/src/mupdf/source/pdf/pdf-link.c

Source
// Copyright (C) 2004-2026 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
// CA 94129, USA, for further information.

#include "mupdf/fitz.h"
#include "pdf-annot-imp.h"

#include <string.h>
#include <math.h>

static pdf_obj *
resolve_dest_rec(fz_context *ctx, pdf_document *doc, pdf_obj *dest, int depth)
{
  if (depth > 10) /* Arbitrary to avoid infinite recursion */
    return NULL;

  if (pdf_is_name(ctx, dest) || pdf_is_string(ctx, dest))
  {
    dest = pdf_lookup_dest(ctx, doc, dest);
    dest = resolve_dest_rec(ctx, doc, dest, depth+1);
    return dest;
  }

  else if (pdf_is_array(ctx, dest))
  {
    return dest;
  }

  else if (pdf_is_dict(ctx, dest))
  {
    dest = pdf_dict_get(ctx, dest, PDF_NAME(D));
    return resolve_dest_rec(ctx, doc, dest, depth+1);
  }

  else if (pdf_is_indirect(ctx, dest))
    return dest;

  return NULL;
}

static pdf_obj *
resolve_dest(fz_context *ctx, pdf_document *doc, pdf_obj *dest)
{
  return resolve_dest_rec(ctx, doc, dest, 0);
}

static void
populate_destination(fz_context *ctx, pdf_document *doc, pdf_obj *dest, int is_remote, fz_link_dest *destination)
{
  pdf_obj *arg1 = pdf_array_get(ctx, dest, 2);
  pdf_obj *arg2 = pdf_array_get(ctx, dest, 3);
  pdf_obj *arg3 = pdf_array_get(ctx, dest, 4);
  pdf_obj *arg4 = pdf_array_get(ctx, dest, 5);
  float arg1v = pdf_to_real(ctx, arg1);
  float arg2v = pdf_to_real(ctx, arg2);
  float arg3v = pdf_to_real(ctx, arg3);
  float arg4v = pdf_to_real(ctx, arg4);
  pdf_obj *type, *page = NULL;
  fz_matrix ctm = fz_identity;
  fz_rect rect;
  fz_point p;
  int pageno;

  if (is_remote)
    pageno = pdf_array_get_int(ctx, dest, 0);
  else
  {
    page = pdf_array_get(ctx, dest, 0);
    if (pdf_is_int(ctx, page))
    {
      pageno = pdf_to_int(ctx, page);
      page = pdf_lookup_page_obj(ctx, doc, pageno);
    }
    else
      pageno = pdf_lookup_page_number(ctx, doc, page);
    pageno = fz_clampi(pageno, 0, pdf_count_pages(ctx, doc) - 1);
    if (pdf_is_dict(ctx, page))
      pdf_page_obj_transform(ctx, page, NULL, &ctm);
  }

  destination->loc.page = pageno;

  type = pdf_array_get(ctx, dest, 1);
  if (type == PDF_NAME(XYZ))
    destination->type = FZ_LINK_DEST_XYZ;
  else if (type == PDF_NAME(Fit))
    destination->type = FZ_LINK_DEST_FIT;
  else if (type == PDF_NAME(FitH))
    destination->type = FZ_LINK_DEST_FIT_H;
  else if (type == PDF_NAME(FitV))
    destination->type = FZ_LINK_DEST_FIT_V;
  else if (type == PDF_NAME(FitR))
    destination->type = FZ_LINK_DEST_FIT_R;
  else if (type == PDF_NAME(FitB))
    destination->type = FZ_LINK_DEST_FIT_B;
  else if (type == PDF_NAME(FitBH))
    destination->type = FZ_LINK_DEST_FIT_BH;
  else if (type == PDF_NAME(FitBV))
    destination->type = FZ_LINK_DEST_FIT_BV;
  else
    destination->type = FZ_LINK_DEST_XYZ;

  switch (destination->type)
  {
  default:
  case FZ_LINK_DEST_FIT:
  case FZ_LINK_DEST_FIT_B:
    break;
  case FZ_LINK_DEST_FIT_H:
  case FZ_LINK_DEST_FIT_BH:
    p = fz_transform_point_xy(0, arg1v, ctm);
    destination->y = arg1 ? p.y : NAN;
    break;
  case FZ_LINK_DEST_FIT_V:
  case FZ_LINK_DEST_FIT_BV:
    p = fz_transform_point_xy(arg1v, 0, ctm);
    destination->x = arg1 ? p.x : NAN;
    break;
  case FZ_LINK_DEST_XYZ:
    p = fz_transform_point_xy(arg1v, arg2v, ctm);
    destination->x = arg1 ? p.x : NAN;
    destination->y = arg2 ? p.y : NAN;
    destination->zoom = arg3 ? (arg3v > 0 ? (arg3v * 100) : NAN) : NAN;
    break;
  case FZ_LINK_DEST_FIT_R:
    rect.x0 = arg1v;
    rect.y0 = arg2v;
    rect.x1 = arg3v;
    rect.y1 = arg4v;
    rect = fz_transform_rect(rect, ctm);
    destination->x = fz_min(rect.x0, rect.x1);
    destination->y = fz_min(rect.y0, rect.y1);
    destination->w = fz_abs(rect.x1 - rect.x0);
    destination->h = fz_abs(rect.y1 - rect.y0);
    break;
  }
}

static char *
pdf_parse_link_dest_to_file_with_uri(fz_context *ctx, pdf_document *doc, const char *uri, pdf_obj *dest)
{
  if (pdf_is_array(ctx, dest) && pdf_array_len(ctx, dest) >= 1)
  {
    fz_link_dest destination = fz_make_link_dest_none();
    populate_destination(ctx, doc, dest, 1, &destination);
    return pdf_append_explicit_dest_to_uri(ctx, uri, destination);
  }
  else if (pdf_is_name(ctx, dest))
  {
    const char *name = pdf_to_name(ctx, dest);
    return pdf_append_named_dest_to_uri(ctx, uri, name);
  }
  else if (pdf_is_string(ctx, dest))
  {
    const char *name = pdf_to_text_string(ctx, dest);
    return pdf_append_named_dest_to_uri(ctx, uri, name);
  }
  else
  {
    fz_warn(ctx, "invalid link destination");
    return NULL;
  }
}

static char *
pdf_parse_link_dest_to_file_with_path(fz_context *ctx, pdf_document *doc, const char *path, pdf_obj *dest, int is_remote)
{
  if (pdf_is_array(ctx, dest) && pdf_array_len(ctx, dest) >= 1)
  {
    fz_link_dest destination = fz_make_link_dest_none();
    if (!is_remote)
      dest = resolve_dest(ctx, doc, dest);
    populate_destination(ctx, doc, dest, is_remote, &destination);
    return pdf_new_uri_from_path_and_explicit_dest(ctx, path, destination);
  }
  else if (pdf_is_name(ctx, dest))
  {
    const char *name = pdf_to_name(ctx, dest);
    return pdf_new_uri_from_path_and_named_dest(ctx, path, name);
  }
  else if (pdf_is_string(ctx, dest))
  {
    const char *name = pdf_to_text_string(ctx, dest);
    return pdf_new_uri_from_path_and_named_dest(ctx, path, name);
  }
  else if (path)
  {
    fz_link_dest destination = fz_make_link_dest_none();
    return pdf_new_uri_from_path_and_explicit_dest(ctx, path, destination);
  }
  else
  {
    fz_warn(ctx, "invalid link destination");
    return NULL;
  }
}

