PowerToys/src/common/com_object_factory.h at master · NotUsedCode/PowerToys · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
#pragma once

#include <Unknwn.h>
#include <winrt/base.h>
#include <atomic>

template<typename T>
class com_object_factory : public IClassFactory
{
public:
    HRESULT __stdcall QueryInterface(const IID& riid, void** ppv) override
    {
        static const QITAB qit[] = {
            QITABENT(com_object_factory, IClassFactory),
            { 0 }
        };
        return QISearch(this, qit, riid, ppv);
    }

    ULONG __stdcall AddRef() override
    {
        return ++_refCount;
    }

    ULONG __stdcall Release() override
    {
        LONG refCount = --_refCount;
        return refCount;
    }

    HRESULT __stdcall CreateInstance(IUnknown* punkOuter, const IID& riid, void** ppv)
    {
        *ppv = nullptr;
        HRESULT hr;
        if (punkOuter)
        {
            hr = CLASS_E_NOAGGREGATION;
        }
        else
        {
            T* psrm = new (std::nothrow) T();
            HRESULT hr = psrm ? S_OK : E_OUTOFMEMORY;
            if (SUCCEEDED(hr))
            {
                hr = psrm->QueryInterface(riid, ppv);
                psrm->Release();
            }
            return hr;
        }
        return hr;
    }

    HRESULT __stdcall LockServer(BOOL)
    {
        return S_OK;
    }

private:
    std::atomic<long> _refCount;
};