/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "PrintTargetPDF.h"

#include "cairo.h"

#include "cairo-pdf.h"

namespace mozilla {

namespace gfx {

static cairo_status_t

write_func(void *closure, const unsigned char *data, unsigned int length)

{

  nsCOMPtr<nsIOutputStream> out = reinterpret_cast<nsIOutputStream*>(closure);

  do {

    uint32_t wrote = 0;

    if (NS_FAILED(out->Write((const char*)data, length, &wrote))) {

      break;

    }

    data += wrote; length -= wrote;

  } while (length > 0);

  NS_ASSERTION(length == 0, "not everything was written to the file");

  return CAIRO_STATUS_SUCCESS;

}

PrintTargetPDF::PrintTargetPDF(cairo_surface_t* aCairoSurface,

                               const IntSize& aSize,

                               nsIOutputStream *aStream)

  : PrintTarget(aCairoSurface, aSize)

  , mStream(aStream)

{

}

PrintTargetPDF::~PrintTargetPDF()

{

  // We get called first, then PrintTarget's dtor.  That means that mStream

  // is destroyed before PrintTarget's dtor calls cairo_surface_destroy.  This

  // can be a problem if Finish() hasn't been called on us, since

  // cairo_surface_destroy will then call cairo_surface_finish and that will

  // end up invoking write_func above with the by now dangling pointer mStream

  // that mCairoSurface stored.  To prevent that from happening we must call

  // Flush here before mStream is deleted.

  Finish();

}

/* static */ already_AddRefed<PrintTargetPDF>

PrintTargetPDF::CreateOrNull(nsIOutputStream *aStream,

                             const IntSize& aSizeInPoints)

{

  cairo_surface_t* surface =

    cairo_pdf_surface_create_for_stream(write_func, (void*)aStream,

                                        aSizeInPoints.width,

                                        aSizeInPoints.height);

  if (cairo_surface_status(surface)) {

    return nullptr;

  }

  // The new object takes ownership of our surface reference.

  RefPtr<PrintTargetPDF> target = new PrintTargetPDF(surface, aSizeInPoints,

                                                     aStream);

  return target.forget();

}

nsresult

PrintTargetPDF::EndPage()

{

  cairo_surface_show_page(mCairoSurface);

  return PrintTarget::EndPage();

}

void

PrintTargetPDF::Finish()

{

  if (mIsFinished) {

    return; // We don't want to call Close() on mStream more than once

  }

  PrintTarget::Finish();

  mStream->Close();

}

} // namespace gfx

} // namespace mozilla