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livetrax/libs/pbd/pbd/stateful.h

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4.3 KiB
C++

/*
* Copyright (C) 2000-2015 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2006 Hans Fugal <hans@fugal.net>
* Copyright (C) 2007-2015 Tim Mayberry <mojofunk@gmail.com>
* Copyright (C) 2009-2011 Carl Hetherington <carl@carlh.net>
* Copyright (C) 2015 Robin Gareus <robin@gareus.org>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#pragma once
#include <atomic>
#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 () const = 0;
virtual int set_state (const XMLNode&, int version) = 0;
virtual bool apply_change (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 (PBD::Command *) const;
virtual void rdiff (std::vector<PBD::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::Signal<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 _stateful_frozen.load() > 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 &) const;
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;
std::atomic<int> _stateful_frozen;
static void set_regenerate_xml_and_string_ids_in_this_thread (bool yn);
};
} // namespace PBD