raven-rhel8/extras/KF6/gear/gwenview/gwenview-24.05.1/lib/print/printhelper.cpp

// vim: set tabstop=4 shiftwidth=4 expandtab:
/*
Gwenview: an image viewer
Copyright 2007 Aurélien Gâteau <agateau@kde.org>

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, 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 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.

*/
// Self
#include "printhelper.h"

// STD
#include <memory>

// Qt
#include <QCheckBox>
#include <QPainter>
#include <QPrintDialog>
#include <QPrintPreviewDialog>
#include <QPrinter>
#include <QUrl>

// KF
#include <KLocalizedString>

// Local
#include "printoptionspage.h"

namespace Gwenview
{
struct PrintHelperPrivate {
    QWidget *mParent = nullptr;

    QSize adjustSize(PrintOptionsPage *optionsPage, Document::Ptr doc, int printerResolution, const QSize &viewportSize)
    {
        QSize size = doc->size();
        PrintOptionsPage::ScaleMode scaleMode = optionsPage->scaleMode();
        if (scaleMode == PrintOptionsPage::ScaleToPage) {
            bool imageBiggerThanPaper = size.width() > viewportSize.width() || size.height() > viewportSize.height();

            if (imageBiggerThanPaper || optionsPage->enlargeSmallerImages()) {
                size.scale(viewportSize, Qt::KeepAspectRatio);
            }

        } else if (scaleMode == PrintOptionsPage::ScaleToCustomSize) {
            double wImg = optionsPage->scaleWidth();
            double hImg = optionsPage->scaleHeight();
            size.setWidth(int(wImg * printerResolution));
            size.setHeight(int(hImg * printerResolution));

        } else {
            // No scale
            const double INCHES_PER_METER = 100. / 2.54;
            const int dpmX = doc->image().dotsPerMeterX();
            const int dpmY = doc->image().dotsPerMeterY();
            if (dpmX > 0 && dpmY > 0) {
                double wImg = double(size.width()) / double(dpmX) * INCHES_PER_METER;
                double hImg = double(size.height()) / double(dpmY) * INCHES_PER_METER;
                size.setWidth(int(wImg * printerResolution));
                size.setHeight(int(hImg * printerResolution));
            }
        }
        return size;
    }

    QPoint adjustPosition(PrintOptionsPage *optionsPage, const QSize &imageSize, const QSize &viewportSize)
    {
        Qt::Alignment alignment = optionsPage->alignment();
        int posX, posY;

        if (alignment & Qt::AlignLeft) {
            posX = 0;
        } else if (alignment & Qt::AlignHCenter) {
            posX = (viewportSize.width() - imageSize.width()) / 2;
        } else {
            posX = viewportSize.width() - imageSize.width();
        }

        if (alignment & Qt::AlignTop) {
            posY = 0;
        } else if (alignment & Qt::AlignVCenter) {
            posY = (viewportSize.height() - imageSize.height()) / 2;
        } else {
            posY = viewportSize.height() - imageSize.height();
        }

        return QPoint(posX, posY);
    }

    void setupPrinter(QPrinter *printer, Document::Ptr doc)
    {
        doc->waitUntilLoaded();
        printer->setDocName(doc->url().fileName());
        const auto docSize = doc->size();
        printer->setPageOrientation(docSize.width() > docSize.height() ? QPageLayout::Landscape : QPageLayout::Portrait);
    }

    void print(QPrinter *printer, Document::Ptr doc, bool showPrinterSetupDialog)
    {
        auto optionsPage = new PrintOptionsPage(doc->size());
        optionsPage->loadConfig();

        QScopedPointer<QPrintDialog> dialog;
        if (showPrinterSetupDialog) {
            dialog.reset(new QPrintDialog(printer, mParent));
#if defined(Q_OS_UNIX) && !defined(Q_OS_DARWIN)
            dialog->setOptionTabs(QList<QWidget *>() << optionsPage);
#else
            optionsPage->setParent(dialog.data());
#endif

            dialog->setWindowTitle(i18n("Print Image"));
            bool wantToPrint = dialog->exec();

            optionsPage->saveConfig();
            if (!wantToPrint) {
                return;
            }
        }

        QPainter painter(printer);
        const QRect rect = painter.viewport();
        const QSize size = adjustSize(optionsPage, doc, printer->resolution(), rect.size());
        const QPoint pos = adjustPosition(optionsPage, size, rect.size());
        painter.setViewport(pos.x(), pos.y(), size.width(), size.height());
        if (!dialog) {
            delete optionsPage;
        }

        const QImage image = doc->image();
        painter.setWindow(image.rect());
        painter.drawImage(0, 0, image);
    }
};

PrintHelper::PrintHelper(QWidget *parent)
    : d(new PrintHelperPrivate)
{
    d->mParent = parent;
}

PrintHelper::~PrintHelper()
{
    delete d;
}

void PrintHelper::print(Document::Ptr doc)
{
    QPrinter printer;
    d->setupPrinter(&printer, doc);
    d->print(&printer, doc, true);
}

void PrintHelper::printPreview(Document::Ptr doc)
{
    QPrinter printer;
    d->setupPrinter(&printer, doc);
    QPrintPreviewDialog dlg(&printer, d->mParent);
    QObject::connect(&dlg, &QPrintPreviewDialog::paintRequested, [this, doc](QPrinter *printer) {
        d->print(printer, doc, false);
    });
    dlg.exec();
}

} // namespace