gfx/thebes/PrintTargetPS.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 "PrintTargetPS.h"
   7
   8 #include "cairo.h"
   9 #include "cairo-ps.h"
  10
  11 namespace mozilla::gfx {
  12
  13 static cairo_status_t write_func(void* closure, const unsigned char* data,
  14                                  unsigned int length) {
  15   nsCOMPtr<nsIOutputStream> out = reinterpret_cast<nsIOutputStream*>(closure);
  16   do {
  17     uint32_t wrote = 0;
  18     if (NS_FAILED(out->Write((const char*)data, length, &wrote))) {
  19       break;
  20     }
  21     data += wrote;
  22     length -= wrote;
  23   } while (length > 0);
  24   NS_ASSERTION(length == 0, "not everything was written to the file");
  25   return CAIRO_STATUS_SUCCESS;
  26 }
  27
  28 PrintTargetPS::PrintTargetPS(cairo_surface_t* aCairoSurface,
  29                              const IntSize& aSize, nsIOutputStream* aStream,
  30                              PageOrientation aOrientation)
  31     : PrintTarget(aCairoSurface, aSize),
  32       mStream(aStream),
  33       mOrientation(aOrientation) {}
  34
  35 PrintTargetPS::~PrintTargetPS() {
  36   // We get called first, then PrintTarget's dtor.  That means that mStream
  37   // is destroyed before PrintTarget's dtor calls cairo_surface_destroy.  This
  38   // can be a problem if Finish() hasn't been called on us, since
  39   // cairo_surface_destroy will then call cairo_surface_finish and that will
  40   // end up invoking write_func above with the by now dangling pointer mStream
  41   // that mCairoSurface stored.  To prevent that from happening we must call
  42   // Flush here before mStream is deleted.
  43   Finish();
  44 }
  45
  46 /* static */
  47 already_AddRefed<PrintTargetPS> PrintTargetPS::CreateOrNull(
  48     nsIOutputStream* aStream, IntSize aSizeInPoints,
  49     PageOrientation aOrientation) {
  50   // The PS output does not specify the page size so to print landscape we need
  51   // to rotate the drawing 90 degrees and print on portrait paper.  If printing
  52   // landscape, swap the width/height supplied to cairo to select a portrait
  53   // print area.  Our consumers are responsible for checking
  54   // RotateForLandscape() and applying a rotation transform if true.
  55   if (aOrientation == LANDSCAPE) {
  56     std::swap(aSizeInPoints.width, aSizeInPoints.height);
  57   }
  58
  59   cairo_surface_t* surface = cairo_ps_surface_create_for_stream(
  60       write_func, (void*)aStream, aSizeInPoints.width, aSizeInPoints.height);
  61   if (cairo_surface_status(surface)) {
  62     return nullptr;
  63   }
  64   cairo_ps_surface_restrict_to_level(surface, CAIRO_PS_LEVEL_2);
  65
  66   // The new object takes ownership of our surface reference.
  67   RefPtr<PrintTargetPS> target =
  68       new PrintTargetPS(surface, aSizeInPoints, aStream, aOrientation);
  69   return target.forget();
  70 }
  71
  72 nsresult PrintTargetPS::BeginPrinting(const nsAString& aTitle,
  73                                       const nsAString& aPrintToFileName,
  74                                       int32_t aStartPage, int32_t aEndPage) {
  75   if (mOrientation == PORTRAIT) {
  76     cairo_ps_surface_dsc_comment(mCairoSurface, "%%Orientation: Portrait");
  77   } else {
  78     cairo_ps_surface_dsc_comment(mCairoSurface, "%%Orientation: Landscape");
  79   }
  80   return NS_OK;
  81 }
  82
  83 nsresult PrintTargetPS::EndPage() {
  84   cairo_surface_show_page(mCairoSurface);
  85   return NS_OK;
  86 }
  87
  88 void PrintTargetPS::Finish() {
  89   if (mIsFinished) {
  90     return;  // We don't want to call Close() on mStream more than once
  91   }
  92   PrintTarget::Finish();
  93   mStream->Close();
  94 }
  95
  96 }  // namespace mozilla::gfx