_SLIDER);
 
-  /**
-   * GtkSettings:gtk-application-prefer-dark-theme:
-   *
-   * Whether the application prefers to use a dark theme. If a GTK theme
-   * includes a dark variant, it will be used instead of the configured
-   * theme.
-   *
-   * Some applications benefit from minimizing the amount of light pollution that
-   * interferes with the content. Good candidates for dark themes are photo and
-   * video editors that make the actual content get all the attention and minimize
-   * the distraction of the chrome.
-   *
-   * Dark themes should not be used for documents, where large spaces are white/light
-   * and the dark chrome creates too much contrast (web browser, text editor...).
-   */
-  result = settings_install_property_parser (class,
-                                             g_param_spec_boolean ("gtk-application-prefer-dark-theme",
-                                                                 P_("Application prefers a dark theme"),
-                                                                 P_("Whether the application prefers to have 
a dark theme."),
-                                                                 FALSE,
-                                                                 GTK_PARAM_READWRITE));
-  g_assert (result == PROP_APPLICATION_PREFER_DARK_THEME);
-
   result = settings_install_property_parser (class,
                                              g_param_spec_boolean ("gtk-entry-select-on-focus",
                                                                    P_("Select on focus"),
@@ -1248,7 +1224,6 @@ gtk_settings_notify (GObject    *object,
       gtk_style_context_reset_widgets (settings->display);
       break;
     case PROP_THEME_NAME:
-    case PROP_APPLICATION_PREFER_DARK_THEME:
       settings_update_theme (settings);
       break;
     case PROP_XFT_DPI:
@@ -1638,62 +1613,37 @@ settings_update_provider (GdkDisplay      *display,
     }
 }
 
-static void
-get_theme_name (GtkSettings  *settings,
-                gchar       **theme_name,
-                gchar       **theme_variant)
+static char *
+get_theme_name (GtkSettings  *settings)
 {
-  gboolean prefer_dark;
-
-  *theme_name = NULL;
-  *theme_variant = NULL;
+  char *theme_name = NULL;
 
   if (g_getenv ("GTK_THEME"))
-    *theme_name = g_strdup (g_getenv ("GTK_THEME"));
-
-  if (*theme_name && **theme_name)
-    {
-      char *p;
-      p = strrchr (*theme_name, ':');
-      if (p) {
-        *p = '\0';
-        p++;
-        *theme_variant = g_strdup (p);
-      }
-
-      return;
-    }
+    theme_name = g_strdup (g_getenv ("GTK_THEME"));
 
-  g_free (*theme_name);
+  if (theme_name)
+    return theme_name;
 
   g_object_get (settings,
-                "gtk-theme-name", theme_name,
-                "gtk-application-prefer-dark-theme", &prefer_dark,
+                "gtk-theme-name", &theme_name,
                 NULL);
 
-  if (prefer_dark)
-    *theme_variant = g_strdup ("dark");
-
-  if (*theme_name && **theme_name)
-    return;
+  if (theme_name)
+    return theme_name;
 
-  g_free (*theme_name);
-  *theme_name = g_strdup (DEFAULT_THEME_NAME);
+  return g_strdup (DEFAULT_THEME_NAME);
 }
 
 static void
 settings_update_theme (GtkSettings *settings)
 {
   gchar *theme_name;
-  gchar *theme_variant;
   const gchar *theme_dir;
   gchar *path;
 
-  get_theme_name (settings, &theme_name, &theme_variant);
+  theme_name = get_theme_name (settings);
 
-  gtk_css_provider_load_named (settings->theme_provider,
-                               theme_name,
-                               theme_variant);
+  gtk_css_provider_load_named (settings->theme_provider, theme_name, NULL);
 
   /* reload per-theme settings */
   theme_dir = _gtk_css_provider_get_theme_dir (settings->theme_provider);
@@ -1706,7 +1656,6 @@ settings_update_theme (GtkSettings *settings)
     }
 
   g_free (theme_name);
-  g_free (theme_variant);
 }
 
 const cairo_font_options_t *