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

template<class T> class Stack
{
public:
	
	Stack(long depth = -1);
	
	virtual ~Stack();
	
	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> 
Stack<T>::Stack(long depth)
{
	maxDepth = depth;
	oldDepth = 0;
}

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

}

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

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

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

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

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

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

#endif