PDF4QT/PdfForQtLib/sources/pdfdocumentbuilder.h

//    Copyright (C) 2020 Jakub Melka
//
//    This file is part of PdfForQt.
//
//    PdfForQt is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Lesser General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    PdfForQt is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public License
//    along with PDFForQt. If not, see <https://www.gnu.org/licenses/>.

#ifndef PDFDOCUMENTBUILDER_H
#define PDFDOCUMENTBUILDER_H

#include "pdfobject.h"
#include "pdfdocument.h"
#include "pdfannotation.h"

namespace pdf
{

struct WrapName
{
    WrapName(const char* name) :
        name(name)
    {

    }

    QByteArray name;
};

struct WrapAnnotationColor
{
    WrapAnnotationColor(QColor color) :
        color(color)
    {

    }

    QColor color;
};

struct WrapFreeTextAlignment
{
    constexpr inline WrapFreeTextAlignment(Qt::Alignment alignment) :
        alignment(alignment)
    {

    }

    Qt::Alignment alignment;
};

struct WrapString
{
    WrapString(const char* string) :
        string(string)
    {

    }

    QByteArray string;
};

struct WrapCurrentDateTime { };
struct WrapEmptyArray { };

/// Factory for creating various PDF objects, such as simple objects,
/// dictionaries, arrays etc.
class PDFObjectFactory
{
public:
    inline explicit PDFObjectFactory() = default;

    void beginArray();
    void endArray();

    void beginDictionary();
    void endDictionary();

    void beginDictionaryItem(const QByteArray& name);
    void endDictionaryItem();

    PDFObjectFactory& operator<<(std::nullptr_t);
    PDFObjectFactory& operator<<(bool value);
    PDFObjectFactory& operator<<(PDFReal value);
    PDFObjectFactory& operator<<(PDFInteger value);
    PDFObjectFactory& operator<<(PDFObjectReference value);
    PDFObjectFactory& operator<<(WrapName wrapName);
    PDFObjectFactory& operator<<(int value);
    PDFObjectFactory& operator<<(const QRectF& value);
    PDFObjectFactory& operator<<(WrapCurrentDateTime);
    PDFObjectFactory& operator<<(WrapAnnotationColor color);
    PDFObjectFactory& operator<<(QString textString);
    PDFObjectFactory& operator<<(WrapEmptyArray);
    PDFObjectFactory& operator<<(TextAnnotationIcon icon);
    PDFObjectFactory& operator<<(LinkHighlightMode mode);
    PDFObjectFactory& operator<<(WrapFreeTextAlignment alignment);
    PDFObjectFactory& operator<<(WrapString string);
    PDFObjectFactory& operator<<(AnnotationLineEnding lineEnding);

    /// Treat containers - write them as array
    template<typename Container, typename ValueType = decltype(*std::begin(std::declval<Container>()))>
    PDFObjectFactory& operator<<(Container container)
    {
        beginArray();

        auto it = std::begin(container);
        auto itEnd = std::end(container);
        for (; it != itEnd; ++it)
        {
            *this << *it;
        }

        endArray();

        return *this;
    }

    PDFObject takeObject();

private:
    void addObject(PDFObject object);

    enum class ItemType
    {
        Object,
        Dictionary,
        DictionaryItem,
        Array
    };

    /// What is stored in this structure, depends on the type.
    /// If type is 'Object', then single simple object is in object,
    /// if type is dictionary, then PDFDictionary is stored in object,
    /// if type is dictionary item, then object and item name is stored
    /// in the data, if item is array, then array is stored in the data.
    struct Item
    {
        inline Item() = default;

        template<typename T>
        inline Item(ItemType type, T&& data) :
            type(type),
            object(qMove(data))
        {

        }

        template<typename T>
        inline Item(ItemType type, const QByteArray& itemName, T&& data) :
            type(type),
            itemName(qMove(itemName)),
            object(qMove(data))
        {

