QtStateMachine in GUI projects

[dyngoman]

The State Machine framework seems very interesting to me since i work on projects that require state devices modeling and graphical interfacing.
I am new to Qt and the tutorials and examples seemed to be logic and straight forward but still i could not get the my state machine learning example to work.
Here's what I did:

-started a new Qt GUI project (using QtCreator) , named my class Dialog and inherited the QDialog.
-added some buttons and a text area.
-added a state machine and some states.
-connected signals and slots.

Dialog::Dialog(QWidget *parent) :
        QDialog(parent),
        ui(new Ui::Dialog)
{
    ui->setupUi(this);
    m =new QStateMachine(this);
 
    s1 = new QState();
    t1 = new QTimer(s1);
    t1->setInterval(3000);
    t1->setSingleShot(true);
    connect(s1,SIGNAL(entered()),t1,SLOT(start()));
    connect(s1,SIGNAL(entered()),this,SLOT(WriteTextA()));
    s1->addTransition(t1,SIGNAL(timeout()),s2);
 
    s2 = new QState();
    t2 = new QTimer(s2);
    t2->setInterval(3000);
    t2->setSingleShot(true);
    connect(s2,SIGNAL(entered()),t2,SLOT(start()));
    connect(s2,SIGNAL(entered()),this,SLOT(WriteTextB()));
    s2->addTransition(t2,SIGNAL(timeout()),s3);
 
    s3 = new QState();
    t3 = new QTimer(s3);
    t3->setInterval(3000);
    t3->setSingleShot(true);
    connect(s3,SIGNAL(entered()),t3,SLOT(start()));
    connect(s3,SIGNAL(entered()),this,SLOT(WriteTextC()));
    s3->addTransition(t3,SIGNAL(timeout()),s1);
 
    connect(this->ui->btnA,SIGNAL(clicked()),this,SLOT(WriteTextA()));
    connect(this->ui->btnB,SIGNAL(clicked()),this,SLOT(WriteTextB()));
    connect(this->ui->btnC,SIGNAL(clicked()),this,SLOT(WriteTextC()));
 
    m->addState(s1);
    m->addState(s2);
    m->addState(s3);
 
    m->setInitialState(s1);
    m->start();
}
 
void Dialog::WriteTextA()
{
    this->ui->textEdit->append("ACTION::A");
}
 
....

Dialog::Dialog(QWidget *parent) :
        QDialog(parent),
        ui(new Ui::Dialog)
{
    ui->setupUi(this);
    m =new QStateMachine(this);

    s1 = new QState();
    t1 = new QTimer(s1);
    t1->setInterval(3000);
    t1->setSingleShot(true);
    connect(s1,SIGNAL(entered()),t1,SLOT(start()));
    connect(s1,SIGNAL(entered()),this,SLOT(WriteTextA()));
    s1->addTransition(t1,SIGNAL(timeout()),s2);

    s2 = new QState();
    t2 = new QTimer(s2);
    t2->setInterval(3000);
    t2->setSingleShot(true);
    connect(s2,SIGNAL(entered()),t2,SLOT(start()));
    connect(s2,SIGNAL(entered()),this,SLOT(WriteTextB()));
    s2->addTransition(t2,SIGNAL(timeout()),s3);

    s3 = new QState();
    t3 = new QTimer(s3);
    t3->setInterval(3000);
    t3->setSingleShot(true);
    connect(s3,SIGNAL(entered()),t3,SLOT(start()));
    connect(s3,SIGNAL(entered()),this,SLOT(WriteTextC()));
    s3->addTransition(t3,SIGNAL(timeout()),s1);

    connect(this->ui->btnA,SIGNAL(clicked()),this,SLOT(WriteTextA()));
    connect(this->ui->btnB,SIGNAL(clicked()),this,SLOT(WriteTextB()));
    connect(this->ui->btnC,SIGNAL(clicked()),this,SLOT(WriteTextC()));

    m->addState(s1);
    m->addState(s2);
    m->addState(s3);

    m->setInitialState(s1);
    m->start();
}

void Dialog::WriteTextA()
{
    this->ui->textEdit->append("ACTION::A");
}

....

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When I build and Run it exits with a random exit code.
Where did I go wrong?

[Lesiok]

In lines 14 and 22 s2 and s3 are not initialised.

[dyngoman]

Wow, that was a rookie mistake...adding a transition to a pointer that was not initialized.
Thanks a lot!