QML swipeview and State Machine

[Montanaro]

I' m very very beginner about QML.
I'm some experience about C for micrcontroller. When I wrote code for microcontroller, i usually used State Machine.
The method for QT Quick and Ui is very similar and i can write the code.
But i dont undestand how to convert my State Machine into QML
For example this is my State Machine for Ui, how i can convert to QML ? (QML is better for my graphic, i have to use draw and not text in my next code)

*MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

ui->label->setStyleSheet("QLabel { background-color : black; color : white; }");          
ui->label->setText("Welcome");
 QTimer *timer = new QTimer(this);

connect (timer, SIGNAL(timeout()), this, SLOT(StateMachine()));                         // 
timer->start(FREQUENCY);                                                               // 

}

 void MainWindow::StateMachine()

 {

QFile k1_file("/sys/class/GIROLO/input_key1");            //
k1_file.open(QIODevice::ReadOnly | QIODevice::Text);

QFile k2_file("/sys/class/GIROLO/input_key2");            // 
k2_file.open(QIODevice::ReadOnly | QIODevice::Text);

QFile k3_file("/sys/class/GIROLO/input_key3");            // 
k3_file.open(QIODevice::ReadOnly | QIODevice::Text);

QFile k4_file("/sys/class/GIROLO/input_key4");            // 
k4_file.open(QIODevice::ReadOnly | QIODevice::Text);


QTextStream stream1(&k1_file);                                 //
QString numberS1 = stream1.readAll();
number1=numberS1.toInt();

QTextStream stream2(&k2_file);
QString numberS2 = stream2.readAll();
number2=numberS2.toInt();

QTextStream stream3(&k3_file);
QString numberS3 = stream3.readAll();
number3=numberS3.toInt();

QTextStream stream4(&k4_file);
QString numberS4 = stream4.readAll();
number4=numberS4.toInt();

switch(step)
    {

 // start: in this case, we show a slide with welcome
 //
   case WELCOME :
  ui->label->setText("Welcome");
   qDebug() << "case 1 :  WELCOME ";

  flagBad1=0;
  flagGood1=0;

 // mainCount=0;

  flagBad2=0;
  flagGood2=0;

     qDebug() << number3;



  if (number3==1)



  {
      step=LIST1;
      }



     break;


     // in this case, we show a list of instruction
     // the case has a list of instruction in several slides.
    // before changing slide, we have to choose BAD or GOOD flag


   case LIST1:

    qDebug() << "case 1 :  LIST1  ";
    ui->label->setText("INSTRUCTION1");


    if(number2==1)
    {      qDebug() << "flag good";
          ui->label->setText("ISTRUCTION1 \n");
          ui->label->setText("flag good");
        flagGood1=1;
        flagBad1=0;
    }
    else if (number4==1)
    {     qDebug() << "flag bad ";
        ui->label->setText("INSTRUCTION1 ");
        ui->label->setText("flag bad");
        flagBad1=1;
        flagGood1=0;

    }





    if (( number3==1) && ((flagGood1==1)||(flagBad1==1)))
     {    qDebug() << "GO TO NEXT INST";
        ui->label->setText("NEXT INSTRUCTION");
        step= LIST2;
    }*