console_helper.h

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#ifndef OOKII_CONSOLE_HELPER_H_
#define OOKII_CONSOLE_HELPER_H_
 
#pragma once
 
#include "platform_helper.h"
#include <iostream>
 
namespace ookii
{
    inline short get_console_width(short default_width = 80) noexcept
    {
        auto width = details::get_console_width();
        if (width)
        {
            return *width;
        }
 
        return default_width;
    }
 
    enum class standard_stream
    {
        input,
        output,
        error
    };
 
    template<typename CharType>
    struct console_stream
    {
    };
 
    template<>
    struct console_stream<char>
    {
        static inline std::ostream &cout()
        {
            return std::cout;
        };
 
        static inline std::ostream &cerr()
        {
            return std::cerr;
        }
 
        static inline std::istream &cin()
        {
            return std::cin;
        }
    };
 
    template<>
    struct console_stream<wchar_t>
    {
        static inline std::wostream &cout()
        {
            return std::wcout;
        };
 
        static inline std::wostream &cerr()
        {
            return std::wcerr;
        }
 
        static inline std::wistream &cin()
        {
            return std::wcin;
        }
    };
 
    namespace details
    {
        inline FILE *get_stream_file(standard_stream stream)
        {
            switch (stream)
            {
            case standard_stream::input:
                return stdin;
 
            case standard_stream::error:
                return stderr;
 
            default:
                return stdout;
            }
        }
 
#ifdef _WIN32
#ifdef OOKII_PLATFORM_FUNC_HAS_BODY
        OOKII_PLATFORM_FUNC(HANDLE get_stream_handle(standard_stream stream))
        {
            switch (stream)
            {
            case standard_stream::input:
                return GetStdHandle(STD_INPUT_HANDLE);
 
            case standard_stream::error:
                return GetStdHandle(STD_ERROR_HANDLE);
 
            default:
                return GetStdHandle(STD_OUTPUT_HANDLE);
            }
        }
#endif
 
        inline int get_stream_fd(standard_stream stream)
        {
            return _fileno(get_stream_file(stream));
        }
 
        OOKII_PLATFORM_FUNC(bool is_console(standard_stream stream))
#ifdef OOKII_PLATFORM_FUNC_HAS_BODY
        {
            return _isatty(get_stream_fd(stream));
        }
#endif
 
#else
        inline int get_stream_fd(standard_stream stream)
        {
            return fileno(get_stream_file(stream));
        }
 
        OOKII_PLATFORM_FUNC(bool is_console(standard_stream stream))
#ifdef OOKII_PLATFORM_FUNC_HAS_BODY
        {
            return isatty(get_stream_fd(stream));
        }
#endif
#endif
    }
 
    enum class vt_result
    {
        failed,
        no_change,
        success
    };
 
#ifdef _WIN32
    OOKII_PLATFORM_FUNC(vt_result set_console_vt_support(standard_stream stream, bool enable) noexcept)
#ifdef OOKII_PLATFORM_FUNC_HAS_BODY
    {
        auto handle = details::get_stream_handle(stream);
        DWORD mode;
        if (!GetConsoleMode(handle, &mode))
        {
            return vt_result::failed;
        }
 
        auto flag = stream == standard_stream::input
            ? ENABLE_VIRTUAL_TERMINAL_INPUT
            : ENABLE_VIRTUAL_TERMINAL_PROCESSING;
 
        auto old_mode = mode;
        if (enable)
        {
            mode |= flag;
        }
        else
        {
            mode &= ~flag;
        }
 
        if (mode == old_mode)
        {
            return vt_result::no_change;
        }
 
        if (!SetConsoleMode(handle, mode))
        {
            return vt_result::failed;
        }
 
        return vt_result::success;
    }
#endif
#else
    inline vt_result set_console_vt_support([[maybe_unused]] standard_stream stream, [[maybe_unused]] bool enable) noexcept
    {
        return vt_result::no_change;
    }
#endif
 
}
 
#endif