[gnome-games] ui: Add styling to distinguish development builds

[Adrien Plazas <aplazas src gnome org>]

commit 68d471f43c07133cabb509c29aebdc7b9a6a608a
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Mon Jul 16 01:09:04 2018 +0500

    ui: Add styling to distinguish development builds

 data/gtk-style.css             | 18 ++++++++++++++++++
 src/ui/application-window.vala |  3 +++
 2 files changed, 21 insertions(+)
---
diff --git a/data/gtk-style.css b/data/gtk-style.css
index bd8b392..a83fec6 100644
--- a/data/gtk-style.css
+++ b/data/gtk-style.css
@@ -12,3 +12,21 @@ gamesgamethumbnail {
        border-color: @theme_bg_color;
        color: @theme_fg_color;
 }
+
+.devel headerbar {
+       background: -gtk-icontheme("system-run-symbolic") right 0/350px 64px no-repeat,
+                   linear-gradient(to left, rgba (165, 177, 189, 0.5) 0,
+                                            rgba (165, 177, 189, 0.5) 200px,
+                                            rgba (  0,   0,   0,   0) 400px),
+                   @theme_bg_color;
+       border-color: @borders;
+}
+
+.devel headerbar:backdrop {
+       background: -gtk-icontheme("system-run-symbolic") right 0/350px 64px no-repeat,
+                   linear-gradient(to left, rgba (165, 177, 189, 0.3) 0,
+                                            rgba (165, 177, 189, 0.3) 200px,
+                                            rgba (  0,   0,   0,   0) 400px),
+                   @theme_unfocused_bg_color;
+       border-color: @unfocused_borders;
+}
diff --git a/src/ui/application-window.vala b/src/ui/application-window.vala
index 17f424d..6fd9ab4 100644
--- a/src/ui/application-window.vala
+++ b/src/ui/application-window.vala
@@ -136,6 +136,9 @@ private class Games.ApplicationWindow : Gtk.ApplicationWindow {
                inhibit_flags = 0;
 
                set_show_menubar (false); // Essential, see bug #771683
+
+               if (Config.PROFILE == "Devel")
+                       get_style_context ().add_class ("devel");
        }
 
        public void run_game (Game game) {