/* Look at an FS object, and find a name. Find any embedded
 * file stream object that corresponds to that and return it.
 * Optionally return the name.
 *
 * Note that for NON-embedded files, this function will return
 * NULL, but may still return a filename.
 *
 * We will never return a file unless we also found a name.
 */
static pdf_obj *
get_file_stream_and_name(fz_context *ctx, pdf_obj *fs, pdf_obj **namep)
{
  pdf_obj *ef = pdf_dict_get(ctx, fs, PDF_NAME(EF));
  pdf_obj *name = pdf_dict_get(ctx, fs, PDF_NAME(UF));
  pdf_obj *file = pdf_dict_get(ctx, ef, PDF_NAME(UF));
  pdf_obj *any_name = name;

  if (!name && !file)
  {
    name = pdf_dict_get(ctx, fs, PDF_NAME(F));
    if (any_name == NULL)
      any_name = name;
    file = pdf_dict_get(ctx, ef, PDF_NAME(F));
  }
  if (!name && !file)
  {
    name = pdf_dict_get(ctx, fs, PDF_NAME(Unix));
    if (any_name == NULL)
      any_name = name;
    file = pdf_dict_get(ctx, ef, PDF_NAME(Unix));
  }
  if (!name && !file)
  {
    name = pdf_dict_get(ctx, fs, PDF_NAME(DOS));
    if (any_name == NULL)
      any_name = name;
    file = pdf_dict_get(ctx, ef, PDF_NAME(DOS));
  }
  if (!name && !file)
  {
    name = pdf_dict_get(ctx, fs, PDF_NAME(Mac));
    if (any_name == NULL)
      any_name = name;
    file = pdf_dict_get(ctx, ef, PDF_NAME(Mac));
  }

  /* bug708587: Some bad files have the name under one
   * entry (e.g. UF), and the entry in EF under another
   * (e.g. F). Strictly speaking this is against the
   * spec, but we'd rather find the embedded file than
   * not. */
  if (any_name && !file)
  {
    name = any_name;
    file = pdf_dict_get(ctx, ef, PDF_NAME(UF));
    if (file == NULL)
      file = pdf_dict_get(ctx, ef, PDF_NAME(F));
    if (file == NULL)
      file = pdf_dict_get(ctx, ef, PDF_NAME(Unix));
    if (file == NULL)
      file = pdf_dict_get(ctx, ef, PDF_NAME(DOS));
    if (file == NULL)
      file = pdf_dict_get(ctx, ef, PDF_NAME(Mac));
  }

  if (namep)
    *namep = name;

  return name ? file : NULL;
}

static char *
convert_file_spec_to_URI(fz_context *ctx, pdf_document *doc, pdf_obj *file_spec, pdf_obj *dest, int is_remote)
{
  pdf_obj *str = NULL;
  int is_url;

  if (pdf_is_string(ctx, file_spec))
    str = file_spec;
  else if (pdf_is_dict(ctx, file_spec))
    (void)get_file_stream_and_name(ctx, file_spec, &str);

  if (!pdf_is_string(ctx, str))
  {
    fz_warn(ctx, "cannot parse file specification");
    return NULL;
  }

  is_url = pdf_dict_get(ctx, file_spec, PDF_NAME(FS)) == PDF_NAME(URL);

  if (is_url)
    return pdf_parse_link_dest_to_file_with_uri(ctx, doc, pdf_to_text_string(ctx, str), dest);
  else
    return pdf_parse_link_dest_to_file_with_path(ctx, doc, pdf_to_text_string(ctx, str), dest, is_remote);
}

int
pdf_is_filespec(fz_context *ctx, pdf_obj *fs)
{
  pdf_obj *name;
  pdf_obj *type = pdf_dict_get(ctx, fs, PDF_NAME(Type));

  // Note: allow "FileSpec" as a common mis-capitalization
  if (type != PDF_NAME(Filespec) && type != PDF_NAME(FileSpec))
    return 0;

  (void)get_file_stream_and_name(ctx, fs, &name);

  return name != NULL;
}

int
pdf_is_embedded_file(fz_context *ctx, pdf_obj *fs)
{
  pdf_obj *type = pdf_dict_get(ctx, fs, PDF_NAME(Type));

  // Note: allow "FileSpec" as a common mis-capitalization
  if (type != PDF_NAME(Filespec) && type != PDF_NAME(FileSpec))
    return 0;

  return pdf_is_stream(ctx, get_file_stream_and_name(ctx, fs, NULL));
}

void
pdf_get_filespec_params(fz_context *ctx, pdf_obj *fs, pdf_filespec_params *out)
{
  pdf_obj *file, *params, *filename, *subtype;
  if (!out)
    return;

  memset(out, 0, sizeof(*out));
  out->created = -1;
  out->modified = -1;
  out->size = -1;

  file = get_file_stream_and_name(ctx, fs, &filename);
  if (!pdf_is_stream(ctx, file))
    return;

  params = pdf_dict_get(ctx, file, PDF_NAME(Params));
  out->filename = pdf_to_text_string(ctx, filename);

  subtype = pdf_dict_get(ctx, file, PDF_NAME(Subtype));
  if (!subtype)
    out->mimetype = "application/octet-stream";
  else
    out->mimetype = pdf_to_name(ctx, subtype);
  out->size = pdf_dict_get_int(ctx, params, PDF_NAME(Size));
  out->created = pdf_dict_get_date(ctx, params, PDF_NAME(CreationDate));
  out->modified = pdf_dict_get_date(ctx, params, PDF_NAME(ModDate));
}

fz_buffer *
pdf_load_embedded_file_contents(fz_context *ctx, pdf_obj *fs)
{
  pdf_obj *file = get_file_stream_and_name(ctx, fs, NULL);

