Hi, On a side note, there's no need to use fromStdString to initialize a QByteArray with a string.

@reina Perhaps AvailableTile has a function to set img_path after it has been constructed with the default constructor ? If not, you must create yourself and insert into the mainwindow. You cannot get Creator to use the other constructor via the UI generator. is AvailableTile your own class?

Yes, sure, and it makes sense, thank you