Extend PDF engine to allow the generation of PDFs with huge pages

Qt's PDF engine previously supported only the PDF v1.4 standard, which
only allows pages of up to 200x200in (about 5x5m). This patch optionally
enables the generation of PDF v1.6-compliant files that allow the
redefinition of user space units, so that pages of up to 381x381km are
now possible. By default, generated files are compliant to v1.4 spec.
v1.6 compliance must be enabled by, e.g., calling QPrinter::setPdfVersion()
with QPrinter::PdfVersion_1_6. PDF v1.6-compliant files require Adobe
Reader 7.0 or newer (also worked with the built-in viewers in current
versions of Chrome, Firefox and Edge).

Task-number: QTBUG-69386
Change-Id: I21708e0d465d5d7d9e46ff06dd04acfe1dfb0858
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Andy Shaw <andy.shaw@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/printsupport/kernel/qprinter.cpp b/src/printsupport/kernel/qprinter.cpp
index ed4292ff3d..829a13863b 100644
--- a/src/printsupport/kernel/qprinter.cpp
+++ b/src/printsupport/kernel/qprinter.cpp
@@ -149,7 +149,12 @@ void QPrinterPrivate::initEngines(QPrinter::OutputFormat format, const QPrinterI
         printEngine = ps->createNativePrintEngine(printerMode, printerName);
         paintEngine = ps->createPaintEngine(printEngine, printerMode);
     } else {
-        const auto pdfEngineVersion = (pdfVersion == QPrinter::PdfVersion_1_4 ? QPdfEngine::Version_1_4 : QPdfEngine::Version_A1b);
+        static const QHash<QPrinter::PdfVersion, QPdfEngine::PdfVersion> engineMapping {
+            {QPrinter::PdfVersion_1_4, QPdfEngine::Version_1_4},
+            {QPrinter::PdfVersion_A1b, QPdfEngine::Version_A1b},
+            {QPrinter::PdfVersion_1_6, QPdfEngine::Version_1_6}
+        };
+        const auto pdfEngineVersion = engineMapping.value(pdfVersion, QPdfEngine::Version_1_4);
         QPdfPrintEngine *pdfEngine = new QPdfPrintEngine(printerMode, pdfEngineVersion);
         paintEngine = pdfEngine;
         printEngine = pdfEngine;