How can I find the extent of the view port?

There is no longer a getAdjustedExtent method.

There has been a systematic elimination of all the methods that worked with an Extent. These have been replaced by methods for managing an Envelope. Operations on the gvSIG extent treated it as a 2D rectangle, which, with the emergence of more complex geometries, is no longer correct.

The methods that used to work on an Extent now work with an Envelope, and so have been renamed.

The getAdjustedExtent method has now become getAdjustedEnvelope.