@GrecKo Thanks for the tips. Initially I had a QList with c++ objects, but now for simplicity I am trying to avoid that. To manage the dynamic objects, each has a signal connection when they are created. Then when something happens, they receive signals and each object manage it self (turns visible, unvisible, gets deleted, ....). I think this approach it is much easier than creating filters and lists or repeaters.

@JonB Thanks for your reply! My goal is to draw a filled triangle like this: [image: 4f650996-8c43-4745-ab2c-97adac261555.png] The only way I'm able to achieve this that I draw two shapes: one fills the whole boundingRect() and a second one draws the outline in boundingRect() adjusted by the pen width. I'm not sure that it's a good way to solve this problem. Any tips?

Thank you, it works!

Hi Well to get below the QWTPlot plot would be QWTPlotptr->y() + QWTPlotptr->height() However, a more solid approach could be to use a QLabel as a canvas using a pixmap. That way, its very easy to position even if using layouts to make GUI auto adjust to different screen sizes. void PaintShapes() { // take size of label int h = ui->label->height(); int w = ui->label->width(); // make a pixmap of the wanted size QPixmap pix(w, h); // assign painter to it so we can paint on it QPainter paint(&pix); // fill it pix.fill( Qt::white ); // paint on canvas paint.setPen(QColor(0, 0, 0, 255)); paint.drawRect(0, 0, w, h); ..other paint operations-.. // set the pixmap to the label so its shown. ui->label->setPixmap(pix); }