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Copyright (C) 2000-2010 Paul Davis
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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#ifndef __pbd_stateful_h__
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#define __pbd_stateful_h__
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#include "pbd/xml++.h"
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#include "pbd/property_basics.h"
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#include "pbd/signals.h"
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class OwnedPropertyList;
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/** Base class for objects with saveable and undoable state */
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virtual XMLNode& get_state (void) = 0;
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virtual int set_state (const XMLNode&, int version) = 0;
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virtual bool apply_changes (PropertyBase const &);
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PropertyChange apply_changes (PropertyList const &);
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const OwnedPropertyList& properties() const { return *_properties; }
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void add_property (PropertyBase& s);
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/* Extra XML node: so that 3rd parties can attach state to the XMLNode
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representing the state of this object.
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void add_extra_xml (XMLNode&);
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XMLNode *extra_xml (const std::string& str, bool add_if_missing = false);
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void save_extra_xml (const XMLNode&);
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const PBD::ID& id() const { return _id; }
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bool set_id (const XMLNode&);
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void set_id (const std::string&);
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/* history management */
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void clear_changes ();
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virtual void clear_owned_changes ();
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PropertyList* get_changes_as_properties (Command *) const;
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virtual void rdiff (std::vector<Command*> &) const;
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/* create a property list from an XMLNode
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virtual PropertyList* property_factory (const XMLNode&) const;
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/* How stateful's notify of changes to their properties
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PBD::Signal1<void,const PropertyChange&> PropertyChanged;
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static int current_state_version;
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static int loading_state_version;
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virtual void suspend_property_changes ();
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virtual void resume_property_changes ();
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bool property_changes_suspended() const { return g_atomic_int_get (const_cast<gint*>(&_stateful_frozen)) > 0; }
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void add_instant_xml (XMLNode&, const std::string& directory_path);
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XMLNode *instant_xml (const std::string& str, const std::string& directory_path);
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void add_properties (XMLNode &);
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PropertyChange set_values (XMLNode const &);
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/* derived classes can implement this to do cross-checking
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of property values after either a PropertyList or XML
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driven property change.
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virtual void post_set (const PropertyChange&) { };
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XMLNode *_instant_xml;
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PBD::PropertyChange _pending_changed;
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Glib::Threads::Mutex _lock;
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std::string _xml_node_name; ///< name of node to use for this object in XML
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OwnedPropertyList* _properties;
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virtual void send_change (const PropertyChange&);
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/** derived classes can implement this in order to process a property change
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within thaw() just before send_change() is called.
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virtual void mid_thaw (const PropertyChange&) { }
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gint _stateful_frozen;
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#endif /* __pbd_stateful_h__ */