@solidtyper said in can't emit a signal from a Thread that is inside of another Thread in QT(GUI): however i find it not very efficient. How many sockets do you want to handle? Are you really sure that using multiple thread will increase application performances? If you want to do multi-threading, please take this hints in account: avoid creating too many threads, the best is not to create more than your CPU has core (cf QThread::idealThreadCount()) override QTcpServer::incomingConnection() to be able to create a QTcpSocket instance and move it in the working thread (as descibred in https://wiki.qt.io/WIP-How_to_create_a_simple_chat_application)

Disregard almost everything I said 🙈, of course the internal storage is sorted on key/value pair insert

@SPlatten AFAIK, QSqlQuery::record() is to be used after QSqlQuery::exec() to get the field information of the current query. So you can find the indexes of the value and decode faster the results: if(query.exec("SELECT * from MyTable where status = 2")) { auto record = query.record(); int nameCol = record.indexOf("name"); while(query.next()) qDebug() << "Found:" << query.value(nameCol ).toString(); } Which is faster as using query.value("name").toString()

@Christian-Ehrlicher Hi Seems to call it from QPushButton::sizeHint() but I failed to find way to trigger it without altering text. I guess for full disclosure the source is needed and single step :9 I use wobog for it.

@GUYUEZUNZHE Try to add a VerticalSpacer at the end in verticalLayout.

@SPlatten because findChild is a function of QObject However QWidgets based classes requiere a QWidget and not a QObject as a parent. Layouts are no QWidgets

you might find it easier to install Qt on your raspi, together with the creator, then just use Remote Desktop session for developing directly on the raspi.

@jeremy_k I put 'regular_expression.optimize();' before the whole loop, and it makes no help.

@Argostin Good job!

What about implementing the changeEvent method to handle your object's translatable strings like shown in the dynamic translation part of the internationalization documentation ?

@Buket said in Cross-compiling with diffrent motherboard: Edit : I solved the problem here. I updated sysroot and before correcting my configure command, I prepared a qmake.conf file suitable for the processor of my motherboard. I adjusted the paths accordingly and got an error-free output. Configure command: ./configure -static -release -opengl es2 -device linux-jetway-arm-g++ -device-option CROSS_COMPILE=~/linaro/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf- -no-eglfs -sysroot ~/linaro/sysroot -opensource -confirm-license -prefix /usr/local/qt5li -extprefix ~/linaro/qt5li -hostprefix ~/linaro/qt5 -opensource -confirm-license -skip qtscript -skip qtwayland -skip qtdatavis3d -nomake examples -make libs -pkg-config -no-use-gold-linker -v I can also optionally share the qmake.conf file. Thanks for your help.

Yes, its a separate pro-file, which creates and populates the database.

Hi, @JonB said in Problems with QSqlTableModel: in particular a particular thread showing a working example using a proxy model ... I tried that code and it turned out, that it is the same as the model I already have (subclass of QAbstractItemModel). QAbstractProxyModel is a subclass of QAbstractItemModel, so ... My question was, whether it is possible to create a model suitable for treeview as a child of QSqlTableModel. Apparently it is not possible. Proxy uses a QSqlTableModel - as I do with my model - so nothing new in that linked thread. I changed my editor to use insertRecord and setRecord only. No things seem to work. For me, this usecase was not obvious from documentation. @JonB said in Problems with QSqlTableModel: Lots of people us SQLite without problem. Apparently I'm not cute enuf. ... any way: thank you for your attention and support!

@hbatalha said in Add widget right aligned to a QTableWidget cell: I getting this error when trying to create a signal in the delegate: Can you show your code? what's so wrong with setIndexWidget, creating a delegate seems so complex so I am asking what are the advantages of it over setIndexWidget? Try creating 1000 rows and scroll through them. You'll realise very quick what the problem is. setIndexWidget is a HOG on resources

@SPlatten said in QObject: Cannot create children for a parent that is in a different thread: @J-Hilk , thank you, I will give that a go, although the UDP goes to all clients. I know, I usually have an ID - byte at the front of my UDP datagrams, that identifies it as a Datagram for all or for a specific recipient

@eyllanesc Thank you my friend! Your method works and I learned a new thing about using QML. :)

Hi, One issue here is that your anaconda installed software is trying to use part your system installed Qt. I would say that the packaging of ParaView is wrong. At the very least the Qt version provided with it looks incomplete.

@JonB thanks for you answer. It works perfectly, even if it isn't Qt, it still does what I want it to do. Thanks :)

https://forum.qt.io/topic/16837/program-started-with-qprocess-results-in-segmentation-fault-works-fine-on-console/7

@WesLow If your program uses functions from libzmq. compiled. and linked cleanly then the linker options are OK (but possibly not perfect). If you built and installed libzmq as you describe then the result is installed under /usr/local/bin, lib etc. The "-L" part of your LIBS variable is wrong but is possibly not required because /usr/local/lib will often be searched by default. If the black screen is from your running program then that is a different problem.

