tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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PrintTargetPDF.cpp (4143B)

      1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 #include "PrintTargetPDF.h"
      7 #ifdef MOZ_ENABLE_SKIA_PDF
      8 #  include "PrintTargetSkPDF.h"
      9 #endif
     10 
     11 #include "cairo.h"
     12 #include "cairo-pdf.h"
     13 #include "mozilla/AppShutdown.h"
     14 #include "mozilla/StaticPrefs_print.h"
     15 #include "nsContentUtils.h"
     16 #include "nsString.h"
     17 
     18 namespace mozilla::gfx {
     19 
     20 static cairo_status_t write_func(void* closure, const unsigned char* data,
     21                                 unsigned int length) {
     22  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
     23    return CAIRO_STATUS_SUCCESS;
     24  }
     25  nsCOMPtr<nsIOutputStream> out = reinterpret_cast<nsIOutputStream*>(closure);
     26  do {
     27    uint32_t wrote = 0;
     28    if (NS_FAILED(out->Write((const char*)data, length, &wrote))) {
     29      break;
     30    }
     31    data += wrote;
     32    length -= wrote;
     33  } while (length > 0);
     34  NS_ASSERTION(length == 0, "not everything was written to the file");
     35  return CAIRO_STATUS_SUCCESS;
     36 }
     37 
     38 PrintTargetPDF::PrintTargetPDF(cairo_surface_t* aCairoSurface,
     39                               const IntSize& aSize, nsIOutputStream* aStream)
     40    : PrintTarget(aCairoSurface, aSize), mStream(aStream) {}
     41 
     42 PrintTargetPDF::~PrintTargetPDF() {
     43  // We get called first, then PrintTarget's dtor.  That means that mStream
     44  // is destroyed before PrintTarget's dtor calls cairo_surface_destroy.  This
     45  // can be a problem if Finish() hasn't been called on us, since
     46  // cairo_surface_destroy will then call cairo_surface_finish and that will
     47  // end up invoking write_func above with the by now dangling pointer mStream
     48  // that mCairoSurface stored.  To prevent that from happening we must call
     49  // Flush here before mStream is deleted.
     50  Finish();
     51 }
     52 
     53 /* static */
     54 already_AddRefed<PrintTarget> PrintTargetPDF::CreateOrNull(
     55    nsIOutputStream* aStream, const IntSize& aSizeInPoints) {
     56  if (NS_WARN_IF(!aStream)) {
     57    return nullptr;
     58  }
     59 
     60 #ifdef MOZ_ENABLE_SKIA_PDF
     61  if (StaticPrefs::print_experimental_skpdf()) {
     62    return PrintTargetSkPDF::CreateOrNull(aStream, aSizeInPoints);
     63  }
     64 #endif
     65 
     66  cairo_surface_t* surface = cairo_pdf_surface_create_for_stream(
     67      write_func, (void*)aStream, aSizeInPoints.width, aSizeInPoints.height);
     68  if (cairo_surface_status(surface)) {
     69    return nullptr;
     70  }
     71 
     72  nsAutoString creatorName;
     73  if (NS_SUCCEEDED(nsContentUtils::GetLocalizedString(
     74          nsContentUtils::eBRAND_PROPERTIES, "brandFullName", creatorName)) &&
     75      !creatorName.IsEmpty()) {
     76    creatorName.Append(u" " MOZILLA_VERSION);
     77    cairo_pdf_surface_set_metadata(surface, CAIRO_PDF_METADATA_CREATOR,
     78                                   NS_ConvertUTF16toUTF8(creatorName).get());
     79  }
     80 
     81  // The new object takes ownership of our surface reference.
     82  RefPtr<PrintTargetPDF> target =
     83      new PrintTargetPDF(surface, aSizeInPoints, aStream);
     84  return target.forget();
     85 }
     86 
     87 nsresult PrintTargetPDF::BeginPage(const IntSize& aSizeInPoints) {
     88  if (StaticPrefs::
     89          print_save_as_pdf_use_page_rule_size_as_paper_size_enabled()) {
     90    cairo_pdf_surface_set_size(mCairoSurface, aSizeInPoints.width,
     91                               aSizeInPoints.height);
     92    if (cairo_surface_status(mCairoSurface)) {
     93      return NS_ERROR_FAILURE;
     94    }
     95  }
     96  MOZ_ALWAYS_SUCCEEDS(PrintTarget::BeginPage(aSizeInPoints));
     97  return NS_OK;
     98 }
     99 
    100 nsresult PrintTargetPDF::EndPage() {
    101  cairo_surface_show_page(mCairoSurface);
    102  bool cairoFailure = cairo_surface_status(mCairoSurface);
    103  MOZ_ALWAYS_SUCCEEDS(PrintTarget::EndPage());
    104  return cairoFailure ? NS_ERROR_FAILURE : NS_OK;
    105 }
    106 
    107 void PrintTargetPDF::Finish() {
    108  if (mIsFinished ||
    109      AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
    110    // We don't want to call Close() on mStream more than once, and we don't
    111    // want to block shutdown if for some reason the user shuts down the
    112    // browser mid print.
    113    return;
    114  }
    115  PrintTarget::Finish();
    116  mStream->Close();
    117 }
    118 
    119 }  // namespace mozilla::gfx