Provide access to external links in PDF documents

autotests/pdfdocumenttest.cpp

@@ -5,6 +5,7 @@
 */
 
 #include <KItinerary/PdfDocument>
+#include <KItinerary/PdfLink>
 
 #include <QFile>
 #include <QObject>
@@ -73,6 +74,24 @@ private Q_SLOTS:
         QCOMPARE(doc->modificationTime(), QDateTime());
     }
 
+    void testPdfLink()
+    {
+        QFile f(QStringLiteral(SOURCE_DIR "/misc/link.pdf"));
+        QVERIFY(f.open(QFile::ReadOnly));
+        QVERIFY(PdfDocument::maybePdf(f.readAll()));
+        f.seek(0);
+        std::unique_ptr<PdfDocument> doc(PdfDocument::fromData(f.readAll()));
+        QVERIFY(doc);
+
+        QCOMPARE(doc->pageCount(), 1);
+        const auto page = doc->page(0);
+        QCOMPARE(page.linkCount(), 1);
+        const auto link = page.link(0);
+        QCOMPARE(link.url(), QLatin1String("https://kde.org"));
+        qDebug() << link.area();
+        QVERIFY(link.area().isValid());
+    }
+
     void testInvalidPdfDocument()
     {
         QVERIFY(!PdfDocument::maybePdf(QByteArray()));

autotests/scriptenginedata/iata-bcbp-demo.pdf.json

@@ -17,6 +17,8 @@
                             "width": 79
                         }
                     ],
+                    "links": [
+                    ],
                     "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n"
                 }
             ],
@@ -76,6 +78,8 @@
                             "width": 79
                         }
                     ],
+                    "links": [
+                    ],
                     "text": "              Akademy Airways\n              Boarding Pass\nFrom: Vienna International, Terminal 2\nTo: Milano Malpensa, Terminal 1\nFlight: AK 1996\nGate: A36\nBoarding Time: 15:20\nDeparture Time: 15:45\nArrival Time: 17:20\nPassenger: Dragon, Dr. Konqi\n"
                 }
             ],

src/lib/CMakeLists.txt

@@ -72,6 +72,7 @@ target_sources(KPimItinerary PRIVATE
     pdf/pdfdocument.cpp
     pdf/pdfextractoroutputdevice.cpp
     pdf/pdfimage.cpp
+    pdf/pdflink.cpp
     pdf/pdfvectorpicture.cpp
     pdf/popplerglobalparams.cpp
     pdf/popplerutils.cpp
@@ -294,6 +295,7 @@ ecm_generate_headers(KItinerary_Pdf_FORWARDING_HEADERS
     HEADER_NAMES
         PdfDocument
         PdfImage
+        PdfLink
     PREFIX KItinerary
     REQUIRED_HEADERS KItinerary_Pdf_HEADERS
     RELATIVE pdf

src/lib/pdf/pdfdocument.cpp

@@ -34,6 +34,7 @@ void PdfPagePrivate::load()
     PopplerGlobalParams gp;
     PdfExtractorOutputDevice device;
     m_doc->m_popplerDoc->displayPageSlice(&device, m_pageNum + 1, 72, 72, 0, false, true, false, -1, -1, -1, -1);
+    m_doc->m_popplerDoc->processLinks(&device, m_pageNum + 1);
     device.finalize();
     const auto pageRect = m_doc->m_popplerDoc->getPage(m_pageNum + 1)->getCropBox();
     std::unique_ptr<GooString> s(device.getText(pageRect->x1, pageRect->y1, pageRect->x2, pageRect->y2));
@@ -47,6 +48,12 @@ void PdfPagePrivate::load()
     for (auto it = m_images.begin(); it != m_images.end(); ++it) {
         (*it).d->m_page = this;
     }
+
+    m_links = std::move(device.m_links);
+    for (auto &link : m_links) {
+        link.convertToPageRect(pageRect);
+    }
+
     m_loaded = true;
 }
 
