How to connect signals and slots with transformed argument values

Question

Any easy way to connect signals and slots with transformed argument values. For example, I have a single signal(bool state), it is connected to a slot slot(bool reversed_state) here the state is a reversed state (logically not) of the signal state.

Answer 1

Create an intermediate slot to link the two: -

class MyClass : public QObject
{
    Q_OBJECT
public:
    signals:
        void SomeSignal(bool state);
        void SomeSignalSwitched(bool state); // reverse the state

    public slots:            

        void ReversedStateSlot(bool reversed_state);
 };


void MyClass::SomeSignalSwitched(bool state)
{
    bool newState = !state
    emit SomeSignalSwitched(newState);
}

// NOTE Qt 5 connect functions

connect(myClassObject, &MyClass::SomeSignal, myClassObject, &MyClass::SomeSignalSwitched);
connect(myClassObject, &MyClass::SomeSignalSwitched, myClassObject, &MyClass::ReversedStateSlot);