  if (!pdf_is_stream(ctx, file))
    return NULL;

  return pdf_load_stream(ctx, file);
}

int
pdf_verify_embedded_file_checksum(fz_context *ctx, pdf_obj *fs)
{
  unsigned char digest[16];
  pdf_obj *params;
  const char *checksum;
  fz_buffer *contents = NULL;
  int valid = 0;
  size_t len;
  pdf_obj *file = get_file_stream_and_name(ctx, fs, NULL);

  fz_var(contents);

  if (!pdf_is_stream(ctx, file))
    return 1;

  params = pdf_dict_get(ctx, file, PDF_NAME(Params));
  checksum = pdf_dict_get_string(ctx, params, PDF_NAME(CheckSum), &len);
  if (!checksum || strlen(checksum) == 0)
    return 1;

  valid = 0;

  fz_try(ctx)
  {
    contents = pdf_load_stream(ctx, file);
    fz_md5_buffer(ctx, contents, digest);
    if (len == nelem(digest) && !memcmp(digest, checksum, nelem(digest)))
      valid = 1;
  }
  fz_always(ctx)
    fz_drop_buffer(ctx, contents);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return valid;
}

static const char *
pdf_guess_mime_type_from_file_name(fz_context *ctx, const char *filename)
{
  const char *ext = filename ? strrchr(filename, '.') : NULL;
  if (ext)
  {
    if (!fz_strcasecmp(ext, ".pdf")) return "application/pdf";
    if (!fz_strcasecmp(ext, ".xml")) return "application/xml";
    if (!fz_strcasecmp(ext, ".zip")) return "application/zip";
    if (!fz_strcasecmp(ext, ".tar")) return "application/x-tar";

    /* Text */
    if (!fz_strcasecmp(ext, ".txt")) return "text/plain";
    if (!fz_strcasecmp(ext, ".rtf")) return "application/rtf";
    if (!fz_strcasecmp(ext, ".csv")) return "text/csv";
    if (!fz_strcasecmp(ext, ".html")) return "text/html";
    if (!fz_strcasecmp(ext, ".htm")) return "text/html";
    if (!fz_strcasecmp(ext, ".css")) return "text/css";

    /* Office */
    if (!fz_strcasecmp(ext, ".doc")) return "application/msword";
    if (!fz_strcasecmp(ext, ".ppt")) return "application/vnd.ms-powerpoint";
    if (!fz_strcasecmp(ext, ".xls")) return "application/vnd.ms-excel";
    if (!fz_strcasecmp(ext, ".docx")) return "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
    if (!fz_strcasecmp(ext, ".pptx")) return "application/vnd.openxmlformats-officedocument.presentationml.presentation";
    if (!fz_strcasecmp(ext, ".xlsx")) return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
    if (!fz_strcasecmp(ext, ".odt")) return "application/vnd.oasis.opendocument.text";
    if (!fz_strcasecmp(ext, ".odp")) return "application/vnd.oasis.opendocument.presentation";
    if (!fz_strcasecmp(ext, ".ods")) return "application/vnd.oasis.opendocument.spreadsheet";

    /* Image */
    if (!fz_strcasecmp(ext, ".bmp")) return "image/bmp";
    if (!fz_strcasecmp(ext, ".gif")) return "image/gif";
    if (!fz_strcasecmp(ext, ".jpeg")) return "image/jpeg";
    if (!fz_strcasecmp(ext, ".jpg")) return "image/jpeg";
    if (!fz_strcasecmp(ext, ".png")) return "image/png";
    if (!fz_strcasecmp(ext, ".svg")) return "image/svg+xml";
    if (!fz_strcasecmp(ext, ".tif")) return "image/tiff";
    if (!fz_strcasecmp(ext, ".tiff")) return "image/tiff";

    /* Sound */
    if (!fz_strcasecmp(ext, ".flac")) return "audio/flac";
    if (!fz_strcasecmp(ext, ".mp3")) return "audio/mpeg";
    if (!fz_strcasecmp(ext, ".ogg")) return "audio/ogg";
    if (!fz_strcasecmp(ext, ".wav")) return "audio/wav";

    /* Movie */
    if (!fz_strcasecmp(ext, ".avi")) return "video/x-msvideo";
    if (!fz_strcasecmp(ext, ".mov")) return "video/quicktime";
    if (!fz_strcasecmp(ext, ".mp4")) return "video/mp4";
    if (!fz_strcasecmp(ext, ".webm")) return "video/webm";
  }
  return "application/octet-stream";
}

pdf_obj *
pdf_add_embedded_file(fz_context *ctx, pdf_document *doc,
  const char *filename, const char *mimetype, fz_buffer *contents,
  int64_t created, int64_t modified, int add_checksum)
{
  pdf_obj *file = NULL;
  pdf_obj *filespec = NULL;
  pdf_obj *params = NULL;

  fz_var(file);
  fz_var(filespec);

  if (!mimetype)
    mimetype = pdf_guess_mime_type_from_file_name(ctx, filename);

  pdf_begin_operation(ctx, doc, "Embed file");
  fz_try(ctx)
  {
    file = pdf_add_new_dict(ctx, doc, 3);
    pdf_dict_put(ctx, file, PDF_NAME(Type), PDF_NAME(EmbeddedFile));
    pdf_dict_put_name(ctx, file, PDF_NAME(Subtype), mimetype);
    pdf_update_stream(ctx, doc, file, contents, 0);

    params = pdf_dict_put_dict(ctx, file, PDF_NAME(Params), 4);
    pdf_dict_put_int(ctx, params, PDF_NAME(Size), fz_buffer_storage(ctx, contents, NULL));
    if (created >= 0)
        pdf_dict_put_date(ctx, params, PDF_NAME(CreationDate), created);
    if (modified >= 0)
        pdf_dict_put_date(ctx, params, PDF_NAME(ModDate), modified);
    if (add_checksum)
    {
      unsigned char digest[16];
      fz_md5_buffer(ctx, contents, digest);
        pdf_dict_put_string(ctx, params, PDF_NAME(CheckSum), (const char *) digest, nelem(digest));
    }

    filespec = pdf_add_filespec(ctx, doc, filename, file);

    pdf_end_operation(ctx, doc);
  }
  fz_always(ctx)
    pdf_drop_obj(ctx, file);
  fz_catch(ctx)
  {
    pdf_drop_obj(ctx, filespec);
    pdf_abandon_operation(ctx, doc);
    fz_rethrow(ctx);
  }

  return filespec;
}

char *
pdf_parse_link_action(fz_context *ctx, pdf_document *doc, pdf_obj *action, int pagenum)
{
  pdf_obj *obj, *dest, *file_spec;

