4. Application always crashed

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Application always crashed


  • Hi everyone
    I'm following c++ lessons on openclassrooms and I have a problem with the TP ZeroClassGenerator
    Indeed, each time I execute the project, the application crashed when I clicked on the button "Generer"

    my .pro

    /QT += widgets

SOURCES += \
    fenprincipale.cpp \
    fencodegenere.cpp \
    main.cpp

HEADERS += \
    fenprincipale.h \
    fencodegenere.h

    main.cpp

    #include <QApplication>
#include <fenprincipale.h>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);


    /*Generateur de class c++
    TP cours openclassroom
    26/01/2018
    */

    //Creation fenetre principal

    FenPrincipale fenetre;

    //Execution

    fenetre.show();

    return app.exec();
}

    fenprincipale.h

    #ifndef FENPRINCIPALE_H
#define FENPRINCIPALE_H

#include <QWidget>
#include <QLayout>
#include <QGroupBox>
#include <QFormLayout>
#include <QLineEdit>
#include <QCheckBox>
#include <QTextEdit>
#include <QDateEdit>
#include <QPushButton>
#include "fencodegenere.h"

class FenPrincipale : public QWidget
{
    Q_OBJECT

    public:
        FenPrincipale();

    private slots:
        void genererClass();

    private:
        QGroupBox *grp1;
        QLayout *afa;
        QLineEdit *nom;
        QLineEdit *mere;
        QFormLayout *layoutGrp1;
        QGroupBox *grp2;
        QCheckBox *check1;
        QCheckBox *check2;
        QCheckBox *check3;
        QVBoxLayout *layoutGrp2;
        QGroupBox *grp3;
        QLineEdit *auteur;
        QDateEdit *date;
        QTextEdit *commentaire;
        QFormLayout *layoutGrp3;
        QPushButton *generer;
        QPushButton *quitter;
        QGridLayout *grp4;
        QVBoxLayout *layoutPrincipal;


};

#endif // FENPRINCIPALE_H

    fenprincipale.cpp

    #include "fenprincipale.h"
#include <QLayout>
#include <QGroupBox>
#include <QFormLayout>
#include <QLineEdit>
#include <QCheckBox>
#include <QTextEdit>
#include <QDateEdit>
#include <QPushButton>
#include <QMessageBox>


FenPrincipale::FenPrincipale()
{
    setWindowTitle("Zero Class Generator");

    //Groupe 1
        QGroupBox *grp1 = new QGroupBox;
        grp1->setTitle("Définition de la classe");

        QLineEdit *nom = new QLineEdit;
        QLineEdit *mere = new QLineEdit;

        QFormLayout *layoutGrp1 = new QFormLayout(grp1);
        layoutGrp1->addRow("&Nom",nom);
        layoutGrp1->addRow("&Classe mère",mere);

        grp1->setLayout(layoutGrp1);

    //Groupe 2
        QGroupBox *grp2 = new QGroupBox;
        grp2->setTitle("Options");

        QCheckBox *check1 = new QCheckBox("Protéger le &header contre les inclusions multiples");
        check1->setChecked(true);
        QCheckBox *check2 = new QCheckBox("Générer un &constructeur par défaut");
        check2->setChecked(true);
        QCheckBox *check3 = new QCheckBox("Générer un &destructeur");

        QVBoxLayout *layoutGrp2 = new QVBoxLayout;
        layoutGrp2->addWidget(check1);
        layoutGrp2->addWidget(check2);
        layoutGrp2->addWidget(check3);

        grp2->setLayout(layoutGrp2);

    //Groupe 3
        QGroupBox *grp3 = new QGroupBox;
        grp3->setTitle("Ajouter des commentaires");
        grp3->setCheckable(true);

        QLineEdit *auteur = new QLineEdit;
        QDateEdit *date = new QDateEdit;
        QTextEdit *commentaire = new QTextEdit;

        QFormLayout *layoutGrp3 = new QFormLayout;
        layoutGrp3->addRow("&Auteur",auteur);
        layoutGrp3->addRow("Da&te de création",date);
        layoutGrp3->addRow("&Rôle de la classe",commentaire);

        grp3->setLayout(layoutGrp3);

    //Groupe 4
        QPushButton *generer = new QPushButton("Générer !");
        QPushButton *quitter = new QPushButton("Quitter");

        QHBoxLayout *grp4 = new QHBoxLayout;
        grp4->addWidget(generer);
        grp4->addWidget(quitter);

        grp4->setAlignment(Qt::AlignRight);

    //Layout principale
        QVBoxLayout *layoutPrincipal = new QVBoxLayout;
        layoutPrincipal->addWidget(grp1);
        layoutPrincipal->addWidget(grp2);
        layoutPrincipal->addWidget(grp3);
        layoutPrincipal->addLayout(grp4);

    setLayout(layoutPrincipal);

    //Connections

    connect(quitter,SIGNAL(clicked(bool)),this,SLOT(close()));
    connect(generer,SIGNAL(clicked(bool)),this,SLOT(genererClass()));

}


void FenPrincipale::genererClass()
{
    if (nom->text().isEmpty())
    {
        QMessageBox::critical(this,"Erreur","Veuillez selectionner au moins un nom de classe");
    }

    QString code;

    if((grp3->isChecked())==true)
    {
        code+="/*\rAuteur : "+auteur->text()+"\rDate de création : "+date->text()+"\nRôle :\r"+commentaire->toPlainText()+"\r*/\n\n";
    }

