+ last_visited = 0;
+}
+
+ViewBTree::ViewBTree (Canvas::Group *parent, const std::string filename)
+ :Canvas::Group (*parent, 0, 0), BTree (filename)
+{
+ /* Cada bytes lo hago de 5 units de ancho */
+ node_width = 4 * header.block_size;
+ node_height = 50;
+ byte_to_pixels = node_width/header.block_size;
+
+ last_selected = NULL;
+ last_visited = 0;
+}
+
+ViewBTree* ViewBTree::Open (Canvas::Group *parent, const std::string &filename)
+{
+ ViewBTree *tree = new ViewBTree (parent, filename);
+
+ if (tree->fp == NULL) {
+ delete tree;
+ return NULL;
+ }
+
+ /* El magic no coincide!! */
+ if (strcmp (tree->header.magic, "DILUMA")) {
+ delete tree;
+ return NULL;
+ }
+ return tree;
+}
+
+void ViewBTree::GoBack ()
+{
+ uint l = back.top ();
+ back.pop ();
+
+ Clear ();
+ AddNode (l, 1);