The separation of the user interface and backend allows us to connect C++ slots to the QML signals. Although it's possible to write processing functions in QML and manipulate interface items in C++, it violates the principle of the separation. Therefore, you may want to know how to connect a C++ slot to a QML signal at first. As for connecting a QML slot to a C++ signal, I'll introduce that later in this book.
In order to demonstrate this, we need to create a C++ class in the first place by right-clicking on the project in the Projects panel and selecting Add New…. Then, click on C++ Class in the pop-up window. The newly created class should at least inherit from
QObject by choosing
QObject as its base class. ...