st/label: Compare shadow spec before invalidating shadow on style change

Just like with the last commit for StEntry, check whether the text
shadow actually changed before invalidating the pipeline on style
changes of StLabel.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1744>

diff --git a/src/st/st-label.c b/src/st/st-label.c
index 1cf0859dfbe5b2dd0fc44b93db226eb70dab171e..e9893fe01e006f6a67c93ec17d87fa003c623953 100644 (file)
--- a/src/st/st-label.c
+++ b/src/st/st-label.c
@@ -62,6 +62,8 @@ struct _StLabelPrivate
 {
   ClutterActor *label;
 
+  StShadow *shadow_spec;
+
   CoglPipeline *text_shadow_pipeline;
   float         shadow_width;
   float         shadow_height;
@@ -119,8 +121,21 @@ static void
 st_label_style_changed (StWidget *self)
 {
   StLabelPrivate *priv = ST_LABEL(self)->priv;
+  StThemeNode *theme_node;
+  StShadow *shadow_spec;
 
-  g_clear_pointer (&priv->text_shadow_pipeline, cogl_object_unref);
+  theme_node = st_widget_get_theme_node (self);
+
+  shadow_spec = st_theme_node_get_text_shadow (theme_node);
+  if (!priv->shadow_spec || !shadow_spec ||
+      !st_shadow_equal (shadow_spec, priv->shadow_spec))
+    {
+      g_clear_pointer (&priv->text_shadow_pipeline, cogl_object_unref);
+
+      g_clear_pointer (&priv->shadow_spec, st_shadow_unref);
+      if (shadow_spec)
+        priv->shadow_spec = st_shadow_ref (shadow_spec);
+    }
 
   _st_set_text_from_style ((ClutterText *)priv->label, st_widget_get_theme_node (self));
 
@@ -194,12 +209,10 @@ st_label_paint (ClutterActor        *actor,
                 ClutterPaintContext *paint_context)
 {
   StLabelPrivate *priv = ST_LABEL (actor)->priv;
-  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
-  StShadow *shadow_spec = st_theme_node_get_text_shadow (theme_node);
 
   st_widget_paint_background (ST_WIDGET (actor), paint_context);
 
-  if (shadow_spec)
+  if (priv->shadow_spec)
     {
       ClutterActorBox allocation;
       float width, height;
@@ -222,7 +235,7 @@ st_label_paint (ClutterActor        *actor,
           priv->shadow_width = width;
           priv->shadow_height = height;
           priv->text_shadow_pipeline =
-            _st_create_shadow_pipeline_from_actor (shadow_spec,
+            _st_create_shadow_pipeline_from_actor (priv->shadow_spec,
                                                    priv->label);
         }
 
@@ -232,7 +245,7 @@ st_label_paint (ClutterActor        *actor,
 
           framebuffer =
             clutter_paint_context_get_framebuffer (paint_context);
-          _st_paint_shadow_with_opacity (shadow_spec,
+          _st_paint_shadow_with_opacity (priv->shadow_spec,
                                          framebuffer,
                                          priv->text_shadow_pipeline,
                                          &allocation,