globaldescriptioncontainer.h

/*
    Copyright (C) 2011 Harald Sitter <sitter@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), Nokia Corporation
    (or its successors, if any) and the KDE Free Qt Foundation, which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PHONON_GLOBALDESCRIPTIONCONTAINER_H
#define PHONON_GLOBALDESCRIPTIONCONTAINER_H

#include <QtCore/QMap>
#include <QtCore/QDebug>
#include <QtCore/QtGlobal>

#include <phonon/objectdescription.h>

namespace Phonon
{

class MediaController;

template <typename D>
class GlobalDescriptionContainer
{
public:
    typedef int global_id_t;
    typedef int local_id_t;

    typedef QMap<global_id_t, D> GlobalDescriptorMap;
    typedef QMapIterator<global_id_t, D> GlobalDescriptorMapIterator;

    typedef QMap<global_id_t, local_id_t> LocalIdMap;
    typedef QMapIterator<global_id_t, local_id_t> LocaIdMapIterator;

public:
    static GlobalDescriptionContainer *self;

    static GlobalDescriptionContainer *instance()
    {
        if (!self)
            self = new GlobalDescriptionContainer;
        return self;
    }

    virtual ~GlobalDescriptionContainer() {}

    QList<int> globalIndexes()
    {
        QList<int> list;
        GlobalDescriptorMapIterator it(m_globalDescriptors);
        while (it.hasNext()) {
            it.next();
            list << it.key();
        }
        return list;
    }

    D fromIndex(global_id_t key)
    {
        return m_globalDescriptors.value(key, D());
    }

    // ----------- MediaController Specific ----------- //

    void register_(void *obj)
    {
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) == m_localIds.end());
        m_localIds[obj] = LocalIdMap();
    }

    void unregister_(void *obj)
    {
        // TODO: remove all descriptions that are *only* associated with this MC
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) != m_localIds.end());
        m_localIds[obj].clear();
        m_localIds.remove(obj);
    }

    void clearListFor(void *obj)
    {
        Q_ASSERT(obj);
        Q_ASSERT_X(m_localIds.find(obj) != m_localIds.end(),
                   "clearing list",
                   "the object is not registered!");
        m_localIds[obj].clear();
    }

    void add(void *obj,
             local_id_t index, const QString &name, const QString &type = QString())
    {
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) != m_localIds.end());

        QHash<QByteArray, QVariant> properties;
        properties.insert("name", name);
        properties.insert("description", "");
        properties.insert("type", type);

        // Empty lists will start at 0.
        global_id_t id = 0;
        {
            // Find id, either a descriptor with name and type is already present
            // or get the next available index.
            GlobalDescriptorMapIterator it(m_globalDescriptors);
            while (it.hasNext()) {
                it.next();
                if (it.value().property("name") == name &&
                        it.value().property("type") == type) {
                    id = it.value().index();
                }
            }
            if (id == 0)
                id = nextFreeIndex();
        }
        D descriptor = D(id, properties);

        m_globalDescriptors.insert(id, descriptor);
        m_localIds[obj].insert(id, index);
    }

    void add(void *obj,
             D descriptor)
    {
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) != m_localIds.end());
        Q_ASSERT(m_globalDescriptors.find(descriptor.index()) == m_globalDescriptors.end());

        m_globalDescriptors.insert(descriptor.index(), descriptor);
        m_localIds[obj].insert(descriptor.index(), descriptor.index());
    }

    QList<D> listFor(const void *obj) const
    {
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) != m_localIds.end());

        QList<D> list;
        LocaIdMapIterator it(m_localIds.value(obj));
        while (it.hasNext()) {
            it.next();
            Q_ASSERT(m_globalDescriptors.find(it.key()) != m_globalDescriptors.end());
            list << m_globalDescriptors[it.key()];
        }
        return list;
    }

    int localIdFor(const void *obj, global_id_t key) const
    {
        Q_ASSERT(obj);
        Q_ASSERT(m_localIds.find(obj) != m_localIds.end());
        if (m_localIds[obj].find(key) == m_localIds[obj].end())
            qWarning() << "WARNING:" << Q_FUNC_INFO
                       << ": supplied global ID is unknown for the object ("
                       << obj << ")";
        return m_localIds[obj].value(key, 0);
    }

protected:
    GlobalDescriptionContainer() :
        m_peak(0)
    {
    }

    global_id_t nextFreeIndex()
    {
        return ++m_peak;
    }

    GlobalDescriptorMap m_globalDescriptors;
    QMap<const void *, LocalIdMap> m_localIds;

    global_id_t m_peak;
};

template <typename D>
GlobalDescriptionContainer<D> *GlobalDescriptionContainer<D>::self = 0;

typedef GlobalDescriptionContainer<AudioChannelDescription> GlobalAudioChannels;
typedef GlobalDescriptionContainer<SubtitleDescription> GlobalSubtitles;

} // Namespace Phonon

#endif // PHONON_GLOBALDESCRIPTIONCONTAINER_H