[libadwaita/wip/exalm/inspector-fixes: 5/5] style-manager: Make our own Empty theme

[Alexander Mikhaylenko <alexm src gnome org>]

commit bad9233106b04f6506f529e16e0cf449305347ad
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Wed Sep 29 18:20:43 2021 +0500

    style-manager: Make our own Empty theme
    
    The GTK empty theme doesn't have a dark variant, so if an app sets
    gtk-application-prefer-dark-theme=true, it can break. Make our own
    Adwaita-empty theme to mitigate that.

 src/adw-style-manager.c                          | 2 +-
 src/stylesheet/adwaita-stylesheet.gresources.xml | 7 +++++++
 src/stylesheet/empty.css                         | 0
 3 files changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/src/adw-style-manager.c b/src/adw-style-manager.c
index 8515e89b..49530b59 100644
--- a/src/adw-style-manager.c
+++ b/src/adw-style-manager.c
@@ -248,7 +248,7 @@ adw_style_manager_constructed (GObject *object)
 
     if (!g_getenv ("GTK_THEME")) {
       g_object_set (gtk_settings_get_for_display (self->display),
-                    "gtk-theme-name", "Empty",
+                    "gtk-theme-name", "Adwaita-empty",
                     NULL);
 
       self->provider = gtk_css_provider_new ();
diff --git a/src/stylesheet/adwaita-stylesheet.gresources.xml 
b/src/stylesheet/adwaita-stylesheet.gresources.xml
index 83ed9c02..e4785906 100644
--- a/src/stylesheet/adwaita-stylesheet.gresources.xml
+++ b/src/stylesheet/adwaita-stylesheet.gresources.xml
@@ -18,4 +18,11 @@
     <file>assets/dash-symbolic.svg</file>
     <file>assets/devel-symbolic.svg</file>
   </gresource>
+
+  <gresource prefix="/org/gtk/libgtk/theme/Adwaita-empty">
+    <file alias='gtk.css'>empty.css</file>
+    <file alias='gtk-dark.css'>empty.css</file>
+    <file alias='gtk-hc.css'>empty.css</file>
+    <file alias='gtk-hc-dark.css'>empty.css</file>
+  </gresource>
 </gresources>
diff --git a/src/stylesheet/empty.css b/src/stylesheet/empty.css
new file mode 100644
index 00000000..e69de29b