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livetrax/libs/pbd/pbd/stateful.h

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4.1 KiB
C++

/*
Copyright (C) 2000-2010 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.
*/
#ifndef __pbd_stateful_h__
#define __pbd_stateful_h__
#include <string>
#include <list>
#include <cassert>
#include "pbd/libpbd_visibility.h"
#include "pbd/id.h"
#include "pbd/xml++.h"
#include "pbd/property_basics.h"
#include "pbd/signals.h"
class XMLNode;
namespace PBD {
namespace sys {
class path;
}
class PropertyList;
class OwnedPropertyList;
/** Base class for objects with saveable and undoable state */
class LIBPBD_API Stateful {
public:
Stateful ();
virtual ~Stateful();
virtual XMLNode& get_state (void) = 0;
virtual int set_state (const XMLNode&, int version) = 0;
virtual bool apply_changes (PropertyBase const &);
PropertyChange apply_changes (PropertyList const &);
const OwnedPropertyList& properties() const { return *_properties; }
void add_property (PropertyBase& s);
/* Extra XML node: so that 3rd parties can attach state to the XMLNode
representing the state of this object.
*/
void add_extra_xml (XMLNode&);
XMLNode *extra_xml (const std::string& str, bool add_if_missing = false);
void save_extra_xml (const XMLNode&);
const PBD::ID& id() const { return _id; }
bool set_id (const XMLNode&);
void set_id (const std::string&);
void reset_id ();
/* RAII structure to manage thread-local ID regeneration.
*/
struct ForceIDRegeneration {
ForceIDRegeneration () {
set_regenerate_xml_and_string_ids_in_this_thread (true);
}
~ForceIDRegeneration () {
set_regenerate_xml_and_string_ids_in_this_thread (false);
}
};
/* history management */
void clear_changes ();
virtual void clear_owned_changes ();
PropertyList* get_changes_as_properties (Command *) const;
virtual void rdiff (std::vector<Command*> &) const;
bool changed() const;
/* create a property list from an XMLNode */
virtual PropertyList* property_factory (const XMLNode&) const;
/* How stateful's notify of changes to their properties */
PBD::Signal1<void,const PropertyChange&> PropertyChanged;
static int current_state_version;
static int loading_state_version;
virtual void suspend_property_changes ();
virtual void resume_property_changes ();
bool property_changes_suspended() const { return g_atomic_int_get (const_cast<gint*>(&_stateful_frozen)) > 0; }
protected:
void add_instant_xml (XMLNode&, const std::string& directory_path);
XMLNode *instant_xml (const std::string& str, const std::string& directory_path);
void add_properties (XMLNode &);
PropertyChange set_values (XMLNode const &);
/* derived classes can implement this to do cross-checking
of property values after either a PropertyList or XML
driven property change.
*/
virtual void post_set (const PropertyChange&) { };
XMLNode *_extra_xml;
XMLNode *_instant_xml;
PBD::PropertyChange _pending_changed;
Glib::Threads::Mutex _lock;
std::string _xml_node_name; ///< name of node to use for this object in XML
OwnedPropertyList* _properties;
virtual void send_change (const PropertyChange&);
/** derived classes can implement this in order to process a property change
within thaw() just before send_change() is called.
*/
virtual void mid_thaw (const PropertyChange&) { }
bool regenerate_xml_or_string_ids () const;
private:
friend struct ForceIDRegeneration;
static Glib::Threads::Private<bool> _regenerate_xml_or_string_ids;
PBD::ID _id;
gint _stateful_frozen;
static void set_regenerate_xml_and_string_ids_in_this_thread (bool yn);
};
} // namespace PBD
#endif /* __pbd_stateful_h__ */