source/texk/web2c/luatexdir/pdf/pdflink.w

   1 % pdflink.w
   2 %
   3 % Copyright 2009-2012 Taco Hoekwater <taco@@luatex.org>
   4 %
   5 % This file is part of LuaTeX.
   6 %
   7 % LuaTeX is free software; you can redistribute it and/or modify it under
   8 % the terms of the GNU General Public License as published by the Free
   9 % Software Foundation; either version 2 of the License, or (at your
  10 % option) any later version.
  11 %
  12 % LuaTeX is distributed in the hope that it will be useful, but WITHOUT
  13 % ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 % FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15 % License for more details.
  16 %
  17 % You should have received a copy of the GNU General Public License along
  18 % with LuaTeX; if not, see <http://www.gnu.org/licenses/>.
  19
  20 @ @c
  21
  22 #include "ptexlib.h"
  23
  24 @ To implement nested link annotations, we need a stack to hold copy of
  25 |pdf_start_link_node|'s that are being written out, together with their box
  26 nesting level.
  27
  28 @c
  29 void push_link_level(PDF pdf, halfword p)
  30 {
  31     if (pdf->link_stack_ptr >= pdf_max_link_level)
  32         overflow("pdf link stack size", pdf_max_link_level);
  33     pdf->link_stack_ptr++;
  34     pdf->link_stack[pdf->link_stack_ptr].nesting_level = cur_s;
  35     pdf->link_stack[pdf->link_stack_ptr].link_node = copy_node_list(p);
  36     pdf->link_stack[pdf->link_stack_ptr].ref_link_node = p;
  37 }
  38
  39 @ @c
  40 void pop_link_level(PDF pdf)
  41 {
  42     flush_node_list(pdf->link_stack[pdf->link_stack_ptr].link_node);
  43     pdf->link_stack_ptr--;
  44 }
  45
  46 @ @c
  47 void do_link(PDF pdf, halfword p, halfword parent_box, scaledpos cur)
  48 {
  49     scaled_whd alt_rule;
  50     int k;
  51     if (type(p) == vlist_node)
  52         normal_error("pdf backend", "'startlink' ended up in vlist");
  53     if (global_shipping_mode == SHIPPING_FORM)
  54         normal_error("pdf backend", "link annotations cannot be inside an xform");
  55     if (is_obj_scheduled(pdf, pdf_link_objnum(p)))
  56         pdf_link_objnum(p) = pdf_create_obj(pdf, obj_type_others, 0);
  57     push_link_level(pdf, p);
  58     alt_rule.wd = width(p);
  59     alt_rule.ht = height(p);
  60     alt_rule.dp = depth(p);
  61     set_rect_dimens(pdf, p, parent_box, cur, alt_rule, pdf_link_margin);
  62     obj_annot_ptr(pdf, pdf_link_objnum(p)) = p; /* the reference for the pdf annot object must be set here */
  63     k = pdf_link_objnum(p);
  64     set_obj_scheduled(pdf, pdf_link_objnum(p));
  65     addto_page_resources(pdf, obj_type_link, k);
  66 }
  67
  68 @ @c
  69 void end_link(PDF pdf, halfword p)
  70 {
  71     halfword q;
  72     scaledpos pos = pdf->posstruct->pos;
  73     if (type(p) == vlist_node)
  74         normal_error("pdf backend","'endlink' ended up in vlist");
  75     if (pdf->link_stack_ptr < 1)
  76         normal_error("pdf backend","pdf link_stack empty, 'endlink' used without 'startlink'");
  77     if (pdf->link_stack[pdf->link_stack_ptr].nesting_level != cur_s)
  78         normal_error("pdf backend","'endlink' ended up in different nesting level than 'startlink'");
  79     /*
  80         NOTA BENE: test for running link must be done on |link_node| and not
  81         |ref_link_node|, as |ref_link_node| can be set by |do_link| or
  82         |append_link| already
  83     */
  84     if (is_running(width(pdf->link_stack[pdf->link_stack_ptr].link_node))) {
