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/location.h"
  12 #include "base/logging.h"
  13 #include "base/metrics/histogram_macros.h"
  14 #include "base/process/process_handle.h"
  15 #include "base/single_thread_task_runner.h"
  16 #include "base/strings/string_number_conversions.h"
  17 #include "base/strings/stringprintf.h"
  18 #include "base/strings/utf_string_conversions.h"
  19 #include "base/thread_task_runner_handle.h"
  20 #include "components/printing/common/print_messages.h"
  21 #include "content/public/common/web_preferences.h"
  22 #include "content/public/renderer/render_frame.h"
  23 #include "content/public/renderer/render_thread.h"
  24 #include "content/public/renderer/render_view.h"
  25 #include "grit/components_resources.h"
  26 #include "net/base/escape.h"
  27 #include "printing/pdf_metafile_skia.h"
  28 #include "printing/units.h"
  29 #include "third_party/WebKit/public/platform/WebSize.h"
  30 #include "third_party/WebKit/public/platform/WebURLRequest.h"
  31 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  32 #include "third_party/WebKit/public/web/WebDocument.h"
  33 #include "third_party/WebKit/public/web/WebElement.h"
  34 #include "third_party/WebKit/public/web/WebFrameClient.h"
  35 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  36 #include "third_party/WebKit/public/web/WebPlugin.h"
  37 #include "third_party/WebKit/public/web/WebPluginDocument.h"
  38 #include "third_party/WebKit/public/web/WebPrintParams.h"
  39 #include "third_party/WebKit/public/web/WebPrintPresetOptions.h"
  40 #include "third_party/WebKit/public/web/WebSandboxFlags.h"
  41 #include "third_party/WebKit/public/web/WebScriptSource.h"
  42 #include "third_party/WebKit/public/web/WebSettings.h"
  43 #include "third_party/WebKit/public/web/WebView.h"
  44 #include "third_party/WebKit/public/web/WebViewClient.h"
  45 #include "ui/base/resource/resource_bundle.h"
  46
  47 using content::WebPreferences;
  48
  49 namespace printing {
  50
  51 namespace {
  52
  53 #define STATIC_ASSERT_PP_MATCHING_ENUM(a, b)                  \
  54     static_assert(static_cast<int>(a) == static_cast<int>(b), \
  55                   "mismatching enums: " #a)
  56
  57 // Check blink::WebDuplexMode and printing::DuplexMode are kept in sync.
  58 STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebUnknownDuplexMode,
  59                                UNKNOWN_DUPLEX_MODE);
  60 STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebSimplex, SIMPLEX);
  61 STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebLongEdge, LONG_EDGE);
  62 STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebShortEdge, SHORT_EDGE);
  63
  64 enum PrintPreviewHelperEvents {
  65   PREVIEW_EVENT_REQUESTED,
  66   PREVIEW_EVENT_CACHE_HIT,  // Unused
  67   PREVIEW_EVENT_CREATE_DOCUMENT,
  68   PREVIEW_EVENT_NEW_SETTINGS,  // Unused
  69   PREVIEW_EVENT_MAX,
  70 };
  71
  72 const double kMinDpi = 1.0;
  73
  74 #if !defined(ENABLE_PRINT_PREVIEW)
  75 bool g_is_preview_enabled_ = false;
  76 #else
  77 bool g_is_preview_enabled_ = true;
  78
  79 const char kPageLoadScriptFormat[] =
  80     "document.open(); document.write(%s); document.close();";
  81
  82 const char kPageSetupScriptFormat[] = "setup(%s);";
  83
  84 void ExecuteScript(blink::WebFrame* frame,
  85                    const char* script_format,
  86                    const base::Value& parameters) {
  87   std::string json;
  88   base::JSONWriter::Write(parameters, &json);
  89   std::string script = base::StringPrintf(script_format, json.c_str());
  90   frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
  91 }
  92 #endif  // !defined(ENABLE_PRINT_PREVIEW)
  93
  94 int GetDPI(const PrintMsg_Print_Params* print_params) {
  95 #if defined(OS_MACOSX)
  96   // On the Mac, the printable area is in points, don't do any scaling based
  97   // on dpi.
  98   return kPointsPerInch;
  99 #else
 100   return static_cast<int>(print_params->dpi);
 101 #endif  // defined(OS_MACOSX)
 102 }
 103
 104 bool PrintMsg_Print_Params_IsValid(const PrintMsg_Print_Params& params) {
 105   return !params.content_size.IsEmpty() && !params.page_size.IsEmpty() &&
 106          !params.printable_area.IsEmpty() && params.document_cookie &&
 107          params.desired_dpi && params.max_shrink && params.min_shrink &&
 108          params.dpi && (params.margin_top >= 0) && (params.margin_left >= 0) &&
 109          params.dpi > kMinDpi && params.document_cookie != 0;
 110 }
 111
 112 PrintMsg_Print_Params GetCssPrintParams(
 113     blink::WebFrame* frame,
 114     int page_index,
 115     const PrintMsg_Print_Params& page_params) {
 116   PrintMsg_Print_Params page_css_params = page_params;
 117   int dpi = GetDPI(&page_params);
 118
 119   blink::WebSize page_size_in_pixels(
 120       ConvertUnit(page_params.page_size.width(), dpi, kPixelsPerInch),
 121       ConvertUnit(page_params.page_size.height(), dpi, kPixelsPerInch));
 122   int margin_top_in_pixels =
 123       ConvertUnit(page_params.margin_top, dpi, kPixelsPerInch);
 124   int margin_right_in_pixels = ConvertUnit(
 125       page_params.page_size.width() -
 126       page_params.content_size.width() - page_params.margin_left,
 127       dpi, kPixelsPerInch);
 128   int margin_bottom_in_pixels = ConvertUnit(
 129       page_params.page_size.height() -
 130       page_params.content_size.height() - page_params.margin_top,
 131       dpi, kPixelsPerInch);
 132   int margin_left_in_pixels = ConvertUnit(
 133       page_params.margin_left,
 134       dpi, kPixelsPerInch);
 135
 136   blink::WebSize original_page_size_in_pixels = page_size_in_pixels;
 137
 138   if (frame) {
 139     frame->pageSizeAndMarginsInPixels(page_index,
 140                                       page_size_in_pixels,
 141                                       margin_top_in_pixels,
 142                                       margin_right_in_pixels,
 143                                       margin_bottom_in_pixels,
 144                                       margin_left_in_pixels);
 145   }
 146
 147   int new_content_width = page_size_in_pixels.width -
 148                           margin_left_in_pixels - margin_right_in_pixels;
 149   int new_content_height = page_size_in_pixels.height -
 150                            margin_top_in_pixels - margin_bottom_in_pixels;
 151
 152   // Invalid page size and/or margins. We just use the default setting.
