Qt Create Slots And Signals
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I have a Qt 'signal-slot connection'.
I want to test the class with the signal
The class with the slot is mocked/stubbed.
Now I would like to verify that when I emit signal, the slot is
called.
I wonder if it is possible to use gmock to verify this.
// class Tx contains the signal, which is protected so I inherit
// to get access to it
class Test : public ::testing::Test, public Tx
{ public:
MockRx *rx;
void SetUp()
{ rx = new MockRx;
rx->rxsignal(); // Just to see it compiles
rx->gmock_rxsignal(); // Compiles, gmock generated function
QObject::connect(this, SIGNAL(txsignal(), rx, SLOT(rxsignal()));
}
void TearDown() { delete rx; }
};
TEST_F(Test, Signal)
{
EXPECT_CALL(*rx, rxsignal()).Times(1).WillOnce(Return());
this->txsignal();
}
class MockRx : public QWidget
{ Q_OBJECT
public:
MOCK_METHOD0(rxsignal, void());
};
When running, I get the error:
QObject::connect: No such slot as RxMock::rxsignal()
If I remove Q_OBJECT in class MockRx, I get: No such slot as
QWidget::rxsignal()
I also tried to QObject::conntect(... SLOT(gmock_rxsignal()));
which gives No such slot as RxMock::rxsignal()
If I replace the MockRx class with a class Rx with rxsignal()
everything works.
I wonder why QObject::connect cannot find RxText::rxsignal() when
- it works if I replace with a regular class Rx instead of class
MockRx
- rx->rxsignal() can be called
Is gmock doing something under the hood that prevents this?
Hope someone can help, thanks a lot
Paul
Is it better practice to create an object of each class in mainwindow (and instantiate it) of ALL the classes that would require signals and slots and then to define all the connections there. In each class, only the signal and slot needs to be defined. This would eliminate the need to create a class (and instantiate it) in each individual class. Signals and slots were one of the distinguishing features that made Qt an exciting and innovative tool back in time. But sometimes you can teach new tricks to an old dog, and QObjects gained a new way to connect between signals and slots in Qt5, plus some extra features to connect to other functions which are not slots. This signal does nothing, by itself; it must be connected to a slot, which is an object that acts as a recipient for a signal and, given one, acts on it. Connecting Built-In PySide/PyQt Signals. Qt widgets have a number of signals built in. For example, when a QPushButton is clicked, it emits its clicked signal.
Qt Create Slots And Signals Play
Quite a frequent problem when working with signals with slots in Qt5, according to my observations on the forum, is the connection of slots in the syntax on the pointers to signals having an overload of the signature. The same applies to slots that have an overload.
Let's take a test class that has overloaded signals.
Qt Create Slots And Signals Post
Here there is a signal, with an overload of the signature. Connect this signal will also be to the slots that are declared in the Widget class, and which also have an overload of the signature.
How it was in Qt4
Qt Create Slots And Signals Free
Within Qt4, everything was solved quite simply by specifying the signature of the signal and the slot in the SIGNAL and SLOT macros.
How it became in Qt5
But in Qt5, when writing in the new syntax of signals and slots, there are some problems. Because you need to make the static_cast of the method signature.
By the way, the new syntax also allows you to connect signals to slots with a smaller signature, as it was in Qt4.
Advantages of the new syntax
And now a stumbling block. Why use the new syntax of signals and slots? I still hear this question from time to time. Especially when people see such terrible castes of signatures.
- Therefore, I will list potential advantages:The ability to track errors in the connection of signals and slots at the compilation stage, rather than in the runtime
- Reducing compilation time by excluding macros from the code
- The ability to connect lambda functions, it's quite an important bun
- We protect ourselves from errors when we try to connect from the outside to a private slot. Yes!! Yes!! The SIGNAL and SLOT macros ignore the access levels of methods, violating OOP.
Qt Creator Slots And Signals
In general, for me this is enough, but for you?