@Override
public void deletePicture(Picture picture) {
synchronized (_sheet) {
DrawingManager dm = ((SheetCtrl)_sheet).getDrawingManager();
ClientAnchor anchor = picture.getPreferredSize();
final RangeImpl rng = (RangeImpl) Ranges.range(_sheet, anchor.getRow1(), anchor.getCol1(), anchor.getRow2(), anchor.getCol2());
final Collection<Ref> refs = rng.getRefs();
dm.deletePicture(_sheet, picture); //must after getPreferredSize() or anchor is gone!
if (refs != null && !refs.isEmpty()) {
final Ref ref = refs.iterator().next();
BookHelper.notifyPictureDelete(ref, picture);