plasma-framework/dataengineconsumer.h
2012-09-24 16:17:25 +02:00

84 lines
2.8 KiB
C++

/*
* Copyright 2012 by Aaron Seigo <aseigo@kde.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, 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 Library 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.
*/
#ifndef PLASMA_DATAENGINECONSUMER_H
#define PLASMA_DATAENGINECONSUMER_H
#include <QtCore/QUrl>
#include <plasma/plasma_export.h>
namespace Plasma
{
class DataEngine;
class DataEngineConsumerPrivate;
/**
* @class DataEngineConsumer plasma/dataengineconsumer.h <Plasma/DataEngineConsumer>
*
* @brief A class that makes it safe and easy to use DataEngines
*
* DataEngineConsumer provides access to DataEngines, which are internally reference
* counted and shared between all users of them. The only public method provided is
* dataEngine which returns engines upon request.
*
* When the DataEngineConsumer class is deleted, all engines accessed using it are
* de-referenced and possibly deleted (in the case that there are no other users of
* the engine in question).
*
* DataEngineConsumer can be subclassed by other C++ classes to allow this simple
* API to be used directly from these classes in a convenient manner.
**/
class PLASMA_EXPORT DataEngineConsumer
{
public:
/**
* Constructs a DataEngineConsumer
**/
DataEngineConsumer();
~DataEngineConsumer();
/**
* Returns a Plasma::DataEngine. It never returns a null pointer, and the
* DataEngine returned should not be deleted. All DataEngines will be dereferenced
* once this DataEngineConsumer instance is deleted.
*
* It is safe and fast to request the same engine more than once.
*
* @param name the name of the DataEngine. This corresponds to the plugin name
* of the DataEngine.
* @param location if a non-empty URI is passed in, then a connection with a
* remote DataEngine at the location is attempted to be made.
* The returned pointer is a proxy object for this connection.
* In the common case, location is always an empty URI (QUrl())
* and the DataEngine is loaded locally.
*/
DataEngine *dataEngine(const QString &name, const QUrl &location = QUrl());
private:
DataEngineConsumerPrivate * const d;
};
} // namespace Plasma
#endif