What is QApplication in Qt?
The QApplication class manages the GUI application’s control flow and main settings. QApplication contains the main event loop, where all events from the window system and other sources are processed and dispatched. It also handles the application’s initialization, finalization, and provides session management.
What does QApplication Exec do?
[static] int QApplication::exec() Enters the main event loop and waits until exit() is called, then returns the value that was set to exit() (which is 0 if exit() is called via quit()). It is necessary to call this function to start event handling.
What is QApplication in Python?
QApplication specializes QGuiApplication with some functionality needed for QWidget -based applications. It handles widget specific initialization, finalization. For any GUI application using Qt, there is precisely one QApplication object, no matter whether the application has 0, 1, 2 or more windows at any given time.
What is exec () in Qt?
exec() enters the main event loop and waits until exit() is called. update: The main event loop and the glue code generated by qmake take care of transferring the event message from the QTcpServer to your ConnectionHandler .
What is QApplication in PyQt5?
The QApplication class manages the GUI application’s control flow and main settings. It specializes in the QGuiApplication with some functionality needed for QWidget based applications. It handles widget specific initialization, finalization.
What is event loop in Qt?
Qt’s event loop starts the moment the underlying application’s exec() function gets called. Once started, the loop repeatedly checks for something to happen in the system, such as user-input through keyboard/mouse.
Are Qt signals thread safe?
It is generally unsafe to provide slots in your QThread subclass, unless you protect the member variables with a mutex. On the other hand, you can safely emit signals from your QThread::run() implementation, because signal emission is thread-safe.