closePage method
Close an open PDF page with given index.
Index is starting with 0.
PDF and PDF page must be opened before, by using the open
and openPage
methods.
Implementation
Future<void> closePage({required int pageIndex}) async {
if (_id == null) throw StateError('Please open the PDF first!');
if (!_pages.contains(pageIndex)) throw StateError('PDF page $pageIndex is not open!');
await PdfImageRenderer.closePdfPage(pdf: _id!, page: pageIndex);
_pages.remove(pageIndex);
}