Improve PDF/A-1b support in QPdfWriter

Add new enum QPrinter::PdfVersion to switch QPdfWriter
into PDF/A-1b mode. In that mode
    - meta data are embedded in XMP format
    - a color profile for sRGB is embedded and an OutputIntent defined
    - the ID key is added to the document trailer dictionary
    - a CIDSet entry is added to the font descriptor
    - transparency is removed from pens, brushes and images

Change-Id: Ia8a24d83609b239e716aefc1ba05f07320dbd290
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/gui/painting/qpdf_p.h b/src/gui/painting/qpdf_p.h
index a6aa2940c8..f5bb4e17a8 100644
--- a/src/gui/painting/qpdf_p.h
+++ b/src/gui/painting/qpdf_p.h
@@ -168,6 +168,12 @@ class Q_GUI_EXPORT QPdfEngine : public QPaintEngine
     Q_DECLARE_PRIVATE(QPdfEngine)
     friend class QPdfWriter;
 public:
+    enum PdfVersion
+    {
+        Version_1_4,
+        Version_A1b
+    };
+
     QPdfEngine();
     QPdfEngine(QPdfEnginePrivate &d);
     ~QPdfEngine() {}
@@ -177,6 +183,8 @@ public:
     void setResolution(int resolution);
     int resolution() const;
 
+    void setPdfVersion(PdfVersion version);
+
     // reimplementations QPaintEngine
     bool begin(QPaintDevice *pdev) Q_DECL_OVERRIDE;
     bool end() Q_DECL_OVERRIDE;
@@ -258,6 +266,7 @@ public:
     bool hasBrush;
     bool simplePen;
     qreal opacity;
+    QPdfEngine::PdfVersion pdfVersion;
 
     QHash<QFontEngine::FaceId, QFontSubset *> fonts;
 
@@ -286,6 +295,8 @@ private:
     int createShadingFunction(const QGradient *gradient, int from, int to, bool reflect, bool alpha);
 
     void writeInfo();
+    int writeXmpMetaData();
+    int writeOutputIntent();
     void writePageRoot();
     void writeFonts();
     void embedFont(QFontSubset *font);