 153   if (new_content_width < 1 || new_content_height < 1) {
 154     CHECK(frame != NULL);
 155     page_css_params = GetCssPrintParams(NULL, page_index, page_params);
 156     return page_css_params;
 157   }
 158
 159   page_css_params.content_size =
 160       gfx::Size(ConvertUnit(new_content_width, kPixelsPerInch, dpi),
 161                 ConvertUnit(new_content_height, kPixelsPerInch, dpi));
 162
 163   if (original_page_size_in_pixels != page_size_in_pixels) {
 164     page_css_params.page_size =
 165         gfx::Size(ConvertUnit(page_size_in_pixels.width, kPixelsPerInch, dpi),
 166                   ConvertUnit(page_size_in_pixels.height, kPixelsPerInch, dpi));
 167   } else {
 168     // Printing frame doesn't have any page size css. Pixels to dpi conversion
 169     // causes rounding off errors. Therefore use the default page size values
 170     // directly.
 171     page_css_params.page_size = page_params.page_size;
 172   }
 173
 174   page_css_params.margin_top =
 175       ConvertUnit(margin_top_in_pixels, kPixelsPerInch, dpi);
 176   page_css_params.margin_left =
 177       ConvertUnit(margin_left_in_pixels, kPixelsPerInch, dpi);
 178   return page_css_params;
 179 }
 180
 181 double FitPrintParamsToPage(const PrintMsg_Print_Params& page_params,
 182                             PrintMsg_Print_Params* params_to_fit) {
 183   double content_width =
 184       static_cast<double>(params_to_fit->content_size.width());
 185   double content_height =
 186       static_cast<double>(params_to_fit->content_size.height());
 187   int default_page_size_height = page_params.page_size.height();
 188   int default_page_size_width = page_params.page_size.width();
 189   int css_page_size_height = params_to_fit->page_size.height();
 190   int css_page_size_width = params_to_fit->page_size.width();
 191
 192   double scale_factor = 1.0f;
 193   if (page_params.page_size == params_to_fit->page_size)
 194     return scale_factor;
 195
 196   if (default_page_size_width < css_page_size_width ||
 197       default_page_size_height < css_page_size_height) {
 198     double ratio_width =
 199         static_cast<double>(default_page_size_width) / css_page_size_width;
 200     double ratio_height =
 201         static_cast<double>(default_page_size_height) / css_page_size_height;
 202     scale_factor = ratio_width < ratio_height ? ratio_width : ratio_height;
 203     content_width *= scale_factor;
 204     content_height *= scale_factor;
 205   }
 206   params_to_fit->margin_top = static_cast<int>(
 207       (default_page_size_height - css_page_size_height * scale_factor) / 2 +
 208       (params_to_fit->margin_top * scale_factor));
 209   params_to_fit->margin_left = static_cast<int>(
 210       (default_page_size_width - css_page_size_width * scale_factor) / 2 +
 211       (params_to_fit->margin_left * scale_factor));
 212   params_to_fit->content_size = gfx::Size(static_cast<int>(content_width),
 213                                           static_cast<int>(content_height));
 214   params_to_fit->page_size = page_params.page_size;
 215   return scale_factor;
 216 }
 217
 218 void CalculatePageLayoutFromPrintParams(
 219     const PrintMsg_Print_Params& params,
 220     PageSizeMargins* page_layout_in_points) {
 221   int dpi = GetDPI(&params);
 222   int content_width = params.content_size.width();
 223   int content_height = params.content_size.height();
 224
 225   int margin_bottom =
 226       params.page_size.height() - content_height - params.margin_top;
 227   int margin_right =
 228       params.page_size.width() - content_width - params.margin_left;
 229
 230   page_layout_in_points->content_width =
 231       ConvertUnit(content_width, dpi, kPointsPerInch);
 232   page_layout_in_points->content_height =
 233       ConvertUnit(content_height, dpi, kPointsPerInch);
 234   page_layout_in_points->margin_top =
 235       ConvertUnit(params.margin_top, dpi, kPointsPerInch);
 236   page_layout_in_points->margin_right =
 237       ConvertUnit(margin_right, dpi, kPointsPerInch);
 238   page_layout_in_points->margin_bottom =
 239       ConvertUnit(margin_bottom, dpi, kPointsPerInch);
 240   page_layout_in_points->margin_left =
 241       ConvertUnit(params.margin_left, dpi, kPointsPerInch);
 242 }
 243
 244 void EnsureOrientationMatches(const PrintMsg_Print_Params& css_params,
 245                               PrintMsg_Print_Params* page_params) {
 246   if ((page_params->page_size.width() > page_params->page_size.height()) ==
 247       (css_params.page_size.width() > css_params.page_size.height())) {
 248     return;
 249   }
 250
 251   // Swap the |width| and |height| values.
 252   page_params->page_size.SetSize(page_params->page_size.height(),
 253                                  page_params->page_size.width());
 254   page_params->content_size.SetSize(page_params->content_size.height(),
 255                                     page_params->content_size.width());
 256   page_params->printable_area.set_size(
 257       gfx::Size(page_params->printable_area.height(),
 258                 page_params->printable_area.width()));
 259 }
 260
 261 void ComputeWebKitPrintParamsInDesiredDpi(
 262     const PrintMsg_Print_Params& print_params,
 263     blink::WebPrintParams* webkit_print_params) {
 264   int dpi = GetDPI(&print_params);
 265   webkit_print_params->printerDPI = dpi;
 266   webkit_print_params->printScalingOption = print_params.print_scaling_option;
 267
 268   webkit_print_params->printContentArea.width = ConvertUnit(
 269       print_params.content_size.width(), dpi, print_params.desired_dpi);
 270   webkit_print_params->printContentArea.height = ConvertUnit(
 271       print_params.content_size.height(), dpi, print_params.desired_dpi);
 272
 273   webkit_print_params->printableArea.x = ConvertUnit(
 274       print_params.printable_area.x(), dpi, print_params.desired_dpi);
 275   webkit_print_params->printableArea.y = ConvertUnit(
 276       print_params.printable_area.y(), dpi, print_params.desired_dpi);
 277   webkit_print_params->printableArea.width = ConvertUnit(
 278       print_params.printable_area.width(), dpi, print_params.desired_dpi);
 279   webkit_print_params->printableArea.height = ConvertUnit(
 280       print_params.printable_area.height(), dpi, print_params.desired_dpi);
 281
 282   webkit_print_params->paperSize.width = ConvertUnit(
 283       print_params.page_size.width(), dpi, print_params.desired_dpi);
 284   webkit_print_params->paperSize.height = ConvertUnit(
 285       print_params.page_size.height(), dpi, print_params.desired_dpi);
 286 }
 287
 288 blink::WebPlugin* GetPlugin(const blink::WebLocalFrame* frame) {
 289   return frame->document().isPluginDocument()
 290              ? frame->document().to<blink::WebPluginDocument>().plugin()
 291              : NULL;
 292 }
 293
 294 bool PrintingNodeOrPdfFrame(const blink::WebLocalFrame* frame,
 295                             const blink::WebNode& node) {
 296   if (!node.isNull())
 297     return true;
 298   blink::WebPlugin* plugin = GetPlugin(frame);
 299   return plugin && plugin->supportsPaginatedPrint();
 300 }
 301
 302 bool PrintingFrameHasPageSizeStyle(blink::WebFrame* frame,
 303                                    int total_page_count) {
 304   if (!frame)
 305     return false;
 306   bool frame_has_custom_page_size_style = false;
 307   for (int i = 0; i < total_page_count; ++i) {
 308     if (frame->hasCustomPageSizeStyle(i)) {
 309       frame_has_custom_page_size_style = true;
 310       break;
 311     }
 312   }
 313   return frame_has_custom_page_size_style;
 314 }
 315
 316 // Disable scaling when either:
 317 // - The PDF specifies disabling scaling.
