chrome/renderer/printing/print_web_view

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This source file includes following definitions.
ExecuteScript
GetDPI
PrintMsg_Print_Params_IsValid
GetCssPrintParams
FitPrintParamsToPage
CalculatePageLayoutFromPrintParams
EnsureOrientationMatches
ComputeWebKitPrintParamsInDesiredDpi
GetPlugin
PrintingNodeOrPdfFrame
PrintingFrameHasPageSizeStyle
GetMarginsForPdf
FitToPageEnabled
GetPrintScalingOption
CalculatePrintParamsForCss
IsPrintPreviewEnabled
IsPrintThrottlingDisabled
Reset
GetFrame
view
PrintHeaderAndFooter
RenderPageContent
frame
node
GetExpectedPageCount
IsLoadingSelection
is_printing_started_
ResizeForPrinting
StartPrinting
CopySelectionIfNeeded
CopySelection
didStopLoading
createChildFrame
frameDetached
CallOnReady
GetPrintCanvasSize
RestoreSize
FinishPrinting
weak_ptr_factory_
IsScriptInitiatedPrintAllowed
DidStartLoading
DidStopLoading
PrintPage
OnMessageReceived
OnPrintForPrintPreview
GetPrintFrame
OnPrintPages
OnPrintForSystemDialog
GetPageSizeAndContentAreaFromPageLayout
UpdateFrameMarginsCssInfo
IsPrintToPdfRequested
OnPrintPreview
PrepareFrameForPreviewDocument
OnFramePreparedForPreviewDocument
CreatePreviewDocument
FinalizePrintReadyDocument
OnPrintingDone
SetScriptedPrintBlocked
OnInitiatePrintPreview
IsPrintingEnabled
PrintNode
DidFinishPrinting
OnFramePreparedForPrintPages
PrintPages
FinishFramePrinting
PrintPagesNative
ComputePageLayoutInPointsForCss
InitPrintSettings
CalculateNumberOfPages
UpdatePrintSettings
GetPrintSettingsFromUser
RenderPagesForPrint
CopyMetafileDataToSharedMem
IsScriptInitiatedPrintTooFrequent
ResetScriptedPrintCount
IncrementScriptedPrintCount
ShowScriptedPrintPreview
RequestPrintPreview
CheckForCancel
PreviewPageRendered
state_
InitWithFrame
InitWithNode
OnPrintPreview
CreatePreviewDocument
RenderedPreviewPage
AllPagesRendered
FinalizePrintReadyDocument
Finished
Failed
GetNextPageNumber
IsRendering
IsModifiable
HasSelection
IsLastPageOfPrintReadyMetafile
IsFinalPageRendered
set_generate_draft_pages
set_error
source_frame
source_node
prepared_frame
prepared_node
total_page_count
generate_draft_pages
metafile
last_error
GetPrintCanvasSize
ClearContext
// Copyright (c) 2012 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.

#include "chrome/renderer/printing/print_web_view_helper.h"

#include <string>

#include "base/auto_reset.h"
#include "base/command_line.h"
#include "base/json/json_writer.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/process/process_handle.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/print_messages.h"
#include "chrome/common/render_messages.h"
#include "chrome/renderer/prerender/prerender_helper.h"
#include "content/public/renderer/render_frame.h"
#include "content/public/renderer/render_thread.h"
#include "content/public/renderer/render_view.h"
#include "content/public/renderer/web_preferences.h"
#include "grit/browser_resources.h"
#include "grit/generated_resources.h"
#include "net/base/escape.h"
#include "printing/metafile.h"
#include "printing/metafile_impl.h"
#include "printing/units.h"
#include "skia/ext/vector_platform_device_skia.h"
#include "third_party/WebKit/public/platform/WebSize.h"
#include "third_party/WebKit/public/platform/WebURLRequest.h"
#include "third_party/WebKit/public/web/WebConsoleMessage.h"
#include "third_party/WebKit/public/web/WebDocument.h"
#include "third_party/WebKit/public/web/WebElement.h"
#include "third_party/WebKit/public/web/WebFrame.h"
#include "third_party/WebKit/public/web/WebFrameClient.h"
#include "third_party/WebKit/public/web/WebPlugin.h"
#include "third_party/WebKit/public/web/WebPluginDocument.h"
#include "third_party/WebKit/public/web/WebPrintParams.h"
#include "third_party/WebKit/public/web/WebPrintScalingOption.h"
#include "third_party/WebKit/public/web/WebScriptSource.h"
#include "third_party/WebKit/public/web/WebSettings.h"
#include "third_party/WebKit/public/web/WebView.h"
#include "third_party/WebKit/public/web/WebViewClient.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/resource/resource_bundle.h"
#include "webkit/common/webpreferences.h"

namespace printing {

namespace {

enum PrintPreviewHelperEvents {
  PREVIEW_EVENT_REQUESTED,
  PREVIEW_EVENT_CACHE_HIT,  // Unused
  PREVIEW_EVENT_CREATE_DOCUMENT,
  PREVIEW_EVENT_NEW_SETTINGS,  // Unused
  PREVIEW_EVENT_MAX,
};

const double kMinDpi = 1.0;

const char kPageLoadScriptFormat[] =
    "document.open(); document.write(%s); document.close();";

const char kPageSetupScriptFormat[] = "setup(%s);";

void ExecuteScript(blink::WebFrame* frame,
                   const char* script_format,
                   const base::Value& parameters) {
  std::string json;
  base::JSONWriter::Write(&parameters, &json);
  std::string script = base::StringPrintf(script_format, json.c_str());
  frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
}

int GetDPI(const PrintMsg_Print_Params* print_params) {
#if defined(OS_MACOSX)
  // On the Mac, the printable area is in points, don't do any scaling based
  // on dpi.
  return kPointsPerInch;
#else
  return static_cast<int>(print_params->dpi);
#endif  // defined(OS_MACOSX)
}

bool PrintMsg_Print_Params_IsValid(const PrintMsg_Print_Params& params) {
  return !params.content_size.IsEmpty() && !params.page_size.IsEmpty() &&
         !params.printable_area.IsEmpty() && params.document_cookie &&
         params.desired_dpi && params.max_shrink && params.min_shrink &&
         params.dpi && (params.margin_top >= 0) && (params.margin_left >= 0);
}

PrintMsg_Print_Params GetCssPrintParams(
    blink::WebFrame* frame,
    int page_index,
    const PrintMsg_Print_Params& page_params) {
  PrintMsg_Print_Params page_css_params = page_params;
  int dpi = GetDPI(&page_params);

  blink::WebSize page_size_in_pixels(
      ConvertUnit(page_params.page_size.width(), dpi, kPixelsPerInch),
      ConvertUnit(page_params.page_size.height(), dpi, kPixelsPerInch));
  int margin_top_in_pixels =
      ConvertUnit(page_params.margin_top, dpi, kPixelsPerInch);
  int margin_right_in_pixels = ConvertUnit(
      page_params.page_size.width() -
      page_params.content_size.width() - page_params.margin_left,
      dpi, kPixelsPerInch);
  int margin_bottom_in_pixels = ConvertUnit(
      page_params.page_size.height() -
      page_params.content_size.height() - page_params.margin_top,
      dpi, kPixelsPerInch);
  int margin_left_in_pixels = ConvertUnit(
      page_params.margin_left,
      dpi, kPixelsPerInch);

  blink::WebSize original_page_size_in_pixels = page_size_in_pixels;

  if (frame) {
    frame->pageSizeAndMarginsInPixels(page_index,
                                      page_size_in_pixels,
                                      margin_top_in_pixels,
                                      margin_right_in_pixels,
                                      margin_bottom_in_pixels,
                                      margin_left_in_pixels);
  }

  int new_content_width = page_size_in_pixels.width -
                          margin_left_in_pixels - margin_right_in_pixels;
  int new_content_height = page_size_in_pixels.height -
                           margin_top_in_pixels - margin_bottom_in_pixels;

