XnEventT.h

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/****************************************************************************
*                                                                           *
*  OpenNI 1.x Alpha                                                         *
*  Copyright (C) 2011 PrimeSense Ltd.                                       *
*                                                                           *
*  This file is part of OpenNI.                                             *
*                                                                           *
*  OpenNI is free software: you can redistribute it and/or modify           *
*  it under the terms of the GNU Lesser General Public License as published *
*  by the Free Software Foundation, either version 3 of the License, or     *
*  (at your option) any later version.                                      *
*                                                                           *
*  OpenNI is distributed in the hope that it will be useful,                *
*  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the             *
*  GNU Lesser General Public License for more details.                      *
*                                                                           *
*  You should have received a copy of the GNU Lesser General Public License *
*  along with OpenNI. If not, see <http://www.gnu.org/licenses/>.           *
*                                                                           *
****************************************************************************/
#ifndef _XN_EVENT_T_H_
#define _XN_EVENT_T_H_ 

//---------------------------------------------------------------------------
// Includes
//---------------------------------------------------------------------------
#include "XnOSCpp.h"
#include "XnListT.h"
#include "XnTypes.h"

//---------------------------------------------------------------------------
// Types
//---------------------------------------------------------------------------

template<typename FuncPtr>
struct XnCallbackT
{
    XnCallbackT(FuncPtr func, void* cookie) : pFunc(func), pCookie(cookie) {}

    FuncPtr pFunc;
    void* pCookie;
};

template<typename FuncPtr>
class XnEventInterfaceT
{
public:
    typedef FuncPtr HandlerPtr;
    typedef XnCallbackT<FuncPtr> TCallback;
    typedef XnEventInterfaceT TInterface;

    ~XnEventInterfaceT()
    {
        Clear();
        xnOSCloseCriticalSection(&m_hLock);
    }

    XnStatus Register(FuncPtr pFunc, void* pCookie, XnCallbackHandle& hCallback)
    {
        XnStatus nRetVal = XN_STATUS_OK;

        XN_VALIDATE_INPUT_PTR(pFunc);

        TCallback* pCallback = NULL;
        XN_VALIDATE_NEW(pCallback, TCallback, pFunc, pCookie);

        // always add to list of added (actual list will be updated in Raise method, to allow registering 
        // from a callback).
        {
            XnAutoCSLocker locker(m_hLock);
            nRetVal = m_toAdd.AddLast(pCallback);
        }

        if (nRetVal != XN_STATUS_OK)
        {
            XN_DELETE(pCallback);
            return nRetVal;
        }

        // return handle
        hCallback = (XnCallbackHandle)pCallback;

        return XN_STATUS_OK;
    }

    XnStatus Unregister(XnCallbackHandle hCallback)
    {
        XnStatus nRetVal = XN_STATUS_OK;

        TCallback* pCallback = (TCallback*)hCallback;

        // add it to a temp list, to allow unregistering from a callback (actual list will be updated in raise
        // function).
        {
            XnAutoCSLocker locker(m_hLock);

            // try to remove it from the ToBeAdded list.
            if (!RemoveCallback(m_toAdd, pCallback))
            {
                // it's not in this list, so it's probably in the main list
                nRetVal = m_toRemove.AddLast(pCallback);
            }
        }
        XN_IS_STATUS_OK(nRetVal);

        return XN_STATUS_OK;
    }

protected:
    typedef XnListT<TCallback*> CallbackPtrList;

    // Constructors are protected, so that this class cannot be instantiated directly.
    XnEventInterfaceT()
    {
        Init();
    }

    XnEventInterfaceT(const XnEventInterfaceT& other)
    {
        Init();
        *this = other;
    }

    XnEventInterfaceT& operator=(const XnEventInterfaceT& other)
    {
        Clear();

        // lock other one (so it won't change while being copied)
        XnAutoCSLocker otherLocker(other.m_hLock);
        // lock this one (we're making changes)
        XnAutoCSLocker locker(m_hLock);

        m_callbacks = other.m_callbacks;
        m_toAdd = other.m_toAdd;
        m_toRemove = other.m_toRemove;

