Adds a user data layer to the layer tree. Each layer is added to the corresponding theme. If the theme layer does not exist yet, it is created according to a set of pre-defined configuration values.
ProtectedisRemoves a user data layer from the layer tree. If the associated theme layer becomes empty after the user layer is removed, the theme layer is also removed.
Manages layers that hold user-derived data such as drawings or local files. Each type of user data layer is grouped under a theme layer in the layer tree. This manager provides functionality for adding, organizing, and toggling visibility of user data layers in the layer tree.