U g^@sPdZddlmZddlmZmZddlmZddlmZdgZ GdddZ d S) z2Utilities common to reading and writing PDF files.)Tuple)genericmisc)DocumentMetadata)PdfError PdfHandlerc@seZdZdZdejedddZeej dddZ ee dd d Z eejdd d Z eej dd dZeeeefdddZddZddZddZdS)rzfAbstract class providing a general interface for quering objects in PDF readers and writers alike.F)refas_metadata_streamcCstdS)aO Retrieve the object associated with the provided reference from this PDF handler. :param ref: An instance of :class:`.generic.Reference`. :param as_metadata_stream: Whether to dereference the object as an XMP metadata stream. :return: A PDF object. NNotImplementedError)selfr r r?/tmp/pip-unpacked-wheel-owvgwkas/pyhanko/pdf_utils/rw_common.py get_objectszPdfHandler.get_object)returncCstdS)a Returns a view of the document trailer of the document represented by this :class:`.PdfHandler` instance. The view is effectively read-only, in the sense that any writes will not be reflected in the actual trailer (if the handler supports writing, that is). :return: A :class:`.generic.DictionaryObject` representing the current state of the document trailer. Nr r rrr trailer_view szPdfHandler.trailer_viewcCstdSNr rrrrdocument_meta_view0szPdfHandler.document_meta_viewcCstdS)zS :return: A reference to the document catalog of this PDF handler. Nr rrrrroot_ref4szPdfHandler.root_refcCs|j}t|tjst|S)zD :return: The document catalog of this PDF handler. )rr isinstancerDictionaryObjectAssertionError)r rootrrrr;s zPdfHandler.rootcCstdSrr rrrr document_idDszPdfHandler.document_idcs|jd}t|tjst|}t|tjs4tz |d}Wntk r\t}YnX|d}dkrv|dkr|ksnt dfddd||t S)N/Pages /Resources/CountrzPage index out of rangec sT|}|d}z|d}Wntk r2YnX|}t|D]\}}t|tjs`tdt|tjspt |j |krtd|} | d} | dkr| d} |kr|| krnn|||||j hBS|| 7}q@| dkr@|kr>r |||fSz| d}Wntk r.YnX||fSq@|d 7}q@t d dS) Nz/Kidsrz0Page tree node children must be indirect objectszCircular reference in page treez/Typerrz/PagerzPage not found) rraw_getKeyError enumeraterrIndirectObjectrZ PdfReadErrorr referencer) Z first_page_ixZ pages_obj_refZlast_rsrc_dictZ refs_seenZ pages_objZkidsZ cur_page_ixZ kid_indexZkid_refZkidZ node_typeZ desc_count_recursepage_ixretrieve_parentrrr%ZsL       z,PdfHandler._walk_page_tree.._recurse) rrrrr"rrrr rset)r r&r'Zpage_tree_root_refZpage_tree_rootZroot_resourcesZ page_countrr$r_walk_page_treeIs  0zPdfHandler._walk_page_treecCs|j|ddS)a Retrieve the node in the page tree containing the page with index ``page_ix``, along with the necessary objects to modify it in an incremental update scenario. :param page_ix: The (zero-indexed) number of the page for which we want to retrieve the parent. A negative number counts pages from the back of the document, with index ``-1`` referring to the last page. :return: A triple with the ``/Pages`` object (or a reference to it), the index of the target page in said ``/Pages`` object, and a (possibly inherited) resource dictionary. Tr'r)r r&rrrfind_page_containerszPdfHandler.find_page_containercCs|j|ddS)a Retrieve the page with index ``page_ix`` from the page tree, along with the necessary objects to modify it in an incremental update scenario. :param page_ix: The (zero-indexed) number of the page to retrieve. A negative number counts pages from the back of the document, with index ``-1`` referring to the last page. :return: A tuple with a reference to the page object and a (possibly inherited) resource dictionary. Fr*r+r,rrrfind_page_for_modifications z%PdfHandler.find_page_for_modificationN)F)__name__ __module__ __qualname____doc__rZ Referenceboolrpropertyrrrrrrrbytesrr)r-r.rrrrr s& CN) r2typingrrrZmetadata.modelrr__all__rrrrrs