Select a file (in the editor, the Project tool window, or navigation bar) or directory (in the Project tool window, or navigation bar) and then either
Right click it and select Diagrams > Show Diagram from the context menu, or
simply type CTRL+ALT+Shift+U
In the resultant diagram window, you can turn on and off features such as showing methods and dependencies. Overall, it does a great job. But it does not provide all the functionality a standalone UML tool would provide. Enough for most uses though.
Select a file (in the editor, the Project tool window, or navigation bar) or directory (in the Project tool window, or navigation bar) and then either
In the resultant diagram window, you can turn on and off features such as showing methods and dependencies. Overall, it does a great job. But it does not provide all the functionality a standalone UML tool would provide. Enough for most uses though.