To start a DartDesigner project, use the "File -> New -> Project..." menu to access the New Project wizard. Then in the Dart Designer category, select the Dart Designer Project. Click "Next" and enter the name of your project, for example, DartDesignerProject. The next page of the wizard let you choose to activate or deactivate some viewpoints. For the moment, there is only one viewpoint available, so just click on "Finish".
A popup will appear to let you select the representations that should be created for the initialisation of your project. Keep the representation "<name of your project> Package Diagram" and uncheck "Dart Package Diagram". And now you have your first representation opened. You can now click on the "Add" action in the "Existing Elements" section to add into your diagram the root of your package (Dart Package) that has been created.
From this diagram with one package, you can use the right click menu to access the navigate menu. In the navigate menu, you can create a new Class diagram. In the Class diagram, just like in any other diagram, you can add new elements using the appropriate tools like "New Class" or "New Library".
Then you just have to test the creation of new diagrams with new elements or existing ones that you can import easily...