  if (!action)
    return NULL;

  obj = pdf_dict_get(ctx, action, PDF_NAME(S));
  if (pdf_name_eq(ctx, PDF_NAME(GoTo), obj))
  {
    dest = pdf_dict_get(ctx, action, PDF_NAME(D));
    return pdf_parse_link_dest(ctx, doc, dest);
  }
  else if (pdf_name_eq(ctx, PDF_NAME(URI), obj))
  {
    /* URI entries are ASCII strings */
    const char *uri = pdf_dict_get_text_string(ctx, action, PDF_NAME(URI));
    if (!fz_is_external_link(ctx, uri))
    {
      pdf_obj *uri_base_obj = pdf_dict_getp(ctx, pdf_trailer(ctx, doc), "Root/URI/Base");
      const char *uri_base = uri_base_obj ? pdf_to_text_string(ctx, uri_base_obj) : "file://";
      char *new_uri = Memento_label(fz_malloc(ctx, strlen(uri_base) + strlen(uri) + 1), "link_action");
      strcpy(new_uri, uri_base);
      strcat(new_uri, uri);
      return new_uri;
    }
    return fz_strdup(ctx, uri);
  }
  else if (pdf_name_eq(ctx, PDF_NAME(Launch), obj))
  {
    file_spec = pdf_dict_get(ctx, action, PDF_NAME(F));
    return convert_file_spec_to_URI(ctx, doc, file_spec, NULL, 0);
  }
  else if (pdf_name_eq(ctx, PDF_NAME(GoToR), obj))
  {
    dest = pdf_dict_get(ctx, action, PDF_NAME(D));
    file_spec = pdf_dict_get(ctx, action, PDF_NAME(F));
    return convert_file_spec_to_URI(ctx, doc, file_spec, dest, 1);
  }
  else if (pdf_name_eq(ctx, PDF_NAME(Named), obj))
  {
    dest = pdf_dict_get(ctx, action, PDF_NAME(N));

    if (pdf_name_eq(ctx, PDF_NAME(FirstPage), dest))
      pagenum = 0;
    else if (pdf_name_eq(ctx, PDF_NAME(LastPage), dest))
      pagenum = pdf_count_pages(ctx, doc) - 1;
    else if (pdf_name_eq(ctx, PDF_NAME(PrevPage), dest) && pagenum >= 0)
    {
      if (pagenum > 0)
        pagenum--;
    }
    else if (pdf_name_eq(ctx, PDF_NAME(NextPage), dest) && pagenum >= 0)
    {
      if (pagenum < pdf_count_pages(ctx, doc) - 1)
        pagenum++;
    }
    else
      return NULL;

    return fz_asprintf(ctx, "#page=%d", pagenum + 1);
  }

  return NULL;
}

static void pdf_drop_link_imp(fz_context *ctx, fz_link *link)
{
  pdf_drop_obj(ctx, ((pdf_link *) link)->obj);
}

static void pdf_set_link_rect(fz_context *ctx, fz_link *link_, fz_rect rect)
{
  pdf_link *link = (pdf_link *) link_;
  if (link == NULL)
    return;

  if (!link->page)
    fz_throw(ctx, FZ_ERROR_ARGUMENT, "link not bound to a page");

  pdf_begin_operation(ctx, link->page->doc, "Set link rectangle");

  fz_try(ctx)
  {
    pdf_dict_put_rect(ctx, link->obj, PDF_NAME(Rect), rect);
    link->super.rect = rect;
    pdf_end_operation(ctx, link->page->doc);
  }
  fz_catch(ctx)
  {
    pdf_abandon_operation(ctx, link->page->doc);
    fz_rethrow(ctx);
  }
}

static void pdf_set_link_uri(fz_context *ctx, fz_link *link_, const char *uri)
{
  pdf_link *link = (pdf_link *) link_;
  if (link == NULL)
    return;

  if (!link->page)
    fz_throw(ctx, FZ_ERROR_ARGUMENT, "link not bound to a page");

  pdf_begin_operation(ctx, link->page->doc, "Set link uri");

  fz_try(ctx)
  {
    pdf_dict_put_drop(ctx, link->obj, PDF_NAME(A),
        pdf_new_action_from_link(ctx, link->page->doc, uri));
    fz_free(ctx, link->super.uri);
    link->super.uri = fz_strdup(ctx, uri);
    pdf_end_operation(ctx, link->page->doc);
  }
  fz_catch(ctx)
  {
    pdf_abandon_operation(ctx, link->page->doc);
    fz_rethrow(ctx);
  }
}

fz_link *pdf_new_link(fz_context *ctx, pdf_page *page, fz_rect rect, const char *uri, pdf_obj *obj)
{
  pdf_link *link = fz_new_derived_link(ctx, pdf_link, rect, uri);
  link->super.drop = pdf_drop_link_imp;
  link->super.set_rect_fn = pdf_set_link_rect;
  link->super.set_uri_fn = pdf_set_link_uri;
  link->page = page; /* only borrowed, as the page owns the link */
  link->obj = pdf_keep_obj(ctx, obj);
  return &link->super;
}

static fz_link *
pdf_load_link(fz_context *ctx, pdf_document *doc, pdf_page *page, pdf_obj *dict, int pagenum, fz_matrix page_ctm)
{
  pdf_obj *action;
  pdf_obj *obj;
  fz_rect bbox;
  char *uri;
  fz_link *link = NULL;

  obj = pdf_dict_get(ctx, dict, PDF_NAME(Subtype));
  if (!pdf_name_eq(ctx, obj, PDF_NAME(Link)))
    return NULL;

  obj = pdf_dict_get(ctx, dict, PDF_NAME(Rect));
  if (!obj)
    return NULL;

  bbox = pdf_to_rect(ctx, obj);
  bbox = fz_transform_rect(bbox, page_ctm);

  obj = pdf_dict_get(ctx, dict, PDF_NAME(Dest));
  if (obj)
    uri = pdf_parse_link_dest(ctx, doc, obj);
  else
  {
    action = pdf_dict_get(ctx, dict, PDF_NAME(A));
    /* fall back to additional action button's down/up action */
    if (!action)
      action = pdf_dict_geta(ctx, pdf_dict_get(ctx, dict, PDF_NAME(AA)), PDF_NAME(U), PDF_NAME(D));
    uri = pdf_parse_link_action(ctx, doc, action, pagenum);
  }

  if (!uri)
    return NULL;

  fz_try(ctx)
    link = (fz_link *) pdf_new_link(ctx, page, bbox, uri, dict);
  fz_always(ctx)
    fz_free(ctx, uri);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return link;
}

fz_link *
pdf_load_link_annots(fz_context *ctx, pdf_document *doc, pdf_page *page, pdf_obj *annots, int pagenum, fz_matrix page_ctm)
{
  fz_link *head, *tail;
  pdf_obj *obj;
  int i, n;

  fz_var(head);

  head = tail = NULL;

  n = pdf_array_len(ctx, annots);
  for (i = 0; i < n; i++)
  {
    fz_link *link;

