[gtk+] cssnode: Set new style if it's animated

[Benjamin Otte <otte src gnome org>]

commit eb97ef05146debfb37821e93d33e4375a6f9d1ed
Author: Benjamin Otte <otte redhat com>
Date:   Sun Dec 13 16:02:34 2015 +0100

    cssnode: Set new style if it's animated
    
    In commit 2c613166771ea9118ebda91c311f11b3462330fb we avoided emitting
    the style-changed signal if no CSS property changed.
    
    Unfortunately, this also caused CSS styles to not be updated when
    animations started if those animations did not change any CSS value
    immediately. In those cases the animation would just never start.
    The obvious example was the spinner.

 gtk/gtkcssnode.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkcssnode.c b/gtk/gtkcssnode.c
index ec89634..a1bbe77 100644
--- a/gtk/gtkcssnode.c
+++ b/gtk/gtkcssnode.c
@@ -959,7 +959,16 @@ gtk_css_node_set_style (GtkCssNode  *cssnode,
 
   style_changed = gtk_css_style_change_has_change (&change);
   if (style_changed)
-    g_signal_emit (cssnode, cssnode_signals[STYLE_CHANGED], 0, &change);
+    {
+      g_signal_emit (cssnode, cssnode_signals[STYLE_CHANGED], 0, &change);
+    }
+  else if (cssnode->style != style &&
+           (GTK_IS_CSS_ANIMATED_STYLE (cssnode->style) || GTK_IS_CSS_ANIMATED_STYLE (style)))
+    {
+      /* This is when animations are starting/stopping but they didn't change any CSS this frame */
+      g_object_unref (cssnode->style);
+      cssnode->style = g_object_ref (style);
+    }
 
   gtk_css_style_change_finish (&change);