1 files changed, 137 insertions, 0 deletions
diff --git a/libs/pbd/stateful.cc b/libs/pbd/stateful.cc
new file mode 100644
index 0000000000..16aa528f59
--- /dev/null
+++ b/libs/pbd/stateful.cc
@@ -0,0 +1,137 @@
+/*
+    Copyright (C) 2000-2001 Paul Davis 
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+    $Id: stateful.cc 629 2006-06-21 23:01:03Z paul $
+*/
+
+#include <unistd.h>
+
+#include <pbd/stateful.h>
+#include <pbd/xml++.h>
+#include <pbd/error.h>
+
+#include "i18n.h"
+
+using namespace PBD;
+
+Stateful::Stateful ()
+{
+	_extra_xml = 0;
+	_instant_xml = 0;
+}
+
+Stateful::~Stateful ()
+{
+	// Do not delete _extra_xml.  The use of add_child_nocopy() 
+	// means it needs to live on indefinately.
+
+	if (_instant_xml) {
+		delete _instant_xml;
+	}
+}
+
+void
+Stateful::add_extra_xml (XMLNode& node)
+{
+	if (_extra_xml == 0) {
+		_extra_xml = new XMLNode ("extra");
+	}
+
+	_extra_xml->remove_nodes (node.name());
+	_extra_xml->add_child_nocopy (node);
+}
+
+XMLNode *
+Stateful::extra_xml (const string& str)
+{
+	if (_extra_xml == 0) {
+		return 0;
+	}
+
+	const XMLNodeList& nlist = _extra_xml->children();
+	XMLNodeConstIterator i;
+
+	for (i = nlist.begin(); i != nlist.end(); ++i) {
+		if ((*i)->name() == str) {
+			return (*i);
+		}
+	}
+
+	return 0;
+}
+
+void
+Stateful::add_instant_xml (XMLNode& node, const string& dir)
+{
+	if (_instant_xml == 0) {
+		_instant_xml = new XMLNode ("instant");
+	}
+
+	_instant_xml->remove_nodes_and_delete (node.name());
+	_instant_xml->add_child_copy (node);
+	
+	XMLTree tree;
+	tree.set_filename(dir+"/instant.xml");
+
+	/* Important: the destructor for an XMLTree deletes
+	   all of its nodes, starting at _root. We therefore
+	   cannot simply hand it our persistent _instant_xml 
+	   node as its _root, because we will lose it whenever
+	   the Tree goes out of scope.
+
+	   So instead, copy the _instant_xml node (which does 
+	   a deep copy), and hand that to the tree.
+	*/
+
+	XMLNode* copy = new XMLNode (*_instant_xml);
+	tree.set_root (copy);
+
+	if (!tree.write()) {
+		error << string_compose(_("Error: could not write %1"), dir+"/instant.xml") << endmsg;
+	}
+}
+
+XMLNode *
+Stateful::instant_xml (const string& str, const string& dir)
+{
+	if (_instant_xml == 0) {
+		string instant_file = dir + "/instant.xml";
+		if (access(instant_file.c_str(), F_OK) == 0) {
+			XMLTree tree;
+			if (tree.read(dir+"/instant.xml")) {
+				_instant_xml = new XMLNode(*(tree.root()));
+			} else {
+				warning << string_compose(_("Could not understand XML file %1"), instant_file) << endmsg;
+				return 0;
+			}
+		} else {
+			return 0;
+		}
+	}
+
+	const XMLNodeList& nlist = _instant_xml->children();
+	XMLNodeConstIterator i;
+
+	for (i = nlist.begin(); i != nlist.end(); ++i) {
+		if ((*i)->name() == str) {
+			return (*i);
+		}
+	}
+
+	return 0;
+}
+