DYTSrouce/src/ui/FramelessDelegateWin.h

#pragma once

#include <Windows.h>

#if __cplusplus >= 201703L
#include <optional>
#else
#include <stdexcept>
namespace std {
    struct nullopt_t { // no-value state indicator
        struct _Tag {
        };
        constexpr explicit nullopt_t(_Tag) {}
    };
    constexpr nullopt_t nullopt{ nullopt_t::_Tag{} };

    class bad_optional_access : public std::exception
    {
    public:
        const char* what() const noexcept override
        {
            return "bad optional access";
        }
    };

    template <class T>
    class optional {
    public:
        constexpr optional() noexcept : _engaged(false) {}
        constexpr optional(nullopt_t) noexcept : _engaged(false) {}

        optional(const optional& other) : _engaged(other._engaged) {
            if (other._engaged) {
                new (_storage) T(*other);
            }
        }

        optional(optional&& other) noexcept : _engaged(other._engaged) {
            if (other._engaged) {
                new (_storage) T(std::move(*other));
                other._engaged = false;
            }
        }

        optional& operator=(const optional& other)
        {
             if(this == &other)
                  return *this;
             if(_engaged && other._engaged)
             {
                 **this = *other;
             }
            else if(other._engaged)
             {
                 new (_storage) T(*other);
                 _engaged = true;
             } else if(_engaged)
            {
               reset();
            }

            return *this;

        }

       optional& operator=(optional&& other) noexcept
        {
            if(this == &other)
                  return *this;
            if(_engaged && other._engaged)
            {
                 **this = std::move(*other);

            } else if (other._engaged)
            {
               new(_storage) T(std::move(*other));
              _engaged = true;

            } else if(_engaged)
            {
               reset();
            }
             other._engaged = false;
            return *this;
        }

        optional(const T& value) : _engaged(true) {
            new (_storage) T(value);
        }

        optional(T&& value) : _engaged(true) {
            new (_storage) T(std::move(value));
        }

        ~optional() {
            reset();
        }

        void reset() noexcept {
             if (_engaged) {
                reinterpret_cast<T*>(_storage)->~T();
                _engaged = false;
            }
        }

       constexpr bool has_value() const noexcept
       {
          return _engaged;
       }

       T& operator*() &
       {
         if(!_engaged)
            throw std::bad_optional_access();
          return *reinterpret_cast<T*>(_storage);
       }
       const T& operator*() const&
       {
           if(!_engaged)
            throw std::bad_optional_access();
          return *reinterpret_cast<const T*>(_storage);
       }

      T&& operator*() &&
      {
        if(!_engaged)
            throw std::bad_optional_access();
           return std::move(*reinterpret_cast<T*>(_storage));
      }

       const T&& operator*() const&&
      {
         if(!_engaged)
            throw std::bad_optional_access();
           return std::move(*reinterpret_cast<T*>(_storage));
      }

       T* operator->() {
           return reinterpret_cast<T*>(_storage);
       }
       const T* operator->() const {
            return reinterpret_cast<const T*>(_storage);
        }

        explicit operator bool() const noexcept {
            return _engaged;
        }

    private:
        bool _engaged;
        char _storage[sizeof(T)];
    };

    
    //
    // template<typename T>
    // class optional {
    // public:
    //     optional() : has_value_(false) {}
    //     optional(const T& value) : has_value_(true), value_(value) {}
    //     optional(T&& value) : has_value_(true), value_(std::move(value)) {}
    //     optional(nullopt_t) : has_value_(false) {}
    //
    //     bool has_value() const {
    //         return has_value_;
    //     }
    //
    //     T& value() {
    //         if (!has_value_) {
    //             throw std::runtime_error("optional has no value");
    //         }
    //         return value_;
    //     }
    //
    //     const T& value() const {
    //         if (!has_value_) {
    //             throw std::runtime_error("optional has no value");
    //         }
    //         return value_;
    //     }
    //
    //     T& operator*() {
    //         return value();
    //     }
    //
    //     const T& operator*() const {
    //         return value();
    //     }
    //
    //     T* operator->() {
    //         return &value();
    //     }
    //
    //     const T* operator->() const {
    //         return &value();
    //     }
    //
    //     bool operator==(const optional& other) const {
    //         if (has_value_ && other.has_value_) {
    //             return value_ == other.value_;
    //         }
    //         return has_value_ == other.has_value_;
    //     }
    //
    //     bool operator!=(const optional& other) const {
    //         return !(*this == other);
    //     }
    //
    //     bool operator!() const {
    //         return !has_value();
    //     }
    //
    // private:
    //     bool has_value_;
    //     T value_;
    // };

}

#endif

#include "FramelessDelegate.h"


class FramelessDelegateWin : public FramelessDelegate {
	Q_OBJECT

public:
    FramelessDelegateWin(QWidget* parent);
	~FramelessDelegateWin() override;

#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    bool nativeEvent(const QByteArray& eventType, void* message, long* result) override;
#else
    bool nativeEvent(const QByteArray& eventType, void* message, qintptr* result) override;
#endif

protected:
    void OnShow() override;
    void OnHide() override;
    void OnClose() override;
    void OnScreenChangeInternaal() override;
    void AddMoveBar(QWidget* moveWidget) override;

private:
    double DpiScale(double value);
    double UnDpiScale(double value); 
    void CheckMonitorChanged();

    void ShowSystemMenu(const QPoint& pos);

    void SetNativeWindowLong();

#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    bool OnNCTitTest(MSG* msg, long* result);
#else
    bool OnNCTitTest(MSG* msg, qintptr* result);
#endif

private:
    bool firstShow_{ true };
    std::optional<QRect> workRect_;
    HMONITOR monitor_{ nullptr };
    WINDOWPLACEMENT wndPlaceMent_{ 0, 0, 0, {0, 0}, {0, 0}, {0, 0, 0, 0} };
};