[FGL Utility] ClipboardString.h

// Public Discord: http://roleplay.FutureGadgetLab.net (Alaestor FGL 2017)
#ifndef CLIPBOARDSTRING_H_INCLUDED
#define CLIPBOARDSTRING_H_INCLUDED
#define WINVER _WIN32_WINNT_WIN7
#include <exception>
#include <string>
#include <windows.h>



// warning: after use, must be destroyed as soon as possible.
// has exclusive clipboard access for lifetime of object.



class ClipboardString
{
    private:

    auto initData() const
    {
        if (!OpenClipboard(nullptr)) throw std::runtime_error(
            "ClipboardData::initData() OpenClipboard() failed");

        const auto& cbd = GetClipboardData(CF_UNICODETEXT);
        if (cbd == nullptr) throw std::runtime_error(
            "ClipboardData::initData() GetClipboardData() failed");

        return cbd;
    }

    const HANDLE m_data;

    public:

    const std::wstring get() const
    {return std::wstring(reinterpret_cast< wchar_t* >(m_data));}

    void set(const std::wstring& wstr)
    {
        EmptyClipboard();
        const std::size_t size = (wstr.size() + 1) * sizeof(wstr[0]);
        const auto& handle = GlobalAlloc(GMEM_MOVEABLE, size);
        if (handle == nullptr) throw std::runtime_error(
            "ClipboardData::set() GlobalAlloc() failed");

        const auto& ptr = GlobalLock(handle);
        if (ptr == nullptr) throw std::runtime_error(
            "ClipboardData::set() GlobalLock() failed");

        memcpy(ptr, wstr.data(), size);
        GlobalUnlock(handle);

        const auto& result = SetClipboardData(CF_UNICODETEXT, handle);
        if (result == nullptr) throw std::runtime_error(
            "ClipboardData::set() SetClipboardData() failed");
    }

    void set(const std::string& str)
    { // converts to wstring, does temp allocation
        std::wstring wstr(str.length(), L' ');
        std::copy(str.cbegin(), str.cend(), wstr.begin());
        set(wstr);
    }

    explicit ClipboardString() :
        m_data(initData())
    {}

    ~ClipboardString()
    { CloseClipboard(); }
};

#endif // CLIPBOARDSTRING_H_INCLUDED