public Point getAttachmentScreenCenter(byte type, int i, Class c) {
		if (modelManager.frame == null)
			return new Point();
		switch (type) {
		case Attachment.ATOM_HOST:
			Atom[] atoms = modelManager.frame.atoms;
			if (i >= 0 && i < modelManager.frame.atomCount) {
				if (SiteAnnotation.class == c)
					return atoms[i].pin.handleCenter();
				if (InteractionCenter.class == c)
					return atoms[i].pin.handleCenter();
			}
			break;
		case Attachment.BOND_HOST:
			Bond[] bonds = modelManager.frame.bonds;
			if (i >= 0 && i < modelManager.frame.bondCount) {
				if (SiteAnnotation.class == c)
					return bonds[i].pin.handleCenter();
				if (InteractionCenter.class == c)
					return bonds[i].pin.handleCenter();
			}
			break;
		}
		return new Point();
	}