To create new source file select the template which souce code you want to be used.
All applicable templates are in the tree in the list of templates.
This template will be used to create new document (source for the class).
Then select a package in which you want to create a new class.
The list of packages contains only those packages that are selected in
Class Browser window (to make the selection more easy).
At the end enter the name of the new class and click on OK button.
It's possible to create a new source from Browser - Object view too.
See
User's Guide chapter I.4.3.5.
To create a new package select parent package for the new package from the package list.
The list contains only packages which are selected in the Class Browser window.
Then the user must enter the new package name.
It's possible to create a new package from Browser - Package view too.
See
User's Guide chapter I.4.2.4.