// Borland C++ - (C) Copyright 1991 by Borland International
/* LISTDEMO.CPP--Example from Getting Started */
// LISTDEMO.CPP Demonstrates dynamic objects
// Link with FIGURES.OBJ and GRAPHICS.LIB
#include <conio.h> // for getch()
#include <alloc.h> // for coreleft()
#include <stdlib.h> // for itoa()
#include <string.h> // for strcpy()
#include <graphics.h>
#include "figures.h"
class Arc : public Circle {
int StartAngle, EndAngle;
public:
// constructor
Arc(int InitX, int InitY, int InitRadius, int InitStartAngle,
int InitEndAngle);
// virtual functions
void Show();
void Hide();
};
struct Node { // the list item
Point *Item; // can be Point or any class derived from Point
Node *Next; // point to next Node object
};
class List { // the list of objects pointed to by nodes
Node *Nodes; // points to a node
public:
// constructor
List();
// destructor
~List();
// add an item to list
void Add(Point *NewItem);
// list the items
void Report();
};
// definitions for standalone functions
void OutTextLn(char *TheText)
{
outtext(TheText);
moveto(0, gety() + 12); // move to equivalent of next line
}
void MemStatus(char *StatusMessage)
{
unsigned long MemLeft; // to match type returned by
// coreleft()
char CharString[12]; // temp string to send to outtext()
outtext(StatusMessage);
MemLeft = long (coreleft());
// convert result to string with ltoa then copy into
// temporary string
ltoa(MemLeft, CharString, 10);
OutTextLn(CharString);
}
// member functions for Arc class
Arc::Arc(int InitX, int InitY, int InitRadius, int InitStartAngle,
int InitEndAngle) : Circle (InitX, InitY,InitRadius)
// calls Circle
// constructor
{
StartAngle = InitStartAngle;
EndAngle = InitEndAngle;
}
void Arc::Show()
{
Visible = true;
arc(X, Y, StartAngle, EndAngle, Radius);
}
void Arc::Hide()
{
unsigned TempColor;
TempColor = getcolor();
setcolor(getbkcolor());
Visible = false;
arc(X, Y, StartAngle, EndAngle, Radius);
setcolor(TempColor);
}
// member functions for List class
List::List () // constructor
{
Nodes = NULL; // initialize Nodes data
}
List::~List() // destructor
{
while (Nodes != NULL) { // until end of list
Node *N = Nodes; // get node pointed to
delete(N->Item); // delete item's memory
Nodes = N->Next; // point to next node
delete N; // delete pointer's memory
};
}
void List::Add(Point *NewItem)
{
Node *N; // N is pointer to a node
N = new Node; // create a new node
N->Item = NewItem; // store pointer to object in node
N->Next = Nodes; // next item points to curent list pos
Nodes = N; // last item in list now points
// to this node
}
void List::Report()
{
char TempString[12];
Node *Current = Nodes;
while (Current != NULL)
{
// get X value of item in current node and convert to string
itoa(Current->Item->GetX(), TempString, 10);
outtext("X = ");
OutTextLn(TempString);
// do the same thing for the Y value
itoa(Current->Item->GetY(), TempString, 10);
outtext("Y = ");
OutTextLn(TempString);
// point to the next node
Current = Current->Next;
};
}
void setlist(void);
// Main program
main()
{
int graphdriver = DETECT, graphmode;
initgraph(&graphdriver, &graphmode, "..\\bgi");
MemStatus("Free memory before list is allocated: ");
setlist();
MemStatus("Free memory after List destructor: ");
getch();
closegraph();
}
void setlist() {
// declare a list (calls List constructor)
List AList;
// create and add several figures to the list
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