Qt signal emitted but slot not called

Signals and Slots Signals and slots are used for communication between objects. The signal/slot mechanism is a central feature of Qt and probably the part that differs most from other toolkits. In most GUI toolkits widgets have a callback for each action they can …

Signals and Slots - Qt Signals and slots are loosely coupled: a class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. 20 ways to debug Qt signals and slots | Sam Dutton’s blog Below are some suggestions for troubleshooting signals and slots in the Qt C++ library. 1. Check for compiler warnings about non-existent signals and/or slots. 2. Use break points or qDebug to check that signal and slot code is definitely reached: – the connect statement – code where the signal is fired – the slot code. 3. Signals & Slots | Qt Core 5.10

A slot is a function that is called in response to a particular signal. Qt's widgets have many pre-defined slots, but it is common practice to subclass widgets and add your own slots so that you ...

Signals & Slots | Qt 4.8 Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. Signals and Slots - Qt Documentation

Feb 6, 2013 ... An introduction to creating PySide/PyQt signals and slots, using QObject. ... You don't have to rely solely on the signals that are provided by Qt widgets, ... so it can emit signals; it has a signal called punched , which carries no data; and it has a punch method which does nothing but emit the punched signal.

Signals are not emitted if QAxControl is put on D-Bus and no other slots connect to the signals. ... If you then connect one of these signals to a regular slot, they are emitted, both on the normal slot, and via the D-Bus. ... if somecontrol dispatches the somesignal event, it will be // emitted as Qt signal, so dummy() will be called, ... Qt 4.3: Signals and Slots

One of the key features of Qt is its use of signals and slots to communicate between objects. Their use encourages the development of reusable components. A signal is emitted when something of potential interest happens. A slot is a Python callable. If a signal is connected to a slot then the slot is called when the signal is emitted.

In Qt, there is an alternative to the callback technique: signals and slots. A signal is emitted when a particular event occurs. Qt's widgets have many predefined signals, but a client programmer may always subclass widgets to add other signals to them. A slot is a function that is called in response to a particular signal. Segmentation fault while emitting signal from other thread in Qt When I am trying to emit a signal from another thread it causes a segfault, not sure why. Both the signal and slot are defined in the same class and running under the main GUI thread, but I call th...