QStateMachine how it works

Question

I've created 4 different QState and i want to hide one object in evry state transition.

This is the code:

QStateMachine partita;

QState *inizio_mano = new QState();
QState *aspetto_G1_primo = new QState();
QState *aspetto_G1_secondo = new QState();
QFinalState *fine_mano = new QFinalState();

partita.setInitialState(inizio_mano);

inizio_mano -> addTransition(this,presa==true,aspetto_G1_primo);
inizio_mano -> addTransition(this,presa==false,aspetto_G1_secondo);
aspetto_G1_primo -> addTransition(this,stato==true,fine_mano);
aspetto_G1_secondo -> addTransition(this,stato==true,fine_mano);

presa and stato are two bool I change in the next step of program.

Now I have a QGraphicsScene and in the scene I've added in it some QGraphicsPixmapItem.

For example I want to update the scene hiding an item:

if(presa==true) {object1->hide();} 

I understand I have to change the QState (in this case from inizio_mano to aspetto_G1_primo), and I've done it adding a transition.

But how I can hide that Item ?

How can I connect the QState aspetto_G1_primo with object1 -> hide();

I hope I explained correctly.

My main problem is: how do I assign to each QState a different configuration of the scene ?

Answer 1

You have all the properties of a QWidget here: http://doc.qt.io/qt-5/qwidget.html#properties

Each child class also have their own additional properties, which are in the doc.

So you can do :

aspetto_G1_primo->assignProperty(object1, "visible", false);

Then when entering that state the property "visible" of object1 will be set to false.

You can also do the same to edit any other property depending on the state, such as the geometry, the stylesheet, or the text of labels...