Support for referencing last link with (x)dvipdfmx

latex3 · Dec 7, 2020 · 7889284 · 7889284
1 parent 057231c
commit 7889284
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Showing 15 changed files with 694 additions and 6 deletions.
diff --git a/l3backend/CHANGELOG.md b/l3backend/CHANGELOG.md
@@ -6,6 +6,10 @@ this project uses date-based 'snapshot' version identifiers.
 
 ## [Unreleased]
 
+### Added
+- Support for referencing last link with `(x)dvipdfmx` (requires an up-to-date
+  backend)
+
 ## [2020-09-24]
 
 ### Fixed

diff --git a/l3backend/l3backend-basics.dtx b/l3backend/l3backend-basics.dtx
@@ -380,6 +380,35 @@
 % \end{macro}
 %
 %    \begin{macrocode}
+%<@@=sys>
+%    \end{macrocode}
+%
+% \begin{macro}{\c__kernel_sys_dvipdfmx_version_int}
+%   A short excursion into the |sys| module to set up the backend version
+%   information.
+%    \begin{macrocode}
+\group_begin:
+  \cs_set:Npn \@@_tmp:w #1 Version ~ #2 ~ #3 \q_stop {#2}
+  \sys_get_shell:nnNTF { extractbb~--version }
+    { \char_set_catcode_space:n { `\  } }
+    \l_@@_internal_tl
+    {
+      \int_const:Nn \c__kernel_sys_dvipdfmx_version_int
+        {
+          \exp_after:wN \@@_tmp:w \l_@@_internal_tl
+            \q_stop
+        }
+    }
+    { \int_const:Nn \c__kernel_sys_dvipdfmx_version_int { 0 } }
+\group_end:
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+%<@@=>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
 %</dvipdfmx|xetex>
 %    \end{macrocode}
 %

diff --git a/l3backend/l3backend-pdf.dtx b/l3backend/l3backend-pdf.dtx
@@ -1404,6 +1404,13 @@
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{variable}{\g_@@_backend_link_int}
+%   To track annotations which are links.
+%    \begin{macrocode}
+\int_new:N \g_@@_backend_link_int
+%    \end{macrocode}
+% \end{variable}
+%
 % \begin{macro}
 %   {\@@_backend_link_begin_goto:nnw, \@@_backend_link_begin_user:nnw}
 % \begin{macro}{\@@_backend_link_begin:n}
@@ -1414,11 +1421,17 @@
   { \@@_backend_link_begin:n { #1 /Subtype /Link /A << /S /GoTo /D ( #2 ) >> } }
 \cs_new_protected:Npn \@@_backend_link_begin_user:nnw #1#2
   { \@@_backend_link_begin:n {#1#2} }
-\cs_new_protected:Npn \@@_backend_link_begin:n #1
+\cs_new_protected:Npx \@@_backend_link_begin:n #1
   {
     \@@_backend:n
       {
-         bann
+         bann ~
+         \int_compare:nNnF \c__kernel_sys_dvipdfmx_version_int < { 20201111 }
+           {
+             @pdf.obj
+             \exp_not:N \int_use:N \exp_not:N  \g_@@_backend_object_int
+             \c_space_tl
+           }
          <<
            /Type /Annot
            #1
@@ -1433,9 +1446,17 @@
 % \end{macro}
 %
 % \begin{macro}{\@@_backend_link_last:}
-%   Data not available.
+%   Available using the backend mechanism with a suitably-recent
+%   version.
 %    \begin{macrocode}
-\cs_new:Npn \@@_backend_link_last: { }
+\cs_new:Npx \@@_backend_link_last:
+  {
+    \int_compare:nNnF \c__kernel_sys_dvipdfmx_version_int < { 20201111 }
+      {
+        @pdf.obj
+          \exp_not:N \int_use:N \exp_not:N \g_@@_backend_link_int
+      }
+  }
 %    \end{macrocode}
 % \end{macro}
 %