    QString nomMaj = nom->text();
    nomMaj = nomMaj.toUpper();

    if(check1->isChecked())
    {
        code+="#ifndef HEADER_"+nomMaj+"\r#define HEADER_"+nomMaj+"\r\r";
    }

    code+="class "+nom->text();

    if(!(mere->text()==""))
    {
        code+=": public "+mere->text();
    }

    code+="\r{\r\tpublic:\r";

    if(check2->isChecked())
    {
        code+="\t\t"+nom->text()+"();";
    }


    if(check3->isChecked())
    {
        code+="\r\t\t~"+nom->text()+"();";
    }

    code+="\r\n\tprotected:\r\n\tprivate:\r\n};";

    if(check1->isChecked())
    {
        code+="#endif "+nomMaj+"_H";
    }

    FenCodeGenere *test = new FenCodeGenere(code,this);
    test->exec();


}

    fencodegenere.h

    #ifndef FENCODEGENERE_H
#define FENCODEGENERE_H

#include <QString>
#include <QDialog>
#include <QTextEdit>
#include <QPushButton>

class FenCodeGenere : public QDialog
{
public:
    FenCodeGenere();
    FenCodeGenere(QString &a, QWidget *parent);
private:
    QTextEdit *zone;
    QTextEdit *quitter;
};

#endif // FENCODEGENERE_H

    fencodegenere.cpp

    #include "fencodegenere.h"
#include <QLayout>

FenCodeGenere::FenCodeGenere()
{

}

FenCodeGenere::FenCodeGenere(QString &a, QWidget *parent = 0) : QDialog(parent)
{
    setWindowTitle("Zero Class Generator");

    QTextEdit *zone = new QTextEdit;
    zone->setText(a);
    QPushButton *quitter = new QPushButton("Quitter");

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(zone);
    layout->addWidget(quitter);

    setLayout(layout);

    QObject::connect(quitter,SIGNAL(clicked(bool)),this,SLOT(close()));
}

    so the program is crashing when the slot genererclass is execute
    i need help please :/
    alex

    0 1 Reply

  • @alex_tu28 Hi, friend. Welcome.

    you should to debug it to see which line has crashed. maybe where is pointer value is NULL.

    you can try dichotomy way to know where has crash in your code. the crash happened after clicked Generer Button,

    so, you can debug some information in genererClass function...to find, crash area.

    good luck.

    void FenPrincipale::genererClass()
{
qDebug("Error: 01");
    if (nom->text().isEmpty())
    {
        QMessageBox::critical(this,"Erreur","Veuillez selectionner au moins un nom de classe");
    }
qDebug("Error: 02");
    QString code;

    if((grp3->isChecked())==true)
    {
        code+="/*\rAuteur : "+auteur->text()+"\rDate de création : "+date->text()+"\nRôle :\r"+commentaire->toPlainText()+"\r*/\n\n";
    }
qDebug("Error: 03");
    QString nomMaj = nom->text();
    nomMaj = nomMaj.toUpper();

    if(check1->isChecked())
    {
        code+="#ifndef HEADER_"+nomMaj+"\r#define HEADER_"+nomMaj+"\r\r";
    }

    code+="class "+nom->text();
qDebug("Error: 04");
    if(!(mere->text()==""))
    {
        code+=": public "+mere->text();
    }

    code+="\r{\r\tpublic:\r";

    if(check2->isChecked())
    {
        code+="\t\t"+nom->text()+"();";
    }


    if(check3->isChecked())
    {
        code+="\r\t\t~"+nom->text()+"();";
    }

    code+="\r\n\tprotected:\r\n\tprivate:\r\n};";

    if(check1->isChecked())
    {
        code+="#endif "+nomMaj+"_H";
    }
qDebug("Error: 05");
    FenCodeGenere *test = new FenCodeGenere(code,this);
    test->exec();
qDebug("Error: 06");

}
    4

  • Ok thanks you @joeQ
    I debug some information in genererClass function like you said and I got a "Error 1" in the output
    So I put the first if condition in comment and when I execute i got this time a "Error 2"!!
    And that's it until "Error 5"
    But the end of the function with the object FenCodeGenere is working correctly
    So after some test I found that the crash is happening when I use attributs in my if condition
    Are my pointers badly declared?

    0
  • Lifetime Qt Champion

    @alex_tu28 said in Application always crashed:

    Are my pointers badly declared?

    Hi
    Its hard to declare them wrongly
    ClassType * varname;
    But you might have forgotten to new them at some point ?
    varname = new ClassType()
    (you seem to new stuff so might be ok)
    But i spotted one classic whoops, you should fix.
    in fencodegenere.h , you declare
    QTextEdit *zone;
    but you new a local copy!
    QTextEdit *zone = new QTextEdit; // that is NOT the one from .h but new one !

    same with QTextEdit *quitter; you later make a QPushButton called quitter, not a QTextEdit. is that intended?
    Make sure you are newing the ones from .h file and not make local copy.

    What is attributs ?
    can you show its declaration ?

    1

  • Thanks to you @mrjj I found the problem !!
    I was always make local copy of my pointers !

    So with the varname = new Classtype(), it's works

    thank you for your help

    1
  • Lifetime Qt Champion

    Hi
    Super
    Its a classic copy & paste error :)

    You seems to be making a code generator ?

    Note if the string+string+string becomes very complex, you might consider using something like

    QString classTemplate =
R"(
class %1 %2 {

};
)";

void MainWindow::on_btGenerate_released()
{
   QString out = classTemplate.arg("classname").arg(":parent;");
   qDebug() << out;

    Or for even more complex generation, something like
    https://github.com/steveire/grantlee
    really helps.

    0

  • It's a code generator indeed
    Yes it could be better if I want to continue
    Thank you for this precisions and help ;)

    0 1 Reply
  • Lifetime Qt Champion

    @alex_tu28
    Well for small generations, the + way works super. im just mentioned it
    as im a big fan of code generators and if they live long and get many options, it became hard
    to read in the due to the MANY + operations and the template being very fragmented to look at.

    0
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