/*
Copyright (C) 2014 Carl Hetherington <cth@carlh.net>
- This program is free software; you can redistribute it and/or modify
+ This file is part of libdcp.
+
+ libdcp 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,
+ libdcp 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.
-
+ along with libdcp. If not, see <http://www.gnu.org/licenses/>.
+
+ In addition, as a special exception, the copyright holders give
+ permission to link the code of portions of this program with the
+ OpenSSL library under certain conditions as described in each
+ individual source file, and distribute linked combinations
+ including the two.
+
+ You must obey the GNU General Public License in all respects
+ for all of the code used other than OpenSSL. If you modify
+ file(s) with this exception, you may extend this exception to your
+ version of the file(s), but you are not obligated to do so. If you
+ do not wish to do so, delete this exception statement from your
+ version. If you delete this exception statement from all source
+ files in the program, then also delete it here.
*/
+/** @file src/ref.h
+ * @brief Ref class.
+ */
+
#ifndef LIBDCP_REF_H
#define LIBDCP_REF_H
#include "exceptions.h"
-#include "object.h"
+#include "asset.h"
+#include "util.h"
#include <boost/shared_ptr.hpp>
#include <string>
namespace dcp {
-template<class T>
+/** @class Ref
+ * @brief A reference to an asset which is identified by a universally-unique identifier (UUID).
+ *
+ * This class is a `pointer' to a thing. It will always know the
+ * UUID of the thing, and it may have a shared_ptr to the C++ object
+ * which represents the thing.
+ *
+ * If the Ref does not have a shared_ptr it may be given one by
+ * calling resolve() with a list of assets. The shared_ptr will be
+ * set up using any object on the list which has a matching ID.
+ */
class Ref
{
public:
- Ref (std::string id)
+ /** Initialise a Ref with an ID but no shared_ptr */
+ explicit Ref (std::string id)
: _id (id)
{}
- Ref (boost::shared_ptr<T> object)
- : _id (object->id ())
- , _object (object)
+ /** Initialise a Ref with a shared_ptr to an asset */
+ explicit Ref (boost::shared_ptr<Asset> asset)
+ : _id (asset->id ())
+ , _asset (asset)
{}
+ /** Set the ID of this Ref */
void set_id (std::string id)
{
_id = id;
}
- void resolve (std::list<boost::shared_ptr<Object> > objects)
- {
- typename std::list<boost::shared_ptr<Object> >::iterator i = objects.begin();
- while (i != objects.end() && (*i)->id() != _id) {
- ++i;
- }
-
- if (i != objects.end ()) {
- _object = boost::dynamic_pointer_cast<T> (*i);
- }
- }
+ void resolve (std::list<boost::shared_ptr<Asset> > assets);
+ /** @return the ID of the thing that we are pointing to */
std::string id () const {
return _id;
}
- boost::shared_ptr<T> object () const {
- if (!_object) {
+ /** @return a shared_ptr to the thing; an UnresolvedRefError is thrown
+ * if the shared_ptr is not known.
+ */
+ boost::shared_ptr<Asset> asset () const {
+ if (!_asset) {
throw UnresolvedRefError (_id);
}
- return _object;
+ return _asset;
}
- T * operator->() const {
- if (!_object) {
+ /** operator-> to access the shared_ptr; an UnresolvedRefError is thrown
+ * if the shared_ptr is not known.
+ */
+ Asset * operator->() const {
+ if (!_asset) {
throw UnresolvedRefError (_id);
}
- return _object.get ();
+ return _asset.get ();
}
+ /** @return true if a shared_ptr is known for this Ref */
bool resolved () const {
- return _object;
+ return static_cast<bool>(_asset);
}
private:
- std::string _id;
- boost::shared_ptr<T> _object;
+ std::string _id; ///< ID; will always be known
+ boost::shared_ptr<Asset> _asset; ///< shared_ptr to the thing, may be null.
};
}