        }

        ItemType type = ItemType::Object;
        QByteArray itemName;
        std::variant<PDFObject, PDFArray, PDFDictionary> object;
    };

    std::vector<Item> m_items;
};

class PDFFORQTLIBSHARED_EXPORT PDFDocumentBuilder
{
public:
    /// Creates a new blank document (with no pages)
    explicit PDFDocumentBuilder();

    ///
    explicit PDFDocumentBuilder(const PDFDocument* document);

    /// Resets the object to the initial state.
    /// \warning All data are lost
    void reset();

    /// Create a new blank document with no pages. If some document
    /// is edited at call of this function, then it is lost.
    void createDocument();

    /// Builds a new document. This function can throw exceptions,
    /// if document being built was invalid.
    PDFDocument build();

    /// If object is reference, the dereference attempt is performed
    /// and object is returned. If it is not a reference, then self
    /// is returned. If dereference attempt fails, then null object
    /// is returned (no exception is thrown).
    const PDFObject& getObject(const PDFObject& object) const;

    /// Returns dictionary from an object. If object is not a dictionary,
    /// then nullptr is returned (no exception is thrown).
    const PDFDictionary* getDictionaryFromObject(const PDFObject& object) const;

    /// Returns object by reference. If dereference attempt fails, then null object
    /// is returned (no exception is thrown).
    const PDFObject& getObjectByReference(PDFObjectReference reference) const;

    /// Returns annotation bounding rectangle
    std::array<PDFReal, 4> getAnnotationReductionRectangle(const QRectF& boundingRect, const QRectF& innerRect) const;

/* START GENERATED CODE */

    /// Appends a new page after last page.
    /// \param mediaBox Media box of the page (size of paper)
    PDFObjectReference appendPage(QRectF mediaBox);


    /// Creates URI action.
    /// \param URL Target URL
    PDFObjectReference createActionURI(QString URL);


    /// Circle annotation displays ellipse (or circle). When opened, they display pop-up window containing 
    /// the text of associated note (and window title). Circle border/fill color can be defined, along with 
    /// border width.
    /// \param page Page to which is annotation added
    /// \param rectangle Area in which is circle/ellipse displayed
    /// \param borderWidth Width of the border line of circle/ellipse
    /// \param fillColor Fill color of rectangle (interior color). If you do not want to have area color filled, 
    ///        then use invalid QColor.
    /// \param strokeColor Stroke color (color of the rectangle border). If you do not want to have a 
    ///        border, then use invalid QColor.
    /// \param title Title (it is displayed as title of popup window)
    /// \param subject Subject (short description of the subject being adressed by the annotation)
    /// \param contents Contents (text displayed, for example, in the marked annotation dialog)
    PDFObjectReference createAnnotationCircle(PDFObjectReference page,
                                              QRectF rectangle,
                                              PDFReal borderWidth,
                                              QColor fillColor,
                                              QColor strokeColor,
                                              QString title,
                                              QString subject,
                                              QString contents);


    /// Free text annotation displays text directly on a page. Text appears directly on the page, in the 
    /// same way, as standard text in PDF document. Free text annotations are usually used to comment 
    /// the document. Free text annotation can also have callout line, with, or without a knee.
    /// \param page Page to which is annotation added
    /// \param rectangle Area in which is text displayed
    /// \param title Title
    /// \param subject Subject
    /// \param contents Contents (text displayed)
    /// \param textAlignment Text alignment. Only horizontal alignment flags are valid.
    PDFObjectReference createAnnotationFreeText(PDFObjectReference page,
                                                QRectF rectangle,
                                                QString title,
                                                QString subject,
                                                QString contents,
                                                TextAlignment textAlignment);


