[gnome-control-center/gnome-3-34] user-accounts: Fix carousel arrow location when animations are disabled

[Ondrej Holy <oholy src gnome org>]

commit 976983c9aad205ac0642a5524f4e4908d9e1cb1b
Author: Philip Withnall <withnall endlessm com>
Date:   Thu Jan 17 16:37:22 2019 +0000

    user-accounts: Fix carousel arrow location when animations are disabled
    
    When animations are disabled, the @keyframes CSS rule doesn’t work, and
    neither does animation-name — so we need to set the margin-left to the
    arrow’s final location directly.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    
    (cherry picked from commit b2d607df4444638ca27aa229304f56013ec8b2a4)

 panels/user-accounts/cc-carousel.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)
---
diff --git a/panels/user-accounts/cc-carousel.c b/panels/user-accounts/cc-carousel.c
index 94f2e4979..f9b8bb8b7 100644
--- a/panels/user-accounts/cc-carousel.c
+++ b/panels/user-accounts/cc-carousel.c
@@ -111,6 +111,8 @@ cc_carousel_move_arrow (CcCarousel *self)
         GtkStyleContext *context;
         gchar *css;
         gint end_x;
+        GtkSettings *settings;
+        gboolean animations;
 
         if (!self->selected_item)
                 return;
@@ -122,13 +124,26 @@ cc_carousel_move_arrow (CcCarousel *self)
                 gtk_style_context_remove_provider (context, self->provider);
         g_clear_object (&self->provider);
 
-        css = g_strdup_printf ("@keyframes arrow_keyframes-%d {\n"
-                               "  from { margin-left: %dpx; }\n"
-                               "  to { margin-left: %dpx; }\n"
-                               "}\n"
-                               "* {\n"
-                               "  animation-name: arrow_keyframes-%d;\n"
-                               "}\n", end_x, self->arrow_start_x, end_x, end_x);
+        settings = gtk_widget_get_settings (GTK_WIDGET (self));
+        g_object_get (settings, "gtk-enable-animations", &animations, NULL);
+
+        /* Animate the arrow movement if animations are enabled. Otherwise,
+         * jump the arrow to the right location instantly. */
+        if (animations)
+        {
+                css = g_strdup_printf ("@keyframes arrow_keyframes-%d {\n"
+                                       "  from { margin-left: %dpx; }\n"
+                                       "  to { margin-left: %dpx; }\n"
+                                       "}\n"
+                                       "* {\n"
+                                       "  animation-name: arrow_keyframes-%d;\n"
+                                       "}\n",
+                                       end_x, self->arrow_start_x, end_x, end_x);
+        }
+        else
+        {
+                css = g_strdup_printf ("* { margin-left: %dpx }", end_x);
+        }
 
         self->provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
         gtk_css_provider_load_from_data (GTK_CSS_PROVIDER (self->provider), css, -1, NULL);