RichTextRenderer.h

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//
// RichTextRenderer.h
//
 
#ifndef MALENA_RICHTEXTRENDERER_H
#define MALENA_RICHTEXTRENDERER_H
 
#pragma once
 
#include <Malena/Core/malena_export.h>
#include <Malena/Graphics/Text/RichTextBuffer.h>
#include <SFML/Graphics/Text.hpp>
#include <SFML/Graphics/RectangleShape.hpp>
#include <SFML/Graphics/RenderTarget.hpp>
#include <vector>
 
namespace ml
{
    // ── RenderedSegment ───────────────────────────────────────────────────────

    struct RenderedSegment
    {
        sf::Text     sfText;       
        std::size_t  bufStart = 0; 
        std::size_t  bufEnd   = 0; 
        sf::Vector2f position;     
 
        RenderedSegment(sf::Text&&   text,
                        std::size_t  start,
                        std::size_t  end,
                        sf::Vector2f pos)
            : sfText(std::move(text)),
              bufStart(start),
              bufEnd(end),
              position(pos)
        {}
    };
 
    // ── RenderedLine ──────────────────────────────────────────────────────────

    struct RenderedLine
    {
        std::vector<RenderedSegment> segments;
        float       y         = 0.f;
        float       height    = 0.f;  
        float       rowHeight = 0.f;  
        std::size_t charStart = 0;
        std::size_t charEnd   = 0;
 
        // List rendering (computed by computeListMarkers).
        int          listType = 0;     
        float        indent   = 0.f;   
        std::string  marker;           
        sf::Vector2f markerPos;        
    };
 
    // ── RichTextRenderer ─────────────────────────────────────────────────────

    class MALENA_API RichTextRenderer
    {
    public:
        RichTextRenderer(const RichTextBuffer& buffer,
                         const sf::Font&       defaultFont,
                         unsigned int          defaultSize,
                         sf::Color             defaultColor);
 
        // ── Layout control ────────────────────────────────────────────────────

        void setOrigin(const sf::Vector2f& origin);

        void setMaxWidth(float width);

        [[nodiscard]] sf::Color getDefaultColor() const { return _defaultColor; }

        void rebuild();

        void reflow();
 
        // ── Drawing ───────────────────────────────────────────────────────────
 
        void draw(sf::RenderTarget& target, const sf::RenderStates& states) const;
 
        void drawSelection(sf::RenderTarget&       target,
                           const sf::RenderStates& states,
                           std::size_t             selStart,
                           std::size_t             selEnd,
                           const sf::Color&        color) const;
 
        void drawCursor(sf::RenderTarget&       target,
                        const sf::RenderStates& states,
                        std::size_t             charIndex,
                        const sf::Color&        color,
                        float                   width = 2.f) const;
 
        // ── Coordinate mapping ────────────────────────────────────────────────
 
        [[nodiscard]] sf::Vector2f charIndexToPosition(std::size_t index) const;
        [[nodiscard]] std::size_t  positionToCharIndex(const sf::Vector2f& pos) const;
        [[nodiscard]] std::size_t  lineIndexForChar(std::size_t charIndex) const;
        [[nodiscard]] std::size_t  charIndexAbove(std::size_t cursorIndex) const;
        [[nodiscard]] std::size_t  charIndexBelow(std::size_t cursorIndex) const;
 
        // ── Layout info ───────────────────────────────────────────────────────
 
        [[nodiscard]] float getTotalHeight() const;
        [[nodiscard]] const std::vector<RenderedLine>& getLines() const;
 
    private:
        const RichTextBuffer& _buffer;
        const sf::Font*       _defaultFont;
        unsigned int          _defaultSize;
        sf::Color             _defaultColor;
 
        sf::Vector2f              _origin;
        float                     _maxWidth = 0.f;
        std::vector<RenderedLine> _lines;
 
        void     buildSegments();
        void     computeListMarkers();   // assign listType/indent/marker per line + numbering
        void     layoutLines();
        // Height basis for an empty line: the size text typed there would take
        // (the preceding character's size), so a blank line after small text isn't
        // stuck at the default height. Falls back to the default.
        [[nodiscard]] unsigned int emptyLineSize(std::size_t charStart) const;
        void     alignLineRows(RenderedLine& line, float maxSize);  // shift rows per paragraph align
        sf::Text makeText(const std::string& str, const TextAttribute& attr) const;
    };
 
} // namespace ml
 
#endif // MALENA_RICHTEXTRENDERER_H