components/printing/renderer/print_web_view_helper.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/printing/renderer/print_web_view_helper.h"
   6
   7 #include <string>
   8
   9 #include "base/auto_reset.h"
  10 #include "base/json/json_writer.h"
  11 #include "base/logging.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/metrics/histogram.h"
  14 #include "base/process/process_handle.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/stringprintf.h"
  17 #include "base/strings/utf_string_conversions.h"
  18 #include "components/printing/common/print_messages.h"
  19 #include "content/public/common/web_preferences.h"
  20 #include "content/public/renderer/render_frame.h"
  21 #include "content/public/renderer/render_thread.h"
  22 #include "content/public/renderer/render_view.h"
  23 #include "grit/components_resources.h"
  24 #include "net/base/escape.h"
  25 #include "printing/pdf_metafile_skia.h"
  26 #include "printing/units.h"
  27 #include "third_party/WebKit/public/platform/WebSize.h"
  28 #include "third_party/WebKit/public/platform/WebURLRequest.h"
  29 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  30 #include "third_party/WebKit/public/web/WebDocument.h"
  31 #include "third_party/WebKit/public/web/WebElement.h"
  32 #include "third_party/WebKit/public/web/WebFrameClient.h"
  33 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  34 #include "third_party/WebKit/public/web/WebPlugin.h"
  35 #include "third_party/WebKit/public/web/WebPluginDocument.h"
  36 #include "third_party/WebKit/public/web/WebPrintParams.h"
  37 #include "third_party/WebKit/public/web/WebPrintPresetOptions.h"
  38 #include "third_party/WebKit/public/web/WebPrintScalingOption.h"
  39 #include "third_party/WebKit/public/web/WebSandboxFlags.h"
  40 #include "third_party/WebKit/public/web/WebScriptSource.h"
  41 #include "third_party/WebKit/public/web/WebSettings.h"
  42 #include "third_party/WebKit/public/web/WebView.h"
  43 #include "third_party/WebKit/public/web/WebViewClient.h"
  44 #include "ui/base/resource/resource_bundle.h"
  45
  46 using content::WebPreferences;
  47
  48 namespace printing {
  49
  50 namespace {
  51
  52 enum PrintPreviewHelperEvents {
  53   PREVIEW_EVENT_REQUESTED,
  54   PREVIEW_EVENT_CACHE_HIT,  // Unused
  55   PREVIEW_EVENT_CREATE_DOCUMENT,
  56   PREVIEW_EVENT_NEW_SETTINGS,  // Unused
  57   PREVIEW_EVENT_MAX,
  58 };
  59
  60 const double kMinDpi = 1.0;
  61
  62 #if !defined(ENABLE_PRINT_PREVIEW)
  63 bool g_is_preview_enabled_ = false;
  64 #else
  65 bool g_is_preview_enabled_ = true;
  66
  67 const char kPageLoadScriptFormat[] =
  68     "document.open(); document.write(%s); document.close();";
  69
  70 const char kPageSetupScriptFormat[] = "setup(%s);";
  71
  72 void ExecuteScript(blink::WebFrame* frame,
  73                    const char* script_format,
  74                    const base::Value& parameters) {
  75   std::string json;
  76   base::JSONWriter::Write(&parameters, &json);
  77   std::string script = base::StringPrintf(script_format, json.c_str());
  78   frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
  79 }
  80 #endif  // !defined(ENABLE_PRINT_PREVIEW)
  81
  82 int GetDPI(const PrintMsg_Print_Params* print_params) {
  83 #if defined(OS_MACOSX)
  84   // On the Mac, the printable area is in points, don't do any scaling based
  85   // on dpi.
  86   return kPointsPerInch;
  87 #else
  88   return static_cast<int>(print_params->dpi);
  89 #endif  // defined(OS_MACOSX)
  90 }
  91
  92 bool PrintMsg_Print_Params_IsValid(const PrintMsg_Print_Params& params) {
  93   return !params.content_size.IsEmpty() && !params.page_size.IsEmpty() &&
  94          !params.printable_area.IsEmpty() && params.document_cookie &&
  95          params.desired_dpi && params.max_shrink && params.min_shrink &&
  96          params.dpi && (params.margin_top >= 0) && (params.margin_left >= 0) &&
  97          params.dpi > kMinDpi && params.document_cookie != 0;
  98 }
  99
 100 PrintMsg_Print_Params GetCssPrintParams(
 101     blink::WebFrame* frame,
 102     int page_index,
 103     const PrintMsg_Print_Params& page_params) {
 104   PrintMsg_Print_Params page_css_params = page_params;
 105   int dpi = GetDPI(&page_params);
 106
 107   blink::WebSize page_size_in_pixels(
 108       ConvertUnit(page_params.page_size.width(), dpi, kPixelsPerInch),
 109       ConvertUnit(page_params.page_size.height(), dpi, kPixelsPerInch));
 110   int margin_top_in_pixels =
 111       ConvertUnit(page_params.margin_top, dpi, kPixelsPerInch);
 112   int margin_right_in_pixels = ConvertUnit(
 113       page_params.page_size.width() -
 114       page_params.content_size.width() - page_params.margin_left,
 115       dpi, kPixelsPerInch);
 116   int margin_bottom_in_pixels = ConvertUnit(
 117       page_params.page_size.height() -
 118       page_params.content_size.height() - page_params.margin_top,
 119       dpi, kPixelsPerInch);
 120   int margin_left_in_pixels = ConvertUnit(
 121       page_params.margin_left,
 122       dpi, kPixelsPerInch);
 123
 124   blink::WebSize original_page_size_in_pixels = page_size_in_pixels;
 125
 126   if (frame) {
 127     frame->pageSizeAndMarginsInPixels(page_index,
 128                                       page_size_in_pixels,
 129                                       margin_top_in_pixels,
 130                                       margin_right_in_pixels,
 131                                       margin_bottom_in_pixels,
 132                                       margin_left_in_pixels);
 133   }
 134
 135   int new_content_width = page_size_in_pixels.width -
 136                           margin_left_in_pixels - margin_right_in_pixels;
 137   int new_content_height = page_size_in_pixels.height -
 138                            margin_top_in_pixels - margin_bottom_in_pixels;
 139
 140   // Invalid page size and/or margins. We just use the default setting.
 141   if (new_content_width < 1 || new_content_height < 1) {
 142     CHECK(frame != NULL);
 143     page_css_params = GetCssPrintParams(NULL, page_index, page_params);
 144     return page_css_params;
 145   }
 146
 147   page_css_params.content_size =
 148       gfx::Size(ConvertUnit(new_content_width, kPixelsPerInch, dpi),
 149                 ConvertUnit(new_content_height, kPixelsPerInch, dpi));
 150
 151   if (original_page_size_in_pixels != page_size_in_pixels) {
 152     page_css_params.page_size =
 153         gfx::Size(ConvertUnit(page_size_in_pixels.width, kPixelsPerInch, dpi),
 154                   ConvertUnit(page_size_in_pixels.height, kPixelsPerInch, dpi));
 155   } else {
 156     // Printing frame doesn't have any page size css. Pixels to dpi conversion
 157     // causes rounding off errors. Therefore use the default page size values
 158     // directly.
