*/
protected void createThumbnailViewer() {
LightweightSystem lws = new LightweightSystem(_overview);
ScalableFreeformRootEditPart rootEditPart = (ScalableFreeformRootEditPart) _graphicalViewer
.getRootEditPart();
_thumbnail = new FixedScrollableThumbnail(
(Viewport) rootEditPart.getFigure());
_thumbnail.setBorder(new MarginBorder(3));
_thumbnail.setSource(rootEditPart
.getLayer(LayerConstants.PRINTABLE_LAYERS));
lws.setContents(_thumbnail);