okular/generators/djvu/generator_djvu.cpp

/*
    SPDX-FileCopyrightText: 2006 Pino Toscano <toscano.pino@tiscali.it>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "generator_djvu.h"

#include <core/action.h>
#include <core/annotations.h>
#include <core/area.h>
#include <core/document.h>
#include <core/fileprinter.h>
#include <core/page.h>
#include <core/textpage.h>
#include <core/utils.h>

#include <QDomDocument>
#include <QMutex>
#include <QPixmap>
#include <QPrinter>
#include <QString>
#include <QUuid>

#include <KAboutData>
#include <KLocalizedString>
#include <QDebug>
#include <QDir>
#include <QTemporaryFile>

static void recurseCreateTOC(QDomDocument &maindoc, const QDomNode &parent, QDomNode &parentDestination, KDjVu *djvu)
{
    QDomNode n = parent.firstChild();
    while (!n.isNull()) {
        QDomElement el = n.toElement();

        QDomElement newel = maindoc.createElement(el.attribute(QStringLiteral("title")));
        parentDestination.appendChild(newel);

        QString dest;
        if (!(dest = el.attribute(QStringLiteral("PageNumber"))).isEmpty()) {
            Okular::DocumentViewport vp;
            vp.pageNumber = dest.toInt() - 1;
            newel.setAttribute(QStringLiteral("Viewport"), vp.toString());
        } else if (!(dest = el.attribute(QStringLiteral("PageName"))).isEmpty()) {
            Okular::DocumentViewport vp;
            vp.pageNumber = djvu->pageNumber(dest);
            newel.setAttribute(QStringLiteral("Viewport"), vp.toString());
        } else if (!(dest = el.attribute(QStringLiteral("URL"))).isEmpty()) {
            newel.setAttribute(QStringLiteral("URL"), dest);
        }

        if (el.hasChildNodes()) {
            recurseCreateTOC(maindoc, n, newel, djvu);
        }
        n = n.nextSibling();
    }
}

OKULAR_EXPORT_PLUGIN(DjVuGenerator, "libokularGenerator_djvu.json")

DjVuGenerator::DjVuGenerator(QObject *parent, const QVariantList &args)
    : Okular::Generator(parent, args)
    , m_docSyn(nullptr)
{
    setFeature(TextExtraction);
    setFeature(Threaded);
    setFeature(PrintPostscript);
    if (Okular::FilePrinter::ps2pdfAvailable())
        setFeature(PrintToFile);

    m_djvu = new KDjVu();
    m_djvu->setCacheEnabled(false);
}

DjVuGenerator::~DjVuGenerator()
{
    delete m_djvu;
}

bool DjVuGenerator::loadDocument(const QString &fileName, QVector<Okular::Page *> &pagesVector)
{
    QMutexLocker locker(userMutex());
    if (!m_djvu->openFile(fileName))
        return false;

    locker.unlock();

    loadPages(pagesVector, 0);

    return true;
}

bool DjVuGenerator::doCloseDocument()
{
    userMutex()->lock();
    m_djvu->closeFile();
    userMutex()->unlock();

    delete m_docSyn;
    m_docSyn = nullptr;

    return true;
}

QImage DjVuGenerator::image(Okular::PixmapRequest *request)
{
    userMutex()->lock();
    QImage img = m_djvu->image(request->pageNumber(), request->width(), request->height(), request->page()->rotation());
    userMutex()->unlock();
    return img;
}

