OpenSystemsDevelopment / qpdf

Commit e62cf819fd8fcf9a0c04adf08a6104fdf8bedd2a

Authored by m-holger
1 parent c1150a44

Refactor `QPDFJob::handleUnderlaysAndOverlays`: streamline logic for handling pa… 

…ges, replace redundant variables, and improve code readability.
Inline Side-by-side
Showing 1 changed file with 16 additions and 15 deletions
libqpdf/QPDFJob.cc
  View file @e62cf81
... ... @@ -1995,6 +1995,8 @@ QPDFJob::handleUnderOverlay(QPDF& pdf)
1995 1995 validateUnderOverlay(pdf, &uo);
1996 1996 }
1997 1997  
  1998 + auto const& main_pages = pdf.getAllPages();
  1999 +
1998 2000 // First map key is 1-based page number. Second is index into the overlay/underlay vector. Watch
1999 2001 // out to not reverse the keys or be off by one.
2000 2002 std::map<int, std::map<size_t, std::vector<int>>> underlay_pagenos;
... ... @@ -2020,29 +2022,27 @@ QPDFJob::handleUnderOverlay(QPDF&amp; pdf)
2020 2022  
2021 2023 std::map<int, std::map<size_t, QPDFObjectHandle>> underlay_fo;
2022 2024 std::map<int, std::map<size_t, QPDFObjectHandle>> overlay_fo;
2023   - QPDFPageDocumentHelper main_pdh(pdf);
2024   - auto main_pages = main_pdh.getAllPages();
2025   - size_t main_npages = main_pages.size();
2026   - for (PageNo page; page.idx < main_npages; ++page) {
2027   - doIfVerbose(
2028   - [&](Pipeline& v, std::string const& prefix) { v << " page " << page.no << "\n"; });
2029   - if (underlay_pagenos[page.no].empty() && overlay_pagenos[page.no].empty()) {
  2025 + PageNo dest_page_no;
  2026 + for (QPDFPageObjectHelper dest_page: main_pages) {
  2027 + doIfVerbose([&](Pipeline& v, std::string const& prefix) {
  2028 + v << " page " << dest_page_no.no << "\n";
  2029 + });
  2030 + if (underlay_pagenos[dest_page_no.no].empty() && overlay_pagenos[dest_page_no.no].empty()) {
  2031 + ++dest_page_no;
2030 2032 continue;
2031 2033 }
2032 2034 // This code converts the original page, any underlays, and any overlays to form XObjects.
2033 2035 // Then it concatenates display of all underlays, the original page, and all overlays. Prior
2034 2036 // to 11.3.0, the original page contents were wrapped in q/Q, but this didn't work if the
2035 2037 // original page had unbalanced q/Q operators. See GitHub issue #904.
2036   - auto& dest_page = main_pages.at(page.idx);
2037   - auto dest_page_oh = dest_page.getObjectHandle();
2038 2038 auto this_page_fo = dest_page.getFormXObjectForPage();
2039 2039 // The resulting form xobject lazily reads the content from the original page, which we are
2040 2040 // going to replace. Therefore, we have to explicitly copy it.
2041 2041 auto content_data = this_page_fo.getRawStreamData();
2042 2042 this_page_fo.replaceStreamData(content_data, QPDFObjectHandle(), QPDFObjectHandle());
2043   - auto resources =
2044   - dest_page_oh.replaceKeyAndGetNew("/Resources", "<< /XObject << >> >>"_qpdf);
2045   - resources.getKey("/XObject").replaceKeyAndGetNew("/Fx0", this_page_fo);
  2043 + auto resources = dest_page.getObjectHandle().replaceKeyAndGetNew(
  2044 + "/Resources", Dictionary({{"/XObject", Dictionary({{"/Fx0", this_page_fo}})}}));
  2045 +
2046 2046 size_t uo_idx{0};
2047 2047 std::string content;
2048 2048 for (auto& underlay: m->underlay) {
... ... @@ -2050,7 +2050,7 @@ QPDFJob::handleUnderOverlay(QPDF&amp; pdf)
2050 2050 pdf,
2051 2051 underlay,
2052 2052 underlay_pagenos,
2053   - page.idx,
  2053 + dest_page_no.idx,
2054 2054 uo_idx,
2055 2055 underlay_fo,
2056 2056 upages[uo_idx],
... ... @@ -2070,14 +2070,15 @@ QPDFJob::handleUnderOverlay(QPDF&amp; pdf)
2070 2070 pdf,
2071 2071 overlay,
2072 2072 overlay_pagenos,
2073   - page.idx,
  2073 + dest_page_no.idx,
2074 2074 uo_idx,
2075 2075 overlay_fo,
2076 2076 opages[uo_idx],
2077 2077 dest_page);
2078 2078 ++uo_idx;
2079 2079 }
2080   - dest_page_oh.replaceKey("/Contents", pdf.newStream(content));
  2080 + dest_page.getObjectHandle().replaceKey("/Contents", pdf.newStream(content));
  2081 + ++dest_page_no;
2081 2082 }
2082 2083 }
2083 2084  
... ...