 159     page_css_params.page_size = page_params.page_size;
 160   }
 161
 162   page_css_params.margin_top =
 163       ConvertUnit(margin_top_in_pixels, kPixelsPerInch, dpi);
 164   page_css_params.margin_left =
 165       ConvertUnit(margin_left_in_pixels, kPixelsPerInch, dpi);
 166   return page_css_params;
 167 }
 168
 169 double FitPrintParamsToPage(const PrintMsg_Print_Params& page_params,
 170                             PrintMsg_Print_Params* params_to_fit) {
 171   double content_width =
 172       static_cast<double>(params_to_fit->content_size.width());
 173   double content_height =
 174       static_cast<double>(params_to_fit->content_size.height());
 175   int default_page_size_height = page_params.page_size.height();
 176   int default_page_size_width = page_params.page_size.width();
 177   int css_page_size_height = params_to_fit->page_size.height();
 178   int css_page_size_width = params_to_fit->page_size.width();
 179
 180   double scale_factor = 1.0f;
 181   if (page_params.page_size == params_to_fit->page_size)
 182     return scale_factor;
 183
 184   if (default_page_size_width < css_page_size_width ||
 185       default_page_size_height < css_page_size_height) {
 186     double ratio_width =
 187         static_cast<double>(default_page_size_width) / css_page_size_width;
 188     double ratio_height =
 189         static_cast<double>(default_page_size_height) / css_page_size_height;
 190     scale_factor = ratio_width < ratio_height ? ratio_width : ratio_height;
 191     content_width *= scale_factor;
 192     content_height *= scale_factor;
 193   }
 194   params_to_fit->margin_top = static_cast<int>(
 195       (default_page_size_height - css_page_size_height * scale_factor) / 2 +
 196       (params_to_fit->margin_top * scale_factor));
 197   params_to_fit->margin_left = static_cast<int>(
 198       (default_page_size_width - css_page_size_width * scale_factor) / 2 +
 199       (params_to_fit->margin_left * scale_factor));
 200   params_to_fit->content_size = gfx::Size(static_cast<int>(content_width),
 201                                           static_cast<int>(content_height));
 202   params_to_fit->page_size = page_params.page_size;
 203   return scale_factor;
 204 }
 205
 206 void CalculatePageLayoutFromPrintParams(
 207     const PrintMsg_Print_Params& params,
 208     PageSizeMargins* page_layout_in_points) {
 209   int dpi = GetDPI(&params);
 210   int content_width = params.content_size.width();
 211   int content_height = params.content_size.height();
 212
 213   int margin_bottom =
 214       params.page_size.height() - content_height - params.margin_top;
 215   int margin_right =
 216       params.page_size.width() - content_width - params.margin_left;
 217
 218   page_layout_in_points->content_width =
 219       ConvertUnit(content_width, dpi, kPointsPerInch);
 220   page_layout_in_points->content_height =
 221       ConvertUnit(content_height, dpi, kPointsPerInch);
 222   page_layout_in_points->margin_top =
 223       ConvertUnit(params.margin_top, dpi, kPointsPerInch);
 224   page_layout_in_points->margin_right =
 225       ConvertUnit(margin_right, dpi, kPointsPerInch);
 226   page_layout_in_points->margin_bottom =
 227       ConvertUnit(margin_bottom, dpi, kPointsPerInch);
 228   page_layout_in_points->margin_left =
 229       ConvertUnit(params.margin_left, dpi, kPointsPerInch);
 230 }
 231
 232 void EnsureOrientationMatches(const PrintMsg_Print_Params& css_params,
 233                               PrintMsg_Print_Params* page_params) {
 234   if ((page_params->page_size.width() > page_params->page_size.height()) ==
 235       (css_params.page_size.width() > css_params.page_size.height())) {
 236     return;
 237   }
 238
 239   // Swap the |width| and |height| values.
 240   page_params->page_size.SetSize(page_params->page_size.height(),
 241                                  page_params->page_size.width());
 242   page_params->content_size.SetSize(page_params->content_size.height(),
 243                                     page_params->content_size.width());
 244   page_params->printable_area.set_size(
 245       gfx::Size(page_params->printable_area.height(),
 246                 page_params->printable_area.width()));
 247 }
 248
 249 void ComputeWebKitPrintParamsInDesiredDpi(
 250     const PrintMsg_Print_Params& print_params,
 251     blink::WebPrintParams* webkit_print_params) {
 252   int dpi = GetDPI(&print_params);
 253   webkit_print_params->printerDPI = dpi;
 254   webkit_print_params->printScalingOption = print_params.print_scaling_option;
 255
 256   webkit_print_params->printContentArea.width = ConvertUnit(
 257       print_params.content_size.width(), dpi, print_params.desired_dpi);
 258   webkit_print_params->printContentArea.height = ConvertUnit(
 259       print_params.content_size.height(), dpi, print_params.desired_dpi);
 260
 261   webkit_print_params->printableArea.x = ConvertUnit(
 262       print_params.printable_area.x(), dpi, print_params.desired_dpi);
 263   webkit_print_params->printableArea.y = ConvertUnit(
 264       print_params.printable_area.y(), dpi, print_params.desired_dpi);
 265   webkit_print_params->printableArea.width = ConvertUnit(
 266       print_params.printable_area.width(), dpi, print_params.desired_dpi);
 267   webkit_print_params->printableArea.height = ConvertUnit(
 268       print_params.printable_area.height(), dpi, print_params.desired_dpi);
 269
 270   webkit_print_params->paperSize.width = ConvertUnit(
 271       print_params.page_size.width(), dpi, print_params.desired_dpi);
 272   webkit_print_params->paperSize.height = ConvertUnit(
 273       print_params.page_size.height(), dpi, print_params.desired_dpi);
 274 }
 275
 276 blink::WebPlugin* GetPlugin(const blink::WebFrame* frame) {
 277   return frame->document().isPluginDocument()
 278              ? frame->document().to<blink::WebPluginDocument>().plugin()
 279              : NULL;
 280 }
 281
 282 bool PrintingNodeOrPdfFrame(const blink::WebFrame* frame,
 283                             const blink::WebNode& node) {
 284   if (!node.isNull())
 285     return true;
 286   blink::WebPlugin* plugin = GetPlugin(frame);
 287   return plugin && plugin->supportsPaginatedPrint();
 288 }
 289
 290 bool PrintingFrameHasPageSizeStyle(blink::WebFrame* frame,
 291                                    int total_page_count) {
 292   if (!frame)
 293     return false;
 294   bool frame_has_custom_page_size_style = false;
 295   for (int i = 0; i < total_page_count; ++i) {
 296     if (frame->hasCustomPageSizeStyle(i)) {
 297       frame_has_custom_page_size_style = true;
 298       break;
 299     }
 300   }
 301   return frame_has_custom_page_size_style;
 302 }
 303
 304 MarginType GetMarginsForPdf(blink::WebFrame* frame,
 305                             const blink::WebNode& node) {
 306   if (frame->isPrintScalingDisabledForPlugin(node))
 307     return NO_MARGINS;
 308   else
 309     return PRINTABLE_AREA_MARGINS;
 310 }
 311
 312 bool FitToPageEnabled(const base::DictionaryValue& job_settings) {
 313   bool fit_to_paper_size = false;
 314   if (!job_settings.GetBoolean(kSettingFitToPageEnabled, &fit_to_paper_size)) {
 315     NOTREACHED();
 316   }
 317   return fit_to_paper_size;
 318 }
 319
 320 // Returns the print scaling option to retain/scale/crop the source page size
 321 // to fit the printable area of the paper.
 322 //
 323 // We retain the source page size when the current destination printer is
 324 // SAVE_AS_PDF.
 325 //
 326 // We crop the source page size to fit the printable area or we print only the
 327 // left top page contents when
 328 // (1) Source is PDF and the user has requested not to fit to printable area
 329 // via |job_settings|.
 330 // (2) Source is PDF. This is the first preview request and print scaling
 331 // option is disabled for initiator renderer plugin.
 332 //
 333 // In all other cases, we scale the source page to fit the printable area.
 334 blink::WebPrintScalingOption GetPrintScalingOption(
 335     blink::WebFrame* frame,
 336     const blink::WebNode& node,
 337     bool source_is_html,
 338     const base::DictionaryValue& job_settings,
 339     const PrintMsg_Print_Params& params) {
 340   if (params.print_to_pdf)
 341     return blink::WebPrintScalingOptionSourceSize;
 342
 343   if (!source_is_html) {
 344     if (!FitToPageEnabled(job_settings))
 345       return blink::WebPrintScalingOptionNone;
 346
 347     bool no_plugin_scaling = frame->isPrintScalingDisabledForPlugin(node);
 348
 349     if (params.is_first_request && no_plugin_scaling)
 350       return blink::WebPrintScalingOptionNone;
 351   }
 352   return blink::WebPrintScalingOptionFitToPrintableArea;
 353 }
 354
 355 PrintMsg_Print_Params CalculatePrintParamsForCss(
 356     blink::WebFrame* frame,
 357     int page_index,
 358     const PrintMsg_Print_Params& page_params,
 359     bool ignore_css_margins,
 360     bool fit_to_page,
 361     double* scale_factor) {
 362   PrintMsg_Print_Params css_params =
 363       GetCssPrintParams(frame, page_index, page_params);
 364
 365   PrintMsg_Print_Params params = page_params;
 366   EnsureOrientationMatches(css_params, &params);
 367
 368   if (ignore_css_margins && fit_to_page)
 369     return params;
 370
 371   PrintMsg_Print_Params result_params = css_params;
 372   if (ignore_css_margins) {
 373     result_params.margin_top = params.margin_top;
 374     result_params.margin_left = params.margin_left;
 375
 376     DCHECK(!fit_to_page);
 377     // Since we are ignoring the margins, the css page size is no longer
 378     // valid.
 379     int default_margin_right = params.page_size.width() -
 380                                params.content_size.width() - params.margin_left;
 381     int default_margin_bottom = params.page_size.height() -
 382                                 params.content_size.height() -
 383                                 params.margin_top;
 384     result_params.content_size =
 385         gfx::Size(result_params.page_size.width() - result_params.margin_left -
 386                       default_margin_right,
 387                   result_params.page_size.height() - result_params.margin_top -
 388                       default_margin_bottom);
 389   }
 390
 391   if (fit_to_page) {
 392     double factor = FitPrintParamsToPage(params, &result_params);
 393     if (scale_factor)
 394       *scale_factor = factor;
 395   }
 396   return result_params;
 397 }
 398
 399 }  // namespace
 400
 401 FrameReference::FrameReference(blink::WebLocalFrame* frame) {
 402   Reset(frame);
 403 }
 404
 405 FrameReference::FrameReference() {
 406   Reset(NULL);
 407 }
 408
 409 FrameReference::~FrameReference() {
 410 }
 411
 412 void FrameReference::Reset(blink::WebLocalFrame* frame) {
 413   if (frame) {
 414     view_ = frame->view();
 415     frame_ = frame;
 416   } else {
 417     view_ = NULL;
 418     frame_ = NULL;
 419   }
 420 }
 421
 422 blink::WebLocalFrame* FrameReference::GetFrame() {
 423   if (view_ == NULL || frame_ == NULL)
 424     return NULL;
 425   for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
 426        frame = frame->traverseNext(false)) {
 427     if (frame == frame_)
 428       return frame_;
 429   }
 430   return NULL;
 431 }
 432
 433 blink::WebView* FrameReference::view() {
 434   return view_;
 435 }
 436
 437 #if defined(ENABLE_PRINT_PREVIEW)
 438 // static - Not anonymous so that platform implementations can use it.