    /// Free text annotation displays text directly on a page. Text appears directly on the page, in the 
    /// same way, as standard text in PDF document. Free text annotations are usually used to comment 
    /// the document. Free text annotation can also have callout line, with, or without a knee. Specify 
    /// start/end point parameters of this function to get callout line.
    /// \param page Page to which is annotation added
    /// \param boundingRectangle Bounding rectangle of free text annotation. It must contain both 
    ///        callout line and text rectangle.
    /// \param textRectangle Rectangle with text, in absolute coordinates. They are then recomputed to 
    ///        match bounding rectangle.
    /// \param title Title
    /// \param subject Subject
    /// \param contents Contents (text displayed)
    /// \param textAlignment Text alignment. Only horizontal alignment flags are valid.
    /// \param startPoint Start point of callout line
    /// \param endPoint End point of callout line
    /// \param startLineType Line ending at the start point
    /// \param endLineType Line ending at the end point
    PDFObjectReference createAnnotationFreeText(PDFObjectReference page,
                                                QRectF boundingRectangle,
                                                QRectF textRectangle,
                                                QString title,
                                                QString subject,
                                                QString contents,
                                                TextAlignment textAlignment,
                                                QPointF startPoint,
                                                QPointF endPoint,
                                                AnnotationLineEnding startLineType,
                                                AnnotationLineEnding endLineType);


    /// Line annotation represents straight line, or some more advanced graphics, such as dimension with 
    /// text. Line annotations are markup annotations, so they can have popup window. Line endings can 
    /// be specified.
    /// \param page Page to which is annotation added
    /// \param boundingRect Line annotation bounding rectangle
    /// \param startPoint Line start
    /// \param endPoint Line end
    /// \param lineWidth Line width
    /// \param fillColor Fill color of line parts (for example, filled line endings)
    /// \param strokeColor Line stroke color
    /// \param title Title (it is displayed as title of popup window)
    /// \param subject Subject (short description of the subject being adressed by the annotation)
    /// \param contents Contents (text displayed, for example, in the marked annotation dialog)
    /// \param startLineType Start line ending type
    /// \param endLineType End line ending type
    PDFObjectReference createAnnotationLine(PDFObjectReference page,
                                            QRectF boundingRect,
                                            QPointF startPoint,
                                            QPointF endPoint,
                                            PDFReal lineWidth,
                                            QColor fillColor,
                                            QColor strokeColor,
                                            QString title,
                                            QString subject,
                                            QString contents,
                                            AnnotationLineEnding startLineType,
                                            AnnotationLineEnding endLineType);


    /// Creates new link annotation. It usually represents clickable hypertext link. User can also specify 
    /// action, which can be executed, for example, link can be also in the PDF document (link to some 
    /// location in document).
    /// \param page Page to which is annotation added
    /// \param linkRectangle Link rectangle
    /// \param action Action to be performed when user clicks on a link
    /// \param highlightMode Highlight mode
    PDFObjectReference createAnnotationLink(PDFObjectReference page,
                                            QRectF linkRectangle,
                                            PDFObjectReference action,
                                            LinkHighlightMode highlightMode);


    /// Creates new link annotation. It usually represents clickable hypertext link. User can also specify 
    /// action, which can be executed, for example, link can be also in the PDF document (link to some 
    /// location in document).
    /// \param page Page to which is annotation added
    /// \param linkRectangle Link rectangle
    /// \param URL URL to be launched when user clicks on the link
    /// \param highlightMode Highlight mode
    PDFObjectReference createAnnotationLink(PDFObjectReference page,
                                            QRectF linkRectangle,
                                            QString URL,
                                            LinkHighlightMode highlightMode);


    /// Creates a new popup annotation on the page. Popup annotation is represented usually by floating 
    /// window, which can be opened, or closed. Popup annotation is associated with parent annotation, 
    /// which can be usually markup annotation. Popup annotation displays parent annotation's texts, for 
    /// example, title, comment, date etc.
    /// \param page Page to which is annotation added
    /// \param parentAnnotation Parent annotation (for which is popup window displayed)
    /// \param rectangle Area on the page, where popup window appears
    /// \param opened Is the window opened?
    PDFObjectReference createAnnotationPopup(PDFObjectReference page,
                                             PDFObjectReference parentAnnotation,
                                             QRectF rectangle,
                                             bool opened);


