@JonB @ChrisW67 Thanks! I'll use a QScopedPointer!

@jdent like the signal onCurrentItemChanged(QTableWidgetItem *current, QTableWidgetItem *previous)

Seems to work nice. @jsulm Thank you very much for your help.

@jsulm Thank you very much. That solved it. The search phrase "Qt 3rd party" never crossed my mind. Afterwards it's kind of obvious.

@JonB Thanks, that worked perfectly. Also, I've decided to write a getter that returns a const reference to the list which also works perfectly.

@SGaist yes, thx, my fault was trying to iterate through the future until not be ready. now i got what i want, not as fast as i want, but it works stable.

@J-Hilk Thanks! Hope it can be fixed soon. @jsulm Same thanks!

@ples76 said in Can you create slots in main.cpp file?: I have solved the problem with all of your help Great, so please don't forget to mark your post as solved! I am trying to find the easiest solution to this since I am under the gun to get this done asap Although you find a solution now, you may want to take into account that having such a main() function is not a good idea as @Christian-Ehrlicher pointed out. So time (and stakeholders) permitting, you might want to look at refactoring your code...

@Robin_Khn Ok super. So its just qmake/moc that is a little slow sometimes. So when you add something to the UI from and go back to the code, you can press ctrl+shift+b (build file) it knows the new Widget right away.

@SnuggleKat said in Difficulties connecting signals with slots (static members): Just didn't know signals mustn't be defined... If you mean "implemented" by "defined", then I wrote this in my first reply :) Yes, you dont implement signals. You just set the signal signature in your header file. After that, you can emit your signal to notify connected classes (-> slots)

The problem was that my class inherited QGraphicsItem, not QObject, but I found another way to do what I wanted. From now on, I will use the new syntax. Thank you!

I tried some different options, and found a solution: void MainWindow::saveSettings() { name = (QCoreApplication::applicationDirPath() +"/logs/"+ui->lineEdit->text() +".txt"); QFile file (name) ; if (newfile == true){ if (file.exists()){ qDebug ()<<"already exists"; NewLog(); timer->stop(); } else { qDebug()<< "Does not exist"; file.open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Append); QString c_time = QTime::currentTime().toString(); QString sText =QString::number(update) + ". "+ c_time + ": rpm = "+ rpm + ", load = "+ QString::number(load) + ", " + name1+ " = " + result1 + ", "+ name2+ " = " + result2 + ", " + name3+ " = " + result3 + ", "+ name4+ " = " + result4 + ", " + name5+ " = " + result5 + ", "+ name6+ " = " + result6 + ", " + name7+ " = " + result7 + ", "+ name8+ " = " + result8 + ", " + name9+ " = " + result9 + ", "+ name10+ " = " + result10; ui->label_log->setText(sText); update++; QTextStream out(&file); out << sText + "\n"; file.close(); newfile = false; }}else{ file.open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Append); QString c_time = QTime::currentTime().toString(); QString sText =QString::number(update) + ". "+ c_time + ": rpm = "+ rpm + ", load = "+ QString::number(load) + ", " + name1+ " = " + result1 + ", "+ name2+ " = " + result2 + ", " + name3+ " = " + result3 + ", "+ name4+ " = " + result4 + ", " + name5+ " = " + result5 + ", "+ name6+ " = " + result6 + ", " + name7+ " = " + result7 + ", "+ name8+ " = " + result8 + ", " + name9+ " = " + result9 + ", "+ name10+ " = " + result10; ui->label_log->setText(sText); update++; QTextStream out(&file); out << sText + "\n"; file.close(); }} Maybe it can be easier, but i am still learning. Thanks for your input. If you have comments on how to change my code, please tell me. (newlog was only to test something else now)

@illud Do you think after 6 years, he's still looking for a solution? ;-) The topic is marked "solved" anyway :-)

@Wael11 For anyone reading this: This is known behaviour, which I stumbled across a long time ago and it was infuriating. With a QSpinbox Qt Internal code uses a timer on clicks/presses. If you step through in debugger you exceed the timeout and get bad/double behaviour. Simplest: change all connect() to QSpinbox click/key to pass Qt::QueuedConnection as last parameter for connection type, not default Qt::DirectConnection. Now you can use debugger breakpoints and all will be well. I wrote a method to connect all my spinboxes like this.

Yep, it works. Thanks :)

I was having the same problem, but for me has worked to disable the Clang code model and restarting Qt.

@kshegunov Yeah, 50% is not Qt enabled so would be an issue. Im just daydreaming :) Hmm, that is actually neat.

Depending on how complex things get, it might make sense to have a "data aggregation layer" between logic and UI. Basically, a UI element would only be connected to a single signal of the aggregation layer, and the aggregation layer would keep track of data changes, and would know when to emit that one signal. It doesn't reduce complexity, but it cleanly distributes it between two parts of your program.