root/android_webview/renderer/print_web_view_helper_linux.cc

DEFINITIONS

1. RenderPreviewPage
2. PrintPagesNative
3. PrintPageInternal

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// TODO(sgurun) copied from chrome/renderer. Remove after crbug.com/322276

#include "android_webview/renderer/print_web_view_helper.h"

#include "android_webview/common/print_messages.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "content/public/renderer/render_thread.h"
#include "printing/metafile.h"
#include "printing/metafile_impl.h"
#include "printing/metafile_skia_wrapper.h"
#include "printing/page_size_margins.h"
#include "skia/ext/platform_device.h"
#include "skia/ext/vector_canvas.h"
#include "third_party/WebKit/public/web/WebFrame.h"

#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
#include "base/process/process_handle.h"
#else
#include "base/file_descriptor_posix.h"
#endif  // !defined(OS_CHROMEOS) && !defined(OS_ANDROID)

namespace printing {

using blink::WebFrame;

bool PrintWebViewHelper::RenderPreviewPage(
    int page_number,
    const PrintMsg_Print_Params& print_params) {
  PrintMsg_PrintPage_Params page_params;
  page_params.params = print_params;
  page_params.page_number = page_number;
  scoped_ptr<Metafile> draft_metafile;
  Metafile* initial_render_metafile = print_preview_context_.metafile();
  if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
    draft_metafile.reset(new PreviewMetafile);
    initial_render_metafile = draft_metafile.get();
  }

  base::TimeTicks begin_time = base::TimeTicks::Now();
  PrintPageInternal(page_params,
                    print_preview_context_.GetPrintCanvasSize(),
                    print_preview_context_.prepared_frame(),
                    initial_render_metafile);
  print_preview_context_.RenderedPreviewPage(
      base::TimeTicks::Now() - begin_time);
  if (draft_metafile.get()) {
    draft_metafile->FinishDocument();
  } else if (print_preview_context_.IsModifiable() &&
             print_preview_context_.generate_draft_pages()) {
    DCHECK(!draft_metafile.get());
    draft_metafile.reset(
        print_preview_context_.metafile()->GetMetafileForCurrentPage());
  }
  return PreviewPageRendered(page_number, draft_metafile.get());
}

bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
                                          int page_count,
                                          const gfx::Size& canvas_size) {
  NativeMetafile metafile;
  if (!metafile.Init())
    return false;

  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
  std::vector<int> printed_pages;

  if (params.pages.empty()) {
    for (int i = 0; i < page_count; ++i) {
      printed_pages.push_back(i);
    }
  } else {
    // TODO(vitalybuka): redesign to make more code cross platform.
    for (size_t i = 0; i < params.pages.size(); ++i) {
      if (params.pages[i] >= 0 && params.pages[i] < page_count) {
        printed_pages.push_back(params.pages[i]);
      }
    }
  }

  if (printed_pages.empty())
    return false;

  PrintMsg_PrintPage_Params page_params;
  page_params.params = params.params;
  for (size_t i = 0; i < printed_pages.size(); ++i) {
    page_params.page_number = printed_pages[i];
    PrintPageInternal(page_params, canvas_size, frame, &metafile);
  }

  // blink::printEnd() for PDF should be called before metafile is closed.
  FinishFramePrinting();

  metafile.FinishDocument();

  // Get the size of the resulting metafile.
  uint32 buf_size = metafile.GetDataSize();
  DCHECK_GT(buf_size, 0u);

#if defined(OS_CHROMEOS) || defined(OS_ANDROID)
  int sequence_number = -1;
  base::FileDescriptor fd;

  // Ask the browser to open a file for us.
  Send(new PrintHostMsg_AllocateTempFileForPrinting(routing_id(),
                                                    &fd,
                                                    &sequence_number));
  if (!metafile.SaveToFD(fd))
    return false;

  // Tell the browser we've finished writing the file.
  Send(new PrintHostMsg_TempFileForPrintingWritten(routing_id(),
                                                   sequence_number));
  return true;
#else
  PrintHostMsg_DidPrintPage_Params printed_page_params;
  printed_page_params.data_size = 0;
  printed_page_params.document_cookie = params.params.document_cookie;

  {
    scoped_ptr<base::SharedMemory> shared_mem(
        content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(
            buf_size).release());
    if (!shared_mem.get()) {
      NOTREACHED() << "AllocateSharedMemoryBuffer failed";
      return false;
    }

    if (!shared_mem->Map(buf_size)) {
      NOTREACHED() << "Map failed";
      return false;
    }
    metafile.GetData(shared_mem->memory(), buf_size);
    printed_page_params.data_size = buf_size;
    shared_mem->GiveToProcess(base::GetCurrentProcessHandle(),
                              &(printed_page_params.metafile_data_handle));
  }

  for (size_t i = 0; i < printed_pages.size(); ++i) {
    printed_page_params.page_number = printed_pages[i];
    Send(new PrintHostMsg_DidPrintPage(routing_id(), printed_page_params));
    // Send the rest of the pages with an invalid metafile handle.
    printed_page_params.metafile_data_handle.fd = -1;
  }
  return true;
#endif  // defined(OS_CHROMEOS) || defined(OS_ANDROID)
}

void PrintWebViewHelper::PrintPageInternal(
    const PrintMsg_PrintPage_Params& params,
    const gfx::Size& canvas_size,
    WebFrame* frame,
    Metafile* metafile) {
  PageSizeMargins page_layout_in_points;
  double scale_factor = 1.0f;
  ComputePageLayoutInPointsForCss(frame, params.page_number, params.params,
                                  ignore_css_margins_, &scale_factor,
                                  &page_layout_in_points);
  gfx::Size page_size;
  gfx::Rect content_area;
  GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
                                          &content_area);
  gfx::Rect canvas_area =
      params.params.display_header_footer ? gfx::Rect(page_size) : content_area;

  SkBaseDevice* device = metafile->StartPageForVectorCanvas(page_size,
                                                            canvas_area,
                                                            scale_factor);
  if (!device)
    return;

  // The printPage method take a reference to the canvas we pass down, so it
  // can't be a stack object.
  skia::RefPtr<skia::VectorCanvas> canvas =
      skia::AdoptRef(new skia::VectorCanvas(device));
  MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
  skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);

  if (params.params.display_header_footer) {
    // |page_number| is 0-based, so 1 is added.
    // TODO(vitalybuka) : why does it work only with 1.25?
    PrintHeaderAndFooter(canvas.get(), params.page_number + 1,
                         print_preview_context_.total_page_count(),
                         scale_factor / 1.25,
                         page_layout_in_points, *header_footer_info_,
                         params.params);
  }
  RenderPageContent(frame, params.page_number, canvas_area, content_area,
                    scale_factor, canvas.get());

  // Done printing. Close the device context to retrieve the compiled metafile.
  if (!metafile->FinishPage())
    NOTREACHED() << "metafile failed";
}

}  // namespace printing