Initial version of Cgraph created.

diff --git a/lib/cgraph/subg.c b/lib/cgraph/subg.c
new file mode 100644 (file)
index 0000000..e2bdd7e
--- /dev/null
+++ b/lib/cgraph/subg.c
@@ -0,0 +1,101 @@
+/* $Id$ $Revision$ */
+/* vim:set shiftwidth=4 ts=8: */
+
+/**********************************************************
+*      This software is part of the graphviz package      *
+*                http://www.graphviz.org/                 *
+*                                                         *
+*            Copyright (c) 1994-2004 AT&T Corp.           *
+*                and is licensed under the                *
+*            Common Public License, Version 1.0           *
+*                      by AT&T Corp.                      *
+*                                                         *
+*        Information and Software Systems Research        *
+*              AT&T Research, Florham Park NJ             *
+**********************************************************/
+
+#include <cghdr.h>
+
+static Agraph_t *agfindsubg_by_id(Agraph_t * g, unsigned long id)
+{
+    Agraph_t template;
+
+    agdtdisc(g, g->g_dict, &Ag_subgraph_id_disc);
+    AGID(&template) = id;
+    return (Agraph_t *) dtsearch(g->g_dict, &template);
+}
+
+static Agraph_t *localsubg(Agraph_t * g, unsigned long id)
+{
+    Agraph_t *subg;
+
+    subg = agfindsubg_by_id(g, id);
+    if (subg)
+       return subg;
+
+    subg = agalloc(g, sizeof(Agraph_t));
+    subg->clos = g->clos;
+    subg->desc = g->desc;
+    subg->desc.maingraph = FALSE;
+    subg->parent = g;
+    subg->root = g->root;
+    AGID(subg) = id;
+    return agopen1(subg);
+}
+
+Agraph_t *agidsubg(Agraph_t * g, unsigned long id, int cflag)
+{
+    Agraph_t *subg;
+    subg = agfindsubg_by_id(g, id);
+    if ((subg == NILgraph) && cflag && agallocid(g, AGRAPH, id))
+       subg = localsubg(g, id);
+    return subg;
+}
+
+Agraph_t *agsubg(Agraph_t * g, char *name, int cflag)
+{
+    unsigned long id;
+    Agraph_t *subg;
+
+    if (name && agmapnametoid(g, AGRAPH, name, &id, FALSE)) {
+       /* might already exist */
+       if ((subg = agfindsubg_by_id(g, id)))
+           return subg;
+    }
+
+    if (cflag && agmapnametoid(g, AGRAPH, name, &id, TRUE))    /* reserve id */
+       return localsubg(g, id);
+
+    return NILgraph;
+}
+
+Agraph_t *agfstsubg(Agraph_t * g)
+{
+    return (Agraph_t *) dtfirst(g->g_dict);
+}
+
+Agraph_t *agnxtsubg(Agraph_t * subg)
+{
+    Agraph_t *g;
+
+    g = agparent(subg);
+    return (Agraph_t *) dtnext(g->g_dict, subg);
+}
+
+Agraph_t *agparent(Agraph_t * g)
+{
+    return g->parent;
+}
+
+Agraph_t *agroot(Agraph_t * g)
+{
+    return g->root;
+}
+
+/* this function is only responsible for deleting the entry
+ * in the parent's subg dict.  the rest is done in agclose().
+ */
+long agdelsubg(Agraph_t * g, Agraph_t * subg)
+{
+    return (long) dtdelete(g->g_dict, subg);
+}