The AlbumListPage needs some data to display. The next step is to be able to add a new album. To do this, at some point, we will have to call an AlbumModel function from QML in order to add this new album. Before building the UI, we have to make a small modification to gallery-core.
The AlbumModel function is already available in QML. However, we cannot directly call AlbumModel::addAlbum(const Album& album) from the QML code: the QML engine will not recognize the function and will throw an error: TypeError: Property 'addAlbum' of object AlbumModel(...) is not a function. This can be fixed by simply decorating the desired function with the Q_INVOKABLE macro (as we did for PictureModel::setAlbumId()).
Nonetheless, there is a second issue here: Album is a C++ class that is not recognized in QML. If we wanted to have full...