//-------------------------------------------------------------------------------------------------------+
// Copyright (C), 1998-2007, Beijing Tangent Software Co. Ltd.
// = FileName	:   TStack 模板类
// = Version	:   ver2.0
// = Author		:   wlw
// = CreateDate	:   2002-09-09
// = Description:   TStack 声明 堆栈抽象类
// = Maintainers: 
//                  
//-------------------------------------------------------------------------------------------------------+
#ifndef _TSTACK_H_
#define _TSTACK_H_

template<class T> class TStack
{
public:
	
	TStack(long depth = -1);
	
	virtual ~TStack();
	
	virtual bool Pop(T&t) = 0;
	
	virtual bool Push(T const&t) = 0;

	virtual void GoBack() = 0;
	
	virtual void GoAhead() = 0;
	
	virtual void Clear() = 0;

	virtual long GetDepth() = 0;
	
	virtual bool GetTopData(T&t) = 0;
	
	virtual T& operator[](long i) = 0;

	void SetMaxDepth(long depth);
	
	long GetMaxDepth();
	
	bool IsDepthLimited();
	
	bool IsEmpty();

	bool CanGoBack();
	
	bool CanGoAhead();

protected:
	
	long maxDepth;
	
	long oldDepth;
};

template<class T> 
TStack<T>::TStack(long depth)
{
	maxDepth = depth;
	oldDepth = 0;
}

template<class T> 
TStack<T>::~TStack()
{

}

template<class T> 
void TStack<T>::SetMaxDepth(long depth)
{
	maxDepth = depth;
}

template<class T> 
long TStack<T>::GetMaxDepth() 
{
	return maxDepth;
}

template<class T> 
bool TStack<T>::IsDepthLimited() 
{
	return maxDepth >= 0;
}

template<class T> 
bool TStack<T>::IsEmpty() 
{
	return GetDepth() == 0;
}

template<class T> 
bool TStack<T>::CanGoBack() 
{
	return !IsEmpty();
}

template<class T> 
bool TStack<T>::CanGoAhead() 
{
	return oldDepth > GetDepth();
}

#endif