PDF4QT/PdfForQtViewer/pdfwidgetutils.cpp

//    Copyright (C) 2019-2020 Jakub Melka
//
//    This file is part of PdfForQt.
//
//    PdfForQt 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 3 of the License, or
//    (at your option) any later version.
//
//    PdfForQt 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 PDFForQt.  If not, see <https://www.gnu.org/licenses/>.

#include "pdfwidgetutils.h"

#ifdef Q_OS_MAC
int qt_default_dpi_x() { return 72; }
int qt_default_dpi_y() { return 72; }
#else
int qt_default_dpi_x() { return 96; }
int qt_default_dpi_y() { return 96; }
#endif

namespace pdfviewer
{

int PDFWidgetUtils::getPixelSize(QWidget* widget, pdf::PDFReal sizeMM)
{
    const int width = widget->width();
    const int height = widget->height();

    if (width > height)
    {
        return pdf::PDFReal(width) * sizeMM / pdf::PDFReal(widget->widthMM());
    }
    else
    {
        return pdf::PDFReal(height) * sizeMM / pdf::PDFReal(widget->heightMM());
    }
}

int PDFWidgetUtils::scaleDPI_x(QWidget* widget, int unscaledSize)
{
    const double logicalDPI_x = widget->logicalDpiX();
    const double defaultDPI_x = qt_default_dpi_x();
    return (logicalDPI_x / defaultDPI_x) * unscaledSize;
}

void PDFWidgetUtils::scaleWidget(QWidget* widget, QSize unscaledSize)
{
    const double logicalDPI_x = widget->logicalDpiX();
    const double logicalDPI_y = widget->logicalDpiY();
    const double defaultDPI_x = qt_default_dpi_x();
    const double defaultDPI_y = qt_default_dpi_y();

    const int width = (logicalDPI_x / defaultDPI_x) * unscaledSize.width();
    const int height = (logicalDPI_y / defaultDPI_y) * unscaledSize.height();

    widget->resize(width, height);
}

} // namespace pdfviewer