cssnode: Refactor node tree modification code

This allows adding more API for it.

It also includes code that tracks modifications and invalidates siblings
and their positions whenever nodes get added or removed.

diff --git a/gtk/gtkcssnode.c b/gtk/gtkcssnode.c
index 816c667d3d812b7fb25070b779122f5e82f8c9b8..92b165dfa3142afd677a78f3b8fcdb8b65d962e9 100644 (file)
--- a/gtk/gtkcssnode.c
+++ b/gtk/gtkcssnode.c
@@ -359,73 +359,118 @@ gtk_css_node_parent_will_be_set (GtkCssNode *node)
     GTK_CSS_NODE_GET_CLASS (node)->dequeue_validate (node);
 }
 
-void
-gtk_css_node_set_parent (GtkCssNode *node,
-                         GtkCssNode *parent)
+static void
+gtk_css_node_unlink_from_siblings (GtkCssNode *node)
 {
-  if (node->parent == parent)
+  if (GTK_IS_CSS_TRANSIENT_NODE (node))
     return;
 
-  /* Take a reference here so the whole function has a reference */
-  g_object_ref (node);
+  if (node->previous_sibling)
+    node->previous_sibling->next_sibling = node->next_sibling;
+  else
+    node->parent->first_child = node->next_sibling;
 
-  if (node->parent != NULL)
+  if (node->next_sibling)
+    node->next_sibling->previous_sibling = node->previous_sibling;
+  else
+    node->parent->last_child = node->previous_sibling;
+
+  node->previous_sibling = NULL;
+  node->next_sibling = NULL;
+}
+
+static void
+gtk_css_node_link_to_siblings (GtkCssNode *node,
+                               GtkCssNode *new_previous)
+{
+  if (GTK_IS_CSS_TRANSIENT_NODE (node))
+    return;
+
+  if (new_previous)
     {
-      if (!GTK_IS_CSS_TRANSIENT_NODE (node))
-        {
-          if (node->previous_sibling)
-            node->previous_sibling->next_sibling = node->next_sibling;
-          else
-            node->parent->first_child = node->next_sibling;
+      node->previous_sibling = new_previous;
+      node->next_sibling = new_previous->next_sibling;
+      new_previous->next_sibling = node;
+    }
+  else
+    {
+      node->next_sibling = node->parent->first_child;
+      node->parent->first_child = node;
+    }
+
+  if (node->next_sibling)
+    node->next_sibling->previous_sibling = node;
+  else
+    node->parent->last_child = node;
+}
 
-          if (node->next_sibling)
-            node->next_sibling->previous_sibling = node->previous_sibling;
-          else
-            node->parent->last_child = node->previous_sibling;
+static void
+gtk_css_node_set_children_changed (GtkCssNode *node)
+{
+  if (node->children_changed)
+    return;
 
-          node->parent->n_children--;
-        }
+  node->children_changed = TRUE;
+  gtk_css_node_set_invalid (node, TRUE);
+}
 
-      node->parent = NULL;
-      node->next_sibling = NULL;
-      node->previous_sibling = NULL;
+static void
+gtk_css_node_reposition (GtkCssNode *node,
+                         GtkCssNode *parent,
+                         GtkCssNode *previous)
+{
+  g_assert (! (parent == NULL && previous != NULL));
 
-      g_object_unref (node);
+  /* Take a reference here so the whole function has a reference */
+  g_object_ref (node);
 
-      if (parent == NULL)
-        gtk_css_node_parent_was_unset (node);
-    }
+  if (node->parent != NULL)
+    gtk_css_node_unlink_from_siblings (node);
 
-  if (parent)
+  if (node->parent != parent)
     {
       if (node->parent == NULL)
-        gtk_css_node_parent_will_be_set (node);
+        {
+          gtk_css_node_parent_will_be_set (node);
+        }
+      else
+        {
+          g_object_unref (node);
+          gtk_css_node_set_children_changed (node->parent);
+        }
 
       node->parent = parent;
 
-      if (!GTK_IS_CSS_TRANSIENT_NODE (node))
+      if (parent)
         {
-          parent->n_children++;
+          gtk_css_node_set_children_changed (parent);
+          g_object_ref (node);
 
-          if (parent->last_child)
-            {
-              parent->last_child->next_sibling = node;
-              node->previous_sibling = parent->last_child;
-            }
-          parent->last_child = node;
-
-          if (parent->first_child == NULL)
-            parent->first_child = node;
+          if (node->invalid)
+            gtk_css_node_set_invalid (parent, TRUE);
+        }
+      else
+        {
+          gtk_css_node_parent_was_unset (node);
         }
-
-      if (node->invalid)
-        gtk_css_node_set_invalid (parent, TRUE);
     }
 
+  if (parent)
+    gtk_css_node_link_to_siblings (node, previous);
+
   gtk_css_node_invalidate (node, GTK_CSS_CHANGE_ANY_PARENT | GTK_CSS_CHANGE_ANY_SIBLING);
 
-  if (node->parent == NULL)
-    g_object_unref (node);
+  g_object_unref (node);
+}
+
+void
+gtk_css_node_set_parent (GtkCssNode *node,
+                         GtkCssNode *parent)
+{
+  if (node->parent == parent)
+    return;
+
+  gtk_css_node_reposition (node, parent, parent ? parent->last_child : NULL);
 }
 
 GtkCssNode *
@@ -638,6 +683,11 @@ gtk_css_node_propagate_pending_changes (GtkCssNode *cssnode)
     return;
 
   change = _gtk_css_change_for_child (cssnode->pending_changes);
+  if (cssnode->children_changed)
+    {
+      change |= GTK_CSS_CHANGE_POSITION | GTK_CSS_CHANGE_ANY_SIBLING;
+      cssnode->children_changed = FALSE;
+    }
 
   for (child = gtk_css_node_get_first_child (cssnode);
        child;
@@ -671,11 +721,11 @@ gtk_css_node_validate (GtkCssNode            *cssnode,
   if (G_UNLIKELY (gtk_get_debug_flags () & GTK_DEBUG_NO_CSS_CACHE))
     change = GTK_CSS_CHANGE_ANY;
 
+  gtk_css_node_propagate_pending_changes (cssnode);
+
   if (!cssnode->invalid && change == 0 && _gtk_bitmask_is_empty (parent_changes))
     return;
 
-  gtk_css_node_propagate_pending_changes (cssnode);
-
   gtk_css_node_set_invalid (cssnode, FALSE);
 
   change = cssnode->pending_changes;

diff --git a/gtk/gtkcssnodeprivate.h b/gtk/gtkcssnodeprivate.h
index 4207d2ff569e9b98655b45cd5baa8949c8dbb852..b1339b0b9c239f9e98af83f3a3319b5b95b0b09c 100644 (file)
--- a/gtk/gtkcssnodeprivate.h
+++ b/gtk/gtkcssnodeprivate.h
@@ -43,7 +43,6 @@ struct _GtkCssNode
   GtkCssNode *next_sibling;
   GtkCssNode *first_child;
   GtkCssNode *last_child;
-  guint n_children;
 
   GtkCssNodeDeclaration *decl;
   GtkCssStyle           *style;
@@ -51,6 +50,7 @@ struct _GtkCssNode
   GtkCssChange           pending_changes;       /* changes that accumulated since the style was last computed */
 
   guint                  invalid :1;            /* node or a child needs to be validated (even if just for animation) */
+  guint                  children_changed :1;   /* the children changed since last validation */
 };
 
 struct _GtkCssNodeClass