An array as a common variable between two classes .

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Hello,

I would like to use an boolean array "M".
Here is what I want to do:
-I fill the QTableWidget .
-After a click on the QPushButton "generer" the boolean array M receives the values that I fiiled in the QTableWidget.
-after a click on the QPushButton "dessiner" a second window is created "FenDessin" which contains a Draw related to the values of the boolean array M.
Here is the code:

Code:

///////////the Headers//////////////////////
//FenPrinicipale.h
#ifndef FENPRINCIPALE_H
#define FENPRINCIPALE_H
#include <QtGui>
 
class FenPrincipale : public QWidget
{
    Q_OBJECT
public:
    FenPrincipale();
    bool  M[10][10];
private slots:
    void FillIn();
    void FenetreDessin();
private:
    QTableWidget  *tabM;
    QPushButton * generer;
    QPushButton * dessiner;
    QVBoxLayout * vbox;
};
#endif // FENPRINCIPALE_H
 
 
//FenDessin.h
#ifndef FENDESSIN_H
#define FENDESSIN_H
#include <QtGui>
class FenDessin : public QDialog
{
public:
    FenDessin ( QWidget *parent);
 
private:
    QPushButton *fermer;
    QPainter *painter;
private slots:
    void paintEvent (QPaintEvent *);
};
#endif // FENDESSIN_H
 
 
 
//FenPrincipale.cpp
#include "qDebug.h"
#include "FenPrincipale.h"
#include "FenDessin.h"
FenPrincipale::FenPrincipale()
{
    tabM =new QTableWidget(this);
    tabM->setRowCount(10);
    tabM->setColumnCount(10);
    generer = new QPushButton("&GÃ©nÃ©rer !",this);
    QVBoxLayout* vbox = new QVBoxLayout();
    vbox->addWidget(generer);
    vbox->addWidget(dessiner);
    vbox->addWidget(tabM);
    this->setLayout(vbox);
    for (int r = 0; r < 10; r++) {
        for (int c = 0; c < 10; c++) {
            QTableWidgetItem *it = new QTableWidgetItem;
            tabM->setItem(r, c, it);
            it->setData(Qt::EditRole, 0);
 
        }
    }
    connect(generer, SIGNAL(clicked()), this, SLOT(FillIn()));
}
void FenPrincipale::FillIn()
{
    for (int r = 0; r < 10; r++) {
        for (int c = 0; c < 10; c++) {
            QTableWidgetItem *it = tabM->item(r,c);;
            Q_ASSERT(it);
            qDebug() <<it;
            int val = (it->data(Qt::EditRole)).toInt();
            M[r][c] = (val == 1)? true: false;
            qDebug() <<M[r][c];
        }
    }
    connect(dessiner, SIGNAL(clicked()), this, SLOT(FenetreDessin()));
}
void FenPrincipale::FenetreDessin()
{
    FenDessin *fenetreCC = new FenDessin( this);
    fenetreCC->exec();
}
 
 
//FenDessin.cpp
#include "FenDessin.h"
FenDessin::FenDessin( QWidget *parent = 0) :QDialog(parent)
{
    fermer = new QPushButton("Fermer",this);
    QPaintEvent *c;
    paintEvent(c);
    connect(fermer, SIGNAL(clicked()), this, SLOT(accept()));
 
}
void FenDessin::paintEvent(QPaintEvent *c)
{
    QPainter painter(this);
    int o,p;
    for (o=0; o<10; o++)
    {
        for (p=0; p<10; p++)
        {
            M[o][p]=0;
        }
    }
    int  tour=0;
    int x=10;
    int y=10;
    int Num_Sommet=0;
    int T_Coordonnees [10][3];
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        (T_Coordonnees[Num_Sommet][0])=x;
        (T_Coordonnees[Num_Sommet][1])=y;
        (T_Coordonnees[Num_Sommet][2])=tour;
 
        if (tour==0)
        {
            x+=35;
            tour=1;
        }
        else
        {
            y+=55;
            tour=0;
        }
 
    }
 
    int w1=0;
    int w2=0;
    int cpt=10;
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        if ( (T_Coordonnees[Num_Sommet][2])==1)
        {   if(w1==0)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+500) ;
                w1=1;
            }
            else
            {
                if(w1==1)
                {
                    (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+250+cpt) ;
                    w1=0;
                    cpt=cpt+15;
                }
            }
            if (Num_Sommet==9)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
 
        }
        else
        {
            if(w2==0)
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+200;
                w2=1;
            }
            else
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+100+cpt;
                w2=0;
                cpt=cpt+15;
            }
 
            if (Num_Sommet==4)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
        }
        painter.drawEllipse((T_Coordonnees[Num_Sommet][0]), (T_Coordonnees[Num_Sommet][1]), 30.0, 30.0);
    }
 
    int i,j;
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if (M[i][j]==1)
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
            }
        }
    }
 
 
 
