Add fitz to pdf downcasting functions for pages and annotations.

3 files changed, 32 insertions, 2 deletions

diff --git a/docs/mutool/run.html b/docs/mutool/run.html
index 19433681..c6bc80e5 100644
--- a/docs/mutool/run.html
+++ b/docs/mutool/run.html
@@ -197,6 +197,8 @@ If alpha is true, the page will be drawn on a transparent background, otherwise
 <dd>Search for 'needle' text on the page, and return an array with rectangles of all matches found.
 <dt>Page#getAnnotations()
 <dd>Return array of all annotations on the page.
+<dt>Page#toPDF()
+<dd>Returns the PDFObject/PDFPage for the page, if the document is a PDF file.
 </dl>
 
 <dl>
@@ -208,6 +210,8 @@ If alpha is true, the page will be drawn on a transparent background, otherwise
 <dd>Render the annotation into a Pixmap, using the transform and colorspace.
 <dt>Annotation#toDisplayList()
 <dd>Record the contents of the annotation into a DisplayList.
+<dt>Annotation#toPDF()
+<dd>Returns the PDFObject/PDFAnnotation for the annotation, if the document is a PDF file.
 </dl>
 
 <h2>
diff --git a/include/mupdf/pdf/document.h b/include/mupdf/pdf/document.h
index 0bec12b0..8a8fdd40 100644
--- a/include/mupdf/pdf/document.h
+++ b/include/mupdf/pdf/document.h
@@ -96,11 +96,22 @@ pdf_document *pdf_open_document_with_stream(fz_context *ctx, fz_stream *file);
 void pdf_drop_document(fz_context *ctx, pdf_document *doc);
 
 /*
-	pdf_specific: down-cast an fz_document to a pdf_document.
+	pdf_specifics: down-cast an fz_document to a pdf_document.
 	Returns NULL if underlying document is not PDF
 */
 pdf_document *pdf_specifics(fz_context *ctx, fz_document *doc);
 
+/*
+	pdf_document_from_fz_document,
+	pdf_page_from_fz_page,
+	pdf_annot_from_fz_annot:
+		Down-cast generic fitz objects into pdf specific variants.
+		Returns NULL if the objects are not from a PDF document.
+*/
+pdf_document *pdf_document_from_fz_document(fz_context *ctx, fz_document *ptr);
+pdf_page *pdf_page_from_fz_page(fz_context *ctx, fz_page *ptr);
+pdf_annot *pdf_annot_from_fz_annot(fz_context *ctx, fz_annot *ptr);
+
 int pdf_needs_password(fz_context *ctx, pdf_document *doc);
 int pdf_authenticate_password(fz_context *ctx, pdf_document *doc, const char *pw);
 
diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c
index 19b1f4f7..82fe7db1 100644
--- a/source/pdf/pdf-xref.c
+++ b/source/pdf/pdf-xref.c
@@ -2698,9 +2698,24 @@ pdf_obj *pdf_progressive_advance(fz_context *ctx, pdf_document *doc, int pagenum
 	return doc->linear_page_refs[pagenum];
 }
 
+pdf_document *pdf_document_from_fz_document(fz_context *ctx, fz_document *ptr)
+{
+	return (pdf_document *)((ptr && ptr->count_pages == (void*)pdf_count_pages) ? ptr : NULL);
+}
+
+pdf_page *pdf_page_from_fz_page(fz_context *ctx, fz_page *ptr)
+{
+	return (pdf_page *)((ptr && ptr->bound_page == (void*)pdf_bound_page) ? ptr : NULL);
+}
+
+pdf_annot *pdf_annot_from_fz_annot(fz_context *ctx, fz_annot *ptr)
+{
+	return (pdf_annot *)((ptr && ptr->bound_annot == (void*)pdf_bound_annot) ? ptr : NULL);
+}
+
 pdf_document *pdf_specifics(fz_context *ctx, fz_document *doc)
 {
-	return (pdf_document *)((doc && doc->close == (fz_document_close_fn *)pdf_close_document) ? doc : NULL);
+	return pdf_document_from_fz_document(ctx, doc);
 }
 
 pdf_obj *