FontAttribs.h

// -*- mode: c++; c-file-style: "linux"; c-basic-offset: 2; indent-tabs-mode: nil -*-
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//  Copyright (C) 2020 Kuba Ober <kuba@mareimbrium.org>
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//  SPDX-License-Identifier: wxWindows
 
#ifndef WXMAXIMA_FONTATTRIBS_H
#define WXMAXIMA_FONTATTRIBS_H
 
#include "Compat.h"   // wxWARN_UNUSED
#include "EnumWrapper.h"
#include <wx/font.h>
#include <wx/version.h>
#include <algorithm>
#include <cstdint>
#include <functional>
#include <limits>
 
using AFontEncoding = EnumWrapper<wxFontEncoding, int16_t, wxFONTENCODING_DEFAULT>;
using AFontFamily = EnumWrapper<wxFontFamily, int16_t, wxFONTFAMILY_DEFAULT>;
using AFontStyle = EnumWrapper<wxFontStyle, int16_t, wxFONTSTYLE_NORMAL>;
using AFontWeight = EnumWrapper<wxFontWeight, int16_t, wxFONTWEIGHT_NORMAL>;
 
// A font size is a value: an AFontSize nobody reads is dead code.
class wxWARN_UNUSED AFontSize final
{
  constexpr static float Size_Unit = 0.05f;
 
public:
  using value_type = int16_t;
 
  constexpr static float Minimum_Size = 4.0f;
  constexpr static float Maximum_Size = std::numeric_limits<value_type>::max() * Size_Unit;
 
  constexpr AFontSize() = default;
  constexpr explicit AFontSize(float size) : m_uSize(ToUSize(size)) {}
  constexpr AFontSize(AFontSize minimum, double size) :
    m_uSize(std::max(minimum.m_uSize, ToUSize(static_cast<float>(size)))) {}
  constexpr AFontSize(AFontSize minimum, AFontSize size) : m_uSize(std::max(minimum.m_uSize, size.m_uSize)) {}
  constexpr AFontSize(const AFontSize &o) = default;
 
  constexpr void Set(float size) { m_uSize = ToUSize(size); }
  constexpr void Clear() { m_uSize = {}; }
  // Old cppcheck bugs:
  // cppcheck-suppress operatorEq
  constexpr AFontSize &operator=(const AFontSize &o) = default;
 
  constexpr auto operator<=>(const AFontSize& o) const = default;
  constexpr float Get() const { return IsValid() ? m_uSize * Size_Unit : Minimum_Size; }
  constexpr long GetAsLong() const { return long(Get() + 0.5f); }
  constexpr auto GetForWX() const;
  constexpr bool IsNull() const { return !IsValid(); }
  constexpr bool IsValid() const { return m_uSize > 0; }
  constexpr bool IsMinimal() const { return m_uSize == ToUSize(Minimum_Size); }
 
  struct Equals {
    bool operator()(AFontSize l, AFontSize r) const { return l == r; }
  };
 
private:
  friend bool EqualToWithin(AFontSize, AFontSize, float);
  value_type m_uSize = {};
  constexpr static value_type ToUSize(float size);
};
 
constexpr double operator*(double factor, AFontSize size)   { return factor * size.Get(); }
constexpr double operator*(AFontSize size, double factor)   { return size.Get() * factor; }
constexpr double operator/(double dividend, AFontSize size) { return dividend / size.Get(); }
constexpr double operator/(AFontSize size, double divisor)  { return size.Get() / divisor; }
constexpr double operator+(double offset, AFontSize size)   { return offset + size.Get(); }
constexpr double operator+(AFontSize size, double offset)   { return size.Get() + offset; }
constexpr double operator-(double offset, AFontSize size)   { return offset - size.Get(); }
constexpr double operator-(AFontSize size, double offset)   { return size.Get() - offset; }
constexpr AFontSize operator-=(AFontSize &size, double factor)
{ return size.Set(static_cast<float>(size - factor)), size; }
 
constexpr AFontSize::value_type AFontSize::ToUSize(float size)
{
  return AFontSize::value_type(std::clamp(size, Minimum_Size, Maximum_Size) / Size_Unit + 0.5f);
}
 
constexpr auto AFontSize::GetForWX() const
{
#if wxCHECK_VERSION(3, 1, 2)
  return static_cast<double>(Get());
#else
  return GetAsLong();
#endif
}
 
bool EqualToWithin(AFontSize left, AFontSize right, float limit);
 
#endif