 439 void PrintWebViewHelper::PrintHeaderAndFooter(
 440     blink::WebCanvas* canvas,
 441     int page_number,
 442     int total_pages,
 443     const blink::WebFrame& source_frame,
 444     float webkit_scale_factor,
 445     const PageSizeMargins& page_layout,
 446     const PrintMsg_Print_Params& params) {
 447   SkAutoCanvasRestore auto_restore(canvas, true);
 448   canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);
 449
 450   blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
 451                                page_layout.content_width,
 452                            page_layout.margin_top + page_layout.margin_bottom +
 453                                page_layout.content_height);
 454
 455   blink::WebView* web_view = blink::WebView::create(NULL);
 456   web_view->settings()->setJavaScriptEnabled(true);
 457
 458   blink::WebLocalFrame* frame = blink::WebLocalFrame::create(NULL);
 459   web_view->setMainFrame(frame);
 460
 461   base::StringValue html(ResourceBundle::GetSharedInstance().GetLocalizedString(
 462       IDR_PRINT_PREVIEW_PAGE));
 463   // Load page with script to avoid async operations.
 464   ExecuteScript(frame, kPageLoadScriptFormat, html);
 465
 466   scoped_ptr<base::DictionaryValue> options(new base::DictionaryValue());
 467   options.reset(new base::DictionaryValue());
 468   options->SetDouble(kSettingHeaderFooterDate, base::Time::Now().ToJsTime());
 469   options->SetDouble("width", page_size.width);
 470   options->SetDouble("height", page_size.height);
 471   options->SetDouble("topMargin", page_layout.margin_top);
 472   options->SetDouble("bottomMargin", page_layout.margin_bottom);
 473   options->SetString("pageNumber",
 474                      base::StringPrintf("%d/%d", page_number, total_pages));
 475
 476   // Fallback to initiator URL and title if it's empty for printed frame.
 477   base::string16 url = source_frame.document().url().string();
 478   options->SetString("url", url.empty() ? params.url : url);
 479   base::string16 title = source_frame.document().title();
 480   options->SetString("title", title.empty() ? params.title : title);
 481
 482   ExecuteScript(frame, kPageSetupScriptFormat, *options);
 483
 484   blink::WebPrintParams webkit_params(page_size);
 485   webkit_params.printerDPI = GetDPI(&params);
 486
 487   frame->printBegin(webkit_params);
 488   frame->printPage(0, canvas);
 489   frame->printEnd();
 490
 491   web_view->close();
 492   frame->close();
 493 }
 494 #endif  // defined(ENABLE_PRINT_PREVIEW)
 495
 496 // static - Not anonymous so that platform implementations can use it.
 497 float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
 498                                             int page_number,
 499                                             const gfx::Rect& canvas_area,
 500                                             const gfx::Rect& content_area,
 501                                             double scale_factor,
 502                                             blink::WebCanvas* canvas) {
 503   SkAutoCanvasRestore auto_restore(canvas, true);
 504   canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
 505                     (content_area.y() - canvas_area.y()) / scale_factor);
 506   return frame->printPage(page_number, canvas);
 507 }
 508
 509 // Class that calls the Begin and End print functions on the frame and changes
 510 // the size of the view temporarily to support full page printing..
 511 class PrepareFrameAndViewForPrint : public blink::WebViewClient,
 512                                     public blink::WebFrameClient {
 513  public:
 514   PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
 515                               blink::WebLocalFrame* frame,
 516                               const blink::WebNode& node,
 517                               bool ignore_css_margins);
 518   virtual ~PrepareFrameAndViewForPrint();
 519
 520   // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
 521   // when completed.
 522   void CopySelectionIfNeeded(const WebPreferences& preferences,
 523                              const base::Closure& on_ready);
 524
 525   // Prepares frame for printing.
 526   void StartPrinting();
 527
 528   blink::WebLocalFrame* frame() { return frame_.GetFrame(); }
 529
 530   const blink::WebNode& node() const { return node_to_print_; }
 531
 532   int GetExpectedPageCount() const { return expected_pages_count_; }
 533
 534   void FinishPrinting();
 535
 536   bool IsLoadingSelection() {
 537     // It's not selection if not |owns_web_view_|.
 538     return owns_web_view_ && frame() && frame()->isLoading();
 539   }
 540
 541   // TODO(ojan): Remove this override and have this class use a non-null
 542   // layerTreeView.
 543   // blink::WebViewClient override:
 544   virtual bool allowsBrokenNullLayerTreeView() const;
 545
 546  protected:
 547   // blink::WebViewClient override:
 548   virtual void didStopLoading();
 549
 550   // blink::WebFrameClient override:
 551   virtual blink::WebFrame* createChildFrame(
 552       blink::WebLocalFrame* parent,
 553       const blink::WebString& name,
 554       blink::WebSandboxFlags sandboxFlags);
 555   virtual void frameDetached(blink::WebFrame* frame);
 556
 557  private:
 558   void CallOnReady();
 559   void ResizeForPrinting();
 560   void RestoreSize();
 561   void CopySelection(const WebPreferences& preferences);
 562
 563   FrameReference frame_;
 564   blink::WebNode node_to_print_;
 565   bool owns_web_view_;
 566   blink::WebPrintParams web_print_params_;
 567   gfx::Size prev_view_size_;
 568   gfx::Size prev_scroll_offset_;
 569   int expected_pages_count_;
 570   base::Closure on_ready_;
 571   bool should_print_backgrounds_;
 572   bool should_print_selection_only_;
 573   bool is_printing_started_;
 574
 575   base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
 576
 577   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 578 };
 579
 580 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
 581     const PrintMsg_Print_Params& params,
 582     blink::WebLocalFrame* frame,
 583     const blink::WebNode& node,
 584     bool ignore_css_margins)
 585     : frame_(frame),
 586       node_to_print_(node),
 587       owns_web_view_(false),
 588       expected_pages_count_(0),
 589       should_print_backgrounds_(params.should_print_backgrounds),
 590       should_print_selection_only_(params.selection_only),
 591       is_printing_started_(false),
 592       weak_ptr_factory_(this) {
 593   PrintMsg_Print_Params print_params = params;
 594   if (!should_print_selection_only_ ||
 595       !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
 596     bool fit_to_page = ignore_css_margins &&
 597                        print_params.print_scaling_option ==
 598                            blink::WebPrintScalingOptionFitToPrintableArea;
 599     ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
 600     frame->printBegin(web_print_params_, node_to_print_);
 601     print_params = CalculatePrintParamsForCss(
 602         frame, 0, print_params, ignore_css_margins, fit_to_page, NULL);
 603     frame->printEnd();
 604   }
 605   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
 606 }
 607
 608 PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
 609   FinishPrinting();
 610 }
 611
 612 void PrepareFrameAndViewForPrint::ResizeForPrinting() {
 613   // Layout page according to printer page size. Since WebKit shrinks the
 614   // size of the page automatically (from 125% to 200%) we trick it to
 615   // think the page is 125% larger so the size of the page is correct for
 616   // minimum (default) scaling.
 617   // This is important for sites that try to fill the page.
 618   gfx::Size print_layout_size(web_print_params_.printContentArea.width,
 619                               web_print_params_.printContentArea.height);
 620   print_layout_size.set_height(
 621       static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
 622
 623   if (!frame())
 624     return;
 625   blink::WebView* web_view = frame_.view();
 626   // Backup size and offset.
 627   if (blink::WebFrame* web_frame = web_view->mainFrame())
 628     prev_scroll_offset_ = web_frame->scrollOffset();
 629   prev_view_size_ = web_view->size();
 630
 631   web_view->resize(print_layout_size);
 632 }
 633
 634 void PrepareFrameAndViewForPrint::StartPrinting() {
 635   ResizeForPrinting();
 636   blink::WebView* web_view = frame_.view();
 637   web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
 638   expected_pages_count_ =
 639       frame()->printBegin(web_print_params_, node_to_print_);
 640   is_printing_started_ = true;
 641 }
 642
 643 void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
 644     const WebPreferences& preferences,
 645     const base::Closure& on_ready) {
 646   on_ready_ = on_ready;
 647   if (should_print_selection_only_) {
 648     CopySelection(preferences);
 649   } else {
 650     // Call immediately, async call crashes scripting printing.
