2 different custom paintevents are not working

Hi,
I have a strange problem. I have custom qlabel with a new paintevent function. This function will paint and connect points on a QLabel image. So far so good. This works, when I only use one label.

But if I create another label or copy the code and rename "RenderArea" to "RenderArea2", it is not working. Painting inside the first label also paints in the second label. If I raise another window, e.g. taskmanager, the application crashed. Really weired.

I hope you can understand my problem. Thanks.

Code:

---

class RenderArea : public QLabel {
    Q_OBJECT
 
    public:
        RenderArea(QWidget *parent = 0);
 
    protected:
        void paintEvent(QPaintEvent *event);
 
    private:
}

---

Code:

---

void RenderArea::paintEvent(QPaintEvent *event)
{
        QPainter painter(this);
 
        painter.setRenderHint(QPainter::SmoothPixmapTransform, true );
        painter.setRenderHint( QPainter::Antialiasing, true);
        painter.fillRect(event->rect(), QBrush(Qt::white));
        painter.translate(30, 30);
        painter.save();
        painter.restore();
 
        QPen pen;
        pen.setColor(Qt::green);
        pen.setWidth(4);
        pen.setJoinStyle(Qt::RoundJoin);
        pen.setCapStyle(Qt::RoundCap);
        painter.setPen(pen);
        QPoint p;
        p.setX(globalX-30);
        p.setY(globalY-30);
 
        for(int i=0; i<pValues.count();i++)
        {
            painter.drawPoint(pValues.at(i));
            if(i > 0)
            {
              if(pValues.at(i).x() == pValues.at(i-1).x() && pValues.at(i).y() == pValues.at(i-1).y())
              {
                i++;
              }
              else
              {
                  painter.drawLine(pValues.at(i-1), pValues.at(i));
              }
 
 
            }
 
        }

---

pValues just stores the painted points so I can repaint them. The strange thing is that the paintevent from label1 paints also the in label2!
I also get the error message "QWidget::repaint: Recursive repaint detected".

That looks fairly ok (other than then obvious unnecessary save/restore).

So you have two instances of that label?
In a layout?
With different data?

Cheers,
_

Yes, two instances of the label. I also tried to use two different classes instead of instancing. Same result.

I added them to the same layout. The data is different. But it seems that the paint event from "label1" is also applied on "label2". I try to provide the whole code in a simplified way so you can understand the problem better. Maybe it is something very simple.

I attached a simple project.

The window shows 2 large labels in white. Try painting on the first one. It will also paint onto the lower one.

I guess that the problem here is that paintEvent will be triggered for every label. But it is strange that it also paints inside the 2nd label. When I paint onto the 2nd label nothing happens.

Attachment 11139

So you have two labels that draw the same data and you are surprised that they look identical?

Cheers,
_

I found my mistake by trying it with another approach (promoting a custom class via the gui). I put all the globals into the custom label class and now every label has its own values. Damn i forgot about the the attributes of an objects. :D

You know, I asked you if the two instances had different data.
A reasonable approach would have been to check that before answering yes despite the facts pointing to the opposite.

Cheers,
_

I thought they were different. At least I thought that the MousePos were Screen Positions. Because the coordinates are based on the widget coordinates they are also appearing in the 2nd widget.

And in my last reply I already said that I did a mistake.

Quote:

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Originally Posted by jho

I thought they were different. At least I thought that the MousePos were Screen Positions. Because the coordinates are based on the widget coordinates they are also appearing in the 2nd widget.

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No, that's not the cause at all.
What the data contains is totally irrelevant.

You are using the same list of points, literally the exactly the same data.

Cheers,
_