ZblSprocket.cpp

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/*
 * Zuble - A run-time system for QML/Javascript applications
 * Copyright (C) 2014 Bob Dinitto
 *
 * Filename:   ZblSprocket.cpp
 * Created on: 12/10/2014
 * Author:     Bob Dinitto
 *
 * Zuble 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) 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
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "ZblSprocket.h"
#include "ZblSprockOb.h"
#include "zglobal.h"
#include <QObject>
#include <QTextStream>
#include <QDebug>

namespace Zbl
{

#if 0
bool ZblSprocket::operator==(const ZblSprocket& other) const
{
    //return (qobject_cast<const QObject*>(other.m_sprocket))
   // == (qobject_cast<const QObject*>(m_sprocket));
    return false;
}
#endif


bool ZblSprocket::registerSprocketObject(
        const char* uri,
        int versionMajor,
        int versionMinor,
        const char* qmlName,
        sprocketObjectConstructor createFunc)
{

    ZblSprockOb* sprock = findSprock(versionMajor, versionMinor, qmlName);

    if(sprock)
    {
        qWarning("ZblSprocket::registerSprocketObject - object "
                 "registration FAILED: object already exists: "
                 "%s:%s:%d:%d", uri, qmlName, versionMajor, versionMinor );
        return false;
    }

    sprock = new ZblSprockOb(uri, versionMajor, versionMinor,
                             qmlName, createFunc);

    if(!sprock)
    {
        qWarning("ZblSprocket::registerSprocketObject - object "
                 "registration FAILED: can't bind sprocket object: "
                 "%s:%s:%d:%d", uri, qmlName, versionMajor, versionMinor );
        return false;
    }

    if(!insertSprock(sprock))
        return false;

    return true;
}

ZblSprockOb* ZblSprocket::findSprock(
    int versionMajor,
    int versionMinor,
    const char* qmlName)
{
    sprocketVersionMap* versions = m_objects.value(qmlName, NULL);

    if(!versions)
        return NULL;

    // Magical QML version semantics implemented here!!! if the key doesn't
    // exist select the version key that is closest to the requested
    // import version ie the highest object version less than import version

    int requestedVersion = versionKey(versionMajor, versionMinor);

    ZblSprockOb* sproc = versions->value(requestedVersion, NULL);

    if(sproc)
        return sproc; // key exists

    // not lucky so work for it!

    QList<int> keys(versions->keys());

    if(keys.isEmpty())
        return NULL; // this shouldn't ever happen due to lazy map construction

    int nextKey;

    for(int i=0,previous=-1; i < keys.size(); i++)
    {
        nextKey = keys.at(i);

        if(nextKey > requestedVersion)
        {
            if(previous == -1)
            {
                return NULL; // no objects of this type in requested version
            }
            else
            {
                // previous is highest object version in requested version

                nextKey = previous;
                break;
            }
        }
        previous = nextKey;
    }

    return versions->value(nextKey, NULL);
}

bool ZblSprocket::insertSprock(ZblSprockOb* sprock)
{
    sprocketVersionMap* versions = m_objects.value(sprock->qmlName(), NULL);

    const int key = versionKey(sprock->versionMajor(), sprock->versionMinor());

    if(!versions)
    {
        versions = new sprocketVersionMap(); // lazy map construction

        m_objects.insert(sprock->qmlName(), versions);
    }
    else
    {
        if(versions->contains(key))
        {
            qWarning() << "ZblSprocket::insertSprock FAILED: object already exists:"
                        << sprocketTag(
                               cStr(sprock->qmlName()),
                               sprock->versionMajor(),
                               sprock->versionMinor()
                               );
            return false;
        }
    }

    versions->insert(key, sprock);

    return true;
}


const QString ZblSprocket::sprocketTag(
        const char* uri,
        int versionMajor,
        int versionMinor
        )
{
    QString ret;
    QTextStream ts(&ret);
    ts << uri << ":" << versionMajor << ":" << versionMinor;
    return ret;
}

const QString ZblSprocket::sprocketTag(const ZblSprocket* sprocket)
{
    return sprocketTag(sprocket->uri().toUtf8().constData(), sprocket->versionMajor(), sprocket->versionMinor());
}

} // Zbl