dataengine.h

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/*
 *   Copyright 2006-2007 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_DATAENGINE_H
#define PLASMA_DATAENGINE_H

#include <QtCore/QHash>
#include <QtCore/QObject>
#include <QtCore/QStringList>

#include <kgenericfactory.h>
#include <kservice.h>

#include <plasma/version.h>
#include <plasma/plasma.h>
#include <plasma/service.h>

namespace Plasma
{

class DataContainer;
class DataEngineScript;
class Package;
class Service;
class DataEnginePrivate;

class PLASMA_EXPORT DataEngine : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QStringList sources READ sources)
    Q_PROPERTY(bool valid READ isValid)
    Q_PROPERTY(QString icon READ icon WRITE setIcon)
    Q_PROPERTY(QString name READ name)

    public:
        typedef QHash<QString, DataEngine*> Dict;
        typedef QHash<QString, QVariant> Data;
        typedef QHashIterator<QString, QVariant> DataIterator;
        typedef QHash<QString, DataContainer*> SourceDict;

        explicit DataEngine(QObject *parent = 0, KService::Ptr service = KService::Ptr(0));
        DataEngine(QObject *parent, const QVariantList &args);
        ~DataEngine();

        virtual void init();

        virtual QStringList sources() const;

        Q_INVOKABLE virtual Service *serviceForSource(const QString &source);

        QString name() const;

        Q_INVOKABLE void connectSource(
            const QString &source, QObject *visualization,
            uint pollingInterval = 0,
            Plasma::IntervalAlignment intervalAlignment = NoAlignment) const;

        Q_INVOKABLE void connectAllSources(QObject *visualization, uint pollingInterval = 0,
                                           Plasma::IntervalAlignment intervalAlignment =
NoAlignment) const;

        Q_INVOKABLE void disconnectSource(const QString &source, QObject *visualization) const;

        Q_INVOKABLE DataContainer *containerForSource(const QString &source);

        Q_INVOKABLE DataEngine::Data query(const QString &source) const;

        bool isValid() const;

        bool isEmpty() const;

        uint maxSourceCount() const;

        QString icon() const;

        const Package *package() const;

        QString pluginName() const;

        Q_INVOKABLE Service* createDefaultService(QObject *parent = 0);

    Q_SIGNALS:
        void sourceAdded(const QString &source);

        void sourceRemoved(const QString &source);

    protected:
        virtual bool sourceRequestEvent(const QString &source);

        virtual bool updateSourceEvent(const QString &source);

        void setData(const QString &source, const QVariant &value);

        void setData(const QString &source, const QString &key, const QVariant &value);

        void setData(const QString &source, const Data &data);

        void removeAllData(const QString &source);

        void removeData(const QString &source, const QString &key);

        void addSource(DataContainer *source);

        void setMaxSourceCount(uint limit);

        void setMinimumPollingInterval(int minimumMs);

        int minimumPollingInterval() const;

        void setPollingInterval(uint frequency);

        void removeAllSources();

        void setValid(bool valid);

        SourceDict containerDict() const;

        void timerEvent(QTimerEvent *event);

        void setName(const QString &name);

        void setIcon(const QString &icon);

        void setDefaultService(const QString &serviceName);

        void setStorageEnabled(const QString &source, bool store);

    protected Q_SLOTS:
        void scheduleSourcesUpdated();

        void removeSource(const QString &source);

        void updateAllSources();

        void forceImmediateUpdateOfAllVisualizations();

    private:
        friend class DataEnginePrivate;
        friend class DataEngineScript;
        friend class DataEngineManager;
        friend class PlasmoidServiceJob;
        friend class NullEngine;

        Q_PRIVATE_SLOT(d, void internalUpdateSource(DataContainer *source))
        Q_PRIVATE_SLOT(d, void sourceDestroyed(QObject *object))

        DataEnginePrivate *const d;
};

} // Plasma namespace

#define K_EXPORT_PLASMA_DATAENGINE(libname, classname) \
K_PLUGIN_FACTORY(factory, registerPlugin<classname>();) \
K_EXPORT_PLUGIN(factory("plasma_engine_" #libname)) \
K_EXPORT_PLUGIN_VERSION(PLASMA_VERSION)

Q_DECLARE_METATYPE(Plasma::DataEngine*)

#endif // multiple inclusion guard