 651     CallOnReady();
 652   }
 653 }
 654
 655 void PrepareFrameAndViewForPrint::CopySelection(
 656     const WebPreferences& preferences) {
 657   ResizeForPrinting();
 658   std::string url_str = "data:text/html;charset=utf-8,";
 659   url_str.append(
 660       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
 661   RestoreSize();
 662   // Create a new WebView with the same settings as the current display one.
 663   // Except that we disable javascript (don't want any active content running
 664   // on the page).
 665   WebPreferences prefs = preferences;
 666   prefs.javascript_enabled = false;
 667   prefs.java_enabled = false;
 668
 669   blink::WebView* web_view = blink::WebView::create(this);
 670   owns_web_view_ = true;
 671   content::RenderView::ApplyWebPreferences(prefs, web_view);
 672   web_view->setMainFrame(blink::WebLocalFrame::create(this));
 673   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
 674   node_to_print_.reset();
 675
 676   // When loading is done this will call didStopLoading() and that will do the
 677   // actual printing.
 678   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 679 }
 680
 681 bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
 682   return true;
 683 }
 684
 685 void PrepareFrameAndViewForPrint::didStopLoading() {
 686   DCHECK(!on_ready_.is_null());
 687   // Don't call callback here, because it can delete |this| and WebView that is
 688   // called didStopLoading.
 689   base::MessageLoop::current()->PostTask(
 690       FROM_HERE, base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
 691                             weak_ptr_factory_.GetWeakPtr()));
 692 }
 693
 694 blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
 695     blink::WebLocalFrame* parent,
 696     const blink::WebString& name,
 697     blink::WebSandboxFlags sandboxFlags) {
 698   blink::WebFrame* frame = blink::WebLocalFrame::create(this);
 699   parent->appendChild(frame);
 700   return frame;
 701 }
 702
 703 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame) {
 704   if (frame->parent())
 705     frame->parent()->removeChild(frame);
 706   frame->close();
 707 }
 708
 709 void PrepareFrameAndViewForPrint::CallOnReady() {
 710   return on_ready_.Run();  // Can delete |this|.
 711 }
 712
 713 void PrepareFrameAndViewForPrint::RestoreSize() {
 714   if (frame()) {
 715     blink::WebView* web_view = frame_.GetFrame()->view();
 716     web_view->resize(prev_view_size_);
 717     if (blink::WebFrame* web_frame = web_view->mainFrame())
 718       web_frame->setScrollOffset(prev_scroll_offset_);
 719   }
 720 }
 721
 722 void PrepareFrameAndViewForPrint::FinishPrinting() {
 723   blink::WebLocalFrame* frame = frame_.GetFrame();
 724   if (frame) {
 725     blink::WebView* web_view = frame->view();
 726     if (is_printing_started_) {
 727       is_printing_started_ = false;
 728       frame->printEnd();
 729       if (!owns_web_view_) {
 730         web_view->settings()->setShouldPrintBackgrounds(false);
 731         RestoreSize();
 732       }
 733     }
 734     if (owns_web_view_) {
 735       DCHECK(!frame->isLoading());
 736       owns_web_view_ = false;
 737       web_view->close();
 738     }
 739   }
 740   frame_.Reset(NULL);
 741   on_ready_.Reset();
 742 }
 743
 744 bool PrintWebViewHelper::Delegate::IsAskPrintSettingsEnabled() {
 745   return true;
 746 }
 747
 748 bool PrintWebViewHelper::Delegate::IsScriptedPrintEnabled() {
 749   return true;
 750 }
 751
 752 PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view,
 753                                        scoped_ptr<Delegate> delegate)
 754     : content::RenderViewObserver(render_view),
 755       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
 756       reset_prep_frame_view_(false),
 757       is_print_ready_metafile_sent_(false),
 758       ignore_css_margins_(false),
 759       is_scripted_printing_blocked_(false),
 760       notify_browser_of_print_failure_(true),
 761       print_for_preview_(false),
 762       delegate_(delegate.Pass()),
 763       print_node_in_progress_(false),
 764       is_loading_(false),
 765       is_scripted_preview_delayed_(false),
 766       weak_ptr_factory_(this) {
 767   if (!delegate_->IsPrintPreviewEnabled())
 768     DisablePreview();
 769 }
 770
 771 PrintWebViewHelper::~PrintWebViewHelper() {
 772 }
 773
 774 // static
 775 void PrintWebViewHelper::DisablePreview() {
 776   g_is_preview_enabled_ = false;
 777 }
 778
 779 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(blink::WebFrame* frame,
 780                                                        bool user_initiated) {
 781   if (!delegate_->IsScriptedPrintEnabled())
 782     return false;
 783
 784   // If preview is enabled, then the print dialog is tab modal, and the user
 785   // can always close the tab on a mis-behaving page (the system print dialog
 786   // is app modal). If the print was initiated through user action, don't
 787   // throttle. Or, if the command line flag to skip throttling has been set.
 788   return !is_scripted_printing_blocked_ &&
 789          (user_initiated || g_is_preview_enabled_ ||
 790           scripting_throttler_.IsAllowed(frame));
 791 }
 792
 793 void PrintWebViewHelper::DidStartLoading() {
 794   is_loading_ = true;
 795 }
 796
 797 void PrintWebViewHelper::DidStopLoading() {
 798   is_loading_ = false;
 799   if (!on_stop_loading_closure_.is_null()) {
 800     on_stop_loading_closure_.Run();
 801     on_stop_loading_closure_.Reset();
 802   }
 803 }
 804
 805 // Prints |frame| which called window.print().
 806 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
 807                                    bool user_initiated) {
 808   DCHECK(frame);
 809
 810   // Allow Prerendering to cancel this print request if necessary.
 811   if (delegate_->CancelPrerender(render_view(), routing_id()))
 812     return;
 813
 814   if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
 815     return;
 816
 817   if (delegate_->OverridePrint(frame))
 818     return;
 819
 820   if (!g_is_preview_enabled_) {
 821     Print(frame, blink::WebNode(), true);
 822   } else {
 823     print_preview_context_.InitWithFrame(frame);
 824     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
 825   }
 826 }
 827
 828 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
 829   bool handled = true;
 830   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
 831 #if defined(ENABLE_BASIC_PRINTING)
 832     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
 833     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
 834 #endif  // ENABLE_BASIC_PRINTING
 835     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
 836     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
 837     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
 838     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
 839     IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
 840                         SetScriptedPrintBlocked)
 841     IPC_MESSAGE_UNHANDLED(handled = false)
 842     IPC_END_MESSAGE_MAP()
 843   return handled;
 844 }
 845
 846 void PrintWebViewHelper::OnPrintForPrintPreview(
 847     const base::DictionaryValue& job_settings) {
 848   // If still not finished with earlier print request simply ignore.
 849   if (prep_frame_view_)
 850     return;
 851
 852   if (!render_view()->GetWebView())
 853     return;
 854   blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
 855   if (!main_frame)
 856     return;
 857
 858   blink::WebDocument document = main_frame->document();
 859   // <object>/<iframe> with id="pdf-viewer" is created in
 860   // chrome/browser/resources/print_preview/print_preview.js
 861   blink::WebElement pdf_element = document.getElementById("pdf-viewer");
 862   if (pdf_element.isNull()) {
 863     NOTREACHED();
 864     return;
 865   }
 866
 867   // The out-of-process plugin element is nested within a frame. In tests, there
 868   // may not be an iframe containing the out-of-process plugin, so continue with
 869   // the element with ID "pdf-viewer" if it isn't an iframe.
 870   blink::WebLocalFrame* plugin_frame = pdf_element.document().frame();
 871   blink::WebElement plugin_element = pdf_element;
 872   if (delegate_->IsOutOfProcessPdfEnabled() &&
 873       pdf_element.hasHTMLTagName("iframe")) {
 874     plugin_frame = blink::WebLocalFrame::fromFrameOwnerElement(pdf_element);
 875     plugin_element = delegate_->GetPdfElement(plugin_frame);
 876     if (plugin_element.isNull()) {
 877       NOTREACHED();
 878       return;
 879     }
 880   }
 881
 882   // Set |print_for_preview_| flag and autoreset it to back to original
 883   // on return.
 884   base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
 885
 886   if (!UpdatePrintSettings(plugin_frame, plugin_element, job_settings)) {
 887     LOG(ERROR) << "UpdatePrintSettings failed";
 888     DidFinishPrinting(FAIL_PRINT);
 889     return;
 890   }
 891
 892   // Print page onto entire page not just printable area. Preview PDF already
 893   // has content in correct position taking into account page size and printable
 894   // area.
 895   // TODO(vitalybuka) : Make this consistent on all platform. This change
 896   // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
 897   // printable_area. Also we can't change printable_area deeper inside
 898   // RenderPagesForPrint for Windows, because it's used also by native
 899   // printing and it expects real printable_area value.
 900   // See http://crbug.com/123408
 901   PrintMsg_Print_Params& print_params = print_pages_params_->params;
 902   print_params.printable_area = gfx::Rect(print_params.page_size);
 903
 904   // Render Pages for printing.