 318 // - All the pages in the PDF are the same size, and that size is the same as
 319 //   the paper size.
 320 bool PDFShouldDisableScalingBasedOnPreset(
 321     const blink::WebPrintPresetOptions& options,
 322     const PrintMsg_Print_Params& params) {
 323   if (options.isScalingDisabled)
 324     return true;
 325
 326   if (!options.isPageSizeUniform)
 327     return false;
 328
 329   int dpi = GetDPI(&params);
 330   if (!dpi) {
 331     // Likely |params| is invalid, in which case the return result does not
 332     // matter. Check for this so ConvertUnit() does not divide by zero.
 333     return true;
 334   }
 335
 336   blink::WebSize page_size(
 337       ConvertUnit(params.page_size.width(), dpi, kPointsPerInch),
 338       ConvertUnit(params.page_size.height(), dpi, kPointsPerInch));
 339   return options.uniformPageSize == page_size;
 340 }
 341
 342 bool PDFShouldDisableScaling(blink::WebLocalFrame* frame,
 343                              const blink::WebNode& node,
 344                              const PrintMsg_Print_Params& params) {
 345   const bool kDefaultPDFShouldDisableScalingSetting = true;
 346   blink::WebPrintPresetOptions preset_options;
 347   if (!frame->getPrintPresetOptionsForPlugin(node, &preset_options))
 348     return kDefaultPDFShouldDisableScalingSetting;
 349   return PDFShouldDisableScalingBasedOnPreset(preset_options, params);
 350 }
 351
 352 MarginType GetMarginsForPdf(blink::WebLocalFrame* frame,
 353                             const blink::WebNode& node,
 354                             const PrintMsg_Print_Params& params) {
 355   return PDFShouldDisableScaling(frame, node, params) ?
 356       NO_MARGINS : PRINTABLE_AREA_MARGINS;
 357 }
 358
 359 bool FitToPageEnabled(const base::DictionaryValue& job_settings) {
 360   bool fit_to_paper_size = false;
 361   if (!job_settings.GetBoolean(kSettingFitToPageEnabled, &fit_to_paper_size)) {
 362     NOTREACHED();
 363   }
 364   return fit_to_paper_size;
 365 }
 366
 367 // Returns the print scaling option to retain/scale/crop the source page size
 368 // to fit the printable area of the paper.
 369 //
 370 // We retain the source page size when the current destination printer is
 371 // SAVE_AS_PDF.
 372 //
 373 // We crop the source page size to fit the printable area or we print only the
 374 // left top page contents when
 375 // (1) Source is PDF and the user has requested not to fit to printable area
 376 // via |job_settings|.
 377 // (2) Source is PDF. This is the first preview request and print scaling
 378 // option is disabled for initiator renderer plugin.
 379 //
 380 // In all other cases, we scale the source page to fit the printable area.
 381 blink::WebPrintScalingOption GetPrintScalingOption(
 382     blink::WebLocalFrame* frame,
 383     const blink::WebNode& node,
 384     bool source_is_html,
 385     const base::DictionaryValue& job_settings,
 386     const PrintMsg_Print_Params& params) {
 387   if (params.print_to_pdf)
 388     return blink::WebPrintScalingOptionSourceSize;
 389
 390   if (!source_is_html) {
 391     if (!FitToPageEnabled(job_settings))
 392       return blink::WebPrintScalingOptionNone;
 393
 394     bool no_plugin_scaling = PDFShouldDisableScaling(frame, node, params);
 395     if (params.is_first_request && no_plugin_scaling)
 396       return blink::WebPrintScalingOptionNone;
 397   }
 398   return blink::WebPrintScalingOptionFitToPrintableArea;
 399 }
 400
 401 PrintMsg_Print_Params CalculatePrintParamsForCss(
 402     blink::WebFrame* frame,
 403     int page_index,
 404     const PrintMsg_Print_Params& page_params,
 405     bool ignore_css_margins,
 406     bool fit_to_page,
 407     double* scale_factor) {
 408   PrintMsg_Print_Params css_params =
 409       GetCssPrintParams(frame, page_index, page_params);
 410
 411   PrintMsg_Print_Params params = page_params;
 412   EnsureOrientationMatches(css_params, &params);
 413
 414   if (ignore_css_margins && fit_to_page)
 415     return params;
 416
 417   PrintMsg_Print_Params result_params = css_params;
 418   if (ignore_css_margins) {
 419     result_params.margin_top = params.margin_top;
 420     result_params.margin_left = params.margin_left;
 421
 422     DCHECK(!fit_to_page);
 423     // Since we are ignoring the margins, the css page size is no longer
 424     // valid.