  // Invalid page size and/or margins. We just use the default setting.
  if (new_content_width < 1 || new_content_height < 1) {
    CHECK(frame != NULL);
    page_css_params = GetCssPrintParams(NULL, page_index, page_params);
    return page_css_params;
  }

  page_css_params.content_size = gfx::Size(
      ConvertUnit(new_content_width, kPixelsPerInch, dpi),
      ConvertUnit(new_content_height, kPixelsPerInch, dpi));

  if (original_page_size_in_pixels != page_size_in_pixels) {
    page_css_params.page_size = gfx::Size(
        ConvertUnit(page_size_in_pixels.width, kPixelsPerInch, dpi),
        ConvertUnit(page_size_in_pixels.height, kPixelsPerInch, dpi));
  } else {
    // Printing frame doesn't have any page size css. Pixels to dpi conversion
    // causes rounding off errors. Therefore use the default page size values
    // directly.
    page_css_params.page_size = page_params.page_size;
  }

  page_css_params.margin_top =
      ConvertUnit(margin_top_in_pixels, kPixelsPerInch, dpi);
  page_css_params.margin_left =
      ConvertUnit(margin_left_in_pixels, kPixelsPerInch, dpi);
  return page_css_params;
}

double FitPrintParamsToPage(const PrintMsg_Print_Params& page_params,
                            PrintMsg_Print_Params* params_to_fit) {
  double content_width =
      static_cast<double>(params_to_fit->content_size.width());
  double content_height =
      static_cast<double>(params_to_fit->content_size.height());
  int default_page_size_height = page_params.page_size.height();
  int default_page_size_width = page_params.page_size.width();
  int css_page_size_height = params_to_fit->page_size.height();
  int css_page_size_width = params_to_fit->page_size.width();

  double scale_factor = 1.0f;
  if (page_params.page_size == params_to_fit->page_size)
    return scale_factor;

  if (default_page_size_width < css_page_size_width ||
      default_page_size_height < css_page_size_height) {
    double ratio_width =
        static_cast<double>(default_page_size_width) / css_page_size_width;
    double ratio_height =
        static_cast<double>(default_page_size_height) / css_page_size_height;
    scale_factor = ratio_width < ratio_height ? ratio_width : ratio_height;
    content_width *= scale_factor;
    content_height *= scale_factor;
  }
  params_to_fit->margin_top = static_cast<int>(
      (default_page_size_height - css_page_size_height * scale_factor) / 2 +
      (params_to_fit->margin_top * scale_factor));
  params_to_fit->margin_left = static_cast<int>(
      (default_page_size_width - css_page_size_width * scale_factor) / 2 +
      (params_to_fit->margin_left * scale_factor));
  params_to_fit->content_size = gfx::Size(
      static_cast<int>(content_width), static_cast<int>(content_height));
  params_to_fit->page_size = page_params.page_size;
  return scale_factor;
}

void CalculatePageLayoutFromPrintParams(
    const PrintMsg_Print_Params& params,
    PageSizeMargins* page_layout_in_points) {
  int dpi = GetDPI(&params);
  int content_width = params.content_size.width();
  int content_height = params.content_size.height();

  int margin_bottom = params.page_size.height() -
                      content_height - params.margin_top;
  int margin_right = params.page_size.width() -
                      content_width - params.margin_left;

  page_layout_in_points->content_width =
      ConvertUnit(content_width, dpi, kPointsPerInch);
  page_layout_in_points->content_height =
      ConvertUnit(content_height, dpi, kPointsPerInch);
  page_layout_in_points->margin_top =
      ConvertUnit(params.margin_top, dpi, kPointsPerInch);
  page_layout_in_points->margin_right =
      ConvertUnit(margin_right, dpi, kPointsPerInch);
  page_layout_in_points->margin_bottom =
      ConvertUnit(margin_bottom, dpi, kPointsPerInch);
  page_layout_in_points->margin_left =
      ConvertUnit(params.margin_left, dpi, kPointsPerInch);
}

void EnsureOrientationMatches(const PrintMsg_Print_Params& css_params,
                              PrintMsg_Print_Params* page_params) {
  if ((page_params->page_size.width() > page_params->page_size.height()) ==
      (css_params.page_size.width() > css_params.page_size.height())) {
    return;
  }

  // Swap the |width| and |height| values.
  page_params->page_size.SetSize(page_params->page_size.height(),
                                 page_params->page_size.width());
  page_params->content_size.SetSize(page_params->content_size.height(),
                                    page_params->content_size.width());
  page_params->printable_area.set_size(
      gfx::Size(page_params->printable_area.height(),
                page_params->printable_area.width()));
}

void ComputeWebKitPrintParamsInDesiredDpi(
    const PrintMsg_Print_Params& print_params,
    blink::WebPrintParams* webkit_print_params) {
  int dpi = GetDPI(&print_params);
  webkit_print_params->printerDPI = dpi;
  webkit_print_params->printScalingOption = print_params.print_scaling_option;

  webkit_print_params->printContentArea.width =
      ConvertUnit(print_params.content_size.width(), dpi,
                  print_params.desired_dpi);
  webkit_print_params->printContentArea.height =
      ConvertUnit(print_params.content_size.height(), dpi,
                  print_params.desired_dpi);

  webkit_print_params->printableArea.x =
      ConvertUnit(print_params.printable_area.x(), dpi,
                  print_params.desired_dpi);
  webkit_print_params->printableArea.y =
      ConvertUnit(print_params.printable_area.y(), dpi,
                  print_params.desired_dpi);
  webkit_print_params->printableArea.width =
      ConvertUnit(print_params.printable_area.width(), dpi,
                  print_params.desired_dpi);
  webkit_print_params->printableArea.height =
      ConvertUnit(print_params.printable_area.height(),
                  dpi, print_params.desired_dpi);

  webkit_print_params->paperSize.width =
      ConvertUnit(print_params.page_size.width(), dpi,
                  print_params.desired_dpi);
  webkit_print_params->paperSize.height =
      ConvertUnit(print_params.page_size.height(), dpi,
                  print_params.desired_dpi);
}

blink::WebPlugin* GetPlugin(const blink::WebFrame* frame) {
  return frame->document().isPluginDocument() ?
         frame->document().to<blink::WebPluginDocument>().plugin() : NULL;
}

bool PrintingNodeOrPdfFrame(const blink::WebFrame* frame,
                            const blink::WebNode& node) {
  if (!node.isNull())
    return true;
  blink::WebPlugin* plugin = GetPlugin(frame);
  return plugin && plugin->supportsPaginatedPrint();
}

bool PrintingFrameHasPageSizeStyle(blink::WebFrame* frame,
                                   int total_page_count) {
  if (!frame)
    return false;
  bool frame_has_custom_page_size_style = false;
  for (int i = 0; i < total_page_count; ++i) {
    if (frame->hasCustomPageSizeStyle(i)) {
      frame_has_custom_page_size_style = true;
      break;
    }
  }
  return frame_has_custom_page_size_style;
}

MarginType GetMarginsForPdf(blink::WebFrame* frame,
                            const blink::WebNode& node) {
  if (frame->isPrintScalingDisabledForPlugin(node))
    return NO_MARGINS;
  else
    return PRINTABLE_AREA_MARGINS;
}

bool FitToPageEnabled(const base::DictionaryValue& job_settings) {
  bool fit_to_paper_size = false;
  if (!job_settings.GetBoolean(kSettingFitToPageEnabled, &fit_to_paper_size)) {
    NOTREACHED();
  }
  return fit_to_paper_size;
}

// Returns the print scaling option to retain/scale/crop the source page size
// to fit the printable area of the paper.
//
// We retain the source page size when the current destination printer is
// SAVE_AS_PDF.
//
// We crop the source page size to fit the printable area or we print only the
// left top page contents when
// (1) Source is PDF and the user has requested not to fit to printable area
// via |job_settings|.
// (2) Source is PDF. This is the first preview request and print scaling
// option is disabled for initiator renderer plugin.
//
// In all other cases, we scale the source page to fit the printable area.
blink::WebPrintScalingOption GetPrintScalingOption(
    blink::WebFrame* frame,
    const blink::WebNode& node,
    bool source_is_html,
    const base::DictionaryValue& job_settings,
    const PrintMsg_Print_Params& params) {
  if (params.print_to_pdf)
    return blink::WebPrintScalingOptionSourceSize;

  if (!source_is_html) {
    if (!FitToPageEnabled(job_settings))
      return blink::WebPrintScalingOptionNone;

    bool no_plugin_scaling = frame->isPrintScalingDisabledForPlugin(node);

    if (params.is_first_request && no_plugin_scaling)
      return blink::WebPrintScalingOptionNone;
  }
  return blink::WebPrintScalingOptionFitToPrintableArea;
}

