Search between a Gas Station

QT QLabel setPixmap from QAbstractVideoSurface I'm implementing my own class for probing video frames from QCamera under windows. It's a subclass of QAbstractVideoSurface. So, my probe generates QPixmap which I tried to draw on QLabel (as viewfinder). And I've got segmentation fault on QLabel setPixmap call. I'm sure my Qpixmap is well made, because I can save it on the disk with a save(). My QLabel is inititalized and works well, because I can load QPixmap from the disk and set it to QLabel. I guess there is problem with a format of a pixmap, but can't clue how to correct it :( My code frameprobe.h #ifndef FRAMEPROBE_H #define FRAMEPROBE_H #include <QAbstractVideoSurface> #include <QList> #include <QPixmap> class FrameProbe : public QAbstractVideoSurface { Q_OBJECT public: explicit FrameProbe(QObject *parent = 0); QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const;...

C++ QThread and connect causing crashes My QThread counter crashes giving odd results for what the number should be as the Thread counts properly but in the SetLabel function I get a different number to whats in the QThread ands it then crashes after 3 seconds and the label doesnt seem to update. QThread* CountThread = new QThread; Counter* Count = new Counter(); Count->moveToThread(CountThread); connect(CountThread, SIGNAL(started()), Count, SLOT(Process())); connect(Count, &Counter::SecondsUpdate, this, [=]{ SetLabel(Count->Seconds) ;}); connect(Count, SIGNAL(finished()), CountThread, SLOT(quit())); CountThread->start(); void Counter::Process() { int secs = 0; while (secs < 1000) { qDebug() << "hello" << secs; secs += 1; Sleep(1000); emit SecondsUpdate(); } emit finished(); } void BaseWindow::SetLabel(int Seconds) { qDebug() << Seconds; this->Test->setText(QString("Seconds: " + QString::number(Seconds))); } c...

Qt C++ “new” operation may cause unexpected errors? There are two UIs in my project, namely, Login and MainWindow. Now I use signal-slot method to transfer some data of Login to some MainWindow class member variables,and here is some key code: Login::Login(QWidget *parent) : QDialog(parent) { setupUi(this); MainWindow *w = new MainWindow; connect(this,SIGNAL(sendData(QList<QString>)),w,SLOT(receiveData(QList<QString>))); } //get data from Login void MainWindow::receiveData(QList<QString> userList){ userName = userList.at(0); password = userList.at(1); QSqlQuery query; bool b = query.exec(QString("SELECT * FROM user WHERE user_id = '%1' AND password = '%2'").arg(userName).arg(password)); if(b){ query.first(); userType = query.value(1).toString(); qDebug()<<"user_type:"<<userType; //always has value in userType qDebug()<<"user_id:"<<userN...

Translating a C++ line to Python 3 I'm trying to translate a Qt plugin from C++ to python, however my knowledge on C++ is minimal, can you please help me to confirm if my translation is Ok? (the plugin is not working as expected). C++ code: /*************************************************************************** * Copyright (C) 2006-2008 by Tomasz Ziobrowski * * http://www.3electrons.com * * e-mail: t.ziobrowski@3electrons.com * * * * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. ...

Deploy Qt application on MAC with Qt framework I developed one Qt application in Mac using Qt creator,Its working fine on my development machine.Then I copied the project output from my build directory to a new machine without Qt framework,but its not working in that machine, Do I need to install any frame work for running Qt application in Mac. How I can include qt framework in my application when deploying the project output? This question appears to be off-topic because it doesn't have SSCCE; doesn't demonstrate a minimal understanding of the problem being solved; and it's asking us to asking us to recommend or find a tool, library or favorite off-site resource. – FakeRainBrigand Jul 28 '13 at 21:45 I solved it by using the "macdeployqt" tool blog.inventic.eu/2012/08/… ...

Compiling OpenCV opencv_world with Qt - unresolved externals I want to compile OpenCV (3.4) with Qt (5.11) (with setting CMake-option WITH_QT and setting Qt5*_DIR paths). The source codes were freshly downloaded from github or Qt-Website. The Solution folder for VC14 is created with the latest CMake. If I compile it with VC14 (Visual Studio 2015 C++) it perfectly compiles and links the single modules. But if I also choose the CMake-option BUILD_opencv_world I get unendless (226) linking errors: "unresolved external symbol ...". All of them related to the project opencv_world. If I remove the CMake-option "WITH_QT" I also can create the opencv_world files. What do I make wrong? Below just a the first entries of the error list: Severity Code Description Project File Line Suppression State Error LNK1120 226 unresolved externals opencv_world D:LIBSopencv-make-VC14binDebugopencv_world341d.dll 1 Error LNK2001 unresolved external symbol "public: stat...

Qt application running with `-platform offscreen` argument cannot establish websocket connection I have a GUI application which contains a websocket server QWebSocketServer . I also have a python script which sends messages and the application processes them. Everything works well. During testing I wanted to run the application in headless mode using -platform offscreen command line argument added to the app executable name (I changed nothing else). But the problem is that when the application runs off-screen, the client script cannot establish connection with the web socket server. I tested this on localhost only. I do not understand how this two things, visibility of GUI and websockets, can interfere. Any ideas what could go wrong? QWebSocketServer -platform offscreen Note: I am using Qt 5.11.1 64-bit with VS 2017 on Windows 10 Pro. I further exploring the issue. I tried the same with another application and it seems to work well even for -platform offscr...