Qt - adding elements to map and memory leaks - c++

Question

I am working on a matrix calculator and I encountered a really annoying problem, have been trying to fix it for 3 hours now, but it's getting worse instead of getting better. Maybe you will be able to help.
This is my MainWindow class:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QPushButton>
#include <QGridLayout>
#include <QLabel>
#include "addmatrix.h"
#include "memory.h"
#include "matrixcreation.h"
#include <QMap>
#include "matrix.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(MainWindow *parent = 0);
~MainWindow();
private slots:
void on_createButton_clicked();
void setMatrix(Matrix *matrix);
private:
Matrix getMatrixFromMemory(QString &name);
void addMatrixToMemory();
Ui::MainWindow *ui;
AddMatrix *add;
MatrixCreation *matrixCreate;
QMap <QString, Matrix> matrixMap;
};
#endif // MAINWINDOW_H
.cpp file
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(MainWindow *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
this->setWindowTitle("Matrix Calculator");
add = NULL;
matrixCreate = NULL;
}
MainWindow::~MainWindow()
{
delete ui;
delete add;
delete matrixCreate;
matrixMap.clear();
}
void MainWindow::on_createButton_clicked()
{
if (add != NULL)
{
delete add;
add = new AddMatrix;
}
else
add = new AddMatrix;
if (matrixCreate != NULL)
{
ui->label->setText(getMatrixFromMemory(matrixCreate->getMatrix()->getName()).getName());
delete matrixCreate;
matrixCreate = new MatrixCreation;
}
else
matrixCreate = new MatrixCreation;
// Polaczenie sygnalow ze slotami
// Sluzy ustawieniu liczby wierszy w matrixCreate
connect(add->getCombo1(), SIGNAL(currentIndexChanged(QString)), matrixCreate, SLOT(setRows(QString)));
// Jak wyzej, tylko kolumn
connect(add->getCombo2(), SIGNAL(currentIndexChanged(QString)), matrixCreate, SLOT(setColumns(QString)));
// Ustawienie pola name w matrixCreate
connect(add->getEdit(), SIGNAL(textChanged(QString)), matrixCreate, SLOT(setName(QString)));
// Po ustawieniu liczby wierszy i kolumn oraz nazwy macierzy - wywola sie slot updateTable
// ktory sluzy do ustawienia rozmiaru okna i tabeli
connect(add, SIGNAL(setupSuccessful()), matrixCreate, SLOT(updateTable()));
// Po ustawieniu wierszy, kolumn, ustawieniu nazwy, rozmiarow, wywola sie slot show matrixCreate
connect(add, SIGNAL(setupSuccessful()), matrixCreate, SLOT(show()));
// Sluzy dodaniu macierzy do pamieci (mapy)
connect(matrixCreate, SIGNAL(matrixReady(Matrix*)), this, SLOT(setMatrix(Matrix*)));
add->show();
}
void MainWindow::setMatrix(Matrix *matrix)
{
matrixMap[matrix->getName()] = *matrix;
}
Matrix MainWindow::getMatrixFromMemory(QString &name)
{
return matrixMap[name];
}
As you can see I have a QMap in my MainWindow. I also have a an instance of MatrixCreation class called matrixCreate.
Here is MatrixCreation class:
#ifndef MATRIXCREATION_H
#define MATRIXCREATION_H
#include <QDialog>
#include <QTableView>
#include <QPushButton>
#include <QStandardItem>
#include <QTableWidget>
#include <QMainWindow>
#include "matrix.h"
#include "memory.h"
#include "addmatrix.h"
#include <windows.h>
namespace Ui {
class MatrixCreation;
}
class MatrixCreation : public QWidget
{
Q_OBJECT
public:
explicit MatrixCreation(QWidget *parent = 0);
~MatrixCreation();
QTableWidget *getTable();
Matrix *getMatrix();
private slots:
void on_okButton_clicked();
void updateTable();
void setRows(QString rows);
void setColumns(QString columns);
void setName(QString name);
signals:
void matrixReady(Matrix *matrix);
private:
Ui::MatrixCreation *ui;
