PowerToys/src/modules/previewpane/GcodePreviewHandlerCpp/ClassFactory.cpp

#include "pch.h"
#include "ClassFactory.h"
#include "GcodePreviewHandler.h"

#include <new>
#include <Shlwapi.h>

extern long g_cDllRef;

ClassFactory::ClassFactory() :
    m_cRef(1)
{
    InterlockedIncrement(&g_cDllRef);
}

ClassFactory::~ClassFactory()
{
    InterlockedDecrement(&g_cDllRef);
}

//
// IUnknown
//

IFACEMETHODIMP ClassFactory::QueryInterface(REFIID riid, void **ppv)
{
    static const QITAB qit[] = {
        QITABENT(ClassFactory, IClassFactory),
        { 0 },
    };
    return QISearch(this, qit, riid, ppv);
}

IFACEMETHODIMP_(ULONG) ClassFactory::AddRef()
{
    return InterlockedIncrement(&m_cRef);
}

IFACEMETHODIMP_(ULONG) ClassFactory::Release()
{
    ULONG cRef = InterlockedDecrement(&m_cRef);
    if (0 == cRef)
    {
        delete this;
    }
    return cRef;
}

//
// IClassFactory
//

IFACEMETHODIMP ClassFactory::CreateInstance(IUnknown *pUnkOuter, REFIID riid, void **ppv)
{
    HRESULT hr = CLASS_E_NOAGGREGATION;

    if (pUnkOuter == NULL)
    {
        hr = E_OUTOFMEMORY;

        GcodePreviewHandler* pExt = new (std::nothrow) GcodePreviewHandler();
        if (pExt)
        {
            hr = pExt->QueryInterface(riid, ppv);
            pExt->Release();
        }
    }

    return hr;
}

IFACEMETHODIMP ClassFactory::LockServer(BOOL fLock)
{
    if (fLock)
    {
        InterlockedIncrement(&g_cDllRef);
    }
    else
    {
        InterlockedDecrement(&g_cDllRef);
    }

    return S_OK;
}