PrintMsg_Print_Params CalculatePrintParamsForCss(
    blink::WebFrame* frame,
    int page_index,
    const PrintMsg_Print_Params& page_params,
    bool ignore_css_margins,
    bool fit_to_page,
    double* scale_factor) {
  PrintMsg_Print_Params css_params = GetCssPrintParams(frame, page_index,
                                                       page_params);

  PrintMsg_Print_Params params = page_params;
  EnsureOrientationMatches(css_params, &params);

  if (ignore_css_margins && fit_to_page)
    return params;

  PrintMsg_Print_Params result_params = css_params;
  if (ignore_css_margins) {
    result_params.margin_top = params.margin_top;
    result_params.margin_left = params.margin_left;

    DCHECK(!fit_to_page);
    // Since we are ignoring the margins, the css page size is no longer
    // valid.
    int default_margin_right = params.page_size.width() -
        params.content_size.width() - params.margin_left;
    int default_margin_bottom = params.page_size.height() -
        params.content_size.height() - params.margin_top;
    result_params.content_size = gfx::Size(
        result_params.page_size.width() - result_params.margin_left -
            default_margin_right,
        result_params.page_size.height() - result_params.margin_top -
            default_margin_bottom);
  }

  if (fit_to_page) {
    double factor = FitPrintParamsToPage(params, &result_params);
    if (scale_factor)
      *scale_factor = factor;
  }
  return result_params;
}

bool IsPrintPreviewEnabled() {
  return CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kRendererPrintPreview);
}

bool IsPrintThrottlingDisabled() {
  return CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kDisableScriptedPrintThrottling);
}

}  // namespace

FrameReference::FrameReference(blink::WebFrame* frame) {
  Reset(frame);
}

FrameReference::FrameReference() {
  Reset(NULL);
}

FrameReference::~FrameReference() {
}

void FrameReference::Reset(blink::WebFrame* frame) {
  if (frame) {
    view_ = frame->view();
    frame_ = frame;
  } else {
    view_ = NULL;
    frame_ = NULL;
  }
}

blink::WebFrame* FrameReference::GetFrame() {
  if (view_ == NULL || frame_ == NULL)
    return NULL;
  for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
           frame = frame->traverseNext(false)) {
    if (frame == frame_)
      return frame;
  }
  return NULL;
}

blink::WebView* FrameReference::view() {
  return view_;
}

// static - Not anonymous so that platform implementations can use it.
void PrintWebViewHelper::PrintHeaderAndFooter(
    blink::WebCanvas* canvas,
    int page_number,
    int total_pages,
    float webkit_scale_factor,
    const PageSizeMargins& page_layout,
    const base::DictionaryValue& header_footer_info,
    const PrintMsg_Print_Params& params) {
  skia::VectorPlatformDeviceSkia* device =
      static_cast<skia::VectorPlatformDeviceSkia*>(canvas->getTopDevice());
  device->setDrawingArea(SkPDFDevice::kMargin_DrawingArea);

  SkAutoCanvasRestore auto_restore(canvas, true);
  canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);

  blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
                            page_layout.content_width,
                            page_layout.margin_top + page_layout.margin_bottom +
                            page_layout.content_height);

  blink::WebView* web_view = blink::WebView::create(NULL);
  web_view->settings()->setJavaScriptEnabled(true);

  blink::WebFrame* frame = blink::WebFrame::create(NULL);
  web_view->setMainFrame(frame);

  base::StringValue html(
      ResourceBundle::GetSharedInstance().GetLocalizedString(
          IDR_PRINT_PREVIEW_PAGE));
  // Load page with script to avoid async operations.
  ExecuteScript(frame, kPageLoadScriptFormat, html);

  scoped_ptr<base::DictionaryValue> options(header_footer_info.DeepCopy());
  options->SetDouble("width", page_size.width);
  options->SetDouble("height", page_size.height);
  options->SetDouble("topMargin", page_layout.margin_top);
  options->SetDouble("bottomMargin", page_layout.margin_bottom);
  options->SetString("pageNumber",
                     base::StringPrintf("%d/%d", page_number, total_pages));

  ExecuteScript(frame, kPageSetupScriptFormat, *options);

  blink::WebPrintParams webkit_params(page_size);
  webkit_params.printerDPI = GetDPI(&params);

  frame->printBegin(webkit_params);
  frame->printPage(0, canvas);
  frame->printEnd();

  web_view->close();
  frame->close();

  device->setDrawingArea(SkPDFDevice::kContent_DrawingArea);
}

// static - Not anonymous so that platform implementations can use it.
float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
                                            int page_number,
                                            const gfx::Rect& canvas_area,
                                            const gfx::Rect& content_area,
                                            double scale_factor,
                                            blink::WebCanvas* canvas) {
  SkAutoCanvasRestore auto_restore(canvas, true);
  if (content_area != canvas_area) {
    canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
                      (content_area.y() - canvas_area.y()) / scale_factor);
    SkRect clip_rect(
        SkRect::MakeXYWH(content_area.origin().x() / scale_factor,
                         content_area.origin().y() / scale_factor,
                         content_area.size().width() / scale_factor,
                         content_area.size().height() / scale_factor));
    SkIRect clip_int_rect;
    clip_rect.roundOut(&clip_int_rect);
    SkRegion clip_region(clip_int_rect);
    canvas->setClipRegion(clip_region);
  }
  return frame->printPage(page_number, canvas);
}

// Class that calls the Begin and End print functions on the frame and changes
// the size of the view temporarily to support full page printing..
class PrepareFrameAndViewForPrint : public blink::WebViewClient,
                                    public blink::WebFrameClient {
 public:
  PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
                              blink::WebFrame* frame,
                              const blink::WebNode& node,
                              bool ignore_css_margins);
  virtual ~PrepareFrameAndViewForPrint();

  // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
  // when completed.
  void CopySelectionIfNeeded(const WebPreferences& preferences,
                             const base::Closure& on_ready);

  // Prepares frame for printing.
  void StartPrinting();

  blink::WebFrame* frame() {
    return frame_.GetFrame();
  }

  const blink::WebNode& node() const {
    return node_to_print_;
  }

  int GetExpectedPageCount() const {
    return expected_pages_count_;
  }

  gfx::Size GetPrintCanvasSize() const;

  void FinishPrinting();

  bool IsLoadingSelection() {
    // It's not selection if not |owns_web_view_|.
    return owns_web_view_ && frame() && frame()->isLoading();
  }

 protected:
  // blink::WebViewClient override:
  virtual void didStopLoading();

  // blink::WebFrameClient override:
  virtual blink::WebFrame* createChildFrame(blink::WebFrame* parent,
                                            const blink::WebString& name);
  virtual void frameDetached(blink::WebFrame* frame);

 private:
  void CallOnReady();
  void ResizeForPrinting();
  void RestoreSize();
  void CopySelection(const WebPreferences& preferences);

  base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;

  FrameReference frame_;
  blink::WebNode node_to_print_;
  bool owns_web_view_;
  blink::WebPrintParams web_print_params_;
  gfx::Size prev_view_size_;
  gfx::Size prev_scroll_offset_;
  int expected_pages_count_;
  base::Closure on_ready_;
  bool should_print_backgrounds_;
  bool should_print_selection_only_;
  bool is_printing_started_;

  DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
};

PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
    const PrintMsg_Print_Params& params,
    blink::WebFrame* frame,
    const blink::WebNode& node,
    bool ignore_css_margins)
    : weak_ptr_factory_(this),
      frame_(frame),
      node_to_print_(node),
      owns_web_view_(false),
      expected_pages_count_(0),
      should_print_backgrounds_(params.should_print_backgrounds),
      should_print_selection_only_(params.selection_only),
      is_printing_started_(false) {
  PrintMsg_Print_Params print_params = params;
  if (!should_print_selection_only_ ||
      !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
    bool fit_to_page = ignore_css_margins &&
                       print_params.print_scaling_option ==
                            blink::WebPrintScalingOptionFitToPrintableArea;
    ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
    frame->printBegin(web_print_params_, node_to_print_);
    print_params = CalculatePrintParamsForCss(frame, 0, print_params,
                                              ignore_css_margins, fit_to_page,
                                              NULL);
    frame->printEnd();
  }
  ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
}

PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
  FinishPrinting();
}

void PrepareFrameAndViewForPrint::ResizeForPrinting() {
  // Layout page according to printer page size. Since WebKit shrinks the
  // size of the page automatically (from 125% to 200%) we trick it to
  // think the page is 125% larger so the size of the page is correct for
  // minimum (default) scaling.
  // This is important for sites that try to fill the page.
  gfx::Size print_layout_size(web_print_params_.printContentArea.width,
                              web_print_params_.printContentArea.height);
  print_layout_size.set_height(
      static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));

  if (!frame())
    return;
  blink::WebView* web_view = frame_.view();
  // Backup size and offset.
  if (blink::WebFrame* web_frame = web_view->mainFrame())
    prev_scroll_offset_ = web_frame->scrollOffset();
  prev_view_size_ = web_view->size();

  web_view->resize(print_layout_size);
}


void PrepareFrameAndViewForPrint::StartPrinting() {
  ResizeForPrinting();
  blink::WebView* web_view = frame_.view();
  web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
  expected_pages_count_ =
      frame()->printBegin(web_print_params_, node_to_print_);
  is_printing_started_ = true;
}

void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
    const WebPreferences& preferences,
    const base::Closure& on_ready) {
  on_ready_ = on_ready;
  if (should_print_selection_only_) {
    CopySelection(preferences);
  } else {
    // Call immediately, async call crashes scripting printing.
    CallOnReady();
  }
}

void PrepareFrameAndViewForPrint::CopySelection(
    const WebPreferences& preferences) {
  ResizeForPrinting();
  std::string url_str = "data:text/html;charset=utf-8,";
  url_str.append(
      net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
  RestoreSize();
  // Create a new WebView with the same settings as the current display one.
  // Except that we disable javascript (don't want any active content running
  // on the page).
  WebPreferences prefs = preferences;
  prefs.javascript_enabled = false;
  prefs.java_enabled = false;

  blink::WebView* web_view = blink::WebView::create(this);
  owns_web_view_ = true;
  content::ApplyWebPreferences(prefs, web_view);
  web_view->setMainFrame(blink::WebFrame::create(this));
  frame_.Reset(web_view->mainFrame());
  node_to_print_.reset();

  // When loading is done this will call didStopLoading() and that will do the
  // actual printing.
  frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
}

void PrepareFrameAndViewForPrint::didStopLoading() {
  DCHECK(!on_ready_.is_null());
  // Don't call callback here, because it can delete |this| and WebView that is
  // called didStopLoading.
  base::MessageLoop::current()->PostTask(
      FROM_HERE,
      base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
                 weak_ptr_factory_.GetWeakPtr()));
}

blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
    blink::WebFrame* parent,
    const blink::WebString& name) {
  blink::WebFrame* frame = blink::WebFrame::create(this);
  parent->appendChild(frame);
  return frame;
}

void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame) {
  if (frame->parent())
    frame->parent()->removeChild(frame);
  frame->close();
}

void PrepareFrameAndViewForPrint::CallOnReady() {
  return on_ready_.Run();  // Can delete |this|.
}

gfx::Size PrepareFrameAndViewForPrint::GetPrintCanvasSize() const {
  DCHECK(is_printing_started_);
  return gfx::Size(web_print_params_.printContentArea.width,
                   web_print_params_.printContentArea.height);
}

void PrepareFrameAndViewForPrint::RestoreSize() {
  if (frame()) {
    blink::WebView* web_view = frame_.GetFrame()->view();
    web_view->resize(prev_view_size_);
    if (blink::WebFrame* web_frame = web_view->mainFrame())
      web_frame->setScrollOffset(prev_scroll_offset_);
  }
}

void PrepareFrameAndViewForPrint::FinishPrinting() {
  blink::WebFrame* frame = frame_.GetFrame();
  if (frame) {
    blink::WebView* web_view = frame->view();
    if (is_printing_started_) {
      is_printing_started_ = false;
      frame->printEnd();
      if (!owns_web_view_) {
        web_view->settings()->setShouldPrintBackgrounds(false);
        RestoreSize();
      }
    }
    if (owns_web_view_) {
      DCHECK(!frame->isLoading());
      owns_web_view_ = false;
      web_view->close();
    }
  }
  frame_.Reset(NULL);
  on_ready_.Reset();
}

PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view)
    : content::RenderViewObserver(render_view),
      content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
      reset_prep_frame_view_(false),
      is_preview_enabled_(IsPrintPreviewEnabled()),
      is_scripted_print_throttling_disabled_(IsPrintThrottlingDisabled()),
      is_print_ready_metafile_sent_(false),
      ignore_css_margins_(false),
      user_cancelled_scripted_print_count_(0),
      is_scripted_printing_blocked_(false),
      notify_browser_of_print_failure_(true),
      print_for_preview_(false),
      print_node_in_progress_(false),
      is_loading_(false),
      is_scripted_preview_delayed_(false),
      weak_ptr_factory_(this) {
}

PrintWebViewHelper::~PrintWebViewHelper() {}

bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(
    blink::WebFrame* frame, bool user_initiated) {
#if defined(OS_ANDROID)
  return false;
#endif  // defined(OS_ANDROID)
  if (is_scripted_printing_blocked_)
    return false;
  // If preview is enabled, then the print dialog is tab modal, and the user
  // can always close the tab on a mis-behaving page (the system print dialog
  // is app modal). If the print was initiated through user action, don't
  // throttle. Or, if the command line flag to skip throttling has been set.
  if (!is_scripted_print_throttling_disabled_ &&
      !is_preview_enabled_ &&
      !user_initiated)
    return !IsScriptInitiatedPrintTooFrequent(frame);
  return true;
}

void PrintWebViewHelper::DidStartLoading() {
  is_loading_ = true;
}

void PrintWebViewHelper::DidStopLoading() {
  is_loading_ = false;
  ShowScriptedPrintPreview();
}

// Prints |frame| which called window.print().
void PrintWebViewHelper::PrintPage(blink::WebFrame* frame,
                                   bool user_initiated) {
  DCHECK(frame);

  // Allow Prerendering to cancel this print request if necessary.
  if (prerender::PrerenderHelper::IsPrerendering(
          render_view()->GetMainRenderFrame())) {
    Send(new ChromeViewHostMsg_CancelPrerenderForPrinting(routing_id()));
    return;
  }

  if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
    return;
  IncrementScriptedPrintCount();

  if (is_preview_enabled_) {
    print_preview_context_.InitWithFrame(frame);
    RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
  } else {
    Print(frame, blink::WebNode());
  }
}

bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
    IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
    IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
    IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
    IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
    IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
    IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
    IPC_MESSAGE_HANDLER(PrintMsg_ResetScriptedPrintCount,
                        ResetScriptedPrintCount)
    IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
                        SetScriptedPrintBlocked)
    IPC_MESSAGE_UNHANDLED(handled = false)
    IPC_END_MESSAGE_MAP()
  return handled;
}

void PrintWebViewHelper::OnPrintForPrintPreview(
    const base::DictionaryValue& job_settings) {
  DCHECK(is_preview_enabled_);
  // If still not finished with earlier print request simply ignore.
  if (prep_frame_view_)
    return;

  if (!render_view()->GetWebView())
    return;
  blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
  if (!main_frame)
    return;

  blink::WebDocument document = main_frame->document();
  // <object> with id="pdf-viewer" is created in
  // chrome/browser/resources/print_preview/print_preview.js
  blink::WebElement pdf_element = document.getElementById("pdf-viewer");
  if (pdf_element.isNull()) {
    NOTREACHED();
    return;
  }

  // Set |print_for_preview_| flag and autoreset it to back to original
  // on return.
  base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);

  blink::WebFrame* pdf_frame = pdf_element.document().frame();
  if (!UpdatePrintSettings(pdf_frame, pdf_element, job_settings)) {
    LOG(ERROR) << "UpdatePrintSettings failed";
    DidFinishPrinting(FAIL_PRINT);
    return;
  }