int rows;
int columns;
int **matrix;
QString name;
Matrix *newMatrix;
};
#endif // MATRIXCREATION_H
.cpp file
#include "matrixcreation.h"
#include "ui_matrixcreation.h"
MatrixCreation::MatrixCreation(QWidget *parent) :
QWidget(parent),
ui(new Ui::MatrixCreation)
{
ui->setupUi(this);
this->resize(150, 50);
// Ustawienie rozmiaru wysokosci wiersza na 40 piksele
ui->tableWidget->verticalHeader()->setDefaultSectionSize(40);
// Ustawienie rozmiaru szerokosci kolumny na 94 piksele
ui->tableWidget->horizontalHeader()->setDefaultSectionSize(94);
// Dopasowanie rozmiaru kolumn do rozmiaru tabeli
ui->tableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
ui->tableWidget->verticalHeader()->setSectionResizeMode(QHeaderView::Stretch);
// Wylaczenie scrollbarow tabeli
ui->tableWidget->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
ui->tableWidget->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
rows = 1;
columns = 1;
matrix = NULL;
newMatrix = new Matrix;
}
MatrixCreation::~MatrixCreation()
{
delete ui;
if (matrix != NULL)
{
for (int i = 0; i < rows; i++)
delete matrix[i];
}
delete newMatrix;
}
void MatrixCreation::setRows(QString rows)
{
this->rows = rows.toInt();
}
void MatrixCreation::setColumns(QString columns)
{
this->columns = columns.toInt();
}
// Metoda odpowiedzialna za utworzenie odpowiedniej ilosci wierszy i kolumn
// oraz ustawienie odpowiedniej wielkosci okna i rozmiaru tabeli
void MatrixCreation::updateTable()
{
// stale roznice miedzy szerokoscia i wysokoscia okna i tabeli
int w = 323 - 305;
int h = 300 - 227 + 15;
for(int i = 0; i < rows; i++)
{
ui->tableWidget->insertRow(i);
h += 35;
}
for(int j = 0; j < columns; j++)
{
ui->tableWidget->insertColumn(j);
w += 50;
}
this->resize(w, h);
this->setMinimumSize(w, h);
ui->retranslateUi(this);
this->setWindowTitle("Matrix Creation");
}
QTableWidget *MatrixCreation::getTable()
{
return ui->tableWidget;
}
void MatrixCreation::on_okButton_clicked()
{
matrix = new int *[rows];
for(int j = 0; j < rows; j++)
{
matrix[j] = new int[columns];
}
for(int i = 0; i<rows; i++)
{
for(int j = 0; j<columns; j++)
{
matrix[i][j] = ui->tableWidget->item(i, j)->text().toInt();
}
}
// Ustawienie pol skladowych w zmiennej newMatrix klasy Matrix
newMatrix->setColumns(columns);
newMatrix->setRows(rows);
newMatrix->setName(name);
newMatrix->setMatrix(matrix);
emit matrixReady(newMatrix);
this->close();
}
void MatrixCreation::setName(QString name)
{
this->name = name;
}
Matrix *MatrixCreation::getMatrix()
{
return newMatrix;
}
What is the problem:
I want to add a created matrix to a QMap by emiting this signal:
emit matrixReady(newMatrix);
a Matrix class is used to hold all the elements of matrix (rows, cols, values of cells and name).
However, Matrix objects are not being added to QMap. But, when I delete this line in MatrixCreation destructor:
delete newMatrix;
It works.
Second problem:
When I am closing my application and MainWindow destructor gets called, while destroying a map it shows an error : BLOC_TYPE_IS_VALID bla bla...
I don't know how to fix it, however I will keep on trying. Any help will be appreciated.

Answer 1

void MainWindow::setMatrix(Matrix *matrix)
{
matrixMap[matrix->getName()] = *matrix;
}
You're adding copy of the matrix to your map. So here you have a leak.
void MainWindow::setMatrix(Matrix *matrix)
{
matrixMap[matrix->getName()] = *matrix;
delete matrix;
}
This should fix your problem.
Use valgrind to profile your application and find memory leaks: http://valgrind.org/docs/manual/quick-start.html