 425     int default_margin_right = params.page_size.width() -
 426                                params.content_size.width() - params.margin_left;
 427     int default_margin_bottom = params.page_size.height() -
 428                                 params.content_size.height() -
 429                                 params.margin_top;
 430     result_params.content_size =
 431         gfx::Size(result_params.page_size.width() - result_params.margin_left -
 432                       default_margin_right,
 433                   result_params.page_size.height() - result_params.margin_top -
 434                       default_margin_bottom);
 435   }
 436
 437   if (fit_to_page) {
 438     double factor = FitPrintParamsToPage(params, &result_params);
 439     if (scale_factor)
 440       *scale_factor = factor;
 441   }
 442   return result_params;
 443 }
 444
 445 }  // namespace
 446
 447 FrameReference::FrameReference(blink::WebLocalFrame* frame) {
 448   Reset(frame);
 449 }
 450
 451 FrameReference::FrameReference() {
 452   Reset(NULL);
 453 }
 454
 455 FrameReference::~FrameReference() {
 456 }
 457
 458 void FrameReference::Reset(blink::WebLocalFrame* frame) {
 459   if (frame) {
 460     view_ = frame->view();
 461     frame_ = frame;
 462   } else {
 463     view_ = NULL;
 464     frame_ = NULL;
 465   }
 466 }
 467
 468 blink::WebLocalFrame* FrameReference::GetFrame() {
 469   if (view_ == NULL || frame_ == NULL)
 470     return NULL;
 471   for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
 472        frame = frame->traverseNext(false)) {
 473     if (frame == frame_)
 474       return frame_;
 475   }
 476   return NULL;
 477 }
 478
 479 blink::WebView* FrameReference::view() {
 480   return view_;
 481 }
 482
 483 #if defined(ENABLE_PRINT_PREVIEW)
 484 // static - Not anonymous so that platform implementations can use it.
 485 void PrintWebViewHelper::PrintHeaderAndFooter(
 486     blink::WebCanvas* canvas,
 487     int page_number,
 488     int total_pages,
 489     const blink::WebFrame& source_frame,
 490     float webkit_scale_factor,
 491     const PageSizeMargins& page_layout,
 492     const PrintMsg_Print_Params& params) {
 493   SkAutoCanvasRestore auto_restore(canvas, true);
 494   canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);
 495
 496   blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
 497                                page_layout.content_width,
 498                            page_layout.margin_top + page_layout.margin_bottom +
 499                                page_layout.content_height);
 500
 501   blink::WebView* web_view = blink::WebView::create(NULL);
 502   web_view->settings()->setJavaScriptEnabled(true);
 503
 504   blink::WebLocalFrame* frame =
 505       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, NULL);
 506   web_view->setMainFrame(frame);
 507
 508   base::StringValue html(ResourceBundle::GetSharedInstance().GetLocalizedString(
 509       IDR_PRINT_PREVIEW_PAGE));
 510   // Load page with script to avoid async operations.
 511   ExecuteScript(frame, kPageLoadScriptFormat, html);
 512
 513   scoped_ptr<base::DictionaryValue> options(new base::DictionaryValue());
 514   options.reset(new base::DictionaryValue());
 515   options->SetDouble(kSettingHeaderFooterDate, base::Time::Now().ToJsTime());
 516   options->SetDouble("width", page_size.width);
 517   options->SetDouble("height", page_size.height);
 518   options->SetDouble("topMargin", page_layout.margin_top);
 519   options->SetDouble("bottomMargin", page_layout.margin_bottom);
 520   options->SetString("pageNumber",
 521                      base::StringPrintf("%d/%d", page_number, total_pages));
 522
 523   options->SetString("url", params.url);
 524   base::string16 title = source_frame.document().title();
 525   options->SetString("title", title.empty() ? params.title : title);
 526
 527   ExecuteScript(frame, kPageSetupScriptFormat, *options);
 528
 529   blink::WebPrintParams webkit_params(page_size);
 530   webkit_params.printerDPI = GetDPI(&params);
 531
 532   frame->printBegin(webkit_params);
 533   frame->printPage(0, canvas);
 534   frame->printEnd();
 535
 536   web_view->close();
 537   frame->close();
 538 }
 539 #endif  // defined(ENABLE_PRINT_PREVIEW)
 540
 541 // static - Not anonymous so that platform implementations can use it.
 542 float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
 543                                             int page_number,
 544                                             const gfx::Rect& canvas_area,
 545                                             const gfx::Rect& content_area,
 546                                             double scale_factor,
 547                                             blink::WebCanvas* canvas) {
 548   SkAutoCanvasRestore auto_restore(canvas, true);
 549   canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
 550                     (content_area.y() - canvas_area.y()) / scale_factor);
 551   return frame->printPage(page_number, canvas);
 552 }
 553
 554 // Class that calls the Begin and End print functions on the frame and changes
 555 // the size of the view temporarily to support full page printing..
 556 class PrepareFrameAndViewForPrint : public blink::WebViewClient,
 557                                     public blink::WebFrameClient {
 558  public:
 559   PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
 560                               blink::WebLocalFrame* frame,
 561                               const blink::WebNode& node,
 562                               bool ignore_css_margins);
 563   virtual ~PrepareFrameAndViewForPrint();
 564
 565   // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
 566   // when completed.
 567   void CopySelectionIfNeeded(const WebPreferences& preferences,
 568                              const base::Closure& on_ready);
 569
 570   // Prepares frame for printing.
 571   void StartPrinting();
 572
 573   blink::WebLocalFrame* frame() { return frame_.GetFrame(); }
 574
 575   const blink::WebNode& node() const { return node_to_print_; }
 576
 577   int GetExpectedPageCount() const { return expected_pages_count_; }
 578
 579   void FinishPrinting();
 580
 581   bool IsLoadingSelection() {
 582     // It's not selection if not |owns_web_view_|.
 583     return owns_web_view_ && frame() && frame()->isLoading();
 584   }
 585
 586   // TODO(ojan): Remove this override and have this class use a non-null
 587   // layerTreeView.
 588   // blink::WebViewClient override:
 589   virtual bool allowsBrokenNullLayerTreeView() const;
 590
 591  protected:
 592   // blink::WebViewClient override:
 593   virtual void didStopLoading();
 594
 595   // blink::WebFrameClient override:
 596   virtual blink::WebFrame* createChildFrame(
 597       blink::WebLocalFrame* parent,
 598       blink::WebTreeScopeType scope,
 599       const blink::WebString& name,
 600       blink::WebSandboxFlags sandboxFlags);
 601   virtual void frameDetached(blink::WebFrame* frame, DetachType type);
 602
 603  private:
 604   void CallOnReady();
 605   void ResizeForPrinting();
 606   void RestoreSize();
 607   void CopySelection(const WebPreferences& preferences);
 608
 609   FrameReference frame_;
 610   blink::WebNode node_to_print_;
 611   bool owns_web_view_;
 612   blink::WebPrintParams web_print_params_;
 613   gfx::Size prev_view_size_;
 614   gfx::Size prev_scroll_offset_;
 615   int expected_pages_count_;
 616   base::Closure on_ready_;
 617   bool should_print_backgrounds_;
 618   bool should_print_selection_only_;
 619   bool is_printing_started_;
 620
 621   base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
 622
 623   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 624 };
 625
 626 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
 627     const PrintMsg_Print_Params& params,
 628     blink::WebLocalFrame* frame,
 629     const blink::WebNode& node,
 630     bool ignore_css_margins)
 631     : frame_(frame),
 632       node_to_print_(node),
 633       owns_web_view_(false),
 634       expected_pages_count_(0),
 635       should_print_backgrounds_(params.should_print_backgrounds),
 636       should_print_selection_only_(params.selection_only),
 637       is_printing_started_(false),
 638       weak_ptr_factory_(this) {
 639   PrintMsg_Print_Params print_params = params;
 640   if (!should_print_selection_only_ ||
 641       !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
 642     bool fit_to_page = ignore_css_margins &&
 643                        print_params.print_scaling_option ==
 644                            blink::WebPrintScalingOptionFitToPrintableArea;
 645     ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
 646     frame->printBegin(web_print_params_, node_to_print_);
 647     print_params = CalculatePrintParamsForCss(
 648         frame, 0, print_params, ignore_css_margins, fit_to_page, NULL);
 649     frame->printEnd();
 650   }
 651   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
 652 }
 653
 654 PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
 655   FinishPrinting();
 656 }
 657
 658 void PrepareFrameAndViewForPrint::ResizeForPrinting() {
 659   // Layout page according to printer page size. Since WebKit shrinks the
 660   // size of the page automatically (from 125% to 200%) we trick it to
 661   // think the page is 125% larger so the size of the page is correct for
 662   // minimum (default) scaling.
