Apparently the problem is activated() signal which is sent even when the choice is not changed. So if I have a single item selected then in the slot item state it toggled to the unchecked state. I have tried to use clicked() signal of the combobox's view but it does not work at all, slot never called. I'm on Linux with Qt 5.9.5.

@pauledd You mean the background color "overspill" to right & bottom? I don't know but you might play with border-... or padding-... (I'm thinking margin- does not use background color, but I might be wrong) having a width/transparency/grey....

What does condition contain ?

Thank you @mrjj and @Christian for answer. I am able to make user Checkable. class CustomListModel : public QStandardItemModel { public: Qt::ItemFlags CustomListModel::flags(const QModelIndex & index) const { Qt::ItemFlags defaultFlags = QStandardItemModel::flags(index); if (index.isValid()) { return defaultFlags | Qt::ItemIsUserCheckable; } return defaultFlags; } CustomListModel(const int row, const int coloumn) : QStandardItemModel(row, coloumn) { } }; and modification. hwListProxyModel->setSourceModel(new CustomListModel (0, 0));

@Sumit Glad u got the result, Happy Coding, Thanks,

Here is a possible solution for solving this "missing check/mark" issue. I implemented the CSS "indicator" solution I got from this qt form post which is problematic. Sources of solution: Doc page: here Implementation: here QPalette p = ui->checkBox->palette(); p.setColor(QPalette::Active, QPalette::Base, QColor(255, 255, 255)); p.setColor(QPalette::Button, QColor(255, 255, 255)); ui->checkBox->setAutoFillBackground(true); ui->checkBox->setPalette(p); QColor(255, 255, 255) refers to your desired background color, possibly the same color as your window background, etc. QPallete::Active, QPalette::base refers to the active checkbox's background (the white box background) QPalette::Button refers to the "actual background" (behind the checkbox and the checkbox text) Hope this helps!

@_compiler said: thanks.

QCheckBox inherits from QAbstractButton, which provides a hitButton method that controls which parts of the button are clickable. All you need to do is make a new subclass of QCheckBox and override hitButton so it always returns true: class BigHitCheckBox : public QCheckBox { bool hitButton(const QPoint & pos) const override { Q_UNUSED(pos); return true; } }; This is much simpler than the solutions previously mentioned, and it should play well with the hovering, disabling, and tristate features of the checkbox without any extra effort. By the way, this makes the entire checkbox widget clickable, but it doesn't make other widgets outside the checkbox clickable. I don't think the OP needed that. --David

Nevermind - in the end it turned out the label was modeled as a separate QLabel instead of the text of the QCheckBox. Once I removed the label, and put the text inside the checkbox, I got exactly what I was asking for.

I am not really sure what you want to do, but maybe a QButtonGroup could be helpful?