    /// Square annotation displays rectangle (or square). When opened, they display pop-up window 
    /// containing the text of associated note (and window title). Square border/fill color can be defined, 
    /// along with border width.
    /// \param page Page to which is annotation added
    /// \param rectangle Area in which is rectangle displayed
    /// \param borderWidth Width of the border line of rectangle
    /// \param fillColor Fill color of rectangle (interior color). If you do not want to have area color filled, 
    ///        then use invalid QColor.
    /// \param strokeColor Stroke color (color of the rectangle border). If you do not want to have a 
    ///        border, then use invalid QColor.
    /// \param title Title (it is displayed as title of popup window)
    /// \param subject Subject (short description of the subject being adressed by the annotation)
    /// \param contents Contents (text displayed, for example, in the marked annotation dialog)
    PDFObjectReference createAnnotationSquare(PDFObjectReference page,
                                              QRectF rectangle,
                                              PDFReal borderWidth,
                                              QColor fillColor,
                                              QColor strokeColor,
                                              QString title,
                                              QString subject,
                                              QString contents);


    /// Creates text annotation. Text annotation is "sticky note" attached to a point in the PDF document. 
    /// When closed, it is displayed as icon, if opened, widget appears with attached text. Text annotations 
    /// do not scale or rotate, they appear independent of zoom/rotate. So, they behave as if flags 
    /// NoZoom or NoRotate to the annotations are being set.
    /// \param page Page to which is annotation added
    /// \param rectangle Area in which is icon displayed
    /// \param iconType Icon type
    /// \param title Title (it is displayed as title of popup window)
    /// \param subject Subject (short description of the subject being adressed by the annotation)
    /// \param contents Contents (text displayed, for example, in the marked annotation dialog)
    /// \param open Is annotation initially displayed as opened?
    PDFObjectReference createAnnotationText(PDFObjectReference page,
                                            QRectF rectangle,
                                            TextAnnotationIcon iconType,
                                            QString title,
                                            QString subject,
                                            QString contents,
                                            bool open);


    /// Creates empty catalog. This function is used, when a new document is being created. Do not call 
    /// this function manually.
    PDFObjectReference createCatalog();


    /// Creates page tree root for the catalog. This function is only called when new document is being 
    /// created. Do not call this function manually.
    PDFObjectReference createCatalogPageTreeRoot();


    /// This function is used to create a new trailer dictionary, when blank document is created. Do not 
    /// call this function manually.
    /// \param catalog Reference to document catalog
    PDFObject createTrailerDictionary(PDFObjectReference catalog);


    /// This function is used to update trailer dictionary. Must be called each time the final document is 
    /// being built.
    /// \param objectCount Number of objects (including empty ones)
    void updateTrailerDictionary(PDFInteger objectCount);


/* END GENERATED CODE */

private:
    PDFObjectReference addObject(PDFObject object);
    void mergeTo(PDFObjectReference reference, PDFObject object);
    void appendTo(PDFObjectReference reference, PDFObject object);
    QRectF getPopupWindowRect(const QRectF& rectangle) const;
    QString getProducerString() const;
    PDFObjectReference getPageTreeRoot() const;
    PDFInteger getPageTreeRootChildCount() const;

    PDFObjectStorage m_storage;
    PDFVersion m_version;
};

// Implementation

inline
const PDFObject& PDFDocumentBuilder::getObject(const PDFObject& object) const
{
    if (object.isReference())
    {
        // Try to dereference the object
        return m_storage.getObject(object.getReference());
    }

    return object;
}

inline
const PDFDictionary* PDFDocumentBuilder::getDictionaryFromObject(const PDFObject& object) const
{
    const PDFObject& dereferencedObject = getObject(object);
    if (dereferencedObject.isDictionary())
    {
        return dereferencedObject.getDictionary();
    }
    else if (dereferencedObject.isStream())
    {
        return dereferencedObject.getStream()->getDictionary();
    }

    return nullptr;
}

inline
const PDFObject& PDFDocumentBuilder::getObjectByReference(PDFObjectReference reference) const
{
    return m_storage.getObject(reference);
}

}   // namespace pdf

#endif // PDFDOCUMENTBUILDER_H