 663   // This is important for sites that try to fill the page.
 664   gfx::Size print_layout_size(web_print_params_.printContentArea.width,
 665                               web_print_params_.printContentArea.height);
 666   print_layout_size.set_height(
 667       static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
 668
 669   if (!frame())
 670     return;
 671   blink::WebView* web_view = frame_.view();
 672   // Backup size and offset.
 673   if (blink::WebFrame* web_frame = web_view->mainFrame())
 674     prev_scroll_offset_ = web_frame->scrollOffset();
 675   prev_view_size_ = web_view->size();
 676
 677   web_view->resize(print_layout_size);
 678 }
 679
 680 void PrepareFrameAndViewForPrint::StartPrinting() {
 681   ResizeForPrinting();
 682   blink::WebView* web_view = frame_.view();
 683   web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
 684   expected_pages_count_ =
 685       frame()->printBegin(web_print_params_, node_to_print_);
 686   is_printing_started_ = true;
 687 }
 688
 689 void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
 690     const WebPreferences& preferences,
 691     const base::Closure& on_ready) {
 692   on_ready_ = on_ready;
 693   if (should_print_selection_only_) {
 694     CopySelection(preferences);
 695   } else {
 696     // Call immediately, async call crashes scripting printing.
 697     CallOnReady();
 698   }
 699 }
 700
 701 void PrepareFrameAndViewForPrint::CopySelection(
 702     const WebPreferences& preferences) {
 703   ResizeForPrinting();
 704   std::string url_str = "data:text/html;charset=utf-8,";
 705   url_str.append(
 706       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
 707   RestoreSize();
 708   // Create a new WebView with the same settings as the current display one.
 709   // Except that we disable javascript (don't want any active content running
 710   // on the page).
 711   WebPreferences prefs = preferences;
 712   prefs.javascript_enabled = false;
 713
 714   blink::WebView* web_view = blink::WebView::create(this);
 715   owns_web_view_ = true;
 716   content::RenderView::ApplyWebPreferences(prefs, web_view);
 717   web_view->setMainFrame(
 718       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, this));
 719   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
 720   node_to_print_.reset();
 721
 722   // When loading is done this will call didStopLoading() and that will do the
 723   // actual printing.
 724   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 725 }
 726
 727 bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
 728   return true;
 729 }
 730
 731 void PrepareFrameAndViewForPrint::didStopLoading() {
 732   DCHECK(!on_ready_.is_null());
 733   // Don't call callback here, because it can delete |this| and WebView that is
 734   // called didStopLoading.
 735   base::ThreadTaskRunnerHandle::Get()->PostTask(
 736       FROM_HERE, base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
 737                             weak_ptr_factory_.GetWeakPtr()));
 738 }
 739
 740 blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
 741     blink::WebLocalFrame* parent,
 742     blink::WebTreeScopeType scope,
 743     const blink::WebString& name,
 744     blink::WebSandboxFlags sandboxFlags) {
 745   blink::WebFrame* frame = blink::WebLocalFrame::create(scope, this);
 746   parent->appendChild(frame);
 747   return frame;
 748 }
 749
 750 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame,
 751                                                 DetachType type) {
 752   DCHECK(type == DetachType::Remove);
 753   if (frame->parent())
 754     frame->parent()->removeChild(frame);
 755   frame->close();
 756 }
 757
 758 void PrepareFrameAndViewForPrint::CallOnReady() {
 759   return on_ready_.Run();  // Can delete |this|.
 760 }
 761
 762 void PrepareFrameAndViewForPrint::RestoreSize() {
 763   if (frame()) {
 764     blink::WebView* web_view = frame_.GetFrame()->view();
 765     web_view->resize(prev_view_size_);
 766     if (blink::WebFrame* web_frame = web_view->mainFrame())
 767       web_frame->setScrollOffset(prev_scroll_offset_);
 768   }
 769 }
 770
 771 void PrepareFrameAndViewForPrint::FinishPrinting() {
 772   blink::WebLocalFrame* frame = frame_.GetFrame();
 773   if (frame) {
 774     blink::WebView* web_view = frame->view();
 775     if (is_printing_started_) {
 776       is_printing_started_ = false;
 777       frame->printEnd();
 778       if (!owns_web_view_) {
 779         web_view->settings()->setShouldPrintBackgrounds(false);
 780         RestoreSize();
 781       }
 782     }
 783     if (owns_web_view_) {
 784       DCHECK(!frame->isLoading());
 785       owns_web_view_ = false;
 786       web_view->close();
 787     }
 788   }
 789   frame_.Reset(NULL);
 790   on_ready_.Reset();
 791 }
 792
 793 bool PrintWebViewHelper::Delegate::IsAskPrintSettingsEnabled() {
 794   return true;
 795 }
 796
 797 bool PrintWebViewHelper::Delegate::IsScriptedPrintEnabled() {
 798   return true;
 799 }
 800
 801 PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view,
 802                                        scoped_ptr<Delegate> delegate)
 803     : content::RenderViewObserver(render_view),
 804       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
 805       reset_prep_frame_view_(false),
 806       is_print_ready_metafile_sent_(false),
 807       ignore_css_margins_(false),
 808       is_scripted_printing_blocked_(false),
 809       notify_browser_of_print_failure_(true),
 810       print_for_preview_(false),
 811       delegate_(delegate.Pass()),
 812       print_node_in_progress_(false),
 813       is_loading_(false),
 814       is_scripted_preview_delayed_(false),
 815       ipc_nesting_level_(0),
 816       weak_ptr_factory_(this) {
 817   if (!delegate_->IsPrintPreviewEnabled())
 818     DisablePreview();
 819 }
 820
 821 PrintWebViewHelper::~PrintWebViewHelper() {
 822 }
 823
 824 // static
 825 void PrintWebViewHelper::DisablePreview() {
 826   g_is_preview_enabled_ = false;
 827 }
 828
 829 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(blink::WebFrame* frame,
 830                                                        bool user_initiated) {
 831   if (!delegate_->IsScriptedPrintEnabled())
 832     return false;
 833
 834   // If preview is enabled, then the print dialog is tab modal, and the user
 835   // can always close the tab on a mis-behaving page (the system print dialog
 836   // is app modal). If the print was initiated through user action, don't
 837   // throttle. Or, if the command line flag to skip throttling has been set.
