DevExtreme Diagram is currently available as a community technology preview (CTP). Expected to officially ship in June 2020.
The Diagram widget can operate in Read Only mode. In this mode, users are not permitted to edit a diagram; therefore, most of the UI elements are disabled. It is for this reason that the Toolbox and Properties panel in this demo are hidden.
To switch the Diagram widget to Read Only mode, set the readOnly option to true.