 905   if (!RenderPagesForPrint(plugin_frame, plugin_element)) {
 906     LOG(ERROR) << "RenderPagesForPrint failed";
 907     DidFinishPrinting(FAIL_PRINT);
 908   }
 909 }
 910
 911 bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
 912   DCHECK(frame);
 913   blink::WebView* webView = render_view()->GetWebView();
 914   DCHECK(webView);
 915   if (!webView)
 916     return false;
 917
 918   // If the user has selected text in the currently focused frame we print
 919   // only that frame (this makes print selection work for multiple frames).
 920   blink::WebLocalFrame* focusedFrame =
 921       webView->focusedFrame()->toWebLocalFrame();
 922   *frame = focusedFrame->hasSelection()
 923                ? focusedFrame
 924                : webView->mainFrame()->toWebLocalFrame();
 925   return true;
 926 }
 927
 928 #if defined(ENABLE_BASIC_PRINTING)
 929 void PrintWebViewHelper::OnPrintPages() {
 930   blink::WebLocalFrame* frame;
 931   if (!GetPrintFrame(&frame))
 932     return;
 933   // If we are printing a PDF extension frame, find the plugin node and print
 934   // that instead.
 935   auto plugin = delegate_->GetPdfElement(frame);
 936   Print(frame, plugin, false);
 937 }
 938
 939 void PrintWebViewHelper::OnPrintForSystemDialog() {
 940   blink::WebLocalFrame* frame = print_preview_context_.source_frame();
 941   if (!frame) {
 942     NOTREACHED();
 943     return;
 944   }
 945   Print(frame, print_preview_context_.source_node(), false);
 946 }
 947 #endif  // ENABLE_BASIC_PRINTING
 948
 949 void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
 950     const PageSizeMargins& page_layout_in_points,
 951     gfx::Size* page_size,
 952     gfx::Rect* content_area) {
 953   *page_size = gfx::Size(
 954       page_layout_in_points.content_width + page_layout_in_points.margin_right +
 955           page_layout_in_points.margin_left,
 956       page_layout_in_points.content_height + page_layout_in_points.margin_top +
 957           page_layout_in_points.margin_bottom);
 958   *content_area = gfx::Rect(page_layout_in_points.margin_left,
 959                             page_layout_in_points.margin_top,
 960                             page_layout_in_points.content_width,
 961                             page_layout_in_points.content_height);
 962 }
 963
 964 void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
 965     const base::DictionaryValue& settings) {
 966   int margins_type = 0;
 967   if (!settings.GetInteger(kSettingMarginsType, &margins_type))
 968     margins_type = DEFAULT_MARGINS;
 969   ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
 970 }
 971
 972 bool PrintWebViewHelper::IsPrintToPdfRequested(
 973     const base::DictionaryValue& job_settings) {
 974   bool print_to_pdf = false;
 975   if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
 976     NOTREACHED();
 977   return print_to_pdf;
 978 }
 979
 980 void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
 981   print_preview_context_.OnPrintPreview();
 982
 983   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
 984                             PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
 985
 986   if (!print_preview_context_.source_frame()) {
 987     DidFinishPrinting(FAIL_PREVIEW);
 988     return;
 989   }
 990
 991   if (!UpdatePrintSettings(print_preview_context_.source_frame(),
 992                            print_preview_context_.source_node(), settings)) {
 993     if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
 994       Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
 995           routing_id(), print_pages_params_
 996                             ? print_pages_params_->params.document_cookie
 997                             : 0));
 998       notify_browser_of_print_failure_ = false;  // Already sent.
 999     }
1000     DidFinishPrinting(FAIL_PREVIEW);
1001     return;
1002   }
1003
1004   // Set the options from document if we are previewing a pdf and send a
1005   // message to browser.
1006   if (print_pages_params_->params.is_first_request &&
1007       !print_preview_context_.IsModifiable()) {
1008     PrintHostMsg_SetOptionsFromDocument_Params params;
1009     SetOptionsFromDocument(params);
1010     Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), params));
1011   }
1012
1013   is_print_ready_metafile_sent_ = false;
1014
1015   // PDF printer device supports alpha blending.
1016   print_pages_params_->params.supports_alpha_blend = true;
1017
1018   bool generate_draft_pages = false;
1019   if (!settings.GetBoolean(kSettingGenerateDraftData, &generate_draft_pages)) {
1020     NOTREACHED();
1021   }
1022   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1023
1024   PrepareFrameForPreviewDocument();
1025 }
1026
1027 void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1028   reset_prep_frame_view_ = false;
1029
1030   if (!print_pages_params_ || CheckForCancel()) {
1031     DidFinishPrinting(FAIL_PREVIEW);
1032     return;
1033   }
1034
1035   // Don't reset loading frame or WebKit will fail assert. Just retry when
1036   // current selection is loaded.
1037   if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1038     reset_prep_frame_view_ = true;
1039     return;
1040   }
1041
1042   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1043   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1044       print_params, print_preview_context_.source_frame(),
1045       print_preview_context_.source_node(), ignore_css_margins_));
1046   prep_frame_view_->CopySelectionIfNeeded(
1047       render_view()->GetWebkitPreferences(),
1048       base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1049                  base::Unretained(this)));
1050 }
1051
1052 void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1053   if (reset_prep_frame_view_) {
1054     PrepareFrameForPreviewDocument();
1055     return;
1056   }
1057   DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1058 }
1059
1060 bool PrintWebViewHelper::CreatePreviewDocument() {
1061   if (!print_pages_params_ || CheckForCancel())
1062     return false;
1063
1064   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1065                             PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1066
1067   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1068   const std::vector<int>& pages = print_pages_params_->pages;
1069
1070   if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1071                                                     pages)) {
1072     return false;
1073   }
1074
1075   PageSizeMargins default_page_layout;
1076   ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1077                                   print_params, ignore_css_margins_, NULL,
1078                                   &default_page_layout);
1079
1080   bool has_page_size_style =
1081       PrintingFrameHasPageSizeStyle(print_preview_context_.prepared_frame(),
1082                                     print_preview_context_.total_page_count());
1083   int dpi = GetDPI(&print_params);
1084
1085   gfx::Rect printable_area_in_points(
1086       ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1087       ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1088       ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1089       ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1090
1091   // Margins: Send default page layout to browser process.
1092   Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1093                                                 default_page_layout,
1094                                                 printable_area_in_points,
1095                                                 has_page_size_style));
1096
1097   PrintHostMsg_DidGetPreviewPageCount_Params params;
1098   params.page_count = print_preview_context_.total_page_count();
1099   params.is_modifiable = print_preview_context_.IsModifiable();
1100   params.document_cookie = print_params.document_cookie;
1101   params.preview_request_id = print_params.preview_request_id;
1102   params.clear_preview_data = print_preview_context_.generate_draft_pages();
1103   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1104   if (CheckForCancel())
1105     return false;
1106
1107   while (!print_preview_context_.IsFinalPageRendered()) {
1108     int page_number = print_preview_context_.GetNextPageNumber();
1109     DCHECK_GE(page_number, 0);
1110     if (!RenderPreviewPage(page_number, print_params))
1111       return false;
1112
1113     if (CheckForCancel())
1114       return false;
1115
1116     // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1117     // print_preview_context_.AllPagesRendered()) before calling
1118     // FinalizePrintReadyDocument() when printing a PDF because the plugin
1119     // code does not generate output until we call FinishPrinting().  We do not
1120     // generate draft pages for PDFs, so IsFinalPageRendered() and
1121     // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1122     // the loop.
1123     if (print_preview_context_.IsFinalPageRendered())
1124       print_preview_context_.AllPagesRendered();
1125
1126     if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1127       DCHECK(print_preview_context_.IsModifiable() ||
1128              print_preview_context_.IsFinalPageRendered());
1129       if (!FinalizePrintReadyDocument())
1130         return false;
1131     }
1132   }
1133   print_preview_context_.Finished();
1134   return true;
1135 }
1136
1137 bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1138   DCHECK(!is_print_ready_metafile_sent_);
1139   print_preview_context_.FinalizePrintReadyDocument();
1140
1141   // Get the size of the resulting metafile.
1142   PdfMetafileSkia* metafile = print_preview_context_.metafile();
1143   uint32 buf_size = metafile->GetDataSize();
1144   DCHECK_GT(buf_size, 0u);
1145
1146   PrintHostMsg_DidPreviewDocument_Params preview_params;
1147   preview_params.data_size = buf_size;
1148   preview_params.document_cookie = print_pages_params_->params.document_cookie;
1149   preview_params.expected_pages_count =
1150       print_preview_context_.total_page_count();
1151   preview_params.modifiable = print_preview_context_.IsModifiable();
1152   preview_params.preview_request_id =
1153       print_pages_params_->params.preview_request_id;
1154
1155   // Ask the browser to create the shared memory for us.