Okular::DocumentInfo DjVuGenerator::generateDocumentInfo(const QSet<Okular::DocumentInfo::Key> &keys) const
{
    Okular::DocumentInfo docInfo;

    if (keys.contains(Okular::DocumentInfo::MimeType))
        docInfo.set(Okular::DocumentInfo::MimeType, QStringLiteral("image/vnd.djvu"));

    if (m_djvu) {
        // compile internal structure reading properties from KDjVu
        if (keys.contains(Okular::DocumentInfo::Author))
            docInfo.set(Okular::DocumentInfo::Title, m_djvu->metaData(QStringLiteral("title")).toString());
        if (keys.contains(Okular::DocumentInfo::Author))
            docInfo.set(Okular::DocumentInfo::Author, m_djvu->metaData(QStringLiteral("author")).toString());
        if (keys.contains(Okular::DocumentInfo::CreationDate))
            docInfo.set(Okular::DocumentInfo::CreationDate, m_djvu->metaData(QStringLiteral("year")).toString());
        if (keys.contains(Okular::DocumentInfo::CustomKeys)) {
            docInfo.set(QStringLiteral("editor"), m_djvu->metaData(QStringLiteral("editor")).toString(), i18n("Editor"));
            docInfo.set(QStringLiteral("publisher"), m_djvu->metaData(QStringLiteral("publisher")).toString(), i18n("Publisher"));
            docInfo.set(QStringLiteral("volume"), m_djvu->metaData(QStringLiteral("volume")).toString(), i18n("Volume"));
            docInfo.set(QStringLiteral("documentType"), m_djvu->metaData(QStringLiteral("documentType")).toString(), i18n("Type of document"));
            QVariant numcomponents = m_djvu->metaData(QStringLiteral("componentFile"));
            docInfo.set(QStringLiteral("componentFile"), numcomponents.type() != QVariant::Int ? i18nc("Unknown number of component files", "Unknown") : numcomponents.toString(), i18n("Component Files"));
        }
    }

    return docInfo;
}

const Okular::DocumentSynopsis *DjVuGenerator::generateDocumentSynopsis()
{
    QMutexLocker locker(userMutex());
    if (m_docSyn)
        return m_docSyn;

    const QDomDocument *doc = m_djvu->documentBookmarks();
    if (doc) {
        m_docSyn = new Okular::DocumentSynopsis();
        recurseCreateTOC(*m_docSyn, *doc, *m_docSyn, m_djvu);
    }
    locker.unlock();

    return m_docSyn;
}

Okular::Document::PrintError DjVuGenerator::print(QPrinter &printer)
{
    // Create tempfile to write to
    QTemporaryFile tf(QDir::tempPath() + QLatin1String("/okular_XXXXXX.ps"));
    if (!tf.open())
        return Okular::Document::TemporaryFileOpenPrintError;
    const QString fileName = tf.fileName();

    QMutexLocker locker(userMutex());
    QList<int> pageList = Okular::FilePrinter::pageList(printer, m_djvu->pages().count(), document()->currentPage() + 1, document()->bookmarkedPageList());

    if (m_djvu->exportAsPostScript(&tf, pageList)) {
        tf.setAutoRemove(false);
        tf.close();
        return Okular::FilePrinter::printFile(printer, fileName, document()->orientation(), Okular::FilePrinter::SystemDeletesFiles, Okular::FilePrinter::ApplicationSelectsPages, document()->bookmarkedPageRange());
    }

    return Okular::Document::UnknownPrintError;
}

QVariant DjVuGenerator::metaData(const QString &key, const QVariant &option) const
{
    Q_UNUSED(option)
    if (key == QLatin1String("DocumentTitle")) {
        return m_djvu->metaData(QStringLiteral("title"));
    }
    return QVariant();
}

Okular::TextPage *DjVuGenerator::textPage(Okular::TextRequest *request)
{
    userMutex()->lock();
    const Okular::Page *page = request->page();
    QList<KDjVu::TextEntity> te;
    if (te.isEmpty())
        te = m_djvu->textEntities(page->number(), QStringLiteral("word"));
    if (te.isEmpty())
        te = m_djvu->textEntities(page->number(), QStringLiteral("line"));
    userMutex()->unlock();
    QList<KDjVu::TextEntity>::ConstIterator it = te.constBegin();
    QList<KDjVu::TextEntity>::ConstIterator itEnd = te.constEnd();
    QList<Okular::TextEntity *> words;
    const KDjVu::Page *djvupage = m_djvu->pages().at(page->number());
    for (; it != itEnd; ++it) {
        const KDjVu::TextEntity &cur = *it;
        words.append(new Okular::TextEntity(cur.text(), new Okular::NormalizedRect(cur.rect(), djvupage->width(), djvupage->height())));
    }
    Okular::TextPage *textpage = new Okular::TextPage(words);
    return textpage;
}