  // Print page onto entire page not just printable area. Preview PDF already
  // has content in correct position taking into account page size and printable
  // area.
  // TODO(vitalybuka) : Make this consistent on all platform. This change
  // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
  // printable_area. Also we can't change printable_area deeper inside
  // RenderPagesForPrint for Windows, because it's used also by native
  // printing and it expects real printable_area value.
  // See http://crbug.com/123408
  PrintMsg_Print_Params& print_params = print_pages_params_->params;
  print_params.printable_area = gfx::Rect(print_params.page_size);

  // Render Pages for printing.
  if (!RenderPagesForPrint(pdf_frame, pdf_element)) {
    LOG(ERROR) << "RenderPagesForPrint failed";
    DidFinishPrinting(FAIL_PRINT);
  }
}

bool PrintWebViewHelper::GetPrintFrame(blink::WebFrame** frame) {
  DCHECK(frame);
  blink::WebView* webView = render_view()->GetWebView();
  DCHECK(webView);
  if (!webView)
    return false;

  // If the user has selected text in the currently focused frame we print
  // only that frame (this makes print selection work for multiple frames).
  blink::WebFrame* focusedFrame = webView->focusedFrame();
  *frame = focusedFrame->hasSelection() ? focusedFrame : webView->mainFrame();
  return true;
}

void PrintWebViewHelper::OnPrintPages() {
  blink::WebFrame* frame;
  if (GetPrintFrame(&frame))
    Print(frame, blink::WebNode());
}

void PrintWebViewHelper::OnPrintForSystemDialog() {
  blink::WebFrame* frame = print_preview_context_.source_frame();
  if (!frame) {
    NOTREACHED();
    return;
  }

  Print(frame, print_preview_context_.source_node());
}

void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
    const PageSizeMargins& page_layout_in_points,
    gfx::Size* page_size,
    gfx::Rect* content_area) {
  *page_size = gfx::Size(
      page_layout_in_points.content_width +
          page_layout_in_points.margin_right +
          page_layout_in_points.margin_left,
      page_layout_in_points.content_height +
          page_layout_in_points.margin_top +
          page_layout_in_points.margin_bottom);
  *content_area = gfx::Rect(page_layout_in_points.margin_left,
                            page_layout_in_points.margin_top,
                            page_layout_in_points.content_width,
                            page_layout_in_points.content_height);
}

void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
    const base::DictionaryValue& settings) {
  int margins_type = 0;
  if (!settings.GetInteger(kSettingMarginsType, &margins_type))
    margins_type = DEFAULT_MARGINS;
  ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
}

bool PrintWebViewHelper::IsPrintToPdfRequested(
    const base::DictionaryValue& job_settings) {
  bool print_to_pdf = false;
  if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
    NOTREACHED();
  return print_to_pdf;
}

void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
  DCHECK(is_preview_enabled_);
  print_preview_context_.OnPrintPreview();

  UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
                            PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);

  if (!print_preview_context_.source_frame()) {
    DidFinishPrinting(FAIL_PREVIEW);
    return;
  }

  if (!UpdatePrintSettings(print_preview_context_.source_frame(),
                           print_preview_context_.source_node(), settings)) {
    if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
      Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
          routing_id(),
          print_pages_params_.get()
              ? print_pages_params_->params.document_cookie
              : 0));
      notify_browser_of_print_failure_ = false;  // Already sent.
    }
    DidFinishPrinting(FAIL_PREVIEW);
    return;
  }

  // If we are previewing a pdf and the print scaling is disabled, send a
  // message to browser.
  if (print_pages_params_->params.is_first_request &&
      !print_preview_context_.IsModifiable() &&
      print_preview_context_.source_frame()->isPrintScalingDisabledForPlugin(
          print_preview_context_.source_node())) {
    Send(new PrintHostMsg_PrintPreviewScalingDisabled(routing_id()));
  }

  is_print_ready_metafile_sent_ = false;

  // PDF printer device supports alpha blending.
  print_pages_params_->params.supports_alpha_blend = true;

  bool generate_draft_pages = false;
  if (!settings.GetBoolean(kSettingGenerateDraftData,
                           &generate_draft_pages)) {
    NOTREACHED();
  }
  print_preview_context_.set_generate_draft_pages(generate_draft_pages);

  PrepareFrameForPreviewDocument();
}

void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
  reset_prep_frame_view_ = false;

  if (!print_pages_params_ || CheckForCancel()) {
    DidFinishPrinting(FAIL_PREVIEW);
    return;
  }

  // Don't reset loading frame or WebKit will fail assert. Just retry when
  // current selection is loaded.
  if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
    reset_prep_frame_view_ = true;
    return;
  }

  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
  prep_frame_view_.reset(
      new PrepareFrameAndViewForPrint(print_params,
                                      print_preview_context_.source_frame(),
                                      print_preview_context_.source_node(),
                                      ignore_css_margins_));
  prep_frame_view_->CopySelectionIfNeeded(
      render_view()->GetWebkitPreferences(),
      base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
                 base::Unretained(this)));
}

void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
  if (reset_prep_frame_view_) {
    PrepareFrameForPreviewDocument();
    return;
  }
  DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
}

bool PrintWebViewHelper::CreatePreviewDocument() {
  if (!print_pages_params_ || CheckForCancel())
    return false;

  UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
                            PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);

  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
  const std::vector<int>& pages = print_pages_params_->pages;

  if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
                                                    pages)) {
    return false;
  }

  PageSizeMargins default_page_layout;
  ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
                                  print_params, ignore_css_margins_, NULL,
                                  &default_page_layout);

  bool has_page_size_style = PrintingFrameHasPageSizeStyle(
      print_preview_context_.prepared_frame(),
      print_preview_context_.total_page_count());
  int dpi = GetDPI(&print_params);

  gfx::Rect printable_area_in_points(
      ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
      ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
      ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
      ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));

  // Margins: Send default page layout to browser process.
  Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
                                                default_page_layout,
                                                printable_area_in_points,
                                                has_page_size_style));

  PrintHostMsg_DidGetPreviewPageCount_Params params;
  params.page_count = print_preview_context_.total_page_count();
  params.is_modifiable = print_preview_context_.IsModifiable();
  params.document_cookie = print_params.document_cookie;
  params.preview_request_id = print_params.preview_request_id;
  params.clear_preview_data = print_preview_context_.generate_draft_pages();
  Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
  if (CheckForCancel())
    return false;

  while (!print_preview_context_.IsFinalPageRendered()) {
    int page_number = print_preview_context_.GetNextPageNumber();
    DCHECK_GE(page_number, 0);
    if (!RenderPreviewPage(page_number, print_params))
      return false;

    if (CheckForCancel())
      return false;

    // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
    // print_preview_context_.AllPagesRendered()) before calling
    // FinalizePrintReadyDocument() when printing a PDF because the plugin
    // code does not generate output until we call FinishPrinting().  We do not
    // generate draft pages for PDFs, so IsFinalPageRendered() and
    // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
    // the loop.
    if (print_preview_context_.IsFinalPageRendered())
      print_preview_context_.AllPagesRendered();

    if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
      DCHECK(print_preview_context_.IsModifiable() ||
             print_preview_context_.IsFinalPageRendered());
      if (!FinalizePrintReadyDocument())
        return false;
    }
  }
  print_preview_context_.Finished();
  return true;
}

bool PrintWebViewHelper::FinalizePrintReadyDocument() {
  DCHECK(!is_print_ready_metafile_sent_);
  print_preview_context_.FinalizePrintReadyDocument();

  // Get the size of the resulting metafile.
  PreviewMetafile* metafile = print_preview_context_.metafile();
  uint32 buf_size = metafile->GetDataSize();
  DCHECK_GT(buf_size, 0u);

  PrintHostMsg_DidPreviewDocument_Params preview_params;
  preview_params.data_size = buf_size;
  preview_params.document_cookie = print_pages_params_->params.document_cookie;
  preview_params.expected_pages_count =
      print_preview_context_.total_page_count();
  preview_params.modifiable = print_preview_context_.IsModifiable();
  preview_params.preview_request_id =
      print_pages_params_->params.preview_request_id;