1156   if (!CopyMetafileDataToSharedMem(metafile,
1157                                    &(preview_params.metafile_data_handle))) {
1158     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1159     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1160     return false;
1161   }
1162   is_print_ready_metafile_sent_ = true;
1163
1164   Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1165   return true;
1166 }
1167
1168 void PrintWebViewHelper::OnPrintingDone(bool success) {
1169   notify_browser_of_print_failure_ = false;
1170   if (!success)
1171     LOG(ERROR) << "Failure in OnPrintingDone";
1172   DidFinishPrinting(success ? OK : FAIL_PRINT);
1173 }
1174
1175 void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1176   is_scripted_printing_blocked_ = blocked;
1177 }
1178
1179 void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1180   blink::WebLocalFrame* frame = NULL;
1181   GetPrintFrame(&frame);
1182   DCHECK(frame);
1183   // If we are printing a PDF extension frame, find the plugin node and print
1184   // that instead.
1185   auto plugin = delegate_->GetPdfElement(frame);
1186   if (!plugin.isNull()) {
1187     PrintNode(plugin);
1188     return;
1189   }
1190   print_preview_context_.InitWithFrame(frame);
1191   RequestPrintPreview(selection_only
1192                           ? PRINT_PREVIEW_USER_INITIATED_SELECTION
1193                           : PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1194 }
1195
1196 bool PrintWebViewHelper::IsPrintingEnabled() {
1197   bool result = false;
1198   Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1199   return result;
1200 }
1201
1202 void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1203   if (node.isNull() || !node.document().frame()) {
1204     // This can occur when the context menu refers to an invalid WebNode.
1205     // See http://crbug.com/100890#c17 for a repro case.
1206     return;
1207   }
1208
1209   if (print_node_in_progress_) {
1210     // This can happen as a result of processing sync messages when printing
1211     // from ppapi plugins. It's a rare case, so its OK to just fail here.
1212     // See http://crbug.com/159165.
1213     return;
1214   }
1215
1216   print_node_in_progress_ = true;
1217
1218   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1219   // its |context_menu_node_|.
1220   if (!g_is_preview_enabled_) {
1221     blink::WebNode duplicate_node(node);
1222     Print(duplicate_node.document().frame(), duplicate_node, false);
1223   } else {
1224     print_preview_context_.InitWithNode(node);
1225     RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1226   }
1227
1228   print_node_in_progress_ = false;
1229 }
1230
1231 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1232                                const blink::WebNode& node,
1233                                bool is_scripted) {
1234   // If still not finished with earlier print request simply ignore.
1235   if (prep_frame_view_)
1236     return;
1237
1238   FrameReference frame_ref(frame);
1239
1240   int expected_page_count = 0;
1241   if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1242     DidFinishPrinting(FAIL_PRINT_INIT);
1243     return;  // Failed to init print page settings.
1244   }
1245
1246   // Some full screen plugins can say they don't want to print.
1247   if (!expected_page_count) {
1248     DidFinishPrinting(FAIL_PRINT);
1249     return;
1250   }
1251
1252   // Ask the browser to show UI to retrieve the final print settings.
1253   if (delegate_->IsAskPrintSettingsEnabled() &&
1254       !GetPrintSettingsFromUser(frame_ref.GetFrame(), node, expected_page_count,
1255                                 is_scripted)) {
1256     DidFinishPrinting(OK);  // Release resources and fail silently.
1257     return;
1258   }
1259
1260   // Render Pages for printing.
1261   if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1262     LOG(ERROR) << "RenderPagesForPrint failed";
1263     DidFinishPrinting(FAIL_PRINT);
1264   }
1265   scripting_throttler_.Reset();
1266 }
1267
1268 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1269   switch (result) {
1270     case OK:
1271       break;
1272
1273     case FAIL_PRINT_INIT:
1274       DCHECK(!notify_browser_of_print_failure_);
1275       break;
1276
1277     case FAIL_PRINT:
1278       if (notify_browser_of_print_failure_ && print_pages_params_) {
1279         int cookie = print_pages_params_->params.document_cookie;
1280         Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1281       }
1282       break;
1283
1284     case FAIL_PREVIEW:
1285       int cookie =
1286           print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1287       if (notify_browser_of_print_failure_) {
1288         LOG(ERROR) << "CreatePreviewDocument failed";
1289         Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1290       } else {
1291         Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1292       }
1293       print_preview_context_.Failed(notify_browser_of_print_failure_);
1294       break;
1295   }
1296   prep_frame_view_.reset();
1297   print_pages_params_.reset();
1298   notify_browser_of_print_failure_ = true;
1299 }
1300
1301 void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1302   PrintPages();
1303   FinishFramePrinting();
1304 }
1305
1306 void PrintWebViewHelper::PrintPages() {
1307   if (!prep_frame_view_)  // Printing is already canceled or failed.
1308     return;
1309   prep_frame_view_->StartPrinting();
1310
1311   int page_count = prep_frame_view_->GetExpectedPageCount();
1312   if (!page_count) {
1313     LOG(ERROR) << "Can't print 0 pages.";
1314     return DidFinishPrinting(FAIL_PRINT);
1315   }
1316
1317   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1318   const PrintMsg_Print_Params& print_params = params.params;
1319
1320 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1321   // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1322   // See http://crbug.com/161576
1323   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1324                                                 print_params.document_cookie,
1325                                                 page_count));
1326 #endif  // !defined(OS_CHROMEOS)
1327
1328   if (print_params.preview_ui_id < 0) {
1329     // Printing for system dialog.
1330     int printed_count = params.pages.empty() ? page_count : params.pages.size();
1331 #if !defined(OS_CHROMEOS)
1332     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1333 #else
1334     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1335                          printed_count);
1336 #endif  // !defined(OS_CHROMEOS)
1337   }
1338
1339   if (!PrintPagesNative(prep_frame_view_->frame(), page_count)) {
1340     LOG(ERROR) << "Printing failed.";
1341     return DidFinishPrinting(FAIL_PRINT);
1342   }
1343 }
1344
1345 void PrintWebViewHelper::FinishFramePrinting() {
1346   prep_frame_view_.reset();
1347 }
1348
1349 #if defined(OS_MACOSX)
1350 bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1351                                           int page_count) {
1352   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1353   const PrintMsg_Print_Params& print_params = params.params;
1354
1355   PrintMsg_PrintPage_Params page_params;
1356   page_params.params = print_params;
1357   if (params.pages.empty()) {
1358     for (int i = 0; i < page_count; ++i) {
1359       page_params.page_number = i;
1360       PrintPageInternal(page_params, frame);
1361     }
1362   } else {
1363     for (size_t i = 0; i < params.pages.size(); ++i) {
1364       if (params.pages[i] >= page_count)
1365         break;
1366       page_params.page_number = params.pages[i];
1367       PrintPageInternal(page_params, frame);
1368     }
1369   }
1370   return true;
1371 }
1372
1373 #endif  // OS_MACOSX
1374
1375 // static - Not anonymous so that platform implementations can use it.
1376 void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1377     blink::WebFrame* frame,
1378     int page_index,
1379     const PrintMsg_Print_Params& page_params,
1380     bool ignore_css_margins,
1381     double* scale_factor,
1382     PageSizeMargins* page_layout_in_points) {
1383   PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1384       frame, page_index, page_params, ignore_css_margins,
1385       page_params.print_scaling_option ==
1386           blink::WebPrintScalingOptionFitToPrintableArea,
1387       scale_factor);
1388   CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1389 }
1390
1391 bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1392   PrintMsg_PrintPages_Params settings;
1393   Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1394                                                 &settings.params));
1395   // Check if the printer returned any settings, if the settings is empty, we
1396   // can safely assume there are no printer drivers configured. So we safely
1397   // terminate.
1398   bool result = true;
1399   if (!PrintMsg_Print_Params_IsValid(settings.params))
1400     result = false;
1401
1402   // Reset to default values.
1403   ignore_css_margins_ = false;
1404   settings.pages.clear();
1405
1406   settings.params.print_scaling_option = blink::WebPrintScalingOptionSourceSize;
1407   if (fit_to_paper_size) {
1408     settings.params.print_scaling_option =
1409         blink::WebPrintScalingOptionFitToPrintableArea;
1410   }
1411
1412   SetPrintPagesParams(settings);
1413   return result;
1414 }
1415
1416 bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1417                                                 const blink::WebNode& node,
1418                                                 int* number_of_pages) {
1419   DCHECK(frame);
1420   bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1421   if (!InitPrintSettings(fit_to_paper_size)) {
1422     notify_browser_of_print_failure_ = false;
1423     Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1424     return false;
1425   }
1426
1427   const PrintMsg_Print_Params& params = print_pages_params_->params;
1428   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1429   prepare.StartPrinting();
1430
1431   *number_of_pages = prepare.GetExpectedPageCount();
1432   return true;
1433 }
1434
1435 void PrintWebViewHelper::SetOptionsFromDocument(
1436     PrintHostMsg_SetOptionsFromDocument_Params& params) {
1437   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
1438   const blink::WebNode& source_node = print_preview_context_.source_node();
1439
1440   blink::WebPrintPresetOptions preset_options;
1441   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
1442                                                     &preset_options)) {
1443     return;
1444   }
1445
1446   params.is_scaling_disabled = preset_options.isScalingDisabled;
1447   params.copies = preset_options.copies;
1448 }
1449
1450 bool PrintWebViewHelper::UpdatePrintSettings(
1451     blink::WebLocalFrame* frame,
1452     const blink::WebNode& node,
1453     const base::DictionaryValue& passed_job_settings) {
1454   const base::DictionaryValue* job_settings = &passed_job_settings;
1455   base::DictionaryValue modified_job_settings;
1456   if (job_settings->empty()) {
1457     if (!print_for_preview_)
1458       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1459     return false;
1460   }
1461
1462   bool source_is_html = true;
1463   if (print_for_preview_) {
1464     if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1465       NOTREACHED();
1466     }
1467   } else {
1468     source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1469   }
1470
1471   if (print_for_preview_ || !source_is_html) {
1472     modified_job_settings.MergeDictionary(job_settings);
1473     modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1474     modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1475     job_settings = &modified_job_settings;
1476   }
1477
1478   // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1479   // possible.