@mpergand said in Memory leak?: I know nothing about QwtPlotMarker , but it must clearly be explained in the doc that setSymbol take ownership of symbol. Yeah, it's bad design in C++. I never used Qwt, but for me, it look like you don't use it as it was designed... Why do you have a QwtSymbol pointer in your Point class? As QwtPlotMarker will take ownerchip of the instance, it is a dangerous class construction.

@Sai-Raul ok. but Qlabels only likes pixmaps.

@KroMignon said in Proper use of QPrivateSignal: @jeremy_k said in Proper use of QPrivateSignal: Did you try the code above? QTimer::timeout is a private signal, and yet still callable using a clang 13 C++. Sorry, now I understand what you are meaning... sad situation :( Or curious. I don't know if this is a failure with Qt, C++, or my understanding.

@jeremy_k said in How to get handle to QQmlApplicationEngine from inside c++ to call retranslate for QML: if (QQmlEngine *engine = qmlEngine(this)) { engine->retranslate(); } Just need to refactor now, thanks

Since you need several objects, you need to use either a list or a dictionary to store these objects depending on how you want to retrieve them later on. Since you are new to this, I would recommend starting with training the basics before launching yourself in a complex applications.

As I already requested: please provide a minimal runnable script that shows that behaviour.

Thank you very much for your explanations and your support.

@jsulm I would really like to do this, but it's impossible for me to post such long code here.

@mimamrafi Can you confirm that you want the individual sub-widgets (i.e. the Off, +, - buttons, sliders etc.) to stay exactly the same size and only the space between them to grow if the total available space grows? Can you post the UI file that you seem to have for your channelFrame?

I have decided to change my funtion. QWidget* addPushButtonInTableCell(U2bYTES row, U2bYTES column, U2bYTES numberToPushButton, QTableWidget * pTableWidget , QWidget* parent, QString ruta, const char* slot) { QWidget *pWidget = new QPushButton(QString::number(numberToPushButton),parent); ... return pWidget; } Invoke QWidget* pWidget = addPushButtonInTableCell(0,15,pQ->u.cue.n, tableWidget , pMW->options, ":/ui/recursos/ExtrasInsert.png"); QObject::connect(pWidget,SIGNAL(clicked()), pMW->options, SLOT(on_pushButton_newJump_clicked())); It works fine.

Oh so it is not the mouse coordinate coming from the mouse event, but the 3D coordinate from inside of the OpenGL scene? I don't know how to do it then, sorry. You will probably need to implement some mapping algorithm yourself. Maybe something from https://doc.qt.io/qt-5/qopenglfunctions.html will help?

Did you get the full chains of certificates up to the CA ?

can you try to call update() of QOpenGLWidget to force repaint after switch?

Thank you for your help.

@mpergand Yes, that's what I want. Thanks. I tested it and it works.

@jsulm ok, sorry for trouble to you. I will learn more and try that.

@IknowQT said in Run the executable file built in Ubuntu on Raspberry Pi Ubuntu: @sierdzio If the arm64 and amd64 architectures are different for the same Ubuntu, do you need to make cross-compilation? Yes, cross-compile or compile natively on Raspberry Pi.

@SanZ Just confirmed that the problematic behaviour occurs when the whole thing is put to another thread. In my mock application I had everything in main thread, now I changed to HANDLE hThread = CreateThread(0, 0, thread_fn_for_web, 0, 0, 0); this is the same way as I did with my original application, and now the mock application is failing with the same issue. Anybody has any insight? Thanks.

Are they all the same versions ? Did you install them the same way on all your devices ? What exact issue are you having ? Since you are using QtQuick, you should start really simple with a basic app and make it work on both sides.

@ mrjj why can't I get a full circle ??? #include "krug_qt.h" Krug_qt::Krug_qt(QWidget *parent) : QMainWindow(parent) { R = 90.0; q = 24; p = 24; kol_toch = 180; } Krug_qt::~Krug_qt() { } void Krug_qt::fillVertexArray() { float grad = 360.0/kol_toch; float grad_kol_toch = 0.0; // градусы*M_PI/180 = радианы int j; for (j = 0; j <= kol_toch; ++j){ integerVector.append(R * cos(grad_kol_toch*M_PI/180.0)); integerVector.append(R * sin(grad_kol_toch*M_PI/180.0)); grad_kol_toch = grad_kol_toch + grad; } } void Krug_qt::paintEvent(QPaintEvent *event) { integerVector.clear(); QPainter painter(this); // Создаём объект отрисовщика QPen pen_abris(Qt::black, 2, Qt::SolidLine, Qt::FlatCap); // кисть обрисовки (компаса) painter.setRenderHint(QPainter::Antialiasing); // убираем резкие кубики painter.setPen(pen_abris); // Устанавливаем кисть обрисовки fillVertexArray(); // Набираем массив painter.translate(this->width()/2, this->height()/2); // смещение отрисовки qDebug() << integerVector.size(); int f = 0; for(int i =0; i<integerVector.size()/2; i++) { i++; f++; painter.drawPoint(QPointF(integerVector[--i],integerVector[i])); qDebug() << "f :"<<f; // painter.drawPoint(QPointF(integerVector[i],integerVector[i++])); // i++; } }