    /* FIXME: Move the try/catch out of the loop for performance? */
    fz_try(ctx)
    {
      obj = pdf_array_get(ctx, annots, i);
      link = pdf_load_link(ctx, doc, page, obj, pagenum, page_ctm);
      if (!head)
        head = tail = link;
      else if (link)
      {
        tail->next = link;
        tail = link;
      }
    }
    fz_catch(ctx)
    {
      if (fz_caught(ctx) == FZ_ERROR_TRYLATER || fz_caught(ctx) == FZ_ERROR_SYSTEM)
      {
        fz_drop_link(ctx, head);
        fz_rethrow(ctx);
      }
      fz_report_error(ctx);
    }

  }

  return head;
}

void pdf_nuke_links(fz_context *ctx, pdf_page *page)
{
  pdf_link *link;
  link = (pdf_link *) page->links;
  while (link)
  {
    pdf_drop_obj(ctx, link->obj);
    link->obj = NULL;
    link = (pdf_link *) link->super.next;
  }
  fz_drop_link(ctx, page->links);
  page->links = NULL;
}

void pdf_sync_links(fz_context *ctx, pdf_page *page)
{
  pdf_obj *annots;

  pdf_nuke_links(ctx, page);

  annots = pdf_dict_get(ctx, page->obj, PDF_NAME(Annots));
  if (annots)
  {
    fz_rect page_cropbox;
    fz_matrix page_ctm;
    pdf_page_transform(ctx, page, &page_cropbox, &page_ctm);
    page->links = pdf_load_link_annots(ctx, page->doc, page, annots, page->super.number, page_ctm);
  }
}

#define isnanorzero(x) (isnan(x) || (x) == 0)

static char*
format_explicit_dest_link_uri(fz_context *ctx, const char *schema, const char *uri, fz_link_dest dest)
{
  int pageno = dest.loc.page < 0 ? 1 : dest.loc.page + 1;
  int has_frag;

  if (!schema)
    schema = "";
  if (!uri)
    uri = "";

  has_frag = !!strchr(uri, '#');

  switch (dest.type)
  {
  default:
    return fz_asprintf(ctx, "%s%s%cpage=%d", schema, uri, "#&"[has_frag], pageno);
  case FZ_LINK_DEST_FIT:
    return fz_asprintf(ctx, "%s%s%cpage=%d&view=Fit", schema, uri, "#&"[has_frag], pageno);
  case FZ_LINK_DEST_FIT_B:
    return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitB", schema, uri, "#&"[has_frag], pageno);
  case FZ_LINK_DEST_FIT_H:
    if (isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitH", schema, uri, "#&"[has_frag], pageno);
    else
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitH,%g", schema, uri, "#&"[has_frag], pageno, dest.y);
  case FZ_LINK_DEST_FIT_BH:
    if (isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitBH", schema, uri, "#&"[has_frag], pageno);
    else
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitBH,%g", schema, uri, "#&"[has_frag], pageno, dest.y);
  case FZ_LINK_DEST_FIT_V:
    if (isnan(dest.x))
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitV", schema, uri, "#&"[has_frag], pageno);
    else
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitV,%g", schema, uri, "#&"[has_frag], pageno, dest.x);
  case FZ_LINK_DEST_FIT_BV:
    if (isnan(dest.x))
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitBV", schema, uri, "#&"[has_frag], pageno);
    else
      return fz_asprintf(ctx, "%s%s%cpage=%d&view=FitBV,%g", schema, uri, "#&"[has_frag], pageno, dest.x);
  case FZ_LINK_DEST_XYZ:
    if (!isnanorzero(dest.zoom) && !isnan(dest.x) && !isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=%g,%g,%g", schema, uri, "#&"[has_frag], pageno, dest.zoom, dest.x, dest.y);
    else if (!isnanorzero(dest.zoom) && !isnan(dest.x) && isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=%g,%g,nan", schema, uri, "#&"[has_frag], pageno, dest.zoom, dest.x);
    else if (!isnanorzero(dest.zoom) && isnan(dest.x) && !isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=%g,nan,%g", schema, uri, "#&"[has_frag], pageno, dest.zoom, dest.y);
    else if (!isnanorzero(dest.zoom) && isnan(dest.x) && isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=%g,nan,nan", schema, uri, "#&"[has_frag], pageno, dest.zoom);
    else if (isnanorzero(dest.zoom)&& !isnan(dest.x) && !isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=nan,%g,%g", schema, uri, "#&"[has_frag], pageno, dest.x, dest.y);
    else if (isnanorzero(dest.zoom) && !isnan(dest.x) && isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=nan,%g,nan", schema, uri, "#&"[has_frag], pageno, dest.x);
    else if (isnanorzero(dest.zoom) && isnan(dest.x) && !isnan(dest.y))
      return fz_asprintf(ctx, "%s%s%cpage=%d&zoom=nan,nan,%g", schema, uri, "#&"[has_frag], pageno, dest.y);
    else
      return fz_asprintf(ctx, "%s%s%cpage=%d", schema, uri, "#&"[has_frag], pageno);
  case FZ_LINK_DEST_FIT_R:
    return fz_asprintf(ctx, "%s%s%cpage=%d&viewrect=%g,%g,%g,%g", schema, uri, "#&"[has_frag], pageno,
      dest.x, dest.y, dest.w, dest.h);
  }
}

static char*
format_named_dest_link_uri(fz_context *ctx, const char *schema, const char *path, const char *name)
{
  if (!schema)
    schema = "";
  if (!path)
    path = "";
  return fz_asprintf(ctx, "%s%s#nameddest=%s", schema, path, name);
}

static char *
pdf_format_remote_link_uri_from_name(fz_context *ctx, const char *name)
{
  char *encoded_name = NULL;
  char *uri = NULL;

  encoded_name = fz_encode_uri_component(ctx, name);
  fz_try(ctx)
    uri = format_named_dest_link_uri(ctx, NULL, NULL, encoded_name);
  fz_always(ctx)
    fz_free(ctx, encoded_name);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return uri;
}

static int
is_file_uri(fz_context *ctx, const char *uri)
{
  return uri && !strncmp(uri, "file:", 5);
}

