Set up the mouse listener for the field. In the mouseClicked() method, check
the click count of the event. If the count is 1, get the cursor position. If
the count is 2 (the double-click), deselect text in the field, and set the
cursor position to what it was at the click count 1. The docs will provide
the necessary detail.

By implementing this logic, you will break the paradigm of selecting text in
the text field, which is always a bad idea.

HTH

Alex Molochnikov
Gestalt Corporation