Solve the problem of class definition and linked list class

tzw110

I want to compile a drawing program, which uses a variety of graphic elements (line, rectangle, circle, etc.), each graphic element must create a class (derived from a self-created graphic class), but when using a linked list class What should I do when storing these graphics? Or how to create this linked list class? What should its data type be? Use CList or CObList?
Thank you,

huanwu

class CElement
{
public:
virtual void Draw(){};
};

class CLine: public CElement {};
class CCircle: public CElement {};

std::vector< CElement*> myList;

sky_hexia

CObList requires that your graphics class must be inherited from MFC's CObject, so it may be better to use the template class CList<...>

dztgw1974

First, you must define a few points, for example, the first node, pointer, and end node.
Store these points again to save the line information

tzw110

Thank you, the big brothers upstairs.
If I want to create only a linked list class to store various graphic elements, what is the data element type of my linked list class? Can I use a base class? Do I have to use pointers?

sky_hexia

Use base class pointers or references, not base class objects

rsq666

// Point3D.h: interface for the CPoint3D class.
//
////////////////////////////////////////////////// ////////////////////
#include <afxtempl.h>

#if !defined(AFX_POINT3D_H__FB60210D_9230_43D0_B3C5_1FA12314F579__INCLUDED_)
#define AFX_POINT3D_H__FB60210D_9230_43D0_B3C5_1FA12314F579__INCLUDED_

#if _MSC_VER> 1000
#pragma once
#endif // _MSC_VER> 1000

#define LIMITVALUE 0.0001 //×ø±êÏàµÈÏÞÖµ 2014.2.25. ËÕ¼Ó¡ £


//Èýά¿ Õ¼äµã×ø±êÀà

class CPoint3D
{
public:
CPoint3D();
CPoint3D(double x);
CPoint3D(double x,double y);
CPoint3D(double x,double y,double z);
virtual ~CPoint3D();

public:
double x;
double y;
double z;

void Maximal(CPoint3D&p);
void Minimal(CPoint3D&p);
void Maximal(double * p);
void Minimal(double * p);
virtual CPoint3D operator= (const CPoint3D&p);
virtual CPoint3D operator+ (const CPoint3D&p);
virtual CPoint3D operator- (const CPoint3D&p);
virtual CPoint3D operator* (const CPoint3D&p);
// 2014.2.25. Ëոġ £
virtual bool operator==(const CPoint3D&p);
virtual CPoint3D operator*=(const double scale);
virtual CPoint3D operator+=(const CPoint3D&p);
virtual CPoint3D operator-=(const CPoint3D&p);
virtual CPoint3D operator= (const double * p);
};

//´øÓÐÊôÐÔÂëά×ø±êµãÀà

class CCodePoint3D: public CPoint3D
{
public:
CCodePoint3D();
virtual ~CCodePoint3D();

public:
long code;

public:
virtual CCodePoint3D operator = (const CCodePoint3D&p);
CCodePoint3D *Create(long Code);
CCodePoint3D *Create(long Code,double x,double y,double z);
};

typedef CArray<CPoint3D,CPoint3D> CPoint3DArray;
typedef CArray<CCodePoint3D,CCodePoint3D> CCodePoint3DArray;
typedef struct
{
long lNo;
CPoint3DArray Point3DArray;
}POINT3DARRAY;
typedef CTypedPtrList<CPtrList, POINT3DARRAY*> CPoint3DArrayList;

#endif // !defined(AFX_POINT3D_H__FB60210D_9230_43D0_B3C5_1FA12314F579__INCLUDED_)

shen_hang_1

Inherit CObject, store it in CList, just use the base class pointer, the example given upstairs is very good, generally write according to this idea.

cirrus

Refer to Microsoft's vector drawing program drawcli. In the above example, you have learned that this is not a problem.
No matter what the linked list is, it can achieve the purpose.