 838   return !is_scripted_printing_blocked_ &&
 839          (user_initiated || g_is_preview_enabled_ ||
 840           scripting_throttler_.IsAllowed(frame));
 841 }
 842
 843 void PrintWebViewHelper::DidStartLoading() {
 844   is_loading_ = true;
 845 }
 846
 847 void PrintWebViewHelper::DidStopLoading() {
 848   is_loading_ = false;
 849   if (!on_stop_loading_closure_.is_null()) {
 850     on_stop_loading_closure_.Run();
 851     on_stop_loading_closure_.Reset();
 852   }
 853 }
 854
 855 // Prints |frame| which called window.print().
 856 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
 857                                    bool user_initiated) {
 858   DCHECK(frame);
 859
 860   // Allow Prerendering to cancel this print request if necessary.
 861   if (delegate_->CancelPrerender(render_view(), routing_id()))
 862     return;
 863
 864   if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
 865     return;
 866
 867   if (delegate_->OverridePrint(frame))
 868     return;
 869
 870   if (!g_is_preview_enabled_) {
 871     Print(frame, blink::WebNode(), true);
 872   } else {
 873     print_preview_context_.InitWithFrame(frame);
 874     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
 875   }
 876 }
 877
 878 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
 879   // The class is not designed to handle recursive messages. This is not
 880   // expected during regular flow. However, during rendering of content for
 881   // printing, lower level code may run nested message loop. E.g. PDF may has
 882   // script to show message box http://crbug.com/502562. In that moment browser
 883   // may receive updated printer capabilities and decide to restart print
 884   // preview generation. When this happened message handling function may
 885   // choose to ignore message or safely crash process.
 886   ++ipc_nesting_level_;
 887
 888   bool handled = true;
 889   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
 890 #if defined(ENABLE_BASIC_PRINTING)
 891     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
 892     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
 893 #endif  // ENABLE_BASIC_PRINTING
 894     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
 895     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
 896     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
 897     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
 898     IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
 899                         SetScriptedPrintBlocked)
 900     IPC_MESSAGE_UNHANDLED(handled = false)
 901   IPC_END_MESSAGE_MAP()
 902
 903   --ipc_nesting_level_;
 904   return handled;
 905 }
 906
 907 void PrintWebViewHelper::OnPrintForPrintPreview(
 908     const base::DictionaryValue& job_settings) {
 909   CHECK_LE(ipc_nesting_level_, 1);
 910   // If still not finished with earlier print request simply ignore.
 911   if (prep_frame_view_)
 912     return;
 913
 914   if (!render_view()->GetWebView())
 915     return;
 916   blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
 917   if (!main_frame)
 918     return;
 919
 920   blink::WebDocument document = main_frame->document();
 921   // <object>/<iframe> with id="pdf-viewer" is created in
 922   // chrome/browser/resources/print_preview/print_preview.js
 923   blink::WebElement pdf_element = document.getElementById("pdf-viewer");
 924   if (pdf_element.isNull()) {
 925     NOTREACHED();
 926     return;
 927   }
 928
 929   // The out-of-process plugin element is nested within a frame. In tests, there
 930   // may not be an iframe containing the out-of-process plugin, so continue with
 931   // the element with ID "pdf-viewer" if it isn't an iframe.
 932   blink::WebLocalFrame* plugin_frame = pdf_element.document().frame();
 933   blink::WebElement plugin_element = pdf_element;
 934   if (pdf_element.hasHTMLTagName("iframe")) {
 935     plugin_frame = blink::WebLocalFrame::fromFrameOwnerElement(pdf_element);
 936     plugin_element = delegate_->GetPdfElement(plugin_frame);
 937     if (plugin_element.isNull()) {
 938       NOTREACHED();
 939       return;
 940     }
 941   }
 942
 943   // Set |print_for_preview_| flag and autoreset it to back to original
 944   // on return.
 945   base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
 946
 947   if (!UpdatePrintSettings(plugin_frame, plugin_element, job_settings)) {
 948     LOG(ERROR) << "UpdatePrintSettings failed";
 949     DidFinishPrinting(FAIL_PRINT);
 950     return;
 951   }
 952
 953   // Print page onto entire page not just printable area. Preview PDF already
 954   // has content in correct position taking into account page size and printable
 955   // area.
 956   // TODO(vitalybuka) : Make this consistent on all platform. This change
 957   // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
 958   // printable_area. Also we can't change printable_area deeper inside
 959   // RenderPagesForPrint for Windows, because it's used also by native
 960   // printing and it expects real printable_area value.
 961   // See http://crbug.com/123408
 962   PrintMsg_Print_Params& print_params = print_pages_params_->params;
 963   print_params.printable_area = gfx::Rect(print_params.page_size);
 964
 965   // Render Pages for printing.
 966   if (!RenderPagesForPrint(plugin_frame, plugin_element)) {
 967     LOG(ERROR) << "RenderPagesForPrint failed";
 968     DidFinishPrinting(FAIL_PRINT);
 969   }
 970 }
 971
 972 bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
 973   DCHECK(frame);
 974   blink::WebView* webView = render_view()->GetWebView();
 975   DCHECK(webView);
 976   if (!webView)
 977     return false;
 978
 979   // If the user has selected text in the currently focused frame we print
 980   // only that frame (this makes print selection work for multiple frames).
 981   blink::WebLocalFrame* focusedFrame =
 982       webView->focusedFrame()->toWebLocalFrame();
 983   *frame = focusedFrame->hasSelection()
 984                ? focusedFrame
 985                : webView->mainFrame()->toWebLocalFrame();
 986   return true;
 987 }
 988
 989 #if defined(ENABLE_BASIC_PRINTING)
 990 void PrintWebViewHelper::OnPrintPages() {
 991   CHECK_LE(ipc_nesting_level_, 1);
 992   blink::WebLocalFrame* frame;
 993   if (!GetPrintFrame(&frame))
 994     return;
 995   // If we are printing a PDF extension frame, find the plugin node and print
 996   // that instead.