1480   int cookie =
1481       print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1482   PrintMsg_PrintPages_Params settings;
1483   bool canceled = false;
1484   Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
1485                                             &settings, &canceled));
1486   if (canceled) {
1487     notify_browser_of_print_failure_ = false;
1488     return false;
1489   }
1490
1491   if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1492     NOTREACHED();
1493     print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1494     return false;
1495   }
1496
1497   if (!print_for_preview_) {
1498     // Validate expected print preview settings.
1499     if (!job_settings->GetInteger(kPreviewRequestID,
1500                                   &settings.params.preview_request_id) ||
1501         !job_settings->GetBoolean(kIsFirstRequest,
1502                                   &settings.params.is_first_request)) {
1503       NOTREACHED();
1504       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1505       return false;
1506     }
1507
1508     settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1509     UpdateFrameMarginsCssInfo(*job_settings);
1510     settings.params.print_scaling_option = GetPrintScalingOption(
1511         frame, node, source_is_html, *job_settings, settings.params);
1512   }
1513
1514   SetPrintPagesParams(settings);
1515
1516   if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1517     if (!print_for_preview_)
1518       print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1519     else
1520       Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1521
1522     return false;
1523   }
1524
1525   return true;
1526 }
1527
1528 bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebFrame* frame,
1529                                                   const blink::WebNode& node,
1530                                                   int expected_pages_count,
1531                                                   bool is_scripted) {
1532   PrintHostMsg_ScriptedPrint_Params params;
1533   PrintMsg_PrintPages_Params print_settings;
1534
1535   params.cookie = print_pages_params_->params.document_cookie;
1536   params.has_selection = frame->hasSelection();
1537   params.expected_pages_count = expected_pages_count;
1538   MarginType margin_type = DEFAULT_MARGINS;
1539   if (PrintingNodeOrPdfFrame(frame, node))
1540     margin_type = GetMarginsForPdf(frame, node);
1541   params.margin_type = margin_type;
1542   params.is_scripted = is_scripted;
1543
1544   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1545
1546   // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1547   // value before and restore it afterwards.
1548   blink::WebPrintScalingOption scaling_option =
1549       print_pages_params_->params.print_scaling_option;
1550
1551   print_pages_params_.reset();
1552   IPC::SyncMessage* msg =
1553       new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1554   msg->EnableMessagePumping();
1555   Send(msg);
1556   print_settings.params.print_scaling_option = scaling_option;
1557   SetPrintPagesParams(print_settings);
1558   return (print_settings.params.dpi && print_settings.params.document_cookie);
1559 }
1560
1561 bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1562                                              const blink::WebNode& node) {
1563   if (!frame || prep_frame_view_)
1564     return false;
1565   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1566   const PrintMsg_Print_Params& print_params = params.params;
1567   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1568       print_params, frame, node, ignore_css_margins_));
1569   DCHECK(!print_pages_params_->params.selection_only ||
1570          print_pages_params_->pages.empty());
1571   prep_frame_view_->CopySelectionIfNeeded(
1572       render_view()->GetWebkitPreferences(),
1573       base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1574                  base::Unretained(this)));
1575   return true;
1576 }
1577
1578 #if defined(OS_POSIX)
1579 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1580     PdfMetafileSkia* metafile,
1581     base::SharedMemoryHandle* shared_mem_handle) {
1582   uint32 buf_size = metafile->GetDataSize();
1583   scoped_ptr<base::SharedMemory> shared_buf(
1584       content::RenderThread::Get()
1585           ->HostAllocateSharedMemoryBuffer(buf_size)
1586           .release());
1587
1588   if (shared_buf) {
1589     if (shared_buf->Map(buf_size)) {
1590       metafile->GetData(shared_buf->memory(), buf_size);
1591       return shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1592                                        shared_mem_handle);
1593     }
1594   }
1595   return false;
1596 }
1597 #endif  // defined(OS_POSIX)
1598
1599 void PrintWebViewHelper::ShowScriptedPrintPreview() {
1600   if (is_scripted_preview_delayed_) {
1601     is_scripted_preview_delayed_ = false;
1602     Send(new PrintHostMsg_ShowScriptedPrintPreview(
1603         routing_id(), print_preview_context_.IsModifiable()));
1604   }
1605 }
1606
1607 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1608   const bool is_modifiable = print_preview_context_.IsModifiable();
1609   const bool has_selection = print_preview_context_.HasSelection();
1610   PrintHostMsg_RequestPrintPreview_Params params;
1611   params.is_modifiable = is_modifiable;
1612   params.has_selection = has_selection;
1613   switch (type) {
1614     case PRINT_PREVIEW_SCRIPTED: {
1615       // Shows scripted print preview in two stages.
1616       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1617       //    pumping messages here.
1618       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1619       //    document has been loaded.
1620       is_scripted_preview_delayed_ = true;
1621       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1622         // Wait for DidStopLoading. Plugins may not know the correct
1623         // |is_modifiable| value until they are fully loaded, which occurs when
1624         // DidStopLoading() is called. Defer showing the preview until then.
1625         on_stop_loading_closure_ =
1626             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1627                        base::Unretained(this));
1628       } else {
1629         base::MessageLoop::current()->PostTask(
1630             FROM_HERE, base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1631                                   weak_ptr_factory_.GetWeakPtr()));
1632       }
1633       IPC::SyncMessage* msg =
1634           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1635       msg->EnableMessagePumping();
1636       Send(msg);
1637       is_scripted_preview_delayed_ = false;
1638       return;
1639     }
1640     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1641       // Wait for DidStopLoading. Continuing with this function while
1642       // |is_loading_| is true will cause print preview to hang when try to
1643       // print a PDF document.
1644       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1645         on_stop_loading_closure_ =
1646             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1647                        base::Unretained(this), type);
1648         return;
1649       }
1650
1651       break;
1652     }
1653     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1654       DCHECK(has_selection);
1655       DCHECK(!GetPlugin(print_preview_context_.source_frame()));
1656       params.selection_only = has_selection;
1657       break;
1658     }
1659     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1660       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1661         on_stop_loading_closure_ =
1662             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1663                        base::Unretained(this), type);
1664         return;
1665       }
1666
1667       params.webnode_only = true;
1668       break;
1669     }
1670     default: {
1671       NOTREACHED();
1672       return;
1673     }
1674   }
1675   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1676 }
1677
1678 bool PrintWebViewHelper::CheckForCancel() {
1679   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1680   bool cancel = false;
1681   Send(new PrintHostMsg_CheckForCancel(routing_id(),
1682                                        print_params.preview_ui_id,
1683                                        print_params.preview_request_id,
1684                                        &cancel));
1685   if (cancel)
1686     notify_browser_of_print_failure_ = false;
1687   return cancel;
1688 }
1689
1690 bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1691                                              PdfMetafileSkia* metafile) {
1692   DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1693
1694   // For non-modifiable files, |metafile| should be NULL, so do not bother
1695   // sending a message. If we don't generate draft metafiles, |metafile| is
1696   // NULL.
1697   if (!print_preview_context_.IsModifiable() ||
1698       !print_preview_context_.generate_draft_pages()) {
1699     DCHECK(!metafile);
1700     return true;
1701   }
1702
1703   if (!metafile) {
1704     NOTREACHED();
1705     print_preview_context_.set_error(
1706         PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1707     return false;
1708   }
1709
1710   PrintHostMsg_DidPreviewPage_Params preview_page_params;
1711   // Get the size of the resulting metafile.
