Deleting annotations in Android

Using the Apryse library, you can delete a single annotation, delete all the annotations on a page, or delete all the annotations in a PDF document.

You can delete an annotation as follows:

public void deleteAnnotation(final PDFViewCtrl pdfViewCtrl, final Annot annot, final int pageNum) throws Exception {
    // Lock the document first, because accessing annotation/doc information isn't thread-safe.
    pdfViewCtrl.docLock(true, new PDFViewCtrl.LockRunnable() {
        @Override
        public void run() throws Exception {
            Page page = pdfViewCtrl.getDoc().getPage(pageNum);
            page.annotRemove(annot);
            pdfViewCtrl.update(annot, pageNum);
        }
    });
}

The following snippet shows how to enumerate all the annotations on a page, as well as how to delete them.

void deleteAnnotationsOnPage(final PDFViewCtrl pdfViewCtrl, final int pageNum) throws Exception {
    // Lock the document first, because accessing annotation/doc information isn't thread-safe.
    pdfViewCtrl.docLock(true, new PDFViewCtrl.LockRunnable() {
        @Override
        public void run() throws Exception {
            Page page = pdfViewCtrl.getDoc().getPage(pageNum);
            int annotCount = page.getNumAnnots();
            while (annotCount > 0) {
                page.annotRemove(0);
                annotCount = page.getNumAnnots();
            }
            pdfViewCtrl.update(true);
        }
    });
}

The following snippet shows how to traverse all the pages in a PDF document and delete all the annotations.

void deleteAllAnnotations(final PDFViewCtrl pdfViewCtrl) throws Exception {
    // Lock the document first, because accessing annotation/doc information isn't thread-safe.
    pdfViewCtrl.docLock(true, new PDFViewCtrl.LockRunnable() {
        @Override
        public void run() throws Exception {
            PDFDoc pdfDoc = pdfViewCtrl.getDoc();
            PageIterator itr = pdfDoc.getPageIterator();
            while (itr.hasNext()) {
                Page page = (Page) itr.next();
                int annotCount = page.getNumAnnots();
                while (annotCount > 0) {
                    page.annotRemove(0);
                    annotCount = page.getNumAnnots();
                }
            }
            pdfViewCtrl.update(true);
        }
    });
}