One very important aspect of creating a user-friendly application is the ability to display vital information regarding the status of the application when a certain event (intended or unintended) occurs. To display such information, we need an external window that can be dismissed by the user once he/she has acknowledged the information.
Qt comes with this functionality, and it's all residing in the QMessageBox class. There are several types of message box you can use in Qt; the most basic one uses just a single line of code, like so:
QMessageBox::information(this, "Alert", "Just to let you know, something happened!");
There are three parameters you need to provide for this function. The first one is the parent of the message box, which we have set as the main window. The second parameter is for the window title, and the third...