  // Ask the browser to create the shared memory for us.
  if (!CopyMetafileDataToSharedMem(metafile,
                                   &(preview_params.metafile_data_handle))) {
    LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
    print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
    return false;
  }
  is_print_ready_metafile_sent_ = true;

  Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
  return true;
}

void PrintWebViewHelper::OnPrintingDone(bool success) {
  notify_browser_of_print_failure_ = false;
  if (!success)
    LOG(ERROR) << "Failure in OnPrintingDone";
  DidFinishPrinting(success ? OK : FAIL_PRINT);
}

void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
  is_scripted_printing_blocked_ = blocked;
}

void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
  DCHECK(is_preview_enabled_);
  blink::WebFrame* frame = NULL;
  GetPrintFrame(&frame);
  DCHECK(frame);
  print_preview_context_.InitWithFrame(frame);
  RequestPrintPreview(selection_only ?
                      PRINT_PREVIEW_USER_INITIATED_SELECTION :
                      PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
}

bool PrintWebViewHelper::IsPrintingEnabled() {
  bool result = false;
  Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
  return result;
}

void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
  if (node.isNull() || !node.document().frame()) {
    // This can occur when the context menu refers to an invalid WebNode.
    // See http://crbug.com/100890#c17 for a repro case.
    return;
  }

  if (print_node_in_progress_) {
    // This can happen as a result of processing sync messages when printing
    // from ppapi plugins. It's a rare case, so its OK to just fail here.
    // See http://crbug.com/159165.
    return;
  }

  print_node_in_progress_ = true;

  // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
  // its |context_menu_node_|.
  if (is_preview_enabled_) {
    print_preview_context_.InitWithNode(node);
    RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
  } else {
    blink::WebNode duplicate_node(node);
    Print(duplicate_node.document().frame(), duplicate_node);
  }

  print_node_in_progress_ = false;
}

void PrintWebViewHelper::Print(blink::WebFrame* frame,
                               const blink::WebNode& node) {
  // If still not finished with earlier print request simply ignore.
  if (prep_frame_view_)
    return;

  FrameReference frame_ref(frame);

  int expected_page_count = 0;
  if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
    DidFinishPrinting(FAIL_PRINT_INIT);
    return;  // Failed to init print page settings.
  }

  // Some full screen plugins can say they don't want to print.
  if (!expected_page_count) {
    DidFinishPrinting(FAIL_PRINT);
    return;
  }

  // Ask the browser to show UI to retrieve the final print settings.
  if (!GetPrintSettingsFromUser(frame_ref.GetFrame(), node,
                                expected_page_count)) {
    DidFinishPrinting(OK);  // Release resources and fail silently.
    return;
  }

  // Render Pages for printing.
  if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
    LOG(ERROR) << "RenderPagesForPrint failed";
    DidFinishPrinting(FAIL_PRINT);
  }
  ResetScriptedPrintCount();
}

void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
  switch (result) {
    case OK:
      break;

    case FAIL_PRINT_INIT:
      DCHECK(!notify_browser_of_print_failure_);
      break;

    case FAIL_PRINT:
      if (notify_browser_of_print_failure_ && print_pages_params_.get()) {
        int cookie = print_pages_params_->params.document_cookie;
        Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
      }
      break;

    case FAIL_PREVIEW:
      DCHECK(is_preview_enabled_);
      int cookie = print_pages_params_.get() ?
          print_pages_params_->params.document_cookie : 0;
      if (notify_browser_of_print_failure_) {
        LOG(ERROR) << "CreatePreviewDocument failed";
        Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
      } else {
        Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
      }
      print_preview_context_.Failed(notify_browser_of_print_failure_);
      break;
  }
  prep_frame_view_.reset();
  print_pages_params_.reset();
  notify_browser_of_print_failure_ = true;
}

void PrintWebViewHelper::OnFramePreparedForPrintPages() {
  PrintPages();
  FinishFramePrinting();
}

void PrintWebViewHelper::PrintPages() {
  if (!prep_frame_view_)  // Printing is already canceled or failed.
    return;
  prep_frame_view_->StartPrinting();

  int page_count = prep_frame_view_->GetExpectedPageCount();
  if (!page_count) {
    LOG(ERROR) << "Can't print 0 pages.";
    return DidFinishPrinting(FAIL_PRINT);
  }

  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
  const PrintMsg_Print_Params& print_params = params.params;

#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
  // TODO(vitalybuka): should be page_count or valid pages from params.pages.
  // See http://crbug.com/161576
  Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
                                                print_params.document_cookie,
                                                page_count));
#endif  // !defined(OS_CHROMEOS)

  if (print_params.preview_ui_id < 0) {
    // Printing for system dialog.
    int printed_count = params.pages.empty() ? page_count : params.pages.size();
#if !defined(OS_CHROMEOS)
    UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
#else
    UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
                         printed_count);
#endif  // !defined(OS_CHROMEOS)
  }


  if (!PrintPagesNative(prep_frame_view_->frame(), page_count,
                        prep_frame_view_->GetPrintCanvasSize())) {
    LOG(ERROR) << "Printing failed.";
    return DidFinishPrinting(FAIL_PRINT);
  }
}

void PrintWebViewHelper::FinishFramePrinting() {
  prep_frame_view_.reset();
}

#if defined(OS_MACOSX) || defined(OS_WIN)
bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
                                          int page_count,
                                          const gfx::Size& canvas_size) {
  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
  const PrintMsg_Print_Params& print_params = params.params;

  PrintMsg_PrintPage_Params page_params;
  page_params.params = print_params;
  if (params.pages.empty()) {
    for (int i = 0; i < page_count; ++i) {
      page_params.page_number = i;
      PrintPageInternal(page_params, canvas_size, frame);
    }
  } else {
    for (size_t i = 0; i < params.pages.size(); ++i) {
      if (params.pages[i] >= page_count)
        break;
      page_params.page_number = params.pages[i];
      PrintPageInternal(page_params, canvas_size, frame);
    }
  }
  return true;
}

#endif  // OS_MACOSX || OS_WIN

// static - Not anonymous so that platform implementations can use it.
void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
    blink::WebFrame* frame,
    int page_index,
    const PrintMsg_Print_Params& page_params,
    bool ignore_css_margins,
    double* scale_factor,
    PageSizeMargins* page_layout_in_points) {
  PrintMsg_Print_Params params = CalculatePrintParamsForCss(
      frame, page_index, page_params, ignore_css_margins,
      page_params.print_scaling_option ==
          blink::WebPrintScalingOptionFitToPrintableArea,
      scale_factor);
  CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
}

bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
  PrintMsg_PrintPages_Params settings;
  Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
                                                &settings.params));
  // Check if the printer returned any settings, if the settings is empty, we
  // can safely assume there are no printer drivers configured. So we safely
  // terminate.
  bool result = true;
  if (!PrintMsg_Print_Params_IsValid(settings.params))
    result = false;

  if (result &&
      (settings.params.dpi < kMinDpi || settings.params.document_cookie == 0)) {
    // Invalid print page settings.
    NOTREACHED();
    result = false;
  }

  // Reset to default values.
  ignore_css_margins_ = false;
  settings.pages.clear();

  settings.params.print_scaling_option =
      blink::WebPrintScalingOptionSourceSize;
  if (fit_to_paper_size) {
    settings.params.print_scaling_option =
        blink::WebPrintScalingOptionFitToPrintableArea;
  }

  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
  return result;
}

bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebFrame* frame,
                                                const blink::WebNode& node,
                                                int* number_of_pages) {
  DCHECK(frame);
  bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
  if (!InitPrintSettings(fit_to_paper_size)) {
    notify_browser_of_print_failure_ = false;
    render_view()->RunModalAlertDialog(
        frame,
        l10n_util::GetStringUTF16(IDS_PRINT_INVALID_PRINTER_SETTINGS));
    return false;
  }

  const PrintMsg_Print_Params& params = print_pages_params_->params;
  PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
  prepare.StartPrinting();

  Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
                                             params.document_cookie));
  *number_of_pages = prepare.GetExpectedPageCount();
  return true;
}

bool PrintWebViewHelper::UpdatePrintSettings(
    blink::WebFrame* frame,
    const blink::WebNode& node,
    const base::DictionaryValue& passed_job_settings) {
  DCHECK(is_preview_enabled_);
  const base::DictionaryValue* job_settings = &passed_job_settings;
  base::DictionaryValue modified_job_settings;
  if (job_settings->empty()) {
    if (!print_for_preview_)
      print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
    return false;
  }

  bool source_is_html = true;
  if (print_for_preview_) {
    if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
      NOTREACHED();
    }
  } else {
    source_is_html = !PrintingNodeOrPdfFrame(frame, node);
  }

  if (print_for_preview_ || !source_is_html) {
    modified_job_settings.MergeDictionary(job_settings);
    modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
    modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
    job_settings = &modified_job_settings;
  }

  // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
  // possible.
  int cookie = print_pages_params_.get() ?
      print_pages_params_->params.document_cookie : 0;
  PrintMsg_PrintPages_Params settings;
  Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
                                            &settings));
  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));

  if (!PrintMsg_Print_Params_IsValid(settings.params)) {
    if (!print_for_preview_) {
      print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
    } else {
      // PrintForPrintPreview
      blink::WebFrame* print_frame = NULL;
      // This may not be the right frame, but the alert will be modal,
      // therefore it works well enough.
      GetPrintFrame(&print_frame);
      if (print_frame) {
        render_view()->RunModalAlertDialog(
            print_frame,
            l10n_util::GetStringUTF16(
                IDS_PRINT_INVALID_PRINTER_SETTINGS));
      }
    }
    return false;
  }

  if (settings.params.dpi < kMinDpi || !settings.params.document_cookie) {
    print_preview_context_.set_error(PREVIEW_ERROR_UPDATING_PRINT_SETTINGS);
    return false;
  }

  if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
    NOTREACHED();
    print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
    return false;
  }

  if (!print_for_preview_) {
    // Validate expected print preview settings.
    if (!job_settings->GetInteger(kPreviewRequestID,
                                  &settings.params.preview_request_id) ||
        !job_settings->GetBoolean(kIsFirstRequest,
                                  &settings.params.is_first_request)) {
      NOTREACHED();
      print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
      return false;
    }

    settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
    UpdateFrameMarginsCssInfo(*job_settings);
    settings.params.print_scaling_option = GetPrintScalingOption(
        frame, node, source_is_html, *job_settings, settings.params);

    // Header/Footer: Set |header_footer_info_|.
    if (settings.params.display_header_footer) {
      header_footer_info_.reset(new base::DictionaryValue());
      header_footer_info_->SetDouble(kSettingHeaderFooterDate,
                                     base::Time::Now().ToJsTime());
      header_footer_info_->SetString(kSettingHeaderFooterURL,
                                     settings.params.url);
      header_footer_info_->SetString(kSettingHeaderFooterTitle,
                                     settings.params.title);
    }
  }

  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
  Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
                                             settings.params.document_cookie));

  return true;
}

bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebFrame* frame,
                                                  const blink::WebNode& node,
                                                  int expected_pages_count) {
  PrintHostMsg_ScriptedPrint_Params params;
  PrintMsg_PrintPages_Params print_settings;

  params.cookie = print_pages_params_->params.document_cookie;
  params.has_selection = frame->hasSelection();
  params.expected_pages_count = expected_pages_count;
  MarginType margin_type = DEFAULT_MARGINS;
  if (PrintingNodeOrPdfFrame(frame, node))
    margin_type = GetMarginsForPdf(frame, node);
  params.margin_type = margin_type;

  Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));

  // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
  // value before and restore it afterwards.
  blink::WebPrintScalingOption scaling_option =
      print_pages_params_->params.print_scaling_option;

  print_pages_params_.reset();
  IPC::SyncMessage* msg =
      new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
  msg->EnableMessagePumping();
  Send(msg);
  print_pages_params_.reset(new PrintMsg_PrintPages_Params(print_settings));

  print_pages_params_->params.print_scaling_option = scaling_option;
  return (print_settings.params.dpi && print_settings.params.document_cookie);
}

bool PrintWebViewHelper::RenderPagesForPrint(blink::WebFrame* frame,
                                             const blink::WebNode& node) {
  if (!frame || prep_frame_view_)
    return false;
  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
  const PrintMsg_Print_Params& print_params = params.params;
  prep_frame_view_.reset(
      new PrepareFrameAndViewForPrint(print_params, frame, node,
                                      ignore_css_margins_));
  DCHECK(!print_pages_params_->params.selection_only ||
         print_pages_params_->pages.empty());
  prep_frame_view_->CopySelectionIfNeeded(
      render_view()->GetWebkitPreferences(),
      base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
                 base::Unretained(this)));
  return true;
}

#if defined(OS_POSIX)
bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
    Metafile* metafile,
    base::SharedMemoryHandle* shared_mem_handle) {
  uint32 buf_size = metafile->GetDataSize();
  scoped_ptr<base::SharedMemory> shared_buf(
      content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(
          buf_size).release());

  if (shared_buf.get()) {
    if (shared_buf->Map(buf_size)) {
      metafile->GetData(shared_buf->memory(), buf_size);
      shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
                                shared_mem_handle);
      return true;
    }
  }
  NOTREACHED();
  return false;
}
#endif  // defined(OS_POSIX)

bool PrintWebViewHelper::IsScriptInitiatedPrintTooFrequent(
    blink::WebFrame* frame) {
  const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
  const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
  bool too_frequent = false;

  // Check if there is script repeatedly trying to print and ignore it if too
  // frequent.  The first 3 times, we use a constant wait time, but if this
  // gets excessive, we switch to exponential wait time. So for a page that
  // calls print() in a loop the user will need to cancel the print dialog
  // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
  // This gives the user time to navigate from the page.
  if (user_cancelled_scripted_print_count_ > 0) {
    base::TimeDelta diff = base::Time::Now() - last_cancelled_script_print_;
    int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
    if (user_cancelled_scripted_print_count_ > 3) {
      min_wait_seconds = std::min(
          kMinSecondsToIgnoreJavascriptInitiatedPrint <<
              (user_cancelled_scripted_print_count_ - 3),
          kMaxSecondsToIgnoreJavascriptInitiatedPrint);
    }
    if (diff.InSeconds() < min_wait_seconds) {
      too_frequent = true;
    }
  }

  if (!too_frequent)
    return false;

  blink::WebString message(
      blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
  frame->addMessageToConsole(
      blink::WebConsoleMessage(
          blink::WebConsoleMessage::LevelWarning, message));
  return true;
}

void PrintWebViewHelper::ResetScriptedPrintCount() {
  // Reset cancel counter on successful print.
  user_cancelled_scripted_print_count_ = 0;
}

void PrintWebViewHelper::IncrementScriptedPrintCount() {
  ++user_cancelled_scripted_print_count_;
  last_cancelled_script_print_ = base::Time::Now();
}


void PrintWebViewHelper::ShowScriptedPrintPreview() {
  if (is_scripted_preview_delayed_) {
    is_scripted_preview_delayed_ = false;
    Send(new PrintHostMsg_ShowScriptedPrintPreview(routing_id(),
            print_preview_context_.IsModifiable()));
  }
}

void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
  const bool is_modifiable = print_preview_context_.IsModifiable();
  const bool has_selection = print_preview_context_.HasSelection();
  PrintHostMsg_RequestPrintPreview_Params params;
  params.is_modifiable = is_modifiable;
  params.has_selection = has_selection;
  switch (type) {
    case PRINT_PREVIEW_SCRIPTED: {
      // Shows scripted print preview in two stages.
      // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
      //    pumping messages here.
      // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
      //    document has been loaded.
      is_scripted_preview_delayed_ = true;
      if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
        // Wait for DidStopLoading. Plugins may not know the correct
        // |is_modifiable| value until they are fully loaded, which occurs when
        // DidStopLoading() is called. Defer showing the preview until then.
      } else {
        base::MessageLoop::current()->PostTask(
            FROM_HERE,
            base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
                       weak_ptr_factory_.GetWeakPtr()));
      }
      IPC::SyncMessage* msg =
          new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
      msg->EnableMessagePumping();
      Send(msg);
      is_scripted_preview_delayed_ = false;
      return;
    }
    case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
      break;
    }
    case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
      DCHECK(has_selection);
      params.selection_only = has_selection;
      break;
    }
    case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
      params.webnode_only = true;
      break;
    }
    default: {
      NOTREACHED();
      return;
    }
  }
  Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
}

bool PrintWebViewHelper::CheckForCancel() {
  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
  bool cancel = false;
  Send(new PrintHostMsg_CheckForCancel(routing_id(),
                                       print_params.preview_ui_id,
                                       print_params.preview_request_id,
                                       &cancel));
  if (cancel)
    notify_browser_of_print_failure_ = false;
  return cancel;
}

bool PrintWebViewHelper::PreviewPageRendered(int page_number,
                                             Metafile* metafile) {
  DCHECK_GE(page_number, FIRST_PAGE_INDEX);

