No. SWT is a completely separate implementation that doesn't build on either AWT or Swing.
Do I have to use SWT to wirte plug-ins for Eclipse? Can I use Swing?
Since Eclipse is written in SWT, if your plug-in has GUI elements, it would probably fit in better if you did it in SWT. You could always have an SWT button or menu in Eclipse launch a Swing JFrame, or you could use something like SwingWT, but it would probably fit better with SWT.
One of the biggest things I noticed missing was a JDesktopPane/JInternalFrame replacement. The graphics context drawing capabilities were nowhere near as good as Graphics2D, though I have heard there have been some improvements in this area.
Write once, run anywhere, because there's nowhere to hide! - /. A.C.