static int
has_explicit_dest(fz_context *ctx, const char *uri)
{
  const char *fragment;
  if (uri == NULL || (fragment = strchr(uri, '#')) == NULL)
    return 0;
  return strstr(fragment, "page=") != NULL;
}

static int
has_named_dest(fz_context *ctx, const char *uri)
{
  const char *fragment;
  if (uri == NULL || (fragment = strchr(uri, '#')) == NULL)
    return 0;
  return (strstr(fragment, "nameddest=") || !has_explicit_dest(ctx, uri));
}

static char *
parse_file_uri_path(fz_context *ctx, const char *uri)
{
  char *frag, *path, *temp;

  temp = fz_strdup(ctx, uri + 5);
  fz_try(ctx)
  {
    frag = strchr(temp, '#');
    if (frag)
      *frag = 0;
    path = fz_decode_uri_component(ctx, temp);
    fz_cleanname(path);
  }
  fz_always(ctx)
    fz_free(ctx, temp);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return path;
}

static char *
parse_uri_named_dest(fz_context *ctx, const char *uri)
{
  const char *nameddest_s = strstr(uri, "nameddest=");
  if (nameddest_s)
  {
    char *temp = fz_strdup(ctx, nameddest_s + 10);
    char *dest;
    fz_try(ctx)
    {
      char *ampersand = strchr(temp, '&');
      if (ampersand)
        *ampersand = 0;
      dest = fz_decode_uri_component(ctx, temp);
    }
    fz_always(ctx)
      fz_free(ctx, temp);
    fz_catch(ctx)
      fz_rethrow(ctx);
    return dest;
  }

  // We know there must be a # because of the check in has_named_dest
  return fz_decode_uri_component(ctx, strchr(uri, '#') + 1);
}

static float next_float(const char *str, int eatcomma, const char **end)
{
  if (eatcomma && *str == ',')
    ++str;
  return fz_strtof(str, (char **) end);
}

static fz_link_dest
pdf_new_explicit_dest_from_uri(fz_context *ctx, pdf_document *doc, const char *uri)
{
  const char *page, *rect, *zoom, *view;
  fz_link_dest val = fz_make_link_dest_none();

  uri = uri ? strchr(uri, '#') : NULL;

  page = uri ? strstr(uri, "page=") : NULL;
  rect = uri ? strstr(uri, "viewrect=") : NULL;
  zoom = uri ? strstr(uri, "zoom=") : NULL;
  view = uri ? strstr(uri, "view=") : NULL;

  val.loc.chapter = 0;

  if (page)
  {
    val.loc.page = fz_atoi(page+5) - 1;
    val.loc.page = fz_maxi(val.loc.page, 0);
  }
  else
    val.loc.page = 0;

  if (rect)
  {
    rect += 9;
    val.type = FZ_LINK_DEST_FIT_R;
    val.x = next_float(rect, 0, &rect);
    val.y = next_float(rect, 1, &rect);
    val.w = next_float(rect, 1, &rect);
    val.h = next_float(rect, 1, &rect);
  }
  else if (zoom)
  {
    zoom += 5;
    val.type = FZ_LINK_DEST_XYZ;
    val.zoom = next_float(zoom, 0, &zoom);
    val.x = next_float(zoom, 1, &zoom);
    val.y = next_float(zoom, 1, &zoom);
    if (val.zoom <= 0 || isinf(val.zoom))
      val.zoom = 100;
  }
  else if (view)
  {
    view += 5;
    if (!fz_strncasecmp(view, "FitH", 4))
    {
      view += 4;
      val.type = FZ_LINK_DEST_FIT_H;
      val.y = strchr(view, ',') ? next_float(view, 1, &view) : NAN;
    }
    else if (!fz_strncasecmp(view, "FitBH", 5))
    {
      view += 5;
      val.type = FZ_LINK_DEST_FIT_BH;
      val.y = strchr(view, ',') ? next_float(view, 1, &view) : NAN;
    }
    else if (!fz_strncasecmp(view, "FitV", 4))
    {
      view += 4;
      val.type = FZ_LINK_DEST_FIT_V;
      val.x = strchr(view, ',') ? next_float(view, 1, &view) : NAN;
    }
    else if (!fz_strncasecmp(view, "FitBV", 5))
    {
      view += 5;
      val.type = FZ_LINK_DEST_FIT_BV;
      val.x = strchr(view, ',') ? next_float(view, 1, &view) : NAN;
    }
    else if (!fz_strncasecmp(view, "FitB", 4))
    {
      val.type = FZ_LINK_DEST_FIT_B;
    }
    else if (!fz_strncasecmp(view, "Fit", 3))
    {
      val.type = FZ_LINK_DEST_FIT;
    }
  }

  return val;
}

char *
pdf_append_named_dest_to_uri(fz_context *ctx, const char *uri, const char *name)
{
  char *encoded_name = NULL;
  char *new_uri = NULL;
  int has_frag;

  if (!uri)
    uri = "";

  has_frag = !!strchr(uri, '#');

  encoded_name = fz_encode_uri_component(ctx, name);
  fz_try(ctx)
    new_uri = fz_asprintf(ctx, "%s%cnameddest=%s", uri, "#&"[has_frag], encoded_name);
  fz_always(ctx)
    fz_free(ctx, encoded_name);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return new_uri;
}

char *
pdf_append_explicit_dest_to_uri(fz_context *ctx, const char *uri, fz_link_dest dest)
{
  return format_explicit_dest_link_uri(ctx, NULL, uri, dest);
}

char *
pdf_new_uri_from_path_and_named_dest(fz_context *ctx, const char *path, const char *name)
{
  const char *schema = NULL;
  char *encoded_name = NULL;
  char *encoded_path = NULL;
  char *uri = NULL;

  fz_var(encoded_name);
  fz_var(encoded_path);

  fz_try(ctx)
  {
    if (path && strlen(path) > 0)
    {
      if (path[0] == '/')
        schema = "file://";
      else
        schema = "file:";
      encoded_path = fz_encode_uri_pathname(ctx, path);
      fz_cleanname(encoded_path);
    }

    encoded_name = fz_encode_uri_component(ctx, name);
    uri = format_named_dest_link_uri(ctx, schema, encoded_path, encoded_name);
  }
  fz_always(ctx)
  {
    fz_free(ctx, encoded_name);
    fz_free(ctx, encoded_path);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);

  return uri;
}

char *
pdf_new_uri_from_path_and_explicit_dest(fz_context *ctx, const char *path, fz_link_dest dest)
{
  const char *schema = NULL;
  char *encoded_path = NULL;
  char *uri = NULL;

