css: Track hover and active state changes separatelywip/matthiasc/css-change

The idea is that this reduce the amount of frequently
changing state that css nodes are sensitive to.

This is going to reduce the amount of style recomputation.

1 files changed, 15 insertions, 1 deletions

diff --git a/gtk/gtkcssnode.c b/gtk/gtkcssnode.c
index 5b0de1323c..bd90df4bf0 100644
--- a/gtk/gtkcssnode.c
+++ b/gtk/gtkcssnode.c
@@ -1210,9 +1210,23 @@ void
 gtk_css_node_set_state (GtkCssNode    *cssnode,
                         GtkStateFlags  state_flags)
 {
+  GtkStateFlags old_state;
+
+  old_state = gtk_css_node_declaration_get_state (cssnode->decl);
+
   if (gtk_css_node_declaration_set_state (&cssnode->decl, state_flags))
     {
-      gtk_css_node_invalidate (cssnode, GTK_CSS_CHANGE_STATE);
+      GtkStateFlags states = old_state ^ state_flags;
+      GtkCssChange change = 0;
+
+      if (states & GTK_STATE_FLAG_PRELIGHT)
+        change |= GTK_CSS_CHANGE_HOVER;
+      if (states & GTK_STATE_FLAG_ACTIVE)
+        change |= GTK_CSS_CHANGE_ACTIVE;
+      if (states & ~(GTK_STATE_FLAG_PRELIGHT|GTK_STATE_FLAG_ACTIVE))
+        change |= GTK_CSS_CHANGE_STATE;
+
+      gtk_css_node_invalidate (cssnode, change);
       g_object_notify_by_pspec (G_OBJECT (cssnode), cssnode_properties[PROP_STATE]);
     }
 }