  // For non-modifiable files, |metafile| should be NULL, so do not bother
  // sending a message. If we don't generate draft metafiles, |metafile| is
  // NULL.
  if (!print_preview_context_.IsModifiable() ||
      !print_preview_context_.generate_draft_pages()) {
    DCHECK(!metafile);
    return true;
  }

  if (!metafile) {
    NOTREACHED();
    print_preview_context_.set_error(
        PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
    return false;
  }

  PrintHostMsg_DidPreviewPage_Params preview_page_params;
  // Get the size of the resulting metafile.
  uint32 buf_size = metafile->GetDataSize();
  DCHECK_GT(buf_size, 0u);
  if (!CopyMetafileDataToSharedMem(
      metafile, &(preview_page_params.metafile_data_handle))) {
    LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
    print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
    return false;
  }
  preview_page_params.data_size = buf_size;
  preview_page_params.page_number = page_number;
  preview_page_params.preview_request_id =
      print_pages_params_->params.preview_request_id;

  Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
  return true;
}

PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
    : total_page_count_(0),
      current_page_index_(0),
      generate_draft_pages_(true),
      print_ready_metafile_page_count_(0),
      error_(PREVIEW_ERROR_NONE),
      state_(UNINITIALIZED) {
}

PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
}

void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
    blink::WebFrame* web_frame) {
  DCHECK(web_frame);
  DCHECK(!IsRendering());
  state_ = INITIALIZED;
  source_frame_.Reset(web_frame);
  source_node_.reset();
}

void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
    const blink::WebNode& web_node) {
  DCHECK(!web_node.isNull());
  DCHECK(web_node.document().frame());
  DCHECK(!IsRendering());
  state_ = INITIALIZED;
  source_frame_.Reset(web_node.document().frame());
  source_node_ = web_node;
}

void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
  DCHECK_EQ(INITIALIZED, state_);
  ClearContext();
}

bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
    PrepareFrameAndViewForPrint* prepared_frame,
    const std::vector<int>& pages) {
  DCHECK_EQ(INITIALIZED, state_);
  state_ = RENDERING;

  // Need to make sure old object gets destroyed first.
  prep_frame_view_.reset(prepared_frame);
  prep_frame_view_->StartPrinting();

  total_page_count_ = prep_frame_view_->GetExpectedPageCount();
  if (total_page_count_ == 0) {
    LOG(ERROR) << "CreatePreviewDocument got 0 page count";
    set_error(PREVIEW_ERROR_ZERO_PAGES);
    return false;
  }

  metafile_.reset(new PreviewMetafile);
  if (!metafile_->Init()) {
    set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
    LOG(ERROR) << "PreviewMetafile Init failed";
    return false;
  }

  current_page_index_ = 0;
  pages_to_render_ = pages;
  // Sort and make unique.
  std::sort(pages_to_render_.begin(), pages_to_render_.end());
  pages_to_render_.resize(std::unique(pages_to_render_.begin(),
                                      pages_to_render_.end()) -
                          pages_to_render_.begin());
  // Remove invalid pages.
  pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
                                           pages_to_render_.end(),
                                           total_page_count_) -
                          pages_to_render_.begin());
  print_ready_metafile_page_count_ = pages_to_render_.size();
  if (pages_to_render_.empty()) {
    print_ready_metafile_page_count_ = total_page_count_;
    // Render all pages.
    for (int i = 0; i < total_page_count_; ++i)
      pages_to_render_.push_back(i);
  } else if (generate_draft_pages_) {
    int pages_index = 0;
    for (int i = 0; i < total_page_count_; ++i) {
      if (pages_index < print_ready_metafile_page_count_ &&
          i == pages_to_render_[pages_index]) {
        pages_index++;
        continue;
      }
      pages_to_render_.push_back(i);
    }
  }

  document_render_time_ = base::TimeDelta();
  begin_time_ = base::TimeTicks::Now();

  return true;
}

void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
    const base::TimeDelta& page_time) {
  DCHECK_EQ(RENDERING, state_);
  document_render_time_ += page_time;
  UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
}

void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
  DCHECK_EQ(RENDERING, state_);
  state_ = DONE;
  prep_frame_view_->FinishPrinting();
}

void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
  DCHECK(IsRendering());

  base::TimeTicks begin_time = base::TimeTicks::Now();
  metafile_->FinishDocument();

  if (print_ready_metafile_page_count_ <= 0) {
    NOTREACHED();
    return;
  }

  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
                             document_render_time_);
  base::TimeDelta total_time = (base::TimeTicks::Now() - begin_time) +
                               document_render_time_;
  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
                             total_time);
  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
                             total_time / pages_to_render_.size());
}

void PrintWebViewHelper::PrintPreviewContext::Finished() {
  DCHECK_EQ(DONE, state_);
  state_ = INITIALIZED;
  ClearContext();
}

void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
  DCHECK(state_ == INITIALIZED || state_ == RENDERING);
  state_ = INITIALIZED;
  if (report_error) {
    DCHECK_NE(PREVIEW_ERROR_NONE, error_);
    UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
                              PREVIEW_ERROR_LAST_ENUM);
  }
  ClearContext();
}

int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
  DCHECK_EQ(RENDERING, state_);
  if (IsFinalPageRendered())
    return -1;
  return pages_to_render_[current_page_index_++];
}

bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
  return state_ == RENDERING || state_ == DONE;
}

bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
  // The only kind of node we can print right now is a PDF node.
  return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
}

bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
  return IsModifiable() && source_frame()->hasSelection();
}

bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
    const {
  DCHECK(IsRendering());
  return current_page_index_ == print_ready_metafile_page_count_;
}

bool  PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
  DCHECK(IsRendering());
  return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
}

void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
    bool generate_draft_pages) {
  DCHECK_EQ(INITIALIZED, state_);
  generate_draft_pages_ = generate_draft_pages;
}

void PrintWebViewHelper::PrintPreviewContext::set_error(
    enum PrintPreviewErrorBuckets error) {
  error_ = error;
}

blink::WebFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
  DCHECK(state_ != UNINITIALIZED);
  return source_frame_.GetFrame();
}

const blink::WebNode&
    PrintWebViewHelper::PrintPreviewContext::source_node() const {
  DCHECK(state_ != UNINITIALIZED);
  return source_node_;
}

blink::WebFrame* PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
  DCHECK(state_ != UNINITIALIZED);
  return prep_frame_view_->frame();
}

const blink::WebNode&
    PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
  DCHECK(state_ != UNINITIALIZED);
  return prep_frame_view_->node();
}

int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
  DCHECK(state_ != UNINITIALIZED);
  return total_page_count_;
}

bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
  return generate_draft_pages_;
}

PreviewMetafile* PrintWebViewHelper::PrintPreviewContext::metafile() {
  DCHECK(IsRendering());
  return metafile_.get();
}

int PrintWebViewHelper::PrintPreviewContext::last_error() const {
  return error_;
}

gfx::Size PrintWebViewHelper::PrintPreviewContext::GetPrintCanvasSize() const {
  DCHECK(IsRendering());
  return prep_frame_view_->GetPrintCanvasSize();
}

void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
  prep_frame_view_.reset();
  metafile_.reset();
  pages_to_render_.clear();
  error_ = PREVIEW_ERROR_NONE;
}

}  // namespace printing
/* [<][>][^][v][top][bottom][index][help] */
root/chrome/renderer/printing/print_web_view_helper.cc

DEFINITIONS
