Extend table tagging / handle tagging issues (#1428)

* add support for row headers

* Declare variable

* update testfiles (braces)

* handle negative row header values

* add testfiles

* extend documentation

* add multirow code

* remove stray plug

* guard variant, update testfiles

* multirow testfile

* handle missing fields for multirow

* issue #432

* add changes, update date

* update luatex testfiles

* handle issue #444

* correct test, default structure

* version update and changes entry for lttagging

* provide sockets if they do not exist

* start ltnews entry

* corrections from review

* s + commas

base/changes.txt

@@ -6,6 +6,11 @@ to completeness or accuracy and it contains some references to files that are
 not part of the distribution.
 ================================================================================
 
+2024-07-27 Ulrike Fischer <[email protected]>
+	* lttagging.dtx: (subsection{Tagging support for table/tabular packages}): 
+      Two sockets added to store and restore cell data when nesting tables to keep track
+      of multirow settings. 
+
 2024-07-27 Ulrike Fischer <[email protected]>
 	* lttagging.dtx: (subsection{Paragraph sockets}): A socket and plug to restore paragraph
 	setting added. 

base/doc/ltnews40.tex

@@ -159,6 +159,14 @@ \section{Introduction}
 
 % To write
 
+\section{News from the \enquote{\LaTeX{} Tagged PDF} project}
+
+The tagging of tabulars has been extended: it is now possible to tag
+also row headers and to create cells that span more than one row. 
+
+\emph{write more details ...}
+
+
 \section{Handling paragraph continuation}
 
 Already \LaTeX~2.09 offered some automatism to detect whether or not

base/lttagging.dtx

@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{lttagging.dtx}
-             [2024/07/27 v1.0e LaTeX Kernel (tagging support)]
+             [2024/08/07 v1.0f LaTeX Kernel (tagging support)]
 % \iffalse
 \documentclass{l3doc}
 \GetFileInfo{lttagging.dtx}
@@ -324,6 +324,14 @@
 %    \end{macrocode}
 % \end{socketdecl}
 %
+% \begin{socketdecl}{tagsupport/tbl/init/celldata}
+%    This socket is used in \cs{tbl_init_cell_data_for_table}, the command
+%    that stores and initialize cell data to handle nested tables.
+%    It can be used to restore similar tagging related values
+%    \begin{macrocode}
+\NewSocket{tagsupport/tbl/init/celldata}{0}
+%    \end{macrocode}
+% \end{socketdecl}
 %
 % \begin{socketdecl}{tagsupport/tbl/finalize}
 %    To fine tune the structure (change cells to header cells, remove
@@ -337,7 +345,14 @@
 %    \end{macrocode}
 % \end{socketdecl}
 %
-
+% \begin{socketdecl}{tagsupport/tbl/restore/celldata}
+%    This socket is used in \cs{tbl_restore_outer_cell_data:}, the command
+%    that restores cell data when quitting a nested table. It can be used to restore
+%    similar tagging related values
+%    \begin{macrocode}
+\NewSocket{tagsupport/tbl/restore/celldata}{0}
+%    \end{macrocode}
+% \end{socketdecl}
 
 % \begin{socketdecl}{tagsupport/tbl/colspan}
 %    This socket is used to manage spanning cells, e.g., a
@@ -633,6 +648,10 @@
                 )
           }
 %    \end{macrocode}
+% Tagging has to initialize cell data too.
+%    \begin{macrocode}
+  \UseTaggingSocket{tbl/init/celldata}
+%    \end{macrocode}
 %    These are the initial values when starting a table:
 %    \begin{macrocode}
   \int_gzero:N \g_@@_row_int
@@ -732,6 +751,7 @@
   \int_gset:Nn \g_@@_row_int { \l_@@_saved_row_tl }
   \tl_gset_eq:NN \g_@@_span_tl \l_@@_saved_span_tl
   \tl_gset_eq:NN \g_@@_table_cols_tl   \l_@@_saved_table_cols_tl
+  \UseTaggingSocket{tbl/restore/celldata} 
   \@@_trace:n { ==>~ restored~cell~data:~
                 \int_use:N \g_@@_row_int,
                 \int_use:N \g_@@_col_int,

required/latex-lab/changes.txt

@@ -1,3 +1,9 @@
+2024-08-06 Ulrike Fischer <[email protected]>
+	* latex-lab-table.dtx: add support for header-columns
+	* latex-lab-table.dtx: add support for multirows
+	* latex-lab-table.dtx: handle issue #432
+	* latex-lab-marginpar.dtx: handle issue #444
+
 2024-07-11 Ulrike Fischer <[email protected]>
 	* latex-lab-footnote.dtx: restore paragraph defaults at the begin of the footnote
 	tagging-project#262

required/latex-lab/latex-lab-marginpar.dtx

@@ -18,8 +18,8 @@
 %
 % for those people who are interested or want to report an issue.
 %
-\def\ltlabmarginpardate{2024-07-05}
-\def\ltlabmarginparversion{0.85b}
+\def\ltlabmarginpardate{2024-08-06}
+\def\ltlabmarginparversion{0.85c}
 
 %<*driver>
 \documentclass[kernel]{l3doc}
@@ -153,13 +153,38 @@
 \socket_new:nn {tagsupport/marginpar/end}{0}
 %    \end{macrocode}
 % \end{socketdecl}
+% 
+% \begin{macro}{\@@_get_marginpar_parent:N,\@@_get_marginpar_parent_aux:nn}
+% In a paragraph we must retrieve 
+% the structure number of the surrounding Part structure
+% TODO: if this is needed in more places this should 
+% go into tagpdf.
+%    \begin{macrocode}
+\cs_new_protected:Npn\@@_get_marginpar_parent_aux:nn #1 #2  
+ { 
+   \str_if_eq:eeT{\use_ii:nn #1}{Part}{\seq_put_right:Nn\l_@@_tmpa_seq {#2}}
+ }
+\cs_new_protected:Npn \@@_get_marginpar_parent:N #1
+ {
+   \seq_clear:N\l_@@_tmpa_seq
+   \seq_map_pairwise_function:NNN
+     \g_@@_struct_tag_stack_seq
+     \g_@@_struct_stack_seq
+     \@@_get_marginpar_parent_aux:nn
+   \seq_put_right:Nn\l_@@_tmpa_seq {2}
+   \seq_get_left:NN \l_@@_tmpa_seq #1 
+ }
+\cs_generate_variant:Nn \tag_struct_begin:n {e}
+%    \end{macrocode}
+% \end{macro}
 % \begin{plugdecl}{tagsupport/marginpar/begin,tagsupport/marginpar/end}
 %    \begin{macrocode}
 \socket_new_plug:nnn {tagsupport/marginpar/begin}{default}
   {
    \if_mode_horizontal:
-    \tag_mc_end: 
-    \tag_struct_begin:n{tag=Aside,parent=\g__tag_para_main_struct_tl}%
+    \tag_mc_end:
+    \@@_get_marginpar_parent:N \l_@@_tmpa_tl
+    \tag_struct_begin:e{tag=Aside,parent=\l_@@_tmpa_tl}%
    \else: 
     \tag_struct_begin:n{tag=Aside}%
    \fi: