From c5fedfb1ec79b97edec4a82b70f082fba93a5b5d Mon Sep 17 00:00:00 2001
From: Aleks Kissinger <aleks0@gmail.com>
Date: Mon, 31 Dec 2018 12:56:32 +0100
Subject: image export in progress

---
 src/data/pdfdocument.cpp | 132 +++++++++++++++++++++++++++++++++++++++++++++++
 src/data/pdfdocument.h   |  28 ++++++++++
 2 files changed, 160 insertions(+)
 create mode 100644 src/data/pdfdocument.cpp
 create mode 100644 src/data/pdfdocument.h

(limited to 'src/data')

diff --git a/src/data/pdfdocument.cpp b/src/data/pdfdocument.cpp
new file mode 100644
index 0000000..bfedeca
--- /dev/null
+++ b/src/data/pdfdocument.cpp
@@ -0,0 +1,132 @@
+#include "pdfdocument.h"
+
+#include <QFile>
+#include <QByteArray>
+#include <QDebug>
+#include <QSvgGenerator>
+#include <QPainter>
+#include <QApplication>
+#include <QClipboard>
+
+PdfDocument::PdfDocument(QString file, QObject *parent) : QObject(parent)
+{
+    // use loadFromData to avoid holding a lock on the PDF file in windows
+    QFile f(file);
+    if (f.open(QFile::ReadOnly)) {
+        QByteArray data = f.readAll();
+        f.close();
+        _doc = Poppler::Document::loadFromData(data);
+    } else {
+        _doc = nullptr;
+    }
+
+    if (!_doc) {
+        _doc = nullptr;
+        _page = nullptr;
+    } else {
+        _doc->setRenderHint(Poppler::Document::Antialiasing);
+        _doc->setRenderHint(Poppler::Document::TextAntialiasing);
+        _doc->setRenderHint(Poppler::Document::TextHinting);
+        _page = _doc->page(0);
+    }
+}
+
+void PdfDocument::renderTo(QLabel *label, QRect rect)
+{
+    if (!isValid()) return;
+
+    QSizeF pageSize = _page->pageSizeF();
+
+    qreal ratio = label->devicePixelRatioF();
+    //QRect rect = ui->scrollArea->visibleRegion().boundingRect();
+    int w = static_cast<int>(ratio * (rect.width() - 20));
+    int h = static_cast<int>(ratio * (rect.height() - 20));
+    qreal scale = fmin(static_cast<qreal>(w) / pageSize.width(),
+                       static_cast<qreal>(h) / pageSize.height());
+
+
+    int dpi = static_cast<int>(scale * 72.0);
+    int w1 = static_cast<int>(scale * pageSize.width());
+    int h1 = static_cast<int>(scale * pageSize.height());
+
+    //qDebug() << "hidpi ratio:" << ratio;
+    //qDebug() << "visible width:" << w;
+    //qDebug() << "visible height:" << h;
+    //qDebug() << "doc width:" << pageSize.width();
+    //qDebug() << "doc height:" << pageSize.height();
+    //qDebug() << "scale:" << scale;
+    //qDebug() << "dpi:" << dpi;
+
+    QPixmap pm = QPixmap::fromImage(_page->renderToImage(dpi, dpi, (w1 - w)/2,  (h1 - h)/2, w, h));
+    pm.setDevicePixelRatio(ratio);
+    label->setPixmap(pm);
+}
+
+bool PdfDocument::isValid()
+{
+    return (_page != nullptr);
+}
+
+bool PdfDocument::exportImage(QString file, const char *format, QSize outputSize)
+{
+    QImage img = asImage(outputSize);
+    if (!img.isNull()) return img.save(file, format);
+    else return false;
+}
+
+bool PdfDocument::exportPdf(QString file)
+{
+    if (!isValid()) return false;
+    Poppler::PDFConverter *conv = _doc->pdfConverter();
+    conv->setOutputFileName(file);
+    bool success = conv->convert();
+    delete conv;
+    return success;
+}
+
+void PdfDocument::copyImageToClipboard(QSize outputSize)
+{
+    QImage img = asImage(outputSize);
+    if (!img.isNull()) {
+        QApplication::clipboard()->setImage(img, QClipboard::Clipboard);
+    }
+}
+
+QImage PdfDocument::asImage(QSize outputSize)
+{
+    if (!isValid()) return QImage();
+    if (outputSize.isNull()) outputSize = size();
+    QSize pageSize = _page->pageSize();
+    int dpix = (72 * outputSize.width()) / pageSize.width();
+    int dpiy = (72 * outputSize.width()) / pageSize.width();
+    QImage img = _page->renderToImage(dpix, dpiy, 0,  0,
+                                      outputSize.width(), outputSize.height());
+    return img;
+}
+
+// CRASHES TikZiT when figures contain text, due to limitations of Arthur backend
+//void PdfDocument::exportToSvg(QString file, QSize size) {
+//    QSvgGenerator gen;
+//    gen.setFileName(file);
+//    gen.setSize(size);
+//    gen.setViewBox(QRect(0,0,size.width(),size.height()));
+//    gen.setDescription("SVG generated from PDF by TikZiT");
+//    QPainter painter;
+
+//    // set the backend to Qt for renderToPainter() support
+//    Poppler::Document::RenderBackend backend = _doc->renderBackend();
+//    _doc->setRenderBackend(Poppler::Document::ArthurBackend);
+//    painter.begin(&gen);
+//    _page->renderToPainter(&painter);
+//    painter.end();
+//    _doc->setRenderBackend(backend);
+//}
+
+QSize PdfDocument::size()
+{
+    if (isValid()) {
+        return _page->pageSize();
+    }
+}
+
+
diff --git a/src/data/pdfdocument.h b/src/data/pdfdocument.h
new file mode 100644
index 0000000..ebd33e9
--- /dev/null
+++ b/src/data/pdfdocument.h
@@ -0,0 +1,28 @@
+#ifndef PDFDOCUMENT_H
+#define PDFDOCUMENT_H
+
+#include <QObject>
+#include <QString>
+#include <QLabel>
+
+#include <poppler/qt5/poppler-qt5.h>
+
+class PdfDocument : public QObject
+{
+    Q_OBJECT
+public:
+    explicit PdfDocument(QString file, QObject *parent = nullptr);
+    void renderTo(QLabel *label, QRect rect);
+    bool isValid();
+//    void exportToSvg(QString file, QSize size);
+    bool exportImage(QString file, const char *format, QSize outputSize=QSize());
+    bool exportPdf(QString file);
+    void copyImageToClipboard(QSize outputSize=QSize());
+    QImage asImage(QSize outputSize=QSize());
+    QSize size();
+private:
+    Poppler::Document *_doc;
+    Poppler::Page *_page;
+};
+
+#endif // PDFDOCUMENT_H
-- 
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