        ApplyListChanges();

        return *this;
    }

    XnStatus Clear()
    {
        XnAutoCSLocker locker(m_hLock);
        ApplyListChanges();

        for (typename CallbackPtrList::ConstIterator it = m_callbacks.Begin(); it != m_callbacks.End(); ++it)
        {
            TCallback* pCallback = *it;
            XN_DELETE(pCallback);
        }

        m_callbacks.Clear();
        m_toRemove.Clear();
        m_toAdd.Clear();
        return (XN_STATUS_OK);
    }

    XnStatus ApplyListChanges()
    {
        XnAutoCSLocker locker(m_hLock);

        // first add all
        for (typename CallbackPtrList::ConstIterator it = m_toAdd.Begin(); it != m_toAdd.End(); ++it)
        {
            m_callbacks.AddLast(*it);
        }
        m_toAdd.Clear();

        // and now remove
        for (typename CallbackPtrList::ConstIterator it = m_toRemove.Begin(); it != m_toRemove.End(); ++it)
        {
            TCallback* pCallback = *it;
            RemoveCallback(m_callbacks, pCallback);
        }
        m_toRemove.Clear();

        return (XN_STATUS_OK);
    }

    XnBool RemoveCallback(CallbackPtrList& list, TCallback* pCallback)
    {
        typename CallbackPtrList::Iterator it = list.Find(pCallback);
        if (it != list.End())
        {
            list.Remove(it);
            XN_DELETE(pCallback);
            return TRUE;
        }

        return FALSE;
    }

    XN_CRITICAL_SECTION_HANDLE m_hLock;
    CallbackPtrList m_callbacks;
    CallbackPtrList m_toAdd;
    CallbackPtrList m_toRemove;

private:
    void Init()
    {
        m_hLock = NULL;
        XnStatus nRetVal = xnOSCreateCriticalSection(&m_hLock);
        if (nRetVal != XN_STATUS_OK)
        {
            XN_ASSERT(FALSE);
        }
    }
};

// Handlers
struct XnHandlerFuncNoArgs
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(void* pCookie);
};

template<class TArg1>
struct XnHandlerFunc1Arg
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(TArg1 arg1, void* pCookie);
};

template<class TArg1, class TArg2>
struct XnHandlerFunc2Args
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(TArg1 arg1, TArg2 arg2, void* pCookie);
};

template<class TArg1, class TArg2, class TArg3>
struct XnHandlerFunc3Args
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(TArg1 arg1, TArg2 arg2, TArg3 arg3, void* pCookie);
};

template<class TArg1, class TArg2, class TArg3, class TArg4>
struct XnHandlerFunc4Args
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(TArg1 arg1, TArg2 arg2, TArg3 arg3, TArg4 arg4, void* pCookie);
};

template<class TArg1, class TArg2, class TArg3, class TArg4, class TArg5>
struct XnHandlerFunc5Args
{
    typedef void (XN_CALLBACK_TYPE* FuncPtr)(TArg1 arg1, TArg2 arg2, TArg3 arg3, TArg4 arg4, TArg5 arg5, void* pCookie);
};

// Event classes (there's a class per number of arguments)
class XnEventNoArgs : public XnEventInterfaceT<XnHandlerFuncNoArgs::FuncPtr>
{
public:
    XnStatus Raise()
    {
        XnAutoCSLocker locker(this->m_hLock);
        ApplyListChanges();

        for (CallbackPtrList::ConstIterator it = m_callbacks.Begin(); it != m_callbacks.End(); ++it)
        {
            TCallback* pCallback = *it;
            pCallback->pFunc(pCallback->pCookie);
        }

        ApplyListChanges();
        return (XN_STATUS_OK);
    }
};


template<class TArg1>
class XnEvent1Arg : public XnEventInterfaceT<typename XnHandlerFunc1Arg<TArg1>::FuncPtr>
{
    typedef XnEventInterfaceT<typename XnHandlerFunc1Arg<TArg1>::FuncPtr> Base;

public:
    XnStatus Raise(TArg1 arg)
    {
        XnAutoCSLocker locker(this->m_hLock);
        this->ApplyListChanges();

        for (typename Base::CallbackPtrList::ConstIterator it = this->m_callbacks.Begin(); it != this->m_callbacks.End(); ++it)
        {
            typename Base::TCallback* pCallback = *it;
            pCallback->pFunc(arg, pCallback->pCookie);
        }

