Implement PDF link annotations: both internal hyperlinks within the

[sgt/halibut] / bk_pdf.c

diff --git a/bk_pdf.c b/bk_pdf.c
index 44f7486..44a9699 100644 (file)
--- a/bk_pdf.c
+++ b/bk_pdf.c
@@ -250,6 +250,54 @@ void pdf_backend(paragraph *sourceform, keywordlist *keywords,
        }
        objstream(cstr, "ET");
 
+       /*
+        * Also, we want an annotation dictionary containing the
+        * cross-references from this page.
+        */
+       if (page->first_xref) {
+           xref *xr;
+           objtext(opage, "/Annots [\n");
+
+           for (xr = page->first_xref; xr; xr = xr->next) {
+               object *annot;
+               char buf[256];
+
+               annot = new_object(&olist);
+               objref(opage, annot);
+               objtext(opage, "\n");
+
+               objtext(annot, "<<\n/Type /Annot\n/Subtype /Link\n/Rect [");
+               sprintf(buf, "%g %g %g %g",
+                       xr->lx / 4096.0, xr->by / 4096.0,
+                       xr->rx / 4096.0, xr->ty / 4096.0);
+               objtext(annot, buf);
+               objtext(annot, "]\n/Border [0 0 0]\n");
+
+               if (xr->dest.type == PAGE) {
+                   objtext(annot, "/Dest [");
+                   objref(annot, (object *)xr->dest.page->spare);
+                   objtext(annot, " /XYZ null null null]\n");
+               } else {
+                   char *p;
+
+                   objtext(annot, "/A <<\n/Type /Action\n/S /URI\n/URI (");
+                   for (p = xr->dest.url; *p; p++) {
+                       char c[2];
+                       c[0] = *p;
+                       c[1] = '\0';
+                       if (*p == '(' || *p == ')' || *p == '\\')
+                           objtext(annot, "\\");
+                       objtext(annot, c);
+                   }
+                   objtext(annot, ")\n>>\n");
+               }
+
+               objtext(annot, ">>\n");
+           }
+
+           objtext(opage, "]\n");
+       }
+
        objtext(opage, ">>\n");
     }