1712   uint32 buf_size = metafile->GetDataSize();
1713   DCHECK_GT(buf_size, 0u);
1714   if (!CopyMetafileDataToSharedMem(
1715           metafile, &(preview_page_params.metafile_data_handle))) {
1716     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1717     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1718     return false;
1719   }
1720   preview_page_params.data_size = buf_size;
1721   preview_page_params.page_number = page_number;
1722   preview_page_params.preview_request_id =
1723       print_pages_params_->params.preview_request_id;
1724
1725   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1726   return true;
1727 }
1728
1729 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1730     : total_page_count_(0),
1731       current_page_index_(0),
1732       generate_draft_pages_(true),
1733       print_ready_metafile_page_count_(0),
1734       error_(PREVIEW_ERROR_NONE),
1735       state_(UNINITIALIZED) {
1736 }
1737
1738 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1739 }
1740
1741 void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1742     blink::WebLocalFrame* web_frame) {
1743   DCHECK(web_frame);
1744   DCHECK(!IsRendering());
1745   state_ = INITIALIZED;
1746   source_frame_.Reset(web_frame);
1747   source_node_.reset();
1748 }
1749
1750 void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1751     const blink::WebNode& web_node) {
1752   DCHECK(!web_node.isNull());
1753   DCHECK(web_node.document().frame());
1754   DCHECK(!IsRendering());
1755   state_ = INITIALIZED;
1756   source_frame_.Reset(web_node.document().frame());
1757   source_node_ = web_node;
1758 }
1759
1760 void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1761   DCHECK_EQ(INITIALIZED, state_);
1762   ClearContext();
1763 }
1764
1765 bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1766     PrepareFrameAndViewForPrint* prepared_frame,
1767     const std::vector<int>& pages) {
1768   DCHECK_EQ(INITIALIZED, state_);
1769   state_ = RENDERING;
1770
1771   // Need to make sure old object gets destroyed first.
1772   prep_frame_view_.reset(prepared_frame);
1773   prep_frame_view_->StartPrinting();
1774
1775   total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1776   if (total_page_count_ == 0) {
1777     LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1778     set_error(PREVIEW_ERROR_ZERO_PAGES);
1779     return false;
1780   }
1781
1782   metafile_.reset(new PdfMetafileSkia);
1783   if (!metafile_->Init()) {
1784     set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1785     LOG(ERROR) << "PdfMetafileSkia Init failed";
1786     return false;
1787   }
1788
1789   current_page_index_ = 0;
1790   pages_to_render_ = pages;
1791   // Sort and make unique.
1792   std::sort(pages_to_render_.begin(), pages_to_render_.end());
1793   pages_to_render_.resize(
1794       std::unique(pages_to_render_.begin(), pages_to_render_.end()) -
1795       pages_to_render_.begin());
1796   // Remove invalid pages.
1797   pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1798                                            pages_to_render_.end(),
1799                                            total_page_count_) -
1800                           pages_to_render_.begin());
1801   print_ready_metafile_page_count_ = pages_to_render_.size();
1802   if (pages_to_render_.empty()) {
1803     print_ready_metafile_page_count_ = total_page_count_;
1804     // Render all pages.
1805     for (int i = 0; i < total_page_count_; ++i)
1806       pages_to_render_.push_back(i);
1807   } else if (generate_draft_pages_) {
1808     int pages_index = 0;
1809     for (int i = 0; i < total_page_count_; ++i) {
1810       if (pages_index < print_ready_metafile_page_count_ &&
1811           i == pages_to_render_[pages_index]) {
1812         pages_index++;
1813         continue;
1814       }
1815       pages_to_render_.push_back(i);
1816     }
1817   }
1818
1819   document_render_time_ = base::TimeDelta();
1820   begin_time_ = base::TimeTicks::Now();
1821
1822   return true;
1823 }
1824
1825 void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1826     const base::TimeDelta& page_time) {
1827   DCHECK_EQ(RENDERING, state_);
1828   document_render_time_ += page_time;
1829   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1830 }
1831
1832 void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1833   DCHECK_EQ(RENDERING, state_);
1834   state_ = DONE;
1835   prep_frame_view_->FinishPrinting();
1836 }
1837
1838 void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1839   DCHECK(IsRendering());
1840
1841   base::TimeTicks begin_time = base::TimeTicks::Now();
1842   metafile_->FinishDocument();
1843
1844   if (print_ready_metafile_page_count_ <= 0) {
1845     NOTREACHED();
1846     return;
1847   }
1848
1849   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1850                              document_render_time_);
1851   base::TimeDelta total_time =
1852       (base::TimeTicks::Now() - begin_time) + document_render_time_;
1853   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1854                              total_time);
1855   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1856                              total_time / pages_to_render_.size());
1857 }
1858
1859 void PrintWebViewHelper::PrintPreviewContext::Finished() {
1860   DCHECK_EQ(DONE, state_);
1861   state_ = INITIALIZED;
1862   ClearContext();
1863 }
1864
1865 void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1866   DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1867   state_ = INITIALIZED;
1868   if (report_error) {
1869     DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1870     UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1871                               PREVIEW_ERROR_LAST_ENUM);
1872   }
1873   ClearContext();
1874 }
1875
1876 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1877   DCHECK_EQ(RENDERING, state_);
1878   if (IsFinalPageRendered())
1879     return -1;
1880   return pages_to_render_[current_page_index_++];
1881 }
1882
1883 bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1884   return state_ == RENDERING || state_ == DONE;
1885 }
1886
1887 bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1888   // The only kind of node we can print right now is a PDF node.
1889   return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1890 }
1891
1892 bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1893   return IsModifiable() && source_frame()->hasSelection();
1894 }
1895
1896 bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1897     const {
1898   DCHECK(IsRendering());
1899   return current_page_index_ == print_ready_metafile_page_count_;
1900 }
1901
1902 bool PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1903   DCHECK(IsRendering());
1904   return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1905 }
1906
1907 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1908     bool generate_draft_pages) {
1909   DCHECK_EQ(INITIALIZED, state_);
1910   generate_draft_pages_ = generate_draft_pages;
1911 }
1912
1913 void PrintWebViewHelper::PrintPreviewContext::set_error(
1914     enum PrintPreviewErrorBuckets error) {
1915   error_ = error;
1916 }
1917
1918 blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
1919   DCHECK(state_ != UNINITIALIZED);
1920   return source_frame_.GetFrame();
1921 }
1922
1923 const blink::WebNode&
1924     PrintWebViewHelper::PrintPreviewContext::source_node() const {
1925   DCHECK(state_ != UNINITIALIZED);
1926   return source_node_;
1927 }
1928
1929 blink::WebLocalFrame*
1930 PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
1931   DCHECK(state_ != UNINITIALIZED);
1932   return prep_frame_view_->frame();
1933 }
1934
1935 const blink::WebNode&
1936     PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
1937   DCHECK(state_ != UNINITIALIZED);
1938   return prep_frame_view_->node();
1939 }
1940
1941 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
1942   DCHECK(state_ != UNINITIALIZED);
1943   return total_page_count_;
1944 }
1945
1946 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
1947   return generate_draft_pages_;
1948 }
1949
1950 PdfMetafileSkia* PrintWebViewHelper::PrintPreviewContext::metafile() {
1951   DCHECK(IsRendering());
1952   return metafile_.get();
1953 }
1954
1955 int PrintWebViewHelper::PrintPreviewContext::last_error() const {
1956   return error_;
1957 }
1958
1959 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
1960   prep_frame_view_.reset();
1961   metafile_.reset();
1962   pages_to_render_.clear();
1963   error_ = PREVIEW_ERROR_NONE;
1964 }
1965
1966 void PrintWebViewHelper::SetPrintPagesParams(
1967     const PrintMsg_PrintPages_Params& settings) {
1968   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
1969   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
1970                                              settings.params.document_cookie));
1971 }
1972
1973 PrintWebViewHelper::ScriptingThrottler::ScriptingThrottler() : count_(0) {
1974 }
1975
1976 bool PrintWebViewHelper::ScriptingThrottler::IsAllowed(blink::WebFrame* frame) {
1977   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
1978   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
1979   bool too_frequent = false;
1980
1981   // Check if there is script repeatedly trying to print and ignore it if too
1982   // frequent.  The first 3 times, we use a constant wait time, but if this
1983   // gets excessive, we switch to exponential wait time. So for a page that
1984   // calls print() in a loop the user will need to cancel the print dialog
1985   // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
1986   // This gives the user time to navigate from the page.
1987   if (count_ > 0) {
1988     base::TimeDelta diff = base::Time::Now() - last_print_;
1989     int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
1990     if (count_ > 3) {
1991       min_wait_seconds =
1992           std::min(kMinSecondsToIgnoreJavascriptInitiatedPrint << (count_ - 3),
1993                    kMaxSecondsToIgnoreJavascriptInitiatedPrint);
1994     }
1995     if (diff.InSeconds() < min_wait_seconds) {
1996       too_frequent = true;
1997     }
1998   }
1999
2000   if (!too_frequent) {
2001     ++count_;
2002     last_print_ = base::Time::Now();
2003     return true;
2004   }
2005
2006   blink::WebString message(
2007       blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
2008   frame->addMessageToConsole(blink::WebConsoleMessage(
2009       blink::WebConsoleMessage::LevelWarning, message));
2010   return false;
2011 }
2012
2013 void PrintWebViewHelper::ScriptingThrottler::Reset() {
2014   // Reset counter on successful print.
2015   count_ = 0;
2016 }
2017
2018 }  // namespace printing