[gtk+/wip/treeview: 3/6] treeview: Make the parity actually store the row number

[Benjamin Otte <otte src gnome org>]

commit 5cbbe9bd0a1a21b5a71e0eefcb50f4a0756b8850
Author: Benjamin Otte <otte redhat com>
Date:   Thu Jul 7 08:48:06 2011 +0200

    treeview: Make the parity actually store the row number
    
    Instead of just storing the least significant bit of the row number,
    store the full row number. This will soon be useful for accessibility.
    But CSS could like it, too.

 gtk/gtkrbtree.c |   23 +++++++----------------
 gtk/gtkrbtree.h |    7 ++-----
 2 files changed, 9 insertions(+), 21 deletions(-)
---
diff --git a/gtk/gtkrbtree.c b/gtk/gtkrbtree.c
index a912530..54d7067 100644
--- a/gtk/gtkrbtree.c
+++ b/gtk/gtkrbtree.c
@@ -64,6 +64,7 @@ _gtk_rbnode_free (GtkRBNode *node)
       node->left = (gpointer) 0xdeadbeef;
       node->right = (gpointer) 0xdeadbeef;
       node->parent = (gpointer) 0xdeadbeef;
+      node->parity = 56789;
       node->offset = 56789;
       node->count = 56789;
       node->flags = 0;
@@ -382,6 +383,7 @@ _gtk_rbtree_remove (GtkRBTree *tree)
   GtkRBNode *tmp_node;
 
   gint height = tree->root->offset;
+  guint parity = tree->root->parity;
 
 #ifdef G_ENABLE_DEBUG  
   if (gtk_get_debug_flags () & GTK_DEBUG_TREE)
@@ -399,10 +401,7 @@ _gtk_rbtree_remove (GtkRBTree *tree)
     {
       _fixup_validation (tmp_tree, tmp_node);
       tmp_node->offset -= height;
-
-      /* If the removed tree was odd, flip all parents */
-      if (tree->root->parity)
-        tmp_node->parity = !tmp_node->parity;
+      tmp_node->parity -= parity;
       
       tmp_node = tmp_node->parent;
       if (tmp_node == tmp_tree->nil)
@@ -1498,7 +1497,6 @@ static guint
 get_parity (GtkRBNode *node)
 {
   guint child_total = 0;
-  guint rem;
 
   /* The parity of a node is node->parity minus
    * the parity of left, right, and children.
@@ -1515,12 +1513,7 @@ get_parity (GtkRBNode *node)
   if (node->children)
     child_total += (guint) node->children->root->parity;
 
-  rem = child_total % 2;
-  
-  if (rem == 0)
-    return node->parity;
-  else
-    return !node->parity;
+  return child_total + 1;
 }
 
 static guint
@@ -1538,13 +1531,11 @@ count_parity (GtkRBTree *tree,
     (guint)1 +
     (node->children ? count_parity (node->children, node->children->root) : 0);
 
-  res = res % (guint)2;
-  
   if (res != node->parity)
     g_print ("parity incorrect for node\n");
 
-  if (get_parity (node) != 1)
-    g_error ("Node has incorrect parity %u", get_parity (node));
+  if (get_parity (node) != node->parity)
+    g_error ("Node has incorrect parity %u, should be %u", node->parity, get_parity (node));
   
   return res;
 }
@@ -1717,7 +1708,7 @@ _gtk_rbtree_debug_spew_helper (GtkRBTree *tree,
 	   node,
 	   (GTK_RBNODE_GET_COLOR (node) == GTK_RBNODE_BLACK)?"BLACK":" RED ",
 	   node->offset,
-	   node->parity?1:0,
+	   node->parity,
 	   (GTK_RBNODE_FLAG_SET (node, GTK_RBNODE_DESCENDANTS_INVALID))?1:0,
 	   (GTK_RBNODE_FLAG_SET (node, GTK_RBNODE_INVALID))?1:0,
 	   (GTK_RBNODE_FLAG_SET (node, GTK_RBNODE_COLUMN_INVALID))?1:0);
diff --git a/gtk/gtkrbtree.h b/gtk/gtkrbtree.h
index eec93a7..22374f3 100644
--- a/gtk/gtkrbtree.h
+++ b/gtk/gtkrbtree.h
@@ -71,12 +71,9 @@ struct _GtkRBNode
    * the total count of children mod 2, where the total count of
    * children gets computed in the same way that the total offset gets
    * computed. i.e. not the same as the "count" field below which
-   * doesn't include children. We could replace parity with a
-   * full-size int field here, and then take % 2 to get the parity flag,
-   * but that would use extra memory.
+   * doesn't include children.
    */
-
-  guint parity : 1;
+  guint parity;
   
   GtkRBNode *left;
   GtkRBNode *right;