signals-slots

I am working through the book "Rapid Gui Programming with Python and Qt" and am having a problem on the signals/slots project. I have downloaded the authors code to compare against my own, and it all looks the same, however, when I emit a signal from a derived spin box class, python just crashes. Here is the entire code that I have: import sys from PySide.QtCore import * from PySide.QtGui import * class ZeroSpinBox(QSpinBox): zeros = 0 def __init__(self, parent=None): super(ZeroSpinBox, self).__init__(parent) self.connect(self, SIGNAL("valueChanged(int)"), self.checkzero) def checkzero(self):

I am very new to Qt; please help me to solve the problem. I am using a thread to perform intensive operations in the background. Meanwhile I want to update the UI, so I am using SIGNALS and SLOTS. To update UI I emit a signal and update UI. Let us consider below sample code, struct sample { QString name; QString address; }; void Update(sample *); void sampleFunction() { sample a; a.name = "Sachin Tendulkar"; a.address = "India" emit Update(&a); } In the above code we are creating a local object and passing the address of a local object. In the Qt document, it says that when we emit a signal it

I'm currently trying to convert an old python program from Python 2 to Python 3, and update from PyQt4 to PyQt5. The application uses the old style signal and slots that are not supported under PyQt5. I have figured out most of what needs to be done, but below are a few lines that I can't seem to get working: self.emit(SIGNAL('currentChanged'), row, col) self.emit(SIGNAL("activated(const QString &)"), self.currentText()) self.connect(self,SIGNAL("currentChanged(const QString&)"), self.currentChanged) The top two lines, I have no idea where to start since they don't seem to be attached to

I have class Ui_MainWindow(object) that creates a window with a progress bar and class OtherClass(object) that contains method in which the local int variable increments in cycle. How to connect local variable value change to progres bar value change? mainGUI.py import sys from PyQt4.uic.Compiler.qtproxies import QtGui from PyQt4 import QtGui from Ui_MainWindow import Ui_MainWindow def main(): app = QtGui.QApplication(sys.argv) MainWindow = QtGui.QMainWindow() ui = Ui_MainWindow() ui.setupUi(MainWindow) MainWindow.show() sys.exit(app.exec_()) if __name__ == '__main__': main() Ui_MainWindow.py

Currently I have some troubles passing a QVector between to threads. At the moment I have a main thread (GUI-Thread) and an worker thread that emits frequently QVector arrays. Directly before emitting the data inside the vector looks good. The receiver is a slot in the main thread but the Data received in by the slot is garbled. Here are some parts of my code: Emit in the worker thread: void Pipeline::process { QVector<float> buffer(w * h * d); // filling the vector with RGB-Values emit this->pushBuffer(buffer, w, h, d); } Connection of signal and slot in the main thread: QObject::connect(this

I can emit signals with structs tagged with Q_GADGET from C++ to QML. Is it possible send such a struct from QML to a C++ slot? My code fails on the first step: creating an instance in QML. This code fails on the first line ... var bs = new BatteryState() bs.percentRemaining = 1.0 bs.chargeDate = new Date() DataProvider.setBatteryState(bs) ... with error: qrc:///main.qml:34: ReferenceError: BatteryState is not defined I can emit a BatteryStatus struct from C++ to QML, but I would like to send one back as a single parameter to a slot. Here is BatteryState.h & BatteryState.cpp: // BatteryState.h