General and Desktop

@Pl45m4 and @mpergand : Thanks! This was the solution -- a combination of both suggestions: // as above, then: pfcb->show(); pfcb->setFixedHeight(pfcb->minimumHeight()); // etc.

@Bonnie Thank you! It is a so bad mistake of mine that I should get ashamed. However, this completely solves my issue. Thank again

@JonB I moved my code into QGraphicsView::drawBackground() as you recommended, it works nicely. Thanks a lot!

@SimonSchroeder said in Building for Linux and Windows: Qt Creator for qmake projects will write a Makefile to the main folder both on Windows and Linux There is no difference between qmake and cmake here. It will put the Makefile in you build directory, so if you have different build dirs for the Linux and Windows builds that just works.

It turns out that the real culprit is another application (on top of which my widget should be) which tries to stay above all other windows

@Nan-Feng What do you mean other than void QTableView::setSpan(int row, int column, int rowSpanCount, int columnSpanCount)?

@jsulm said in If Statement with QTime: Do you remember the "Port Qt to Rust" thread? :-) That was what I had in mind.... Maybe that would enforce half the C++ rules, without needing to impose an equal number of new ones for Rust?

@zabitqt said in How remove extra spaces from character using QFontMetrics?: If I draw Hello I see it correctly but if I draw character per character I see a space between character. This is because the font has embedded information how to adjust the distance between specific neighboring characters. If you draw them separately, this information is lost for the font renderer. Here is the definition of kerning from Wikipedia: In typography, kerning is the process of adjusting the spacing between characters in a proportional font, usually to achieve a visually pleasing result. Kerning adjusts the space between individual letterforms. I am not sure if Qt provides any way to get to this kind of information. You can disable kerning (for a whole word and not individual letters) and see if you get the same result when you are drawing the letters separately. If this is the case you know that you need to further research kerning.

@masa4 It would be new to me that layouts can have styles. Layouts are not widgets and have no graphical representation. You need to set stylesheet on your widget.

@ChrisW67 thank you.

@jeremy_k Adding this QRectF TreeViewNode::boundingRect() const { return QRectF(-25, -25, 50, 50); } fixed it instantly.. such a silly mistake, it's almost as if I started learning about Qt last week.. (it's true). What can I say, thank you so much to everyone for your time and your suggestions, I'll make sure to remove m_scene and use scene() as well and keep learning more in detail about the classes I'm using. Thank you!

@JonB said in Setting limit size to vector and overwriting the oldest value when limit reached: I suggested earlier you can avoid this if you wish to be efficient. You would need to be able to read the oldest sample you are overwriting/discarding. MUST...FIGHT...URGE...TO...RESPOND!...but you read my mind. LOL

@mpergand Thanks - this works as expected for the main Window. I think it should also work for each Tab in a QMdiSubWindow - but if i set this for such a window it has no effect.

@NextSaturday It's indeed the paint event that ultimately causes the crash. It is consumed by a widget inheriting from QAbstractButton. That widget has a dangling d-pointer. It's theoretically possible but pretty unlikely, that it's not yet properly constructed. Unlikely because it already receives a mouse event. It's more likely on the way to destruction and still receiving a mouse event. The painting as such is doomed to fail, but it already fails when trying to obtain the d-pointer, so the crash happens before any painting is done. Sharing all the code in question would help to get to the bottom of it.

If you've a commercial license then you will get 15.15.12, otherwise you have to stay with 5.15.2 when you want a pre-built binary package or 5.15.8 when you want to compile Qt on your own.