css_length.h

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#ifndef LH_CSS_LENGTH_H
#define LH_CSS_LENGTH_H
 
#include "types.h"
#include "css_tokenizer.h"
 
namespace litehtml
{
    // from_token options (flags)
    enum {
        f_length     = 1, // <length> (includes unitless zero)
        f_percentage = 2, // <percentage>
        f_length_percentage = f_length | f_percentage, // <length-percentage>
        f_number     = 4, // <number>
        f_integer    = 8, // <integer>
        f_positive   = 16 // ⩾0 (non-negative)
    };
 
    // <length> | <percentage> | <number> | auto | none | normal
    // https://developer.mozilla.org/en-US/docs/Web/CSS/length
    class css_length
    {
        union
        {
            float   m_value;
            int     m_predef;
        };
        css_units   m_units;
        bool        m_is_predefined;
    public:
        css_length();
        css_length(float val, css_units units = css_units_px);
        css_length& operator=(float val);
 
        bool        is_predefined() const;
        void        predef(int val);
        int         predef() const;
        static css_length predef_value(int val = 0);
        void        set_value(float val, css_units units);
        float       val() const;
        css_units   units() const;
        int         calc_percent(int width) const;
        bool        from_token(const css_token& token, int options, const string& predefined_keywords = "");
        string      to_string() const;
    };
 
    using length_vector = vector<css_length>;
 
    // css_length inlines
 
    inline css_length::css_length()
    {
        m_value         = 0;
        m_predef        = 0;
        m_units         = css_units_none;
        m_is_predefined = false;
    }
 
    inline css_length::css_length(float val, css_units units)
    {
        m_value = val;
        m_units = units;
        m_is_predefined = false;
    }
 
    inline css_length&  css_length::operator=(float val)
    {
        m_value = val;
        m_units = css_units_px;
        m_is_predefined = false;
        return *this;
    }
 
    inline bool css_length::is_predefined() const
    { 
        return m_is_predefined;                 
    }
 
    inline void css_length::predef(int val)     
    { 
        m_predef        = val; 
        m_is_predefined = true; 
    }
 
    inline int css_length::predef() const
    { 
        if(m_is_predefined)
        {
            return m_predef; 
        }
        return 0;
    }
 
    inline void css_length::set_value(float val, css_units units)
    { 
        m_value         = val; 
        m_is_predefined = false;    
        m_units         = units;
    }
 
    inline float css_length::val() const
    {
        if(!m_is_predefined)
        {
            return m_value;
        }
        return 0;
    }
 
    inline css_units css_length::units() const
    {
        return m_units;
    }
 
    inline int css_length::calc_percent(int width) const
    {
        if(!is_predefined())
        {
            if(units() == css_units_percentage)
            {
                return (int) ((double) width * (double) m_value / 100.0);
            } else
            {
                return (int) val();
            }
        }
        return 0;
    }
}
 
#endif  // LH_CSS_LENGTH_H