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if ((M[i][j]==1) &&  (M[j][i]==1))
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
                if(  (T_Coordonnees[i][1]>45)||(T_Coordonnees[j][1]>45)  )
                {
                    painter.drawLine(((T_Coordonnees[i][0]+20)-10),(T_Coordonnees[i][1]),((T_Coordonnees[j][0]+20)-10),(T_Coordonnees[j][1]));
                }
                else
                {
                    painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]+30),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]+30));
                }
            }
        }
    }
    ////////////////////////////////////////////////
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        QPoint point = QPoint( (((T_Coordonnees[Num_Sommet][0])+15)), ((T_Coordonnees[Num_Sommet][1])+15) );
        QString str;
        str.setNum(Num_Sommet);
        painter.drawText( point,str);
 
    }
}
 
//main.cpp
#include <QApplication>
#include "FenPrincipale.h"
int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    FenPrincipale fenetre;
    fenetre.show();
    return app.exec();
}

I would like to declare the array M as a global variable so that the class FenDessin can use it to make the drawing without the error:
" M is not declared in this scope"
Thank you for the attention given to this message.

21st February 2012, 22:00
ChrisW67

Re: An array as a common variable between two classes .
If you want access to the data in the public FenPrincipale::M member variable in another class then you need one of these:
- Pass a pointer (or reference as appropriate) to the FenPrincipale instance to the other class and access M through that
- Supply the other class with a pointer (or reference) to the FenPrincipale::M member directly
- Supply the other class with a copy of the FenPrincipale::M member
which you choose is up to you and your requirements.

This is 100% C++ knowledge, and nothing to do with Qt.

Re: An array as a common variable between two classes .

Thank you for your response,
As the title of the forum is saying I am a newbie, so can't you be more specific and give me a code of what you are suggesting?
Thanks in advance!!!

Added after 39 minutes:

Hello,
I've modified the code only the "FenDessin.h" and "FenDessin.cpp" but the program crashed.

Code:

//FenDessin.h
#ifndef FENDESSIN_H
#define FENDESSIN_H
#include <QtGui>
#include"FenPrincipale.h"
class FenDessin : public QDialog
{
public:
    FenDessin ( FenPrincipale* parent);
 
 
private:
    QPushButton *fermer;
    QPainter *painter;
    FenPrincipale * ref;
private slots:
    void paintEvent (QPaintEvent *);
};
#endif // FENDESSIN_H
 
 
 
//FenDessin.cpp
#include "FenDessin.h"
 
FenDessin::FenDessin( FenPrincipale *parent) :QDialog(parent),ref(parent)
{
    fermer = new QPushButton("Fermer",this);
    QPaintEvent *c;
    paintEvent(c);
    connect(fermer, SIGNAL(clicked()), this, SLOT(accept()));
 
}
void FenDessin::paintEvent(QPaintEvent *c)
{
    QPainter painter(this);
 
 
    int  tour=0;
    int x=10;
    int y=10;
    int Num_Sommet=0;
    int T_Coordonnees [10][3];
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        (T_Coordonnees[Num_Sommet][0])=x;
        (T_Coordonnees[Num_Sommet][1])=y;
        (T_Coordonnees[Num_Sommet][2])=tour;
 
        if (tour==0)
        {
            x+=35;
            tour=1;
        }
        else
        {
            y+=55;
            tour=0;
        }
 
    }
 
    int w1=0;
    int w2=0;
    int cpt=10;
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        if ( (T_Coordonnees[Num_Sommet][2])==1)
        {   if(w1==0)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+500) ;
                w1=1;
            }
            else
            {
                if(w1==1)
                {
                    (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+250+cpt) ;
                    w1=0;
                    cpt=cpt+15;
                }
            }
            if (Num_Sommet==9)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
 
        }
        else
        {
            if(w2==0)
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+200;
                w2=1;
            }
            else
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+100+cpt;
                w2=0;
                cpt=cpt+15;
            }
 
            if (Num_Sommet==4)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
        }
        painter.drawEllipse((T_Coordonnees[Num_Sommet][0]), (T_Coordonnees[Num_Sommet][1]), 30.0, 30.0);
    }
 
    int i,j;
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if ((ref->M[i][j])==1)
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
            }
        }
    }
 
 
 
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if ((ref->M[i][j]==1) &&  (ref->M[j][i]==1))
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
                if(  (T_Coordonnees[i][1]>45)||(T_Coordonnees[j][1]>45)  )
                {
                    painter.drawLine(((T_Coordonnees[i][0]+20)-10),(T_Coordonnees[i][1]),((T_Coordonnees[j][0]+20)-10),(T_Coordonnees[j][1]));
                }
                else
                {
                    painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]+30),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]+30));
                }
            }
        }
    }
    ////////////////////////////////////////////////
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        QPoint point = QPoint( (((T_Coordonnees[Num_Sommet][0])+15)), ((T_Coordonnees[Num_Sommet][1])+15) );
        QString str;
        str.setNum(Num_Sommet);
        painter.drawText( point,str);
 
    }
}

Thanks for the attention given to this message.

