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livetrax/libs/pbd/pbd/property_basics.h

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3.9 KiB
C++

/*
Copyright (C) 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 __libpbd_property_basics_h__
#define __libpbd_property_basics_h__
#include <glib.h>
#include <set>
#include "pbd/xml++.h"
class Command;
namespace PBD {
class PropertyList;
/** A unique identifier for a property of a Stateful object */
typedef GQuark PropertyID;
template<typename T>
struct PropertyDescriptor {
PropertyDescriptor () : property_id (0) {}
PropertyDescriptor (PropertyID pid) : property_id (pid) {}
PropertyID property_id;
typedef T value_type;
};
/** A list of IDs of Properties that have changed in some situation or other */
class PropertyChange : public std::set<PropertyID>
{
public:
PropertyChange() {}
template<typename T> PropertyChange(PropertyDescriptor<T> p);
PropertyChange(const PropertyChange& other) : std::set<PropertyID> (other) {}
PropertyChange operator=(const PropertyChange& other) {
clear ();
insert (other.begin (), other.end ());
return *this;
}
template<typename T> PropertyChange operator=(PropertyDescriptor<T> p);
template<typename T> bool contains (PropertyDescriptor<T> p) const;
bool contains (const PropertyChange& other) const {
for (const_iterator x = other.begin (); x != other.end (); ++x) {
if (find (*x) != end ()) {
return true;
}
}
return false;
}
void add (PropertyID id) { insert (id); }
void add (const PropertyChange& other) { insert (other.begin (), other.end ()); }
template<typename T> void add (PropertyDescriptor<T> p);
};
/** Base (non template) part of Property */
class PropertyBase
{
public:
PropertyBase (PropertyID pid)
: _property_id (pid)
{}
virtual ~PropertyBase () {}
/** Forget about any old value for this state */
virtual void clear_history () = 0;
/** Make XML that allows us to get from some previous state to the current state
* of this property, and add it to @param history_node
*/
virtual void add_history_state (XMLNode* history_node) const = 0;
/** Add information to two property lists: one that allows
* undo of the changes in this property's state betwen now and
* the last call to clear_history, and one that allows redo
* of those changes.
*/
virtual void diff (PropertyList& undo, PropertyList& redo, Command*) const = 0;
virtual PropertyBase* maybe_clone_self_if_found_in_history_node (const XMLNode&) const { return 0; }
/** Set state from an XML node previously generated by add_history_state */
virtual bool set_state_from_owner_state (XMLNode const&) = 0;
/** Add complete current state in XML form to an existing XML node @param node */
virtual void add_state_to_owner_state (XMLNode& node) const = 0;
/** @return true if this property has changed in value since construction or since
* the last call to clear_history(), whichever was more recent.
*/
virtual bool changed() const = 0;
/** Set the value of this property from another */
virtual void set_state_from_property (PropertyBase const *) = 0;
const gchar*property_name () const { return g_quark_to_string (_property_id); }
PropertyID property_id () const { return _property_id; }
bool operator==(PropertyID pid) const {
return _property_id == pid;
}
protected:
PropertyID _property_id;
};
}
#endif /* __libpbd_property_basics_h__ */