[gnome-control-center] night-light: Turn on Night Light for 5 seconds when adjusting Color Temp

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 0858fd5d36f2a0c595fc331be9e9b69464f6884a
Author: Jeremy Bicha <jbicha ubuntu com>
Date:   Wed Dec 19 08:13:40 2018 -0500

    night-light: Turn on Night Light for 5 seconds when adjusting Color Temp
    
    Closes: https://gitlab.gnome.org/GNOME/gnome-control-center/issues/147

 panels/display/cc-night-light-dialog.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
---
diff --git a/panels/display/cc-night-light-dialog.c b/panels/display/cc-night-light-dialog.c
index 462c69198..8ab9d4ca0 100644
--- a/panels/display/cc-night-light-dialog.c
+++ b/panels/display/cc-night-light-dialog.c
@@ -66,6 +66,7 @@ G_DEFINE_TYPE (CcNightLightDialog, cc_night_light_dialog, GTK_TYPE_DIALOG);
 #define CLOCK_SCHEMA     "org.gnome.desktop.interface"
 #define DISPLAY_SCHEMA   "org.gnome.settings-daemon.plugins.color"
 #define CLOCK_FORMAT_KEY "clock-format"
+#define NIGHT_LIGHT_PREVIEW_TIMEOUT_SECONDS 5
 
 static void
 dialog_adjustments_set_frac_hours (CcNightLightDialog *self,
@@ -381,6 +382,16 @@ dialog_color_temperature_value_changed_cb (GtkAdjustment      *adjustment,
 
   g_debug ("new value = %.0f", value);
 
+  if (self->proxy_color != NULL)
+    g_dbus_proxy_call (self->proxy_color,
+                       "NightLightPreview",
+                       g_variant_new ("(u)", NIGHT_LIGHT_PREVIEW_TIMEOUT_SECONDS),
+                       G_DBUS_CALL_FLAGS_NONE,
+                       5000,
+                       NULL,
+                       NULL,
+                       NULL);
+
   g_settings_set_uint (self->settings_display, "night-light-temperature", (guint) value);
 }