Filter QGraphicsItems type in a scene from items()

I'm looking for a way to get all the QGraphicsLineItem from a scene, using items().

It gives a list of all the QGraphicsItem, but I want to perform actions only on QGraphicsLine for example. How can I sort this list/extract the items I want with a specific type ?

You can go through the list and test the type with a dynamic_cast:

// I'm not sure where you want to implement this,
// but it can be in your derived GraphicsScene class.
// Else, just call scene->items() and make a new list
// outside of the scene class.
void CustomScene::foo()
{
    QList<QGraphicsItem*> itemList = items();
    for (int i = 0; i < itemList.size(); ++i) {
         if (auto lineItem{dynamic_cast<QGraphicsLineItem*>(itemList[i])})
             // do a specific action or put this in a QList of QGraphicsLiteItem*s
             // and return that list instead of void
             ;
    }
}

I haven't tested this code, but something like this should be possible.