 997   auto plugin = delegate_->GetPdfElement(frame);
 998   Print(frame, plugin, false);
 999 }
1000
1001 void PrintWebViewHelper::OnPrintForSystemDialog() {
1002   CHECK_LE(ipc_nesting_level_, 1);
1003   blink::WebLocalFrame* frame = print_preview_context_.source_frame();
1004   if (!frame) {
1005     NOTREACHED();
1006     return;
1007   }
1008   Print(frame, print_preview_context_.source_node(), false);
1009 }
1010 #endif  // ENABLE_BASIC_PRINTING
1011
1012 void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
1013     const PageSizeMargins& page_layout_in_points,
1014     gfx::Size* page_size,
1015     gfx::Rect* content_area) {
1016   *page_size = gfx::Size(
1017       page_layout_in_points.content_width + page_layout_in_points.margin_right +
1018           page_layout_in_points.margin_left,
1019       page_layout_in_points.content_height + page_layout_in_points.margin_top +
1020           page_layout_in_points.margin_bottom);
1021   *content_area = gfx::Rect(page_layout_in_points.margin_left,
1022                             page_layout_in_points.margin_top,
1023                             page_layout_in_points.content_width,
1024                             page_layout_in_points.content_height);
1025 }
1026
1027 void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
1028     const base::DictionaryValue& settings) {
1029   int margins_type = 0;
1030   if (!settings.GetInteger(kSettingMarginsType, &margins_type))
1031     margins_type = DEFAULT_MARGINS;
1032   ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
1033 }
1034
1035 bool PrintWebViewHelper::IsPrintToPdfRequested(
1036     const base::DictionaryValue& job_settings) {
1037   bool print_to_pdf = false;
1038   if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
1039     NOTREACHED();
1040   return print_to_pdf;
1041 }
1042
1043 void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
1044   CHECK_LE(ipc_nesting_level_, 1);
1045
1046   print_preview_context_.OnPrintPreview();
1047
1048   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1049                             PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
1050
1051   if (!print_preview_context_.source_frame()) {
1052     DidFinishPrinting(FAIL_PREVIEW);
1053     return;
1054   }
1055
1056   if (!UpdatePrintSettings(print_preview_context_.source_frame(),
1057                            print_preview_context_.source_node(), settings)) {
1058     if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
1059       Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
1060           routing_id(), print_pages_params_
1061                             ? print_pages_params_->params.document_cookie
1062                             : 0));
1063       notify_browser_of_print_failure_ = false;  // Already sent.
1064     }
1065     DidFinishPrinting(FAIL_PREVIEW);
1066     return;
1067   }
1068
1069   // Set the options from document if we are previewing a pdf and send a
1070   // message to browser.
1071   if (print_pages_params_->params.is_first_request &&
1072       !print_preview_context_.IsModifiable()) {
1073     PrintHostMsg_SetOptionsFromDocument_Params options;
1074     if (SetOptionsFromPdfDocument(&options))
1075       Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), options));
1076   }
1077
1078   is_print_ready_metafile_sent_ = false;
1079
1080   // PDF printer device supports alpha blending.
1081   print_pages_params_->params.supports_alpha_blend = true;
1082
1083   bool generate_draft_pages = false;
1084   if (!settings.GetBoolean(kSettingGenerateDraftData, &generate_draft_pages)) {
1085     NOTREACHED();
1086   }
1087   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1088
1089   PrepareFrameForPreviewDocument();
1090 }
1091
1092 void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1093   reset_prep_frame_view_ = false;
1094
1095   if (!print_pages_params_ || CheckForCancel()) {
1096     DidFinishPrinting(FAIL_PREVIEW);
1097     return;
1098   }
1099
1100   // Don't reset loading frame or WebKit will fail assert. Just retry when
1101   // current selection is loaded.
1102   if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1103     reset_prep_frame_view_ = true;
1104     return;
1105   }
1106
1107   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1108   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1109       print_params, print_preview_context_.source_frame(),
1110       print_preview_context_.source_node(), ignore_css_margins_));
1111   prep_frame_view_->CopySelectionIfNeeded(
1112       render_view()->GetWebkitPreferences(),
1113       base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1114                  base::Unretained(this)));
1115 }
1116
1117 void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1118   if (reset_prep_frame_view_) {
1119     PrepareFrameForPreviewDocument();
1120     return;
1121   }
1122   DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1123 }
1124
1125 bool PrintWebViewHelper::CreatePreviewDocument() {
1126   if (!print_pages_params_ || CheckForCancel())
1127     return false;
1128
1129   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1130                             PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1131
1132   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1133   const std::vector<int>& pages = print_pages_params_->pages;
1134
1135   if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1136                                                     pages)) {
1137     return false;
1138   }
1139
1140   PageSizeMargins default_page_layout;
1141   ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1142                                   print_params, ignore_css_margins_, NULL,
1143                                   &default_page_layout);
1144
1145   bool has_page_size_style =
1146       PrintingFrameHasPageSizeStyle(print_preview_context_.prepared_frame(),
1147                                     print_preview_context_.total_page_count());
1148   int dpi = GetDPI(&print_params);
1149
1150   gfx::Rect printable_area_in_points(
1151       ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1152       ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1153       ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1154       ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1155
1156   // Margins: Send default page layout to browser process.
1157   Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1158                                                 default_page_layout,
1159                                                 printable_area_in_points,
1160                                                 has_page_size_style));
1161
1162   PrintHostMsg_DidGetPreviewPageCount_Params params;
1163   params.page_count = print_preview_context_.total_page_count();
1164   params.is_modifiable = print_preview_context_.IsModifiable();
1165   params.document_cookie = print_params.document_cookie;
1166   params.preview_request_id = print_params.preview_request_id;
1167   params.clear_preview_data = print_preview_context_.generate_draft_pages();
1168   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1169   if (CheckForCancel())
1170     return false;
1171
1172   while (!print_preview_context_.IsFinalPageRendered()) {
1173     int page_number = print_preview_context_.GetNextPageNumber();
1174     DCHECK_GE(page_number, 0);
1175     if (!RenderPreviewPage(page_number, print_params))
1176       return false;
1177
1178     if (CheckForCancel())
1179       return false;
1180
1181     // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1182     // print_preview_context_.AllPagesRendered()) before calling
1183     // FinalizePrintReadyDocument() when printing a PDF because the plugin
1184     // code does not generate output until we call FinishPrinting().  We do not
1185     // generate draft pages for PDFs, so IsFinalPageRendered() and
1186     // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1187     // the loop.
