Text from a QTableView's cell shows through inline QComboBox - OSX

[rpadrela]

Hi,

I'm seeing an issue with a QComboBox in a QTableView letting the original value of the cell showing through as if the QComboBox is behind the table's cell.

Image of when the table's cell is initially clicked on and the QComboBox shows up although not expanded - see text showing through

Image of when the QComboBox is expanded - fine

Apart from this visual glitch, the QComboBox works as expected.

Qt's version is 6.0.3.

This is on Mac OS X 11.2.3. I haven't had the chance to test this on any other platforms.

Thank you.

[SGaist]

Hi and welcome to devnet,

Are you calling setCellWidget ?

[rpadrela]

@SGaist If that's a method from the QTableWidget, then, nope. I'm not using a QTableWidget, I'm using a QTableView.

Btw, I have other types of delegates to embed other widgets (e.g. QSpinBox) in the table and those work fine. It's just the QComboBox that seems to have this problem.

[SGaist]

Can you show the code of that delegate ?

[rpadrela]

@SGaist Sure.

    class ComboBoxDelegate : public QStyledItemDelegate
    {
        Q_OBJECT

    public:
        explicit ComboBoxDelegate(QObject* parent);
        ~ComboBoxDelegate() override = default;

        QWidget* createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
        void setEditorData(QWidget *editor, const QModelIndex &index) const override;
        void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const override;
    };

    ComboBoxDelegate::ComboBoxDelegate(QObject* parent)
    : QStyledItemDelegate(parent)
    {
    }

    QWidget* ComboBoxDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const
    {
        QComboBox* comboBox = new QComboBox(parent);
        comboBox->setModel(new ValueListModel(index));
        return comboBox;
    }

    void ComboBoxDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const
    {
        qobject_cast<QComboBox*>(editor)->setCurrentText(index.data(Qt::EditRole).toString());
    }

    void ComboBoxDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const
    {
        model->setData(index, qobject_cast<QComboBox*>(editor)->currentText());
    }

Thank you for looking into this.

[VRonin]

Try adding:

public:
void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &) const override{
editor->setGeometry(option.rect);
}

[rpadrela]

@VRonin Thanks for the suggestion. Unfortunately, it makes no difference.

[VRonin]

this is very odd... do you have a custom stylesheet applyed?

[rpadrela]

@VRonin Nope

[nagesh]

@rpadrela I feel there is some thing wrong here(not sure)

    {
        qobject_cast<QComboBox*>(editor)->setCurrentText(index.data(Qt::EditRole).toString());
    }

Why are you setting the combo box text here?
Is it editable comboBox?
Set the comboBox setCurrentIndex here. If comboBox list of elements is set through model.

[VRonin]

@nagesh The current code is correct.

from https://doc.qt.io/qt-5/qcombobox.html#currentText-prop

The setter setCurrentText() simply calls setEditText() if the combo box is editable. Otherwise, if there is a matching text in the list, currentIndex is set to the corresponding index.

[rpadrela]

@nagesh QComboBox is not editable.

Could this be an issue currently affecting Mac OS X only?

[VRonin]

@rpadrela said in Text from a QTableView's cell shows through inline QComboBox - OSX:

Could this be an issue currently affecting Mac OS X only?

On windows, both the windows style and Fusion work correctly with this delegate.

Could you try adding QApplication::setStyle(QStyleFactory::create("Fusion")); after you create the QApplication in your main()? and see if you still have the problem on Fusion?

[SGaist]

Did you test with 6.1 ?
From the looks of it's indeed macOS specific. IIRC there have been several glitches in the rendering of widgets with item views.

[rpadrela]

@VRonin

This

QApplication::setStyle(QStyleFactory::create("Fusion"));

fixes it.

I haven't looked into styles yet but it seems like I should. :D

Thank you for your help.

[VRonin]

This means it's a bug in MacOS style, might be worth reporting it

[rpadrela]

@VRonin just reported it here https://bugreports.qt.io/browse/QTBUG-93731

Thank you everyone for your help.