Added after 43 minutes:

Hello,
Finally the code works.
I 've modified the FenDessin.cpp and FenDessin.h

Code:

//FenDessin.h
#ifndef FENDESSIN_H
#define FENDESSIN_H
#include <QtGui>
#include"FenPrincipale.h"
class FenDessin : public QDialog
{
public:
    FenDessin ( FenPrincipale* parent);
 
 
private:
    QPushButton *fermer;
    QPainter *painter;
    FenPrincipale * ref;
private slots:
    void paintEvent (QPaintEvent *);
};
#endif // FENDESSIN_H
 
 
//FenDessin.cpp
#include "FenDessin.h"
 
FenDessin::FenDessin( FenPrincipale *parent) :QDialog(parent),ref(parent)
{
    fermer = new QPushButton("Fermer",this);
    QPaintEvent *c;
    paintEvent(c);
    connect(fermer, SIGNAL(clicked()), this, SLOT(accept()));
 
}
void FenDessin::paintEvent(QPaintEvent *c)
{
    QPainter painter(this);
 
 
    int  tour=0;
    int x=10;
    int y=10;
    int Num_Sommet=0;
    int T_Coordonnees [10][3];
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        (T_Coordonnees[Num_Sommet][0])=x;
        (T_Coordonnees[Num_Sommet][1])=y;
        (T_Coordonnees[Num_Sommet][2])=tour;
 
        if (tour==0)
        {
            x+=35;
            tour=1;
        }
        else
        {
            y+=55;
            tour=0;
        }
 
    }
 
    int w1=0;
    int w2=0;
    int cpt=10;
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        if ( (T_Coordonnees[Num_Sommet][2])==1)
        {   if(w1==0)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+500) ;
                w1=1;
            }
            else
            {
                if(w1==1)
                {
                    (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+250+cpt) ;
                    w1=0;
                    cpt=cpt+15;
                }
            }
            if (Num_Sommet==9)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
 
        }
        else
        {
            if(w2==0)
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+200;
                w2=1;
            }
            else
            {
                (T_Coordonnees[Num_Sommet][0])=(T_Coordonnees[Num_Sommet][0])+100+cpt;
                w2=0;
                cpt=cpt+15;
            }
 
            if (Num_Sommet==4)
            {
                (T_Coordonnees[Num_Sommet][0])=((T_Coordonnees[Num_Sommet][0])+45) ;
            }
        }
        painter.drawEllipse((T_Coordonnees[Num_Sommet][0]), (T_Coordonnees[Num_Sommet][1]), 30.0, 30.0);
    }
 
    int i,j;
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if ((ref->M[i][j])==1)
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
            }
        }
    }
 
 
 
    for (i=0; i<10; i++)
    {
        for (j=0; j<10; j++)
        {
            if ((ref->M[i][j]==1) &&  (ref->M[j][i]==1))
            {
                painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]));
                if(  (T_Coordonnees[i][1]>45)||(T_Coordonnees[j][1]>45)  )
                {
                    painter.drawLine(((T_Coordonnees[i][0]+20)-10),(T_Coordonnees[i][1]),((T_Coordonnees[j][0]+20)-10),(T_Coordonnees[j][1]));
                }
                else
                {
                    painter.drawLine((T_Coordonnees[i][0]+20),(T_Coordonnees[i][1]+30),(T_Coordonnees[j][0]+20),(T_Coordonnees[j][1]+30));
                }
            }
        }
    }
    ////////////////////////////////////////////////
    Num_Sommet=0;
    for (Num_Sommet=0; Num_Sommet<10; Num_Sommet++)
    {
        QPoint point = QPoint( (((T_Coordonnees[Num_Sommet][0])+15)), ((T_Coordonnees[Num_Sommet][1])+15) );
        QString str;
        str.setNum(Num_Sommet);
        painter.drawText( point,str);
 
    }
}

Thank you very much.

Re: An array as a common variable between two classes .

[quote]As the title of the forum is saying I am a newbie, so can't you be more specific and give me a code of what you are suggesting?[/code]

More examples:

Quote:

Originally Posted by me

Pass a pointer (or reference as appropriate) to the FenPrincipale instance to the other class and access M through that
Code:

class A { public: A() { memberVar = 1; } int memberVar; }; class B { public: B(): myData(7) { } void doStuff(A *a) { qDebug() << myData * a->memberVar; } void doStuff(const A &a) { qDebug() << myData * a.memberVar; } private: int myData; };
Quote:

Originally Posted by me

Supply the other class with a pointer (or reference) to the FenPrincipale::M member directly
Code:

class A { public: A() { memberVar = 1; } int memberVar; }; class B { public: B(): myData(7) { } void doStuff(int *aMemberVar) { qDebug() << myData + *aMemberVar; } void doStuff(int &aMemberVar) { qDebug() << myData + aMemberVar; } private: int myData; };
Quote:

Originally Posted by me

Supply the other class with a copy of the FenPrincipale::M member
Code:

class A { public: A() { memberVar = 1; } int memberVar; }; class B { public: B(): myData(7) { } void doStuff(int aMemberVarCopy) { qDebug() << myData - aMemberVarCopy; } private: int myData; };