void DjVuGenerator::loadPages(QVector<Okular::Page *> &pagesVector, int rotation)
{
    const QVector<KDjVu::Page *> &djvu_pages = m_djvu->pages();
    int numofpages = djvu_pages.count();
    pagesVector.resize(numofpages);

    for (int i = 0; i < numofpages; ++i) {
        const KDjVu::Page *p = djvu_pages.at(i);
        if (pagesVector[i])
            delete pagesVector[i];
        int w = p->width();
        int h = p->height();
        if (rotation % 2 == 1)
            qSwap(w, h);
        Okular::Page *page = new Okular::Page(i, w, h, (Okular::Rotation)(p->orientation() + rotation));
        pagesVector[i] = page;

        QList<KDjVu::Annotation *> annots;
        QList<KDjVu::Link *> links;
        userMutex()->lock();
        m_djvu->linksAndAnnotationsForPage(i, &links, &annots);
        userMutex()->unlock();
        if (!links.isEmpty()) {
            QLinkedList<Okular::ObjectRect *> rects;
            QList<KDjVu::Link *>::ConstIterator it = links.constBegin();
            QList<KDjVu::Link *>::ConstIterator itEnd = links.constEnd();
            for (; it != itEnd; ++it) {
                KDjVu::Link *curlink = (*it);
                Okular::ObjectRect *newrect = convertKDjVuLink(i, curlink);
                if (newrect)
                    rects.append(newrect);
                // delete the links as soon as we process them
                delete curlink;
            }
            if (rects.count() > 0)
                page->setObjectRects(rects);
        }
        if (!annots.isEmpty()) {
            QList<KDjVu::Annotation *>::ConstIterator it = annots.constBegin();
            QList<KDjVu::Annotation *>::ConstIterator itEnd = annots.constEnd();
            for (; it != itEnd; ++it) {
                KDjVu::Annotation *ann = (*it);
                Okular::Annotation *newann = convertKDjVuAnnotation(w, h, ann);
                if (newann)
                    page->addAnnotation(newann);
                // delete the annotations as soon as we process them
                delete ann;
            }
        }
    }
}

Okular::ObjectRect *DjVuGenerator::convertKDjVuLink(int page, KDjVu::Link *link) const
{
    Okular::Action *newlink = nullptr;
    Okular::ObjectRect *newrect = nullptr;
    switch (link->type()) {
    case KDjVu::Link::PageLink: {
        KDjVu::PageLink *l = static_cast<KDjVu::PageLink *>(link);
        bool ok = true;
        QString target = l->page();
        if ((target.length() > 0) && target.at(0) == QLatin1Char('#'))
            target.remove(0, 1);
        int tmppage = target.toInt(&ok);
        if (ok || target.isEmpty()) {
            Okular::DocumentViewport vp;
            if (!target.isEmpty())
                vp.pageNumber = (target.at(0) == QLatin1Char('+') || target.at(0) == QLatin1Char('-')) ? page + tmppage : tmppage - 1;
            newlink = new Okular::GotoAction(QString(), vp);
        }
        break;
    }
    case KDjVu::Link::UrlLink: {
        KDjVu::UrlLink *l = static_cast<KDjVu::UrlLink *>(link);
        QString url = l->url();
        newlink = new Okular::BrowseAction(QUrl(url));
        break;
    }
    }
    if (newlink) {
        const KDjVu::Page *p = m_djvu->pages().at(page);
        int width = p->width();
        int height = p->height();
        bool scape_orientation = false; // hack by tokoe, should always create default page
        if (scape_orientation)
            qSwap(width, height);
        switch (link->areaType()) {
        case KDjVu::Link::RectArea:
        case KDjVu::Link::EllipseArea: {
            QRect r(QPoint(link->point().x(), p->height() - link->point().y() - link->size().height()), link->size());
            bool ellipse = (link->areaType() == KDjVu::Link::EllipseArea);
            newrect = new Okular::ObjectRect(Okular::NormalizedRect(Okular::Utils::rotateRect(r, width, height, 0), width, height), ellipse, Okular::ObjectRect::Action, newlink);
            break;
        }
        case KDjVu::Link::PolygonArea: {
            QPolygon poly = link->polygon();
            QPolygonF newpoly;
            for (int i = 0; i < poly.count(); ++i) {
                int x = poly.at(i).x();
                int y = poly.at(i).y();
                if (scape_orientation)
                    qSwap(x, y);
                else {
                    y = height - y;
                }
                newpoly << QPointF((double)(x) / width, (double)(y) / height);
            }
            if (!newpoly.isEmpty()) {
                newpoly << newpoly.first();
                newrect = new Okular::ObjectRect(newpoly, Okular::ObjectRect::Action, newlink);
            }
            break;
        }
        default:;
        }
        if (!newrect) {
            delete newlink;
        }
    }
    return newrect;
}

