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