@@ -147,6 +154,27 @@ QVariantList PdfPage::imagesInRect(double left, double top, double right, double
     return l;
 }
 
+int PdfPage::linkCount() const
+{
+    d->load();
+    return d->m_links.size();
+}
+
+PdfLink PdfPage::link(int index) const
+{
+    d->load();
+    return d->m_links[index];
+}
+
+QVariantList PdfPage::linksVariant() const
+{
+    d->load();
+    QVariantList l;
+    l.reserve(d->m_links.size());
+    std::transform(d->m_links.begin(), d->m_links.end(), std::back_inserter(l), [](const PdfLink &link) { return QVariant::fromValue(link); });
+    return l;
+}
+
 
 PdfDocument::PdfDocument(QObject *parent)
     : QObject(parent)

src/lib/pdf/pdfdocument.h

@@ -20,6 +20,7 @@
 
 namespace KItinerary {
 
+class PdfLink;
 class PdfPagePrivate;
 
 /** A page in a PDF document.
@@ -29,6 +30,7 @@ class KITINERARY_EXPORT PdfPage
     Q_GADGET
     Q_PROPERTY(QString text READ text)
     Q_PROPERTY(QVariantList images READ imagesVariant)
+    Q_PROPERTY(QVariantList links READ linksVariant)
 public:
     PdfPage();
     PdfPage(const PdfPage&);
@@ -54,8 +56,15 @@ public:
      */
     Q_INVOKABLE QVariantList imagesInRect(double left, double top, double right, double bottom) const;
 
+    /** The number of links found in this document. */
+    int linkCount() const;
+
+    /** The n-th link found in this document. */
+    PdfLink link(int index) const;
+
 private:
     QVariantList imagesVariant() const;
+    QVariantList linksVariant() const;
 
     friend class PdfDocument;
     QExplicitlySharedDataPointer<PdfPagePrivate> d;

src/lib/pdf/pdfdocument_p.h

@@ -22,6 +22,7 @@ namespace KItinerary {
 
 class PdfDocumentPrivate;
 class PdfImage;
+class PdfLink;
 class PdfPage;
 
 class PdfPagePrivate : public QSharedData {
@@ -32,6 +33,7 @@ public:
     bool m_loaded = false;
     QString m_text;
     std::vector<PdfImage> m_images;
+    std::vector<PdfLink> m_links;
     PdfDocumentPrivate *m_doc;
 };
 

src/lib/pdf/pdfextractoroutputdevice.cpp

@@ -10,6 +10,10 @@
 #include "pdfimage_p.h"
 #include "popplerutils_p.h"
 
+#include <Annot.h>
+#include <Link.h>
+#include <Page.h>
+
 #include <QDebug>
 
 using namespace KItinerary;
@@ -233,3 +237,21 @@ void PdfExtractorOutputDevice::addVectorImage(const PdfVectorPicture &pic)
     img.d->m_vectorPicture = pic;
     m_images.push_back(img);
 }
+
+void PdfExtractorOutputDevice::processLink(AnnotLink *link)
+{
+    TextOutputDev::processLink(link);
+    if (!link->isOk() || link->getAction()->getKind() != actionURI) {
+        return;
+    }
+
+    const auto uriLink = static_cast<LinkURI*>(link->getAction());
+    double xd1, yd1, xd2, yd2;
+    link->getRect(&xd1, &yd1, &xd2, &yd2);
+
+    double xu1, yu1, xu2, yu2;
+    cvtDevToUser(xd1, yd1, &xu1, &yu1);
+    cvtDevToUser(xd2, yd2, &xu2, &yu2);
+    PdfLink l(QString::fromStdString(uriLink->getURI()), QRectF(QPointF(std::min(xu1, xu2), std::min(yu1, yu2)), QPointF(std::max(xu1, xu2), std::max(yu1, yu2))));
+    m_links.push_back(std::move(l));
+}

src/lib/pdf/pdfextractoroutputdevice_p.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include "pdflink.h"
 #include "pdfvectorpicture_p.h"
 #include "popplertypes_p.h"
 
