Problem in Paint Focus for Q3Table

[Hans]

I had a class MyTable inherited from Q3Table.
I want to highlight the cell that's clicked by mouse by adding a red rectangular around the cell's bundary.
So I re-implemented paintFocus(QPainter * p, const QRect & cr) like this:

void MyTable:aintFocus ( QPainter * painter, const QRect & cr )
{
Q3Table:aintFocus(painter,cr);
painter->setPen(QPen(QColor(155,10,10), 2));
QRect highlight_rect = cr.adjusted(2,2, -2, -2);
painter->drawRect(highlight_rect);
update();
}

But the red Rect only appear for the first column in the first row. When clicking other cells, just the default black frame.
Why????????
Capture1.PNG Capture2.PNG

[Hans]

simply put, given the col and row number, how to hight light the cell?

[norobro]

From the Q3Table::paintFocus() docs:

The painter p is already translated to the cell's origin, ...

[ChrisW67]

Try removing the call to QWidget::update() because all this Qt 3 compatibility code is likely called from within QWidget::paintEvent() of the Qt4 widget wrapper and, as the docs say:

Note: Generally, you should refrain from calling update() or repaint() inside a paintEvent(). For example, calling update() or repaint() on children inside a paintevent() results in undefined behavior; the child may or may not get a paint event.

If you are writing a new program do not continue use the Qt 3 compatibility classes. Learn to use the Qt4/5 QTableWidget or QTableView.