For the historical record, I finally got it working. My code:

`

QRect screenGeometry = QGuiApplication::primaryScreen( )->geometry( ); int x13; int x23; int y13; int y23; if( screenGeometry.width( ) < width( )) { x13 = m_image->getScrollX( ) + screenGeometry.width( ) / 3.0; x23 = m_image->getScrollX( ) + 2 * screenGeometry.width( ) / 3.0; } else { x13 = m_image->getScrollX( ) + width( ) / 3.0; x23 = m_image->getScrollX( ) + 2 * width( ) / 3.0; } if( screenGeometry.height( ) < height( )) { y13 = m_image->getScrollY( ) + screenGeometry.height( ) / 3.0; y23 = m_image->getScrollY( ) + 2 * screenGeometry.height( ) / 3.0; } else { y13 = m_image->getScrollY( ) + height( ) / 3.0; y23 = m_image->getScrollY( ) + 2 * height( ) / 3.0; } QPainter painter( this ); painter.setPen( QPen( Qt::red, 4, Qt::SolidLine, Qt::FlatCap )); painter.drawLine( 0, y13, width( ), y13 ); painter.drawLine( 0, y23, width( ), y23 ); painter.drawLine( x13, 0, x13, height( )); painter.drawLine( x23, 0, x23, height( ));

}

`

@herocon

Ok next attempt:

ui->label->setPixmap(p.scaled(ui->label->size()));

Each iteration scales the pixmap to current label size and then sets the pixmap to the label.
By doing this, the size of the label increases with the pixmap (because of border/frame... IIRC 1px per side by default, so 2px in total).
Then you take the new label size again in the next iteration and apply this new (by 2px) increased size to the pixmap... the label gets the pixmap, grows by about 2px in height and there you have your loop where your label and consequently the whole widget grows ;-)

So still no bug :)
And it's exactly the behavior you would expect from the debug output.
(The height increases by 2 each timer interval).
When using another layout setup, the layout/other widgets might "buffer" that, so the main app window does not grow.
But even there, the label itself should definitely grow when you periodically set content which has the exact same size as the outter boundings of the label.
Why though?!

Try (not tested):

int w = ui->label->width(); int h = ui->label->height(); ui->label->setPixmap(p.scaled(w - 2, h - 2)); // or this and set the pixmap only once ui->label->setScaledContents(true);

Because a label with w=500, h=500 for example, can't display a pixmap with w=500, h=500. If you set a pixmap with the same size as the label itself, it will start to grow.

@Emrecp
I believe @SGaist is telling you that you cannot guarantee that a widget with a stylesheet will look identical to one you construct with coded style attributes. As soon as you place a stylesheet on a widget you are (potentially) losing some styles which are inbuilt, so it may differ.

I suggested earlier you remove the weight stuff in your example and see whether just with the font in "normal" it does or does not look identical using the same font in both code and stylesheet.

If you are coding inside paintEvent() then, as you say, you cannot use stylesheet. You can only set the attributes on a QFont as you have done.

I don't know whether you can go through the sources of Qt to discover just what a current style like Fusion does.

@timob256 said in How include "qfont" in "qlabel" ??:

I did not understand which command to write to make it work

Open documentation for setFont: https://doc.qt.io/qt-6/qwidget.html#font-prop
As you can clearly see setFont does not take a pointer to QFont, but you're trying to give it a pointer. This is basic C++ knowledge.
Change to:

ui->label->setFont(*font);

Or, even better, don't declare font as pointer...

Hi all,

I finally managed to find out what was the problem. The fix is the following

@@ -26,7 +26,7 @@ void MainWindow::mousePressEvent(QMouseEvent* event) // If a QLabel contains the mouse pointer, then this is the QLabel that was selected QList<QLabel*> qLabelList = ui->videoStreamsFrame->findChildren<QLabel*>(); foreach(QLabel *l, qLabelList) { - QPoint mappedMousePosition = l->mapFromGlobal(mousePosition); + QPoint mappedMousePosition = l->mapToParent(l->mapFromGlobal(mousePosition)); if (l->geometry().contains(mappedMousePosition)) { rubberBand = new QRubberBand(QRubberBand::Rectangle, l); rubberBand->setGeometry(l->rect());

So, the mapFromGlobal() is translating the global coordinates to widget coordinates and the geometry(), where we use in order to check if the mouse coordinates are contained in the label, has the coordinates relative to the parent widget. So, we need to map the mouse coordinates to the parent widget, hence the function mapToParent().

Kind regards,

Stavros

@BigBen

Store them in a container yourself as you create them: QList<QLabel *> labels; for (int i = 0; i < 10; i++) { QLabel *label = new QLabel; someLayout->addWidget(label); labels.append(label); } Assign them an objectName for future reference to recall an individual one: QList<QLabel *> labels; for (int i = 0; i < 10; i++) { QLabel *label = new QLabel; label->setObjectName(QString("label_%1").arg(i)); someLayout->addWidget(label); } QLabel *label_2 = someParentWidget->findChild<QLabel *>("label_2"); Collect them all via findChildren(): QList<QLabel *> labels = someParentWidget->findChildren<QLabel *>();

I see. Thank you.

Awesome, I will check that out, thank you very much!

@new-qt_user-2022 All the best! Feel free to post new questions if you'd like further help.

@jsulm said in Cout in a loop for QLabel Widgets:

@Swati777999

Names[ii] = new QLabel(QString("Name %1").arg(ii));

Works perfectly! Thanks.

@DougyDrumz2 said in How do I make a QLabel Blink?:

The consensus is evidently to l hide and show a QLabel

Not my "consensus :) So far as I am aware, hiding can cause different layout redraw in at least some circumstances. I retain visibility but toggle foreground color to QColor(Qt::transparent) or toggle alpha color value between 255 (opaque) and 0 (transparent) on palette QPalette::setColor(QPalette::Text, colour).

Also, creating multiple QTimer::singleShot()s doesn't scale very well if you want to change the number of flashes or the interval between. Or of you have multiple labels to blink and you'd like them all to be "in sync". I use one regular repeating QTimer with a "countdown" and cancellation when it reaches 0.

Up to you on both of these.

@Sai-Raul

ok.
but Qlabels only likes pixmaps.

@Sai-Raul Start here: https://doc.qt.io/qt-5/videooverview.html

@Sai-Raul said in Image showing in QLabel:

Already tried that

And what was the outcome? Please update your code accordingly.

@eyllanesc Oh I see, it's working now. Thank you!

@J-Hilk Thanks for the response, I'll look into that stackoverlfow thread

@ChrisW67
Thanks! It work like a charm.

For the reason to why I was using QLabel, well I'm mostly testing for stuffs. I'll switch it up later.

@JonB Thanks, this is new information for me. Actually the "QVTKWidget" was sufficing my problem to display point cloud data. For now it is working properly because I m using VTK 7.0. It seems post VTK 8.0, the QVTKOpenglWidget needs to be used.

@TUStudi said:

I actually have 6 QLabels, so I now have 6 timer and so on

Derive a class from QLabel and add that functionality to it. Don't write the same code 6 times!

My QLabels have the sizePolicy horizontal: preferred and vertical: fixed and a vertical length of 20.
When a text is displayed, the QLabel expands so that the elements above the QLabel are also moved upwards and after the text disappears, they go back to their initial place.

Fixed size policy means that widget uses its sizeHint() as the size. If you change the text the size hint also changes, so label grows/shrinks.