gfx/thebes/PrintTargetPDF.cpp

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