common/cenumpins.hpp

// Copyright (c) 2010 The WebM project authors. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license and patent
// grant that can be found in the LICENSE file in the root of the source
// tree. All contributing project authors may be found in the AUTHORS
// file in the root of the source tree.

#pragma once
#include "tenumxxx.hpp"
#include <vector>

class CEnumPins : public TEnumXXX<IEnumPins, IPin*>
{
    virtual ~CEnumPins();    
    CEnumPins(const CEnumPins&);    
    CEnumPins& operator=(const CEnumPins&);
    
public:

    CEnumPins(IPin* const*, ULONG);

    template<typename T>
    explicit CEnumPins(T* const*, ULONG);

    static HRESULT CreateInstance(IPin* const*, ULONG, IEnumPins**);
    
    template<typename T>
    static HRESULT CreateInstance(T* const*, ULONG, IEnumPins**);
    
    HRESULT STDMETHODCALLTYPE Clone(IEnumPins**);

protected:

    HRESULT GetCount(ULONG&) const;
    HRESULT GetItem(ULONG, IPin*&);
    void ReleaseItems(IPin**, ULONG);

private:

    typedef std::vector<IPin*> pins_t;
    pins_t m_pins;
    
};


template<typename T>
inline CEnumPins::CEnumPins(T* const* i, ULONG n)
{
    m_pins.reserve(n);
    
    T* const* j = i + n;
    
    while (i != j)
    {
        IPin* const p = *i++;
        p->AddRef();
        
        m_pins.push_back(p);
    }
}

template<typename T>
inline HRESULT CEnumPins::CreateInstance(
    T* const* i,
    ULONG n,
    IEnumPins** pp)
{
    if (pp == 0)
        return E_POINTER;
        
    IEnumPins*& p = *pp;
    
    p = new (std::nothrow) CEnumPins(i, n);
    
    return p ? S_OK : E_OUTOFMEMORY;
}