I have the following code that when compiles with my test program gives me a segmentation fault, I hope you guys can help me with this. I am compiling on a gcc compiler using:
g++ a3test.cpp screen.cpp dtio.c -lncurses
screen.h header file:
extern "C" {
#include "dtio.h"
}
class Field{
public:
virtual ~Field() {}
virtual void display() = 0;
virtual int edit() = 0;
virtual bool editable() const = 0;
virtual void *data() = 0;
virtual Field *clone() const = 0;
};
class LField : public Field{
private:
int row_loc;
int col_loc;
int width_tot;
int index;
char *initval;
bool edib;
public:
LField(int row, int col, int width, const char *s = 0, bool editable = true);
~LField();
void display();
int edit();
bool editable() const;
void *data();
Field *clone() const;
LField& operator = (const LField & rhs);
LField(const LField & source );
};
class Screen{
private:
Field *fields[50];
int count;
int last;
public:
Screen();
int add(int row, int column, int width, const char * s = "", bool editable = true);
int add(const Field &f);
void display(bool clear = false);
int edit(int *pfield = NULL, bool clear = false);
Field *getField(int i);
int remove(int i);
Screen& operator += (const Field &temp);
Screen(const Screen& pass);
Screen& operator = (const Screen& pass);
~Screen();
};The screen.cpp file:
#include <string>
#include <iostream>
#include <new>
using namespace std;
#include "screen.h"
//LField class functions
//Different intiailization calls
LField::LField(int row, int col, int width, const char *s, bool editable){
//Checks for valid coords
if(row < 0){
row = 0;
}
if(row >= dtioRows()){
row = dtioRows() - 1;
}
if(col < 0){
col = 0;
}
if(col > dtioColumns()){
col = dtioColumns() - 1;
}
//Checks for width and location
if((col + width) > dtioColumns()){
width = width - ((col + width) - dtioColumns());
}
if(strlen(s)){
if(strlen(s) > width){
initval = new char[width];
for(int i = 0; i < width; i++){
initval[i] = s[i];
}
}
else{
initval = new char[strlen(s) + 1];
strcpy(initval, s);
}
}
else{
initval = NULL;
}
row_loc = row;
col_loc = col;
width_tot = width;
edib = editable;
index = 0;
}
LField& LField::operator = (const LField & rhs){
if(&rhs != this){
delete [] initval;
initval = new char[strlen(rhs.initval) + 1];
strcpy(initval, rhs.initval);
row_loc = rhs.row_loc;
col_loc = rhs.col_loc;
width_tot = rhs.width_tot;
edib = rhs.edib;
index = rhs.index;
}
return *this;
}
LField::LField(const LField & source){
initval = NULL;
initval = new char[strlen(source.initval) + 1];
strcpy(initval, source.initval);
row_loc = source.row_loc;
col_loc = source.col_loc;
width_tot = source.width_tot;
edib = source.edib;
index = source.index;
}
void LField::display(){
dtioDisplay(initval, row_loc, col_loc, width_tot);
}
int LField::edit(){
int retval = 0;
if(edib){
retval = dtioEdit(initval, row_loc, col_loc, width_tot, &index);
}
else{
dtioDisplay(initval, row_loc, col_loc, width_tot);
retval = 0;
}
return retval;
}
bool LField::editable() const{
return edib;
}
void *LField::data(){
return &initval;
}
Field *LField::clone() const{
return new LField(*this);
}
LField::~LField(){
delete [] initval;
}
// Screen class and its member functions
Screen::Screen(){
count = 0;
last = 0;
for(int i = 0; i < 50; i++){
fields[i] = NULL;
}
}
int Screen::add(int row, int col, int width, const char * s, bool editable){
int retval = 0;
if(last < 50){
fields[last] = new LField(row, col, width, s, editable);
count += 1;
last += 1;
retval = count;
}
return retval;
}
int Screen::add(const Field &f){
int retval = 0;
if(last < 50){
fields[last] = f.clone();
count += 1;
last += 1;
retval = count;
}
return retval;
}
void Screen::display(bool clear){
if(clear){
dtioClear();
}
for(int i = 0; i < count; i++){
fields[i]->display();
}
}
int Screen::edit(int *pfield, bool clear){
int key;
int fld_idx;
int done = 1;
if(clear){
dtioClear();
}
if(pfield != NULL){
fld_idx = *pfield;
}
else{
fld_idx = 0;
}
while(done){
key = fields[fld_idx]->edit();
if(key == UP){
int counter = fld_idx;
while(!fields[counter]->editable() && counter < last){
counter++;
}
if(counter >= last){
done = 0;
}
else{
fld_idx = counter;
}
}
else if(key == DOWN){
int counter = fld_idx;
while(!fields[counter]->editable() && counter > 0){
counter--;
}
if(counter <= 0){
done = 0;
}
else{
fld_idx = counter;
}
}
else if(key == TAB){
int counter = fld_idx;
while(!fields[counter]->editable() && counter > 0){
counter--;
}
if(counter <= 0){
done = 0;
}
else{
fld_idx = counter;
}
}
else if(key == ENTER){
int counter = fld_idx;
while(!fields[counter]->editable() && counter < last){
counter++;
}
if(counter >= last){
done = 0;
}
else{
fld_idx = counter;
}
}
else{
done = 0;
}
}
*pfield = fld_idx;
return key;
}
Field *Screen::getField(int i){
if(i >= 0 && i <= last){
return fields[i];
}
else{
return NULL;
}
}
int Screen::remove(int i){
if(i >= 0 && i <= last){
delete fields[i];
for(int x = i; x < count; x++){
fields[x] = fields[x + 1];
}
last -= 1;
count-= 1;
}
return count;
}
Screen& Screen::operator += (const Field &temp){
add(temp);
return *this;
}
Screen& Screen::operator = (const Screen& pass){
if(&pass != this){
for(int i = 0; i < 50; i++){
Field * copy;
copy = fields[i];
delete copy;
fields[i] = NULL;
}
for(int i = 0; i < pass.count; i++){
Field * copy;
copy = pass.fields[i];
fields[i] = copy;
}
count = pass.count;
last = pass.last;
}
return *this;
}
Screen::Screen(const Screen & pass){
for(int i = 0; i < 50; i++){
Field * copy;
copy = fields[i];
delete copy;
fields[i] = NULL;
}
for(int i = 0; i < pass.count; i++){
Field * copy;
copy = pass.fields[i];
fields[i] = copy;
}
count = pass.count;
last = pass.last;
}
Screen::~Screen(){
for(int i = 0; i < 50; i++){
delete fields[i];
}
}I have attached the other files I am using as well as the specification of what I had to do. I don't know why it gives me a segmentation fault but it appears to happen when a constructor gets called. Any help with this is really appreciated! Thank you!