        this->ApplyListChanges();
        return (XN_STATUS_OK);
    }
};

template<class TEventArgs>
class XnEventT : public XnEvent1Arg<const TEventArgs&>
{};

template<class TArg1, class TArg2>
class XnEvent2Args : public XnEventInterfaceT<typename XnHandlerFunc2Args<TArg1, TArg2>::FuncPtr>
{
    typedef XnEventInterfaceT<typename XnHandlerFunc2Args<TArg1, TArg2>::FuncPtr> Base;

public:
    XnStatus Raise(TArg1 arg1, TArg2 arg2)
    {
        XnAutoCSLocker locker(this->m_hLock);
        this->ApplyListChanges();

        for (typename Base::CallbackPtrList::ConstIterator it = this->m_callbacks.Begin(); it != this->m_callbacks.End(); ++it)
        {
            typename Base::TCallback* pCallback = *it;
            pCallback->pFunc(arg1, arg2, pCallback->pCookie);
        }

        this->ApplyListChanges();
        return (XN_STATUS_OK);
    }
};

template<class TArg1, class TArg2, class TArg3>
class XnEvent3Args : public XnEventInterfaceT<typename XnHandlerFunc3Args<TArg1, TArg2, TArg3>::FuncPtr>
{
    typedef XnEventInterfaceT<typename XnHandlerFunc3Args<TArg1, TArg2, TArg3>::FuncPtr> Base;
    
public:
    XnStatus Raise(TArg1 arg1, TArg2 arg2, TArg3 arg3)
    {
        XnAutoCSLocker locker(this->m_hLock);
        this->ApplyListChanges();

        for (typename Base::CallbackPtrList::ConstIterator it = this->m_callbacks.Begin(); it != this->m_callbacks.End(); ++it)
        {
            typename Base::TCallback* pCallback = *it;
            pCallback->pFunc(arg1, arg2, arg3, pCallback->pCookie);
        }

        this->ApplyListChanges();
        return (XN_STATUS_OK);
    }
};

template<class TArg1, class TArg2, class TArg3, class TArg4>
class XnEvent4Args : public XnEventInterfaceT<typename XnHandlerFunc4Args<TArg1, TArg2, TArg3, TArg4>::FuncPtr>
{
    typedef XnEventInterfaceT<typename XnHandlerFunc4Args<TArg1, TArg2, TArg3, TArg4>::FuncPtr> Base;
    
public:
    XnStatus Raise(TArg1 arg1, TArg2 arg2, TArg3 arg3, TArg4 arg4)
    {
        XnAutoCSLocker locker(this->m_hLock);
        this->ApplyListChanges();

        for (typename Base::CallbackPtrList::ConstIterator it = this->m_callbacks.Begin(); it != this->m_callbacks.End(); ++it)
        {
            typename Base::TCallback* pCallback = *it;
            pCallback->pFunc(arg1, arg2, arg3, arg4, pCallback->pCookie);
        }

        this->ApplyListChanges();
        return (XN_STATUS_OK);
    }
};

template<class TArg1, class TArg2, class TArg3, class TArg4, class TArg5>
class XnEvent5Args : public XnEventInterfaceT<typename XnHandlerFunc5Args<TArg1, TArg2, TArg3, TArg4, TArg5>::FuncPtr>
{
    typedef XnEventInterfaceT<typename XnHandlerFunc5Args<TArg1, TArg2, TArg3, TArg4, TArg5>::FuncPtr> Base;
    
public:
    XnStatus Raise(TArg1 arg1, TArg2 arg2, TArg3 arg3, TArg4 arg4, TArg5 arg5)
    {
        XnAutoCSLocker locker(this->m_hLock);
        this->ApplyListChanges();

        for (typename Base::CallbackPtrList::ConstIterator it = this->m_callbacks.Begin(); it != this->m_callbacks.End(); ++it)
        {
            typename Base::TCallback* pCallback = *it;
            pCallback->pFunc(arg1, arg2, arg3, arg4, arg5, pCallback->pCookie);
        }

        this->ApplyListChanges();
        return (XN_STATUS_OK);
    }
};

#endif // _XN_EVENT_T_H_