dblinkedlist.cpp

数字图像处理

#include "stdafx.h"
#include "DBLinkedList.h"
#include "stdlib.h"

Node::Node():avai(false),next(NULL),previous(NULL){
	// 数据置空
	nodedata.data = NULL;
	nodedata.size = 0;
}

Node::Node(void *_info,int size, Node *_next,Node *_previous):
next(_next),previous(_previous),avai(true){
	nodedata.data = malloc(size);      // 数据内存空间
	memcpy(nodedata.data,_info,size);
	nodedata.size = size;
}

Node::~Node(){
	// 释放数据内存空间
	free(nodedata.data);

}
void * Node::GetInfo(){
	return nodedata.data;
}

void Node::SetInfo(void *info,int size){
	//this->info = info;
	if(this->nodedata.data != NULL)
		free(nodedata.data);
	
	// 数据拷贝
	nodedata.data = malloc(size);
	memcpy(nodedata.data,info,size);

}

void Node::SetNext(Node *next){
	this->next = next;
}

void Node::SetPrevious(Node *previous){
	this->previous = previous;
}

Node* Node::GetPrevious(){
	return this->previous;
}

Node* Node::GetNext(){
	return this->next;
}

bool Node::GetAvai(){
	return this->avai;
}

DBLinkedList::DBLinkedList():head(NULL),rear(NULL),currentPtr(NULL){
	head = NULL;
	rear = NULL;
	
}

DBLinkedList::~DBLinkedList(){
	Destory();
}

// 最加数据
bool DBLinkedList::Append(void *info,int size){
	if(head == NULL){
		head = new Node(info,size,NULL,NULL);
		rear = head;
		currentPtr = head;
	}else{
		rear->SetNext(new Node(info,size,NULL,rear));
		rear = rear->GetNext();
	}
	return true;
}

// 插入数据
// last是前一个指针
bool DBLinkedList::Add(void *info,int size,Node* last){

	// 如果是最后一个元素
	if(last == NULL || last == rear || head == NULL){
		this->Append(info,size);
		return true;
	}

	Node* next = last->GetNext();
	
	last->SetNext(new Node(info,size,next,last));

	if(next != NULL)
		next->SetPrevious(last->GetNext());

	if(this->rear == last){
		rear = last->GetNext();
	}

	return true;

}

bool DBLinkedList::Delete(Node *curr){
	if(curr == NULL)
		return false;

	// 如果只有一个元素
	if(curr->GetPrevious() == NULL && curr->GetNext() == NULL){
		//如果是第一个元素删除,或者唯一一个元素
		head = NULL;
		rear = NULL;
		
		delete curr;

		return true;
	}
	
	// 如果删除的是第一个元素
	if(curr->GetPrevious() == NULL){
		// 取得下一个元素
		head = curr->GetNext();

		head->SetPrevious(NULL);

		delete curr;
		
		return true;
	}

	// 如果删除的是最后一个元素
	if(curr->GetNext() == NULL){
		// 如果删除的是最后一个元素
		rear = curr->GetPrevious();
		
		rear->SetNext(NULL);

		delete curr;

		return true;
	}
	

	// 如果删除的是中间元素
	if(curr->GetNext() != NULL && curr->GetPrevious() != NULL)
	{
	
		// 如果删除的是中间的元素
		Node * previous = curr->GetPrevious();
		Node * next = curr->GetNext();

		delete curr;

		previous->SetNext(next);
		next->SetPrevious(previous);

		return true;
	}

	return true;
}

void* DBLinkedList::GetInfo(Node *node){
	return node->GetInfo();
}



Node* DBLinkedList::GetNext(){
	return currentPtr->GetNext();

}

Node* DBLinkedList::GetPrevious(){
	return currentPtr->GetNext();

}

Node* DBLinkedList::GetCurrent(){
	return currentPtr;
}

void* DBLinkedList::GetCurrentInfo(){
	if(currentPtr == NULL) return NULL;
	return currentPtr->GetInfo();
}

void* DBLinkedList::GetNextInfo(){
	currentPtr = currentPtr->GetNext();
	
	if(currentPtr == NULL){
		currentPtr = head;	
		return NULL;
	}
	return currentPtr->GetInfo();
}

void * DBLinkedList::GetPreviousInfo(){
	currentPtr = currentPtr->GetPrevious();

	if(currentPtr == NULL){
		currentPtr = rear;	
		return NULL;
	}
	return currentPtr->GetInfo();
}

/*
* 函数：Destory 
* 功能：销毁
*/
void DBLinkedList::Destory(){
	//遍历
	Node *curr = head;
	Node *next = NULL;
	if(head != NULL)
		next = head->GetNext();
	else 
		return;

	for(;curr != NULL;curr = next){



		next = curr->GetNext();
		delete curr;
	}

	head = NULL;
	rear = NULL;

}
/*
* 函数： ResetCurrentPtr
* 功能： 重新设置CurrentPtr的位置到头或者尾
*/
void DBLinkedList::ResetCurrentPtr(bool head){
	if(head){
		currentPtr = this->head;
	}else{
		currentPtr = rear;
	}
}

/*
* GetLastInfo
* 功能：获得表末尾的数据
*/
void *DBLinkedList::GetLastInfo(){

	if(rear != NULL)
		return rear->GetInfo();
	
	return NULL;
}

/*
*  DeleteLast
* 功能：删除最后一个位置的节点
*/
bool DBLinkedList::DeleteLast(){

	return this->Delete(this->rear);

}