/*
    This file is part of KDevelop

    Copyright 2013 Milian Wolff <mail@milianw.de>

    This library 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 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#ifndef KDEVPLATFORM_IPROJECTFILTERPROVIDER_H
#define KDEVPLATFORM_IPROJECTFILTERPROVIDER_H

#include "../projectexport.h"

#include <QObject>
#include <QSharedPointer>

namespace KDevelop
{

class IProject;
class IProjectFilter;

/**
 * @short An interface to create project filters.
 *
 * Plugins implement this interface and return an instance of a custom
 * IProjectFilter implementation, which is then doing the actual filtering.
 *
 * The filter should then allow filtering of files and folders in a
 * threadsafe way.
 *
 * Project managers are supposed to listen to the filterChanged signal
 * and update the project filter accordingly, i.e. by creating a new
 * filter instance.
 *
 * This interface was designed such that project filtering can be done in a
 * multithreaded project manager without the need for any locks.
 *
 * @author Milian Wolff
 */
class KDEVPLATFORMPROJECT_EXPORT IProjectFilterProvider
{
public:
    virtual ~IProjectFilterProvider();

    /**
     * Factory function to create threadsafe project filter instances.
     *
     * @param project The project that the filter should operate on.
     *
     * @return A threadsafe implementation of the IProjectFilter instance.
     */
    virtual QSharedPointer<IProjectFilter> createFilter(IProject* project) const = 0;

Q_SIGNALS:
    /**
     * Should be emitted whenever the filter rules for the given @p project changed.
     *
     * Listeners should act on this signal by replacing their current filter
     * with a new instance.
     */
    void filterChanged(KDevelop::IProjectFilterProvider*, KDevelop::IProject* project);
};

}

Q_DECLARE_INTERFACE( KDevelop::IProjectFilterProvider, "org.kdevelop.IProjectFilterProvider")

#endif // KDEVPLATFORM_IPROJECTFILTERPROVIDER_H