  fz_var(encoded_path);

  fz_try(ctx)
  {
    if (path && strlen(path) > 0)
    {
      if (path[0] == '/')
        schema = "file://";
      else
        schema = "file:";
      encoded_path = fz_encode_uri_pathname(ctx, path);
      fz_cleanname(encoded_path);
    }

    uri = format_explicit_dest_link_uri(ctx, schema, encoded_path, dest);
  }
  fz_always(ctx)
    fz_free(ctx, encoded_path);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return uri;
}

char *
pdf_new_uri_from_explicit_dest(fz_context *ctx, fz_link_dest dest)
{
  return format_explicit_dest_link_uri(ctx, NULL, NULL, dest);
}

char *
pdf_parse_link_dest(fz_context *ctx, pdf_document *doc, pdf_obj *dest)
{
  if (pdf_is_array(ctx, dest) && pdf_array_len(ctx, dest) >= 1)
  {
    fz_link_dest destination = fz_make_link_dest_none();
    populate_destination(ctx, doc, dest, 0, &destination);
    return format_explicit_dest_link_uri(ctx, NULL, NULL, destination);
  }
  else if (pdf_is_name(ctx, dest))
  {
    const char *name = pdf_to_name(ctx, dest);
    return pdf_format_remote_link_uri_from_name(ctx, name);
  }
  else if (pdf_is_string(ctx, dest))
  {
    const char *name = pdf_to_text_string(ctx, dest);
    return pdf_format_remote_link_uri_from_name(ctx, name);
  }
  else
  {
    fz_warn(ctx, "invalid link destination");
    return NULL;
  }
}

static pdf_obj *
pdf_add_filespec_from_link(fz_context *ctx, pdf_document *doc, const char *uri)
{
  char *file = NULL;
  pdf_obj *filespec = NULL;
  fz_var(file);
  fz_try(ctx)
  {
    if (is_file_uri(ctx, uri))
    {
      file = parse_file_uri_path(ctx, uri);
      filespec = pdf_add_filespec(ctx, doc, file, NULL);
    }
    else if (fz_is_external_link(ctx, uri))
      filespec = pdf_add_url_filespec(ctx, doc, uri);
    else
      fz_throw(ctx, FZ_ERROR_ARGUMENT, "can not add non-uri as file specification");
  }
  fz_always(ctx)
    fz_free(ctx, file);
  fz_catch(ctx)
    fz_rethrow(ctx);
  return filespec;
}


pdf_obj *
pdf_new_action_from_link(fz_context *ctx, pdf_document *doc, const char *uri)
{
  pdf_obj *action = pdf_new_dict(ctx, doc, 2);
  char *file = NULL;

  fz_var(file);

  if (uri == NULL)
    return NULL;

  fz_try(ctx)
  {
    if (uri[0] == '#')
    {
      pdf_dict_put(ctx, action, PDF_NAME(S), PDF_NAME(GoTo));
      pdf_dict_put_drop(ctx, action, PDF_NAME(D),
        pdf_new_dest_from_link(ctx, doc, uri, 0));
    }
    else if (!strncmp(uri, "file:", 5))
    {
      pdf_dict_put(ctx, action, PDF_NAME(S), PDF_NAME(GoToR));
      pdf_dict_put_drop(ctx, action, PDF_NAME(D),
        pdf_new_dest_from_link(ctx, doc, uri, 1));
      pdf_dict_put_drop(ctx, action, PDF_NAME(F),
        pdf_add_filespec_from_link(ctx, doc, uri));
    }
    else if (fz_is_external_link(ctx, uri))
    {
      pdf_dict_put(ctx, action, PDF_NAME(S), PDF_NAME(URI));
      pdf_dict_put_text_string(ctx, action, PDF_NAME(URI), uri);
    }
    else
      fz_throw(ctx, FZ_ERROR_ARGUMENT, "unsupported link URI type");
  }
  fz_always(ctx)
    fz_free(ctx, file);
  fz_catch(ctx)
  {
    pdf_drop_obj(ctx, action);
    fz_rethrow(ctx);
  }

  return action;
}


pdf_obj *pdf_add_filespec(fz_context *ctx, pdf_document *doc, const char *filename, pdf_obj *embedded_file)
{
  pdf_obj *filespec = NULL;
  char *asciiname = NULL;
  const char *s;
  size_t len, i;

  if (!filename)
    filename = "";

  fz_var(asciiname);
  fz_var(filespec);

  fz_try(ctx)
  {
    len = strlen(filename) + 1;
    asciiname = fz_malloc(ctx, len);

    for (i = 0, s = filename; *s && i + 1 < len; ++i)
    {
      int c;
      s += fz_chartorune(&c, s);
      asciiname[i] = (c >= 32 && c <= 126) ? c : '_';
    }
    asciiname[i] = 0;

    filespec = pdf_add_new_dict(ctx, doc, 4);
    pdf_dict_put(ctx, filespec, PDF_NAME(Type), PDF_NAME(Filespec));
    pdf_dict_put_text_string(ctx, filespec, PDF_NAME(F), asciiname);
    pdf_dict_put_text_string(ctx, filespec, PDF_NAME(UF), filename);
    if (embedded_file)
    {
      pdf_obj *ef = pdf_dict_put_dict(ctx, filespec, PDF_NAME(EF), 1);
      pdf_dict_put(ctx, ef, PDF_NAME(F), embedded_file);
      pdf_dict_put(ctx, ef, PDF_NAME(UF), embedded_file);
    }
  }
  fz_always(ctx)
    fz_free(ctx, asciiname);
  fz_catch(ctx)
    fz_rethrow(ctx);

  return filespec;
}

pdf_obj *pdf_add_url_filespec(fz_context *ctx, pdf_document *doc, const char *url)
{
  pdf_obj *filespec = pdf_add_new_dict(ctx, doc, 3);
  fz_try(ctx)
  {
    pdf_dict_put(ctx, filespec, PDF_NAME(Type), PDF_NAME(Filespec));
    pdf_dict_put(ctx, filespec, PDF_NAME(FS), PDF_NAME(URL));
    pdf_dict_put_text_string(ctx, filespec, PDF_NAME(F), url);
  }
  fz_catch(ctx)
  {
    pdf_drop_obj(ctx, filespec);
    fz_rethrow(ctx);
  }
  return filespec;
}

pdf_obj *
pdf_new_dest_from_link(fz_context *ctx, pdf_document *doc, const char *uri, int is_remote)
{
  pdf_obj *dest = NULL;

  fz_var(dest);

  if (has_named_dest(ctx, uri))
  {
    char *name = parse_uri_named_dest(ctx, uri);

