Qt signal slot get sender

Qt is well known for its signals and slots mechanism. But how does it work? In this blog post, we will explore the internals of QObject and QMetaObject and discover how signals and slot work under the hood. In this blog article, I show portions of Qt5 code, sometimes edited for formatting and brevity. QVector<QComboBox*> signal and slot problem | Qt Forum

Can a signal call a non-slot method | Qt Forum Nothing Qt 5 specific, these macros have the same functionality since the beginning. They are used by moc to generate the adequate code. With Qt 5, "slot" can be omitted as you have more freedoms for what you can connect to a signal. Qt 4.6: Signals and Slots - Developpez.com 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. Reasons for signal/slot connection with sender == receiver ... @Bart_Vandewoestyne said in Reasons for signal/slot connection with sender == receiver?: But in the code I'm reviewing, fooSignal is only connected to fooSlot Do you mean in the same class or in the whole project? What do I do if a slot is not invoked? - KDAB

Konzolové programy v Qt 4 – 3 (TCP server)

Nothing Qt 5 specific, these macros have the same functionality since the beginning. They are used by moc to generate the adequate code. With Qt 5, "slot" can be omitted as you have more freedoms for what you can connect to a signal. Qt 4.6: Signals and Slots - Developpez.com 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. Reasons for signal/slot connection with sender == receiver ...

A Deeper Look at Signals and Slots ScottCollins2005.12.19 what are signals and slots? There'sashortanswerandalonganswer.We'regoingtohavethe ...

Qt Signals and Slots Olivier Go art October 2013. About Me. About Me QStyleSheetStyle Itemviews Animation Framework QtScript (porting to JSC and V8) QObject, moc ... 1 QObject::connect(const QObject *sender, const char *signal, const QObject *receiver, const char *slot, Qt::ConnectionType type) c++ - Qt: Signal main thread - Stack Overflow I can emit from this thread, but only if I connect the slot using Qt::DirectConnection. The upshot is that QObject::sender() in the SLOT will always return NULL. I wish to call deleteLater() for instance, but that can only be scheduled in a QThread. I think I need to get back to the main thread, but how can I signal the object on the main thread? Mapping Many Signals to One - Qt Documentation Qt allows us to connect multiple signals to the same signal or slot. This can be useful when we provide the user with many ways of performing the same operation. Sometimes, however, we would like the slot to behave slightly differently depending on which widget invoked it.

Qt Signals and Slots - KDAB

Signals & Slots | Qt 4.8 Signals and Slots. In Qt, we have an alternative to the callback technique: We use signals and slots. A signal is emitted when a particular event occurs. Qt's widgets have many predefined signals, but we can always subclass widgets to add our own signals to them. A slot is a function that is called in response to a particular signal. QObject Class | Qt Core 5.12.3 Detailed Description. The QObject class is the base class of all Qt objects.. QObject is the heart of the Qt Object Model.The central feature in this model is a very powerful mechanism for seamless object communication called signals and slots. c++ - Qt Slots and C++11 lambda - Stack Overflow Try Stack Overflow for Business. Our new business plan for private Q&A offers single sign-on and advanced features. Get started by May 31 for 2 months free. c++ - Qt: Signal main thread - Stack Overflow

Can a signal call a non-slot method | Qt Forum

I STRONGLY NEED to know slot where signal is connected to. I STRONGLY NEED to know slot where signal is connected to. ... and actually manages it. That means that if the actual data is destructed, the actual Qt signal/slot connection is also removed. That means that you can easily store such items in a container, and just remove them and be sure that the actual connection they represent is also removed ... How Qt Signals and Slots Work - Part 3 - Queued and Inter ... How Qt Signals and Slots Work - Part 3 - Queued and Inter Thread Connections ... activate to prepare a Qt::QueuedConnection slot call. The code showed here has been slightly simplified and commented: static void queued_activate(QObject *sender, int signal ... (c->slotObj, sender, signal, nargs, types, args) : ... Signals and Slots in Qt5 - Woboq

I have class A, which dynamically allocates an instance of class B when a method is called, and emits a signal which carries the instance of B. In another class named handler, I have a slot which recives an object of type B. And in the main function, I connect them like this: connect(a, SIGNAL(changed(B*)), handler, SLOT(process(B*)));