/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#ifndef INCLUDED_VCL_EMBEDDEDFONTSHELPER_HXX
#define INCLUDED_VCL_EMBEDDEDFONTSHELPER_HXX

#include <vcl/dllapi.h>

#include <rtl/ustring.hxx>
#include <tools/fontenum.hxx>
#include <tools/long.hxx>

#include <string_view>
#include <vector>

namespace com::sun::star::io { class XInputStream; }
namespace com::sun::star::uno { template <typename > class Reference; }

/**
 Helper functions for handling embedded fonts in documents.

*/
class VCL_DLLPUBLIC EmbeddedFontsHelper
{
private:
    std::vector<std::pair<OUString, OUString>> m_aAccumulatedFonts;

    /**
      Adds the given font to the list of known fonts. The font is used only until application
      exit.

      @param fontName name of the font (e.g. 'Times New Roman')
      @param fileUrl URL of the font file
    */
    static void activateFont( const OUString& fontName, const OUString& fileUrl );

public:
    /// Specification of what kind of operation is allowed when embedding a font
    enum class FontRights
    {
        ViewingAllowed, ///< Font may be embedded for viewing the document (but not editing)
        EditingAllowed ///< Font may be embedded for editing document (implies viewing)
    };

    /**
      Returns URL for a font file for the given font, or empty if it does not exist.
    */
    static OUString fontFileUrl(
        std::u16string_view familyName, FontFamily family, FontItalic italic,
        FontWeight weight, FontPitch pitch, FontRights rights );

    /**
      Reads a font from the input stream, saves it to a temporary font file and adds it to the list of
      fonts that activateFonts will activate.
      @param stream stream of font data
      @param fontName name of the font (e.g. 'Times New Roman')
      @param extra additional text to use for name (e.g. to distinguish regular from bold, italic,...), "?" for unique
      @param key key to xor the data with, from the start until the key's length (not repeated)
      @param eot whether the data is compressed in Embedded OpenType format
    */
    bool addEmbeddedFont( const css::uno::Reference< css::io::XInputStream >& stream,
        const OUString& fontName, const char* extra,
        std::vector< unsigned char > const & key, bool eot = false);

    /**
      Returns a URL for a file where to store contents of a given temporary font.
      The file may or not may not exist yet, and will be cleaned up automatically as appropriate.
      Use activateTemporaryFont() to actually enable usage of the font.

      @param fontName name of the font (e.g. 'Times New Roman')
      @param extra additional text to use for name (e.g. to distinguish regular from bold, italic,...), "?" for unique
    */
    static OUString fileUrlForTemporaryFont( const OUString& fontName, const char* extra );

    /**
      Adds the accumulated fonts to the list of known fonts. The fonts are used only until application
      exit.
    */
    void activateFonts();

    /**
      Returns if the restrictions specified in the font (if present) allow embedding
      the font for a particular purpose.
      @param data font data
      @param size size of the font data
      @param rights type of operation to be allowed for the font
    */
    static bool sufficientTTFRights( const void* data, tools::Long size, FontRights rights );

    /**
      Removes all temporary fonts in the path used by fileUrlForTemporaryFont().
      @internal
    */
    static void clearTemporaryFontFiles();

    ~EmbeddedFontsHelper() COVERITY_NOEXCEPT_FALSE
    {
        activateFonts();
    }
};

#endif

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