    fz_try(ctx)
      dest = pdf_new_text_string(ctx, name);
    fz_always(ctx)
      fz_free(ctx, name);
    fz_catch(ctx)
      fz_rethrow(ctx);
  }
  else
  {
    fz_matrix ctm, invctm;
    fz_link_dest val;
    pdf_obj *pageobj;
    fz_point p;
    fz_rect r;

    fz_try(ctx)
    {
      val = pdf_new_explicit_dest_from_uri(ctx, doc, uri);

      dest = pdf_new_array(ctx, doc, 6);

      if (is_remote)
      {
        pdf_array_push_int(ctx, dest, val.loc.page);
        invctm = fz_identity;
      }
      else
      {
        pageobj = pdf_lookup_page_obj(ctx, doc, val.loc.page);
        pdf_array_push(ctx, dest, pageobj);

        pdf_page_obj_transform(ctx, pageobj, NULL, &ctm);
        invctm = fz_invert_matrix(ctm);
      }

      switch (val.type)
      {
      default:
      case FZ_LINK_DEST_FIT:
        pdf_array_push(ctx, dest, PDF_NAME(Fit));
        break;
      case FZ_LINK_DEST_FIT_H:
        p = fz_transform_point_xy(0, val.y, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(FitH));
        if (isnan(p.y))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.y);
        break;
      case FZ_LINK_DEST_FIT_BH:
        p = fz_transform_point_xy(0, val.y, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(FitBH));
        if (isnan(p.y))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.y);
        break;
      case FZ_LINK_DEST_FIT_V:
        p = fz_transform_point_xy(val.x, 0, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(FitV));
        if (isnan(p.x))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.x);
        break;
      case FZ_LINK_DEST_FIT_BV:
        p = fz_transform_point_xy(val.x, 0, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(FitBV));
        if (isnan(p.x))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.x);
        break;
      case FZ_LINK_DEST_XYZ:
        if (invctm.a == 0 && invctm.d == 0)
        {
          /* Rotating by 90 or 270 degrees. */
          p = fz_transform_point_xy(isnan(val.x) ? 0 : val.x, isnan(val.y) ? 0 : val.y, invctm);
          if (isnan(val.x))
            p.y = val.x;
          if (isnan(val.y))
            p.x = val.y;
        }
        else if (invctm.b == 0 && invctm.c == 0)
        {
          /* No rotation, or 180 degrees. */
          p = fz_transform_point_xy(isnan(val.x) ? 0 : val.x, isnan(val.y) ? 0 : val.y, invctm);
          if (isnan(val.x))
            p.x = val.x;
          if (isnan(val.y))
            p.y = val.y;
        }
        else
          p = fz_transform_point_xy(val.x, val.y, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(XYZ));
        if (isnan(p.x))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.x);
        if (isnan(p.y))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, p.y);
        if (isnan(val.zoom))
          pdf_array_push(ctx, dest, PDF_NULL);
        else
          pdf_array_push_real(ctx, dest, val.zoom / 100);
        break;
      case FZ_LINK_DEST_FIT_R:
        r.x0 = val.x;
        r.y0 = val.y;
        r.x1 = val.x + val.w;
        r.y1 = val.y + val.h;
        r = fz_transform_rect(r, invctm);
        pdf_array_push(ctx, dest, PDF_NAME(FitR));
        pdf_array_push_real(ctx, dest, r.x0);
        pdf_array_push_real(ctx, dest, r.y0);
        pdf_array_push_real(ctx, dest, r.x1);
        pdf_array_push_real(ctx, dest, r.y1);
        break;
      }
    }
    fz_catch(ctx)
    {
      pdf_drop_obj(ctx, dest);
      fz_rethrow(ctx);
    }
  }

  return dest;
}

fz_link_dest
pdf_resolve_link_dest(fz_context *ctx, pdf_document *doc, const char *uri)
{
  fz_link_dest dest = fz_make_link_dest_none();
  pdf_obj *page_obj;
  fz_matrix page_ctm;
  fz_rect mediabox;
  pdf_obj *needle = NULL;
  char *name = NULL;
  char *desturi = NULL;
  pdf_obj *destobj = NULL;

  fz_var(needle);
  fz_var(name);
  fz_var(desturi);

  fz_try(ctx)
  {
    if (has_explicit_dest(ctx, uri))
    {
      dest = pdf_new_explicit_dest_from_uri(ctx, doc, uri);
      if (!isnan(dest.x) || !isnan(dest.y) || !isnan(dest.w) || !isnan(dest.h))
      {
        page_obj = pdf_lookup_page_obj(ctx, doc, dest.loc.page);
        pdf_page_obj_transform(ctx, page_obj, &mediabox, &page_ctm);
        mediabox = fz_transform_rect(mediabox, page_ctm);

        /* clamp coordinates to remain on page */
        dest.x = fz_clamp(dest.x, 0, mediabox.x1 - mediabox.x0);
        dest.y = fz_clamp(dest.y, 0, mediabox.y1 - mediabox.y0);
        dest.w = fz_clamp(dest.w, 0, mediabox.x1 - dest.x);
        dest.h = fz_clamp(dest.h, 0, mediabox.y1 - dest.y);
      }
    }
    else if (has_named_dest(ctx, uri))
    {
      name = parse_uri_named_dest(ctx, uri);

      needle = pdf_new_text_string(ctx, name);
      destobj = resolve_dest(ctx, doc, needle);
      if (destobj)
      {
        fz_link_dest destdest;
        desturi = pdf_parse_link_dest(ctx, doc, destobj);
        destdest = pdf_resolve_link_dest(ctx, doc, desturi);
        if (dest.type == FZ_LINK_DEST_XYZ && isnan(dest.x) && isnan(dest.y) && isnan(dest.zoom))
          dest = destdest;
        else
          dest.loc = destdest.loc;
      }
    }
    else
      dest.loc.page = fz_atoi(uri) - 1;
  }
  fz_always(ctx)
  {
    fz_free(ctx, desturi);
    fz_free(ctx, name);
    pdf_drop_obj(ctx, needle);
  }
  fz_catch(ctx)
    fz_rethrow(ctx);

  return dest.loc.page >= 0 ? dest : fz_make_link_dest_none();
}

int
pdf_resolve_link(fz_context *ctx, pdf_document *doc, const char *uri, float *xp, float *yp)
{
  fz_link_dest dest = pdf_resolve_link_dest(ctx, doc, uri);
  if (xp) *xp = dest.x;
  if (yp) *yp = dest.y;
  return dest.loc.page;
}

Coverage Report

Created: 2026-11-12 07:07