Add additional logic into custom module

I read a post from Stanislav Velikov and added a comment asking how to do this for a custom module and thought I would post here as well in case anyone had already done this.
I want to use the widget's generated from creating a custom module using Module Builder and add/override logic. For example I need to allow the user to sort the data in the master view.
I really hope this is possible as I have already tried using a custom widget which works but I lose so much functionality like paging, control designer, master detail relationship and so on. I looked for the class I need to inherit but have not found it yet. I found classes for backend but not frontend. In the Toolboxes section I can see the widget but I only get master/detail template key.