plasma-framework/src/declarativeimports/core/datasource.cpp

/*
 *   Copyright 2009 by Alan Alpert <alan.alpert@nokia.com>
 *   Copyright 2010 by Ménard Alexis <menard@kde.org>
 *   Copyright 2010 by Marco Martin <mart@kde.org>
 *   Copyright 2013 by Sebastian Kügler <sebas@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.
 */

#include "datasource.h"

namespace Plasma
{
DataSource::DataSource(QObject *parent)
    : QObject(parent),
      m_ready(false),
      m_interval(0),
      m_intervalAlignment(Plasma::Types::NoAlignment),
      m_dataEngine(0),
      m_dataEngineConsumer(0)
{
    m_models = new QQmlPropertyMap(this);
    m_data = new QQmlPropertyMap(this);
    setObjectName("DataSource");
}

void DataSource::classBegin()
{

}

void DataSource::componentComplete()
{
    m_ready = true;
    setupData();
}

void DataSource::setConnectedSources(const QStringList &sources)
{
    bool sourcesChanged = false;
    foreach (const QString &source, sources) {
        if (!m_connectedSources.contains(source)) {
            sourcesChanged = true;
            if (m_dataEngine) {
                m_connectedSources.append(source);
                m_dataEngine->connectSource(source, this, m_interval, m_intervalAlignment);
                emit sourceConnected(source);
            }
        }
    }

    foreach (const QString &source, m_connectedSources) {
        if (!sources.contains(source)) {
            m_data->clear(source);
            sourcesChanged = true;
            if (m_dataEngine) {
                m_dataEngine->disconnectSource(source, this);
                emit sourceDisconnected(source);
            }
        }
    }

    if (sourcesChanged) {
        m_connectedSources = sources;
        emit connectedSourcesChanged();
    }
}

void DataSource::setEngine(const QString &e)
{
    if (e == m_engine) {
        return;
    }

    m_engine = e;

    if (m_engine.isEmpty()) {
        emit engineChanged();
        return;
    }

    m_dataEngineConsumer = new Plasma::DataEngineConsumer();
    Plasma::DataEngine *engine = dataEngine(m_engine);
    if (!engine) {
        qWarning() << "DataEngine" << m_engine << "not found";
        emit engineChanged();
        return;
    }

    if (m_dataEngine) {
        m_dataEngine->disconnect(this);
        // Deleting the consumer triggers the reference counting
        delete m_dataEngineConsumer;
        m_dataEngineConsumer = 0;
    }

    /*
     * It is due little explanation why this is a queued connection:
     * If sourceAdded arrives immediately, in the case we have a datamodel
     * with items at source level we connect too soon (before setData for
     * all roles is done), having a dataupdated in the datamodel with only
     * the first role, killing off the other roles.
     * Besides causing a model reset more, unfortunately setRoleNames can be done a single time, so is not possible adding new roles after the
     * first setRoleNames() is called.
     * This fixes engines that have 1 item per source like the
     * recommendations engine.
     */
    m_dataEngine = engine;
    connect(m_dataEngine, SIGNAL(sourceAdded(QString)), this, SLOT(updateSources()), Qt::QueuedConnection);
    connect(m_dataEngine, SIGNAL(sourceRemoved(QString)), this, SLOT(updateSources()));

    connect(m_dataEngine, SIGNAL(sourceAdded(QString)), this, SIGNAL(sourceAdded(QString)), Qt::QueuedConnection);
    connect(m_dataEngine, SIGNAL(sourceRemoved(QString)), this, SLOT(removeSource(QString)));
    connect(m_dataEngine, SIGNAL(sourceRemoved(QString)), this, SIGNAL(sourceRemoved(QString)));

    updateSources();

    emit engineChanged();
}

void DataSource::setInterval(const int interval)
{
    if (interval == m_interval) {
        return;
    }

    m_interval = interval;
    setupData();
    emit intervalChanged();
}

void DataSource::setIntervalAlignment(Plasma::Types::IntervalAlignment intervalAlignment)
{
    if (intervalAlignment == m_intervalAlignment) {
        return;
    }

    m_intervalAlignment = intervalAlignment;
    setupData();
    emit intervalAlignmentChanged();
}

void DataSource::setupData()
{
    if (!m_ready) {
        return;
    }

//     qDebug() << " loading engine " << m_engine;
    //FIXME: should all services be deleted just because we're changing the interval, etc?
    qDeleteAll(m_services);
    m_services.clear();

    foreach (const QString &source, m_connectedSources) {
        m_dataEngine->connectSource(source, this, m_interval, m_intervalAlignment);
        emit sourceConnected(source);
    }
}

void DataSource::dataUpdated(const QString &sourceName, const Plasma::DataEngine::Data &data)
{
    //it can arrive also data we don't explicitly connected a source
    if (m_connectedSources.contains(sourceName)) {
        m_data->insert(sourceName.toLatin1(), data);
        emit dataChanged();
        emit newData(sourceName, data);
    } else if (m_dataEngine) {
        m_dataEngine->disconnectSource(sourceName, this);
    }
}

void DataSource::modelChanged(const QString &sourceName, QAbstractItemModel *model)
{
    if (!model) {
        m_models->clear(sourceName);
        return;
    }

    m_models->insert(sourceName, QVariant::fromValue(model));
    //FIXME: this will break in the case a second model is set
    connect(model, &QObject::destroyed, m_models, [ = ]() {
        m_models->clear(sourceName);
    });
}

void DataSource::removeSource(const QString &source)
{
    m_data->clear(source);
    m_models->clear(source);

    //TODO: emit those signals as last thing
    if (m_connectedSources.contains(source)) {
        m_connectedSources.removeAll(source);
        emit sourceDisconnected(source);
        emit connectedSourcesChanged();
    }

    if (m_dataEngine) {
        QHash<QString, Plasma::Service *>::iterator it = m_services.find(source);
        if (it != m_services.end()) {
            delete it.value();
            m_services.erase(it);
        }
    }
}

QObject *DataSource::serviceForSource(const QString &source)
{
    if (!m_services.contains(source)) {
        Plasma::Service *service = m_dataEngine->serviceForSource(source);
        if (!service) {
            return 0;
        }
        m_services[source] = service;
    }

    return m_services.value(source);
}

void DataSource::connectSource(const QString &source)
{
    if (m_connectedSources.contains(source)) {
        return;
    }

    m_connectedSources.append(source);
    if (m_dataEngine) {
        m_dataEngine->connectSource(source, this, m_interval, m_intervalAlignment);
        emit sourceConnected(source);
        emit connectedSourcesChanged();
    }
}

void DataSource::disconnectSource(const QString &source)
{
    if (m_dataEngine && m_connectedSources.contains(source)) {
        m_connectedSources.removeAll(source);
        m_dataEngine->disconnectSource(source, this);
        emit sourceDisconnected(source);
        emit connectedSourcesChanged();
    }
}

void DataSource::updateSources()
{
    QStringList sources;
    if (m_dataEngine) {
        sources = m_dataEngine->sources();
    }

    if (sources != m_sources) {
        m_sources = sources;
        emit sourcesChanged();
    }
}

}