86 lines
2.5 KiB
C
86 lines
2.5 KiB
C
|
//+-------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// Microsoft Windows
|
||
|
|
//
|
||
|
|
// Copyright (C) Microsoft Corporation, 1999 - 1999
|
||
|
|
//
|
||
|
|
// File: observer.h
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------
|
||
|
|
|
||
|
|
#ifndef _OBSERVER_H_
|
||
|
|
#define _OBSERVER_H_
|
||
|
|
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
// Event source interface template
|
||
|
|
// Defines event source class for specific observer class
|
||
|
|
template <class Observer>
|
||
|
|
class EventSource
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
STDMETHOD(Advise)(Observer* pObserver, LONG_PTR* pCookie) = 0;
|
||
|
|
STDMETHOD(Unadvise)(LONG_PTR Cookie) = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Event source implementation template
|
||
|
|
// Defines implementation of event source for a specific observer class
|
||
|
|
// maintains a vector of the active observers of this event source
|
||
|
|
template <class Observer>
|
||
|
|
class ATL_NO_VTABLE EventSourceImpl : EventSource<Observer>
|
||
|
|
{
|
||
|
|
typedef std::list<Observer*> ObserverList;
|
||
|
|
typedef std::list<Observer*>::iterator ObserverIter;
|
||
|
|
|
||
|
|
public:
|
||
|
|
STDMETHOD(Advise)(Observer* pObserver, LONG_PTR* plCookie);
|
||
|
|
STDMETHOD(Unadvise)(LONG_PTR lCookie);
|
||
|
|
|
||
|
|
protected:
|
||
|
|
~EventSourceImpl()
|
||
|
|
{
|
||
|
|
// verify there are no obervers when going away
|
||
|
|
ASSERT(m_Observers.empty());
|
||
|
|
}
|
||
|
|
|
||
|
|
ObserverList m_Observers;
|
||
|
|
};
|
||
|
|
|
||
|
|
template <class Observer>
|
||
|
|
STDMETHODIMP EventSourceImpl<Observer>::Advise(Observer* pObserver, LONG_PTR* plCookie)
|
||
|
|
{
|
||
|
|
ASSERT(pObserver != NULL);
|
||
|
|
ASSERT(plCookie != NULL);
|
||
|
|
|
||
|
|
ObserverIter iter = m_Observers.insert(m_Observers.end(), pObserver);
|
||
|
|
|
||
|
|
// can't cast iterator to LONG_PTR so check size before cheating
|
||
|
|
ASSERT(sizeof(ObserverIter) == sizeof(LONG_PTR));
|
||
|
|
*(ObserverIter*)plCookie = iter;
|
||
|
|
|
||
|
|
return S_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Observer>
|
||
|
|
STDMETHODIMP EventSourceImpl<Observer>::Unadvise(LONG_PTR lCookie)
|
||
|
|
{
|
||
|
|
// Can't cast LONG_PTR to iterator, so have to cheat
|
||
|
|
// see Advise method for size check
|
||
|
|
ObserverIter iter;
|
||
|
|
*(LONG_PTR*)&iter = lCookie;
|
||
|
|
|
||
|
|
m_Observers.erase(iter);
|
||
|
|
return S_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Observer enumerator helper
|
||
|
|
// Provides for-loop header for iterating over observers of a specified observer class
|
||
|
|
#define FOR_EACH_OBSERVER(ObserverClass, ObserverIter) \
|
||
|
|
for ( \
|
||
|
|
std::list<ObserverClass*>::iterator ObserverIter = EventSourceImpl<ObserverClass>::m_Observers.begin(); \
|
||
|
|
ObserverIter != EventSourceImpl<ObserverClass>::m_Observers.end(); \
|
||
|
|
++ObserverIter \
|
||
|
|
)
|
||
|
|
|
||
|
|
#endif // _OBSERVER_H_
|