Setting "ItemisAutoTristate" on a QTreeWidgetItem disable it.

[Mummoc]

Hi, i'm currently trying to build a tree using QTreeWidget and QTreeWidgetItem in Qt6.2.1.
I simply have a MainWindow widget that contains everything, in the constructor i have the following code:

QTreeWidget* treeA = new QTreeWidget(this);
    QTreeWidgetItem* parentItemA = new QTreeWidgetItem(treeA, QStringList(QString("parent 1")));
    QTreeWidgetItem* childItemA1 = new QTreeWidgetItem(parentItemA, QStringList(QString("child 1")));
    QTreeWidgetItem* childItemA2 = new QTreeWidgetItem(parentItemA, QStringList(QString("child 2")));
    QTreeWidgetItem* childItemA3 = new QTreeWidgetItem(childItemA1, QStringList(QString("child 2")));

    parentItemA->setCheckState(0, Qt::Unchecked);
    childItemA1->setCheckState(0, Qt::Unchecked);
    childItemA2->setCheckState(0, Qt::Unchecked);
    childItemA3->setCheckState(0, Qt::Unchecked);

    QTreeWidget* treeB = new QTreeWidget(this);
    QTreeWidgetItem* parentItemB = new QTreeWidgetItem(treeB, QStringList(QString("parent 1")));
    QTreeWidgetItem* childItemB1 = new QTreeWidgetItem(parentItemB, QStringList(QString("child 1")));
    QTreeWidgetItem* childItemB2 = new QTreeWidgetItem(parentItemB, QStringList(QString("child 2")));
    QTreeWidgetItem* childItemB3 = new QTreeWidgetItem(childItemB1, QStringList(QString("child 2")));

    parentItemB->setFlags(Qt::ItemIsAutoTristate);
    parentItemB->setCheckState(0, Qt::Unchecked);
    childItemB1->setCheckState(0, Qt::Unchecked);
    childItemB2->setCheckState(0, Qt::Unchecked);
    childItemB3->setCheckState(0, Qt::Unchecked);

    QHBoxLayout* layout = new QHBoxLayout(this);
    layout->addWidget(treeA);
    layout->addWidget(treeB);

As seen in the screenshot, treeB (the one the right) is greyed out.
Adding the following line seems to solve the issue.

parentItemB->setDisabled(false);

The only difference between treeA and treeB is that treeB's toplevel item has the ItemIsAutoTriState flag set.

Is this a know bug ? Or is it a normal behaviour i wasn't aware of ?

[Gojir4]

@Mummoc Hi,

By doing this, you are removing all flags previously defined.
You should try this instead:
parentItemB->setFlags(parentItemB->flags() | Qt::ItemIsAutoTristate);

Default flags are, as defined in the docs:
Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled

[Mummoc]

That fixed the issue, didn't know setFlags() reset existing flags, i feel dumb now...

Thank you !!! :)