  85         q = pdf->link_stack[pdf->link_stack_ptr].ref_link_node;
  86         if (global_shipping_mode == SHIPPING_PAGE && matrixused()) {
  87             matrixrecalculate(pos.h + pdf_link_margin);
  88             pdf_ann_left(q) = getllx() - pdf_link_margin;
  89             pdf_ann_top(q) = getlly() - pdf_link_margin;
  90             pdf_ann_right(q) = geturx() + pdf_link_margin;
  91             pdf_ann_bottom(q) = getury() + pdf_link_margin;
  92         } else {
  93             switch (pdf->posstruct->dir) {
  94                 case dir_TLT:
  95                     pdf_ann_right(q) = pos.h + pdf_link_margin;
  96                     break;
  97                 case dir_TRT:
  98                     pdf_ann_left(q) = pos.h - pdf_link_margin;
  99                     break;
 100                 case dir_LTL:
 101                 case dir_RTT:
 102                     pdf_ann_bottom(q) = pos.v - pdf_link_margin;
 103                     break;
 104                 default:
 105                     pdf_ann_right(q) = pos.h + pdf_link_margin;
 106                     formatted_warning("pdf backend","forcing bad dir %i to TLT in link",pdf->posstruct->dir);
 107             }
 108         }
 109     }
 110     pop_link_level(pdf);
 111 }
 112
 113 @ For ``running'' annotations we must append a new node when the end of
 114 annotation is in other box than its start. The new created node is identical to
 115 corresponding whatsit node representing the start of annotation, but its |info|
 116 field is |max_halfword|. We set |info| field just before destroying the node, in
 117 order to use |flush_node_list| to do the job.
 118
 119 @ Append a new pdf annot to |pdf_link_list|.
 120
 121 @c
 122 void append_link(PDF pdf, halfword parent_box, scaledpos cur, small_number i)
 123 {
 124     halfword p;
 125     int k;
 126     scaled_whd alt_rule;
 127     p = copy_node(pdf->link_stack[(int) i].link_node);
 128     pdf->link_stack[(int) i].ref_link_node = p;
 129     subtype(p) = pdf_link_data_node;    /* this node is not a normal link node */
 130     alt_rule.wd = width(p);
 131     alt_rule.ht = height(p);
 132     alt_rule.dp = depth(p);
 133     set_rect_dimens(pdf, p, parent_box, cur, alt_rule, pdf_link_margin);
 134     k = pdf_create_obj(pdf, obj_type_others, 0);
 135     obj_annot_ptr(pdf, k) = p;
 136     set_obj_scheduled(pdf, pdf_link_objnum(p));
 137     addto_page_resources(pdf, obj_type_link, k);
 138 }
 139
 140 @ @c
 141 void scan_startlink(PDF pdf)
 142 {
 143     int k;
 144     halfword r;
 145     if (abs(cur_list.mode_field) == vmode)
 146         normal_error("pdf backend", "startlink cannot be used in vertical mode");
 147     k = pdf_create_obj(pdf, obj_type_others, 0);
 148     new_annot_whatsit(pdf_start_link_node);
 149     set_pdf_link_attr(cur_list.tail_field, null);
 150     if (scan_keyword("attr")) {
 151         scan_toks(false, true);
 152         set_pdf_link_attr(cur_list.tail_field, def_ref);
 153     }
 154     r = scan_action(pdf);
 155     set_pdf_link_action(cur_list.tail_field, r);
 156     set_pdf_link_objnum(cur_list.tail_field, k);
 157     pdf_last_link = k;
 158     /*
 159         NOTA BENE: although it is possible to set |obj_annot_ptr(k) := tail|
 160         here, it is not safe if nodes are later copied/destroyed/moved; a better
 161         place to do this is inside |do_link|, when the whatsit node is written
 162         out
 163     */
 164 }