2 Copyright (C) 2000-2010 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #ifndef __pbd_stateful_h__
21 #define __pbd_stateful_h__
27 #include "pbd/xml++.h"
28 #include "pbd/enumwriter.h"
29 #include "pbd/properties.h"
39 /** Base class for objects with saveable and undoable state */
45 virtual XMLNode& get_state (void) = 0;
46 virtual int set_state (const XMLNode&, int version) = 0;
47 /* derived types do not have to implement this, but probably should
48 give it serious attention.
50 virtual PropertyChange set_property (const PropertyBase&) { return PropertyChange (0); }
52 PropertyChange set_properties (const PropertyList&);
54 void add_property (PropertyBase& s) {
58 /* Extra XML node: so that 3rd parties can attach state to the XMLNode
59 representing the state of this object.
62 void add_extra_xml (XMLNode&);
63 XMLNode *extra_xml (const std::string& str);
65 const PBD::ID& id() const { return _id; }
67 void clear_history ();
68 std::pair<XMLNode *, XMLNode*> diff () const;
69 void changed (PropertyChange&) const;
71 static int current_state_version;
72 static int loading_state_version;
76 void add_instant_xml (XMLNode&, const sys::path& directory_path);
77 XMLNode *instant_xml (const std::string& str, const sys::path& directory_path);
78 void add_properties (XMLNode &);
79 /* derived types can call this from ::set_state() (or elsewhere)
80 to get basic property setting done.
82 PropertyChange set_properties (XMLNode const &);
85 /* derived classes can implement this to do cross-checking
86 of property values after either a PropertyList or XML
87 driven property change.
89 virtual void post_set () { };
92 XMLNode *_instant_xml;
95 std::string _xml_node_name; ///< name of node to use for this object in XML
96 OwnedPropertyList _properties;
101 #endif /* __pbd_stateful_h__ */