pdf_analyzer.h

/*
For general Scribus (>=1.3.2) copyright and licensing information please refer
to the COPYING file provided with the program. Following this notice may exist
a copyright and/or license notice that predates the release of Scribus 1.3.2
for which a new license (GPL+exception) is in place.
*/

#ifndef PDFANALYZER_H
#define PDFANALYZER_H

#include <QList>
#include <QPair>
#include <QString>
#include <QMatrix>
#include "scconfig.h"

#ifdef HAVE_PODOFO
#include <podofo/podofo.h>
#endif

enum PDFContentStreamKeyword
{
    KW_k,
    KW_K,
    KW_rg,
    KW_RG,
    KW_g,
    KW_G,
    KW_CS,
    KW_cs,
    KW_SC,
    KW_SCN,
    KW_sc,
    KW_scn,
    KW_Do,
    KW_BI,
    KW_ID,
    KW_EI,
    KW_gs,
    KW_Tf,
    KW_cm,
    KW_q,
    KW_Q,
    KW_w,
    KW_J,
    KW_j,
    KW_M,
    KW_d,
    KW_Undefined
};
enum PDFColorSpace
{
    CS_DeviceGray,
    CS_DeviceRGB,
    CS_DeviceCMYK,
    CS_CalGray,
    CS_CalRGB,
    CS_Lab,
    CS_ICCBased,
    CS_Pattern,
    CS_Indexed,
    CS_Separation,
    CS_DeviceN,
    CS_Unknown
};
enum PDFFontType
{
    F_Type1,
    F_MMType1,
    F_TrueType,
    F_Type3,
    F_CIDFontType0,
    F_CIDFontType2,
    F_Unknown
};
struct PDFFont
{
    PDFFontType fontType;
    bool isEmbedded;
    bool isOpenType;
    PDFFont()
    {
        fontType = F_Unknown;
        isEmbedded = false;
        isOpenType = false;
    }
};
struct PDFGraphicState
{
    QMatrix ctm;
    PDFColorSpace strokeCS;
    PDFColorSpace fillCS;
    QList<double> strokeColor;
    QList<double> fillColor;
    double lineWidth;
    int lineCap;
    int lineJoin;
    double miterLimit;
    QPair<QList<int>, int> dashPattern;
    QPair<PDFFont, double> font;
    QList<QString> blendModes;
    double fillAlphaConstant;
    double strokeAlphaConstant;
    PDFGraphicState()
    {
        strokeCS = CS_DeviceGray;
        fillCS = CS_DeviceGray;
        strokeColor.append(0);
        fillColor.append(0);
        lineWidth = 1;
        lineCap = 0;
        lineJoin = 0;
        miterLimit = 10;
        QList<int> dashArray;
        int dashPhase = 0;
        dashPattern.first = dashArray;
        dashPattern.second = dashPhase;
        blendModes.append("Normal");
        fillAlphaConstant = 1;
        strokeAlphaConstant = 1;
    }
};
struct PDFImage
{
    QString imgName;
    int dpiX;
    int dpiY;
};

class PDFAnalyzer : public QObject
{
    Q_OBJECT

public:
    PDFAnalyzer(QString& filename);
    ~PDFAnalyzer();

    bool inspectPDF(int pageNum, QList<PDFColorSpace> & usedColorSpaces, bool & hasTransparency, QList<PDFFont> & usedFonts, QList<PDFImage> & imgs);
#ifdef HAVE_PODOFO
private:
    // pointer to the PoDoFo Pdf's object
    PoDoFo::PdfMemDocument* m_doc;

    // Call to this method to inspect a PdfCanvas (either a PdfPage or PdfXObject of subtype Form). This method will be called by inspectPDF
    // to start inspecting a PDF's page; it could well be called recursively to continue analyzing further in case form XObjects are painted
    // onto the page.
    bool inspectCanvas(PoDoFo::PdfCanvas* canvas, QList<PDFColorSpace> & usedColorSpaces, bool & hasTransparency, QList<PDFFont> & usedFonts, QList<PDFImage> & imgs);

    // Helper method to analyze a ColorSpace's array. They all have the form [/csType ...] (section 4.5 in PDF Spec 1.6).
    // csObject is a pointer to a PoDoFo's PdfObject which is in fact a PdfArray underneath.
    // A color space's type is returned.
    PDFColorSpace getCSType(PoDoFo::PdfObject* csObject);

    // Helper method to inspect a graphic state parameter dictionary (ExtGState subdictionary in the resource dictionary; Section 4.3.4 in PDF Spec 1.6).
    // Triggered by hitting a gs operator in the content stream.
    // extGStateObj is a pointer to a PoDoFo's PdfObject which is in fact a dictionary underneath.
    void inspectExtGStateObj(PoDoFo::PdfObject* extGStateObj, QList<PDFColorSpace> & usedColorSpaces, bool & hasTransparency, QList<PDFFont> & usedFonts, PDFGraphicState & currGS);

    // Helper method to analyze a font dictionary (section 5.4-5.8 in PDF Spec 1.6)
    // A PDFFont struct is returned containing some basic info regarding the specified font.
    PDFFont getFontInfo(PoDoFo::PdfObject* fontObj);
#endif
};
#endif