VariantConverter.cs

using System;
using System.Runtime.InteropServices;

namespace PaintDotNet.Interop;

// This contains items that are missing from TerraFX.Interop.Windows.dll
internal static unsafe class Windows2
{
    public static HRESULT InitPropVariantFromBoolean(bool fVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_BOOL;
        ppropvar->boolVal = fVal ? VARIANT_TRUE : VARIANT_FALSE;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromBooleanVector(
        BOOL* prgf,
        uint cElems,
        PROPVARIANT* ppropvar);

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromBuffer(
        void* pv,
        uint cb,
        PROPVARIANT* ppropvar);

    // Not in propvarutil.h
    public static HRESULT InitPropVariantFromDate(double date, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->date = date;
        ppropvar->vt = (ushort)VT_DATE;
        return S_OK;
    }

    // Not in propvarutil.h
    public static HRESULT InitPropVariantFromDecimal(DECIMAL* pDecimal, PROPVARIANT* ppropvar)
    {
        if (pDecimal == null || ppropvar == null)
        {
            return E_POINTER;
        }

        // As per documentation, we must set decVal first, then set vt
        ppropvar->decVal = *pDecimal;
        ppropvar->vt = (ushort)VT_DECIMAL;
        return S_OK;
    }

    public static HRESULT InitPropVariantFromDouble(double dblVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_R8;
        ppropvar->dblVal = dblVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromDoubleVector(
        double* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromFileTime(
        FILETIME* pftIn,
        PROPVARIANT* ppropVar);
    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromFileTimeVector(
        FILETIME* prgft,
        uint cElems,
        PROPVARIANT* ppropvar);

    // Not in propvarutil.h
    public static HRESULT InitPropVariantFromFloat(float fltVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_R4;
        ppropvar->fltVal = fltVal;
        return S_OK;
    }

    // Not in propvarutil.h
    public static HRESULT InitPropVariantFromFloatVector(
        float* prgn,
        uint cElems,
        PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        nuint cbElems = (nuint)sizeof(float) * cElems;
        float* pElems = (float*)CoTaskMemAlloc(cbElems);
        if (pElems == null)
        {
            return E_OUTOFMEMORY;
        }

        if (prgn != null)
        {
            BufferUtil.Copy(pElems, prgn, cbElems);
        }
        else
        {
            BufferUtil.Fill(pElems, 0, cbElems);
        }

        ppropvar->vt = (ushort)(VT_VECTOR | VT_R4);
        ppropvar->caflt.cElems = cElems;
        ppropvar->caflt.pElems = pElems;
        return S_OK;
    }

    public static HRESULT InitPropVariantFromGUIDAsBuffer(Guid guid, PROPVARIANT* ppropvar)
    {
        return Windows2.InitPropVariantFromBuffer(&guid, (uint)sizeof(Guid), ppropvar);
    }

    public static HRESULT InitPropVariantFromInt16(short nVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_I2;
        ppropvar->iVal = nVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromInt16Vector(
        short* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static HRESULT InitPropVariantFromInt32(int lVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_I4;
        ppropvar->lVal = lVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromInt32Vector(
        int* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static HRESULT InitPropVariantFromInt64(long llVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_I8;
        ppropvar->hVal.QuadPart = llVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromInt64Vector(
        long* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static HRESULT InitPropVariantFromString(ushort* psz, PROPVARIANT* ppropvar)
    {
        HRESULT hr = (psz != null) ? S_OK : E_INVALIDARG;

        if (hr.SUCCEEDED)
        {
            nuint byteCount = ((nuint)WindowsUtil.GetStringLength((char*)psz) + 1) * sizeof(ushort);
            ppropvar->pwszVal = (ushort*)CoTaskMemAlloc(byteCount);
            hr = (ppropvar->pwszVal != null) ? S_OK : E_OUTOFMEMORY;
            if (hr.SUCCEEDED)
            {
                BufferUtil.Copy(ppropvar->pwszVal, psz, byteCount);
                ppropvar->vt = (ushort)VT_LPWSTR;
            }
        }

        if (hr.FAILED)
        {
            PropVariantInit(ppropvar);
        }

        return hr;
    }

    public static HRESULT InitPropVariantFromUInt16(ushort uiVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_UI2;
        ppropvar->uiVal = uiVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromUInt16Vector(
        ushort* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static HRESULT InitPropVariantFromUInt32(uint ulVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_UI4;
        ppropvar->ulVal = ulVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromUInt32Vector(
        uint* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static HRESULT InitPropVariantFromUInt64(ulong ullVal, PROPVARIANT* ppropvar)
    {
        if (ppropvar == null)
        {
            return E_POINTER;
        }

        ppropvar->vt = (ushort)VT_UI8;
        ppropvar->uhVal.QuadPart = ullVal;
        return S_OK;
    }

    [DllImport("propsys", ExactSpelling = true)]
    public static extern HRESULT InitPropVariantFromUInt64Vector(
        ulong* prgn,
        uint cElems,
        PROPVARIANT* ppropvar);

    public static void PropVariantInit(PROPVARIANT* pvar)
    {
        BufferUtil.Fill(pvar, 0, sizeof(PROPVARIANT));
    }

    [DllImport("oleaut32", ExactSpelling = true)]
    public static extern HRESULT VariantClear(VARIANT* pvarg);

    [DllImport("oleaut32", ExactSpelling = true)]
    public static extern void VariantInit(VARIANT* pvarg);
}