An example selection listener to open an Xtext element in the editor given its URI

Opener.xtend

@Inject IURIEditorOpener editorOpener
...
selectionListener = [ event | 
  val selection = event.selection as IStructuredSelection
  if(selection.size == 1) {
    val selectedElement = selection.firstElement
    if(selectedElement instanceof URI)
      editorOpener.open(selectedElement, true)
  }
]