QTreeView and custom model from QAbstractItemModel

[croscato]

Hi all!

I have created a custom model subclassing a QAbstractItemModel and inserted items with the following code:

QTreeNode* root = new QTreeNode("Root", 0);
 
    QTreeNode* n1 = new QTreeNode("N1", root);
 
    QTreeNode* n2 = new QTreeNode("N2", root);
    QTreeNode* n21 = new QTreeNode("N21", n2);
    QTreeNode* n22 = new QTreeNode("N22", n2);
    QTreeNode* n23 = new QTreeNode("N23", n2);
 
    QTreeNode* n3 = new QTreeNode("N3", root);
 
    QTreeModel* model = new QTreeModel(this);
 
    model->setRootNode(root);
 
    treeFolders->setRootIsDecorated(true);
    treeFolders->setModel(model);

QTreeNode* root = new QTreeNode("Root", 0);

    QTreeNode* n1 = new QTreeNode("N1", root);

    QTreeNode* n2 = new QTreeNode("N2", root);
    QTreeNode* n21 = new QTreeNode("N21", n2);
    QTreeNode* n22 = new QTreeNode("N22", n2);
    QTreeNode* n23 = new QTreeNode("N23", n2);

    QTreeNode* n3 = new QTreeNode("N3", root);

    QTreeModel* model = new QTreeModel(this);

    model->setRootNode(root);

    treeFolders->setRootIsDecorated(true);
    treeFolders->setModel(model);

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What I get as result is:
|-N1
|-N2
| |-N21
| |-N22
| |-N23
|-N3

How can I manage to get it this way:
Root
|-N1
|-N2
| |-N21
| |-N22
| |-N23
|-N3

I have attached a file containing my model implementation if needed for
further examination.

Thanks in advance!