Front-end Architecture

UGS uses a Model-View-Presenter architecture. What this means is that at a high level there are three layers which each serve different purposes. A Model for all backend logic, a View displayed to the user and a Presenter which serves as a buffer between the model and one or more views.


The model contains all backend logic. Things like opening a connection, listing serial ports, streaming a file, and handling firmware specific nuances. All of this is hidden from the front end as much as possible.


The view only has access to the presenter. It is responsible for all user interaction and feedback. The main logic in here should be things like enabling or disabling components based on the current state of the model.

Classic GUI

The Classic GUI is built using NetBeans. There are a number of custom Swing components, and they are all initialized with the NetBeans GUI builder. The vast majority of the Classic GUI code is contained in There isn't a lot to expand on here, this front end has grown organically over the years and is fairly rigid. The Visualizer component is a standalone JOGL window which is updated using events from the backend (it was a model for many of the improvements in the current applications architecture).

UGS Platform

The UGS Platform build is also built using NetBeans. It is a built ontop of the NetBeans Platform which provides it a robust set of tools like flexible windows, a plugin framework, and a suite of tools for module communications. At the core of this is a module named UGSLib which is a simple wrapper to the standard UGS JAR file. There is a suite of modules named UGSCore which provides many of the standard UI elements seen in the Classic GUI, in addition there are other modules that provide new functionality.

Extending the GUI is now a matter of creating a new plugin, for details on how to do this see the Plugin Tutorial.


The presenter serves as an API for the model. All the heavy lifting needed for the GUI should happen here. For example the controller model object knows how to stream a processed file, but it doesn't know how to process the file. So the presenter will pass data to the gcode processor and generate a processed object which can be passed to the controller.

Similarly, all notifications from the model are reinterpreted for the view with a simpler message strategy.

In this way, all updates to the backend code can be leveraged by all front ends which utilize UGS.


In UGS interfaces named BackendAPI and BackendAPIReadOnly provide the presenter layer. The read only methods are split off into a sub-interface in case a developer wants to be sure they don't change any state. For instance a widget that displays the current machine location probably has no need for pausing a stream.

These APIs are used by all front ends (Classic GUI, PendantUI and UGS Platform).