Insert/Delete points over image

Hi!

I'm working with the QT Example "image viewer". Now I open an image like this:

Code:

---

QString fileName = QFileDialog::getOpenFileName(this,
                                     tr("Open File"), tr("C:"));
     if (!fileName.isEmpty()) {
         QImage image(fileName);
         if (image.isNull()) {
             QMessageBox::information(this, tr("Image Viewer"),
                                      tr("Cannot load %1.").arg(fileName));
             return;
         }
         imageLabel->setPixmap(QPixmap::fromImage(image));
     }

---

imageLabel is QLabel.

Well, I want to draw something (circle, ellipse...) on the image every time I clicked (at mouse position). I have the mouse position (x, y). But I can't draw nothing. I would still see the image.

What I've done?

Code:

---

void SubQLabel::paintEvent(QPaintEvent *event){
	painter.begin(this);
	painter.setBackgroundMode(Qt::TransparentMode);
	painter.setCompositionMode(QPainter::CompositionMode_DestinationOver);
	painter.drawEllipse(10,10,10,10);
	painter.end();
 }

---

I subclased the QLabel I I override the paintEvent. But the image dissapears and it shows the Ellipse with white background.

I would like to put a lot of points and delete this points on image.

How can I do that? :confused:

Thanks!!!!! :D:D:D

Quote:

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But the image dissapears and it shows the Ellipse with white background.

---

Because now the paintEvent() is only painting the ellipse.
Add QLabel::paintEvent(event); before your drawing code.

try calling QLabel::Paint at the beginning of ur subclassed method

Thanks!!! :D

It works!!. I'm going to try if I can draw an ellipse and then detele it. The code is:

Code:

---

void SubQLabel::paintEvent(QPaintEvent *event){
	QLabel::paintEvent(event);
	painter.begin(this);
	painter.drawEllipse(10,10,10,10);
	painter.end();
 }

---

Painter is QPainter.

Also I'm going to try how can I scale the ellipse at the same time I scale the image.

Thank you very much!!! :D