Change default selection color for QTableView - qt

Question

I am using a QTableView with QAbstractTableModel.
I have subclassed QAbstractTableModel and in my model class for Qt::BackgroundRole and Qt::ForegroundRole I have returned some color depending on some condition.
And I have subclassed QTableView class.
When I select any row/cell on the table, the row/cell is highlighted in the default color of the tabelVeiw, it does not show the color returned from my model class.
How can I change this behavior? How can I avoid/ignore this default coloring of QTableView and have only the colors returned by my model class?

Answer 1

You have to use a custom delegate.
Subclass the QStyledItemDelegate and implement it's paint() method like this:
void MyDelegate::paint(QPainter* painter, const QStyleOptionViewItem & option, const QModelIndex & index) const
{
QStyleOptionViewItem itemOption(option);
initStyleOption(&itemOption, index);
if ((itemOption.state & QStyle::State_Selected) &&
(itemOption.state & QStyle::State_Active))
itemOption.palette.setColor(QPalette::Highlight, Qt::red); // set your color here
QApplication::style()->drawControl(QStyle::CE_ItemViewItem, &itemOption, painter, nullptr);
}
If you want to get yout selecion color from the model, I suggest to define a special custom role for that purpose:
enum MyRoles
{
HighlightColorRole = Qt::UserRole
};
Your model will use this role to return your custom highlight (selection) color through the QAbstractItemModel::data() method.
In your delegate you can obtain that color like this:
QColor color = index.data(HighlightColorRole).value<QColor>();

Answer 2

If you want to change the the color of the QTableview when a cell is selected you can do something like this :
QPalette palette = tableview->palette();
palette.setColor(QPalette::Highlight, QColor(255,255,255,100)); //set your own colors and transparency level in QColor
tableview->setPalette(palette);