@@ -35,6 +36,7 @@ public:
     void stroke(GfxState *state) override;
     void fill(GfxState *state) override;
     void eoFill(GfxState *state) override;
+    void processLink(AnnotLink *link) override;
 
     void addVectorImage(const PdfVectorPicture &pic);
 
@@ -48,6 +50,9 @@ public:
         PdfVectorPicture::PathStroke stroke;
     };
     std::vector<VectorOp> m_vectorOps;
+
+    // extracted links
+    std::vector<PdfLink> m_links;
 };
 
 }

src/lib/pdf/pdflink.cpp

+/*
+    SPDX-FileCopyrightText: 2022 Volker Krause <vkrause@kde.org>
+    SPDX-License-Identifier: LGPL-2.0-or-later
+*/
+
+#include "pdflink.h"
+
+#include <QDebug>
+
+#include <Page.h>
+
+using namespace KItinerary;
+
+namespace KItinerary {
+class PdfLinkPrivate : public QSharedData
+{
+public:
+    QString url;
+    QRectF area;
+};
+}
+
+PdfLink::PdfLink()
+    : d(new PdfLinkPrivate)
+{
+}
+
+PdfLink::PdfLink(const QString& url, const QRectF& area)
+    : d(new PdfLinkPrivate)
+{
+    d->url = url;
+    d->area = area;
+}
+
+PdfLink::PdfLink(const PdfLink&) = default;
+PdfLink::~PdfLink() = default;
+
+PdfLink& PdfLink::operator=(const PdfLink&) = default;
+
+QString PdfLink::url() const
+{
+    return d->url;
+}
+
+QRectF PdfLink::area() const
+{
+    return d->area;
+}
+
+static double toRatio(double low, double high, double value)
+{
+    return (value - low) / (high - low);
+}
+
+void PdfLink::convertToPageRect(const PDFRectangle *pageRect)
+{
+    d->area.setLeft(toRatio(pageRect->x1, pageRect->x2, d->area.left()));
+    d->area.setRight(toRatio(pageRect->x1, pageRect->x2, d->area.right()));
+    d->area.setTop(toRatio(pageRect->y1, pageRect->y2, d->area.top()));
+    d->area.setBottom(toRatio(pageRect->y1, pageRect->y2, d->area.bottom()));
+}

src/lib/pdf/pdflink.h

+/*
+    SPDX-FileCopyrightText: 2022 Volker Krause <vkrause@kde.org>
+    SPDX-License-Identifier: LGPL-2.0-or-later
+*/
+
+#ifndef KITINERARY_PDFLINK_H
+#define KITINERARY_PDFLINK_H
+
+#include "kitinerary_export.h"
+
+#include <QExplicitlySharedDataPointer>
+#include <QMetaType>
+#include <QRectF>
+
+class PDFRectangle;
+
+namespace KItinerary {
+
+class PdfExtractorOutputDevice;
+class PdfLinkPrivate;
+class PdfPagePrivate;
+
+/** An external link in a PDF file. */
+class KITINERARY_EXPORT PdfLink
+{
+    Q_GADGET
+    Q_PROPERTY(QString url READ url)
+    Q_PROPERTY(QRectF area READ area)
+
+public:
+    PdfLink();
+    ~PdfLink();
+    PdfLink(const PdfLink&);
+    PdfLink& operator=(const PdfLink&);
+
+    QString url() const;
+    QRectF area() const;
+
+private:
+    friend class PdfExtractorOutputDevice;
+    friend class PdfPagePrivate;
+
+    explicit PdfLink(const QString &url, const QRectF &area);
+    void convertToPageRect(const PDFRectangle *pageRect);
+
+    QExplicitlySharedDataPointer<PdfLinkPrivate> d;
+};
+
+}
+
+Q_DECLARE_METATYPE(KItinerary::PdfLink)
+
+#endif // KITINERARY_PDFLINK_H