Okular::Annotation *DjVuGenerator::convertKDjVuAnnotation(int w, int h, KDjVu::Annotation *ann) const
{
    Okular::Annotation *newann = nullptr;
    switch (ann->type()) {
    case KDjVu::Annotation::TextAnnotation: {
        KDjVu::TextAnnotation *txtann = static_cast<KDjVu::TextAnnotation *>(ann);
        Okular::TextAnnotation *newtxtann = new Okular::TextAnnotation();
        // boundary
        QRect rect(QPoint(txtann->point().x(), h - txtann->point().y() - txtann->size().height()), txtann->size());
        newtxtann->setBoundingRectangle(Okular::NormalizedRect(Okular::Utils::rotateRect(rect, w, h, 0), w, h));
        // type
        newtxtann->setTextType(txtann->inlineText() ? Okular::TextAnnotation::InPlace : Okular::TextAnnotation::Linked);
        newtxtann->style().setOpacity(txtann->color().alphaF());
        // FIXME remove once the annotation text handling is fixed
        newtxtann->setContents(ann->comment());
        newann = newtxtann;
        break;
    }
    case KDjVu::Annotation::LineAnnotation: {
        KDjVu::LineAnnotation *lineann = static_cast<KDjVu::LineAnnotation *>(ann);
        Okular::LineAnnotation *newlineann = new Okular::LineAnnotation();
        // boundary
        QPoint a(lineann->point().x(), h - lineann->point().y());
        QPoint b(lineann->point2().x(), h - lineann->point2().y());
        QRect rect = QRect(a, b).normalized();
        newlineann->setBoundingRectangle(Okular::NormalizedRect(Okular::Utils::rotateRect(rect, w, h, 0), w, h));
        // line points
        QLinkedList<Okular::NormalizedPoint> points;
        points.append(Okular::NormalizedPoint(a.x(), a.y(), w, h));
        points.append(Okular::NormalizedPoint(b.x(), b.y(), w, h));
        newlineann->setLinePoints(points);
        // arrow?
        if (lineann->isArrow())
            newlineann->setLineEndStyle(Okular::LineAnnotation::OpenArrow);
        // width
        newlineann->style().setWidth(lineann->width());
        newann = newlineann;
        break;
    }
    }
    if (newann) {
        // setting the common parameters
        newann->style().setColor(ann->color());
        newann->setContents(ann->comment());
        // creating an id as name for the annotation
        QString uid = QUuid::createUuid().toString();
        uid.remove(0, 1);
        uid.chop(1);
        uid.remove(QLatin1Char('-'));
        newann->setUniqueName(uid);
        // is external
        newann->setFlags(newann->flags() | Okular::Annotation::External);
    }
    return newann;
}

#include "generator_djvu.moc"