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Change item's color in table-view on click

  • Hi

    I have table-view and I want to change color of item with help QColorDialog after click on it.

    I created subclass of QItemDelegate and overrided functions createEditor and setModelData

    QWidget *ColorItemDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &,
    const QModelIndex &) const

    QColorDialog* colorDialog = new QColorDialog();
    return colorDialog;


    void ColorItemDelegate::setModelData(QWidget *editor, QAbstractItemModel model,
    const QModelIndex &index) const
    colorDialog = static_cast<QColorDialog>( editor );
    QColor color = colorDialog->selectedColor();
    if ( color.isValid() )
    model->setData(index, color, Qt::EditRole);

    But it doesn't work because of model-view system considers editor widget as simple widget not dialog. And color in
    @ QColor color = colorDialog->selectedColor(); @
    is always not valid.

    What are there adequate methods to solve this problem?

  • you could try to create a "color edit fields", which has a color field and a button (like a combo box) and open the dialog from there. It could perhaps work, esopecially, as QComboBox also works.

  • On our application we have similar needs (dialog to edit an item index). We do it this way:

    • in the delegate check in createEditor(), if a dialog is needed for editing. If yes, return a null pointer (that restrains the view from editing the index); if no return the base class' implementation
    • connect signal "QAbstractItemView::doubleClicked() ": (or some overload signal from the specialized item views) to a slot
    • in that slot, check if the dialog is needed, if yes create it, show it with exec() and set the value if it returns with "OK"

    This way you still have inline editing for text fields, and create a dialog for the complex editing.

  • Hi!

    Volker, I implemented this idea.

    I created model's class
    class XPenTableModel : public QAbstractTableModel

    XPenTableModel( QObject* parent = NULL );
    QVariant headerData(int section, Qt::Orientation orientation, int role) const;
    int rowCount(const QModelIndex &parent = QModelIndex()) const;
    int columnCount(const QModelIndex &parent = QModelIndex()) const;
    QVariant data(const QModelIndex &index, int role) const;
    bool setData(const QModelIndex &index, const QVariant &value, int role);
    Qt::ItemFlags flags(const QModelIndex &index) const;

    public slots:
    void showDialogIfNeed( QModelIndex index );

    In view's class I call showDialogIfNeed

    void Trend::Settings::XPenTableWidget::on_penTableView_doubleClicked(QModelIndex index)
    model->showDialogIfNeed( index );

    and I implemented showDialogIfNeed and overrode function flags to disable editable of color column

    void XPenTableModel::showDialogIfNeed( QModelIndex index )
    if ( index.column() == PrivateData::ColorOrder )
    QColor color = QColorDialog::getColor();

    Qt::ItemFlags flags( Qt::ItemIsEnabled )
    Qt::ItemFlags flags( Qt::ItemIsEnabled );

    if ( index.column() != PrivateData::ColorOrder )
        flags |= Qt::ItemIsSelectable;
    if ( index.column() == PrivateData::NameOrder )
        flags |= Qt::ItemIsEditable;
    return flags;


    It works fine but function showDialogIfNeed places in Model. It is mix gui and logic.

    Are there more correct solutions without the mix?

  • You can handle everything in the view class or another class that has access to the view. Just show the dialog in the on_penTableView_doubleClicked() slot and set the retrieved data in the model with setData().

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