1188     if (print_preview_context_.IsFinalPageRendered())
1189       print_preview_context_.AllPagesRendered();
1190
1191     if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1192       DCHECK(print_preview_context_.IsModifiable() ||
1193              print_preview_context_.IsFinalPageRendered());
1194       if (!FinalizePrintReadyDocument())
1195         return false;
1196     }
1197   }
1198   print_preview_context_.Finished();
1199   return true;
1200 }
1201
1202 bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1203   DCHECK(!is_print_ready_metafile_sent_);
1204   print_preview_context_.FinalizePrintReadyDocument();
1205
1206   // Get the size of the resulting metafile.
1207   PdfMetafileSkia* metafile = print_preview_context_.metafile();
1208   uint32 buf_size = metafile->GetDataSize();
1209   DCHECK_GT(buf_size, 0u);
1210
1211   PrintHostMsg_DidPreviewDocument_Params preview_params;
1212   preview_params.data_size = buf_size;
1213   preview_params.document_cookie = print_pages_params_->params.document_cookie;
1214   preview_params.expected_pages_count =
1215       print_preview_context_.total_page_count();
1216   preview_params.modifiable = print_preview_context_.IsModifiable();
1217   preview_params.preview_request_id =
1218       print_pages_params_->params.preview_request_id;
1219
1220   // Ask the browser to create the shared memory for us.
1221   if (!CopyMetafileDataToSharedMem(metafile,
1222                                    &(preview_params.metafile_data_handle))) {
1223     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1224     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1225     return false;
1226   }
1227   is_print_ready_metafile_sent_ = true;
1228
1229   Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1230   return true;
1231 }
1232
1233 void PrintWebViewHelper::OnPrintingDone(bool success) {
1234   CHECK_LE(ipc_nesting_level_, 1);
1235   notify_browser_of_print_failure_ = false;
1236   if (!success)
1237     LOG(ERROR) << "Failure in OnPrintingDone";
1238   DidFinishPrinting(success ? OK : FAIL_PRINT);
1239 }
1240
1241 void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1242   is_scripted_printing_blocked_ = blocked;
1243 }
1244
1245 void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1246   CHECK_LE(ipc_nesting_level_, 1);
1247   blink::WebLocalFrame* frame = NULL;
1248   GetPrintFrame(&frame);
1249   DCHECK(frame);
1250   // If we are printing a PDF extension frame, find the plugin node and print
1251   // that instead.
1252   auto plugin = delegate_->GetPdfElement(frame);
1253   if (!plugin.isNull()) {
1254     PrintNode(plugin);
1255     return;
1256   }
1257   print_preview_context_.InitWithFrame(frame);
1258   RequestPrintPreview(selection_only
1259                           ? PRINT_PREVIEW_USER_INITIATED_SELECTION
1260                           : PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1261 }
1262
1263 bool PrintWebViewHelper::IsPrintingEnabled() {
1264   bool result = false;
1265   Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1266   return result;
1267 }
1268
1269 void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1270   if (node.isNull() || !node.document().frame()) {
1271     // This can occur when the context menu refers to an invalid WebNode.
1272     // See http://crbug.com/100890#c17 for a repro case.
1273     return;
1274   }
1275
1276   if (print_node_in_progress_) {
1277     // This can happen as a result of processing sync messages when printing
1278     // from ppapi plugins. It's a rare case, so its OK to just fail here.
1279     // See http://crbug.com/159165.
1280     return;
1281   }
1282
1283   print_node_in_progress_ = true;
1284
1285   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1286   // its |context_menu_node_|.
1287   if (!g_is_preview_enabled_) {
1288     blink::WebNode duplicate_node(node);
1289     Print(duplicate_node.document().frame(), duplicate_node, false);
1290   } else {
1291     print_preview_context_.InitWithNode(node);
1292     RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1293   }
1294
1295   print_node_in_progress_ = false;
1296 }
1297
1298 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1299                                const blink::WebNode& node,
1300                                bool is_scripted) {
1301   // If still not finished with earlier print request simply ignore.
1302   if (prep_frame_view_)
1303     return;
1304
1305   FrameReference frame_ref(frame);
1306
1307   int expected_page_count = 0;
1308   if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1309     DidFinishPrinting(FAIL_PRINT_INIT);
1310     return;  // Failed to init print page settings.
1311   }
1312
1313   // Some full screen plugins can say they don't want to print.
1314   if (!expected_page_count) {
1315     DidFinishPrinting(FAIL_PRINT);
1316     return;
1317   }
1318
1319   // Ask the browser to show UI to retrieve the final print settings.
1320   if (delegate_->IsAskPrintSettingsEnabled() &&
1321       !GetPrintSettingsFromUser(frame_ref.GetFrame(), node, expected_page_count,
1322                                 is_scripted)) {
1323     DidFinishPrinting(OK);  // Release resources and fail silently.
1324     return;
1325   }
1326
1327   // Render Pages for printing.
1328   if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1329     LOG(ERROR) << "RenderPagesForPrint failed";
1330     DidFinishPrinting(FAIL_PRINT);
1331   }
1332   scripting_throttler_.Reset();
1333 }
1334
1335 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1336   switch (result) {
1337     case OK:
1338       break;
1339
1340     case FAIL_PRINT_INIT:
1341       DCHECK(!notify_browser_of_print_failure_);
1342       break;
1343
1344     case FAIL_PRINT:
1345       if (notify_browser_of_print_failure_ && print_pages_params_) {
1346         int cookie = print_pages_params_->params.document_cookie;
1347         Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1348       }
1349       break;
1350
1351     case FAIL_PREVIEW:
1352       int cookie =
1353           print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1354       if (notify_browser_of_print_failure_) {
1355         LOG(ERROR) << "CreatePreviewDocument failed";
1356         Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1357       } else {
1358         Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1359       }
1360       print_preview_context_.Failed(notify_browser_of_print_failure_);
1361       break;
1362   }
1363   prep_frame_view_.reset();
1364   print_pages_params_.reset();
1365   notify_browser_of_print_failure_ = true;
1366 }
1367
1368 void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1369   PrintPages();
1370   FinishFramePrinting();
1371 }
1372
1373 void PrintWebViewHelper::PrintPages() {
1374   if (!prep_frame_view_)  // Printing is already canceled or failed.
1375     return;
1376   prep_frame_view_->StartPrinting();
1377
1378   int page_count = prep_frame_view_->GetExpectedPageCount();
1379   if (!page_count) {
1380     LOG(ERROR) << "Can't print 0 pages.";
1381     return DidFinishPrinting(FAIL_PRINT);
1382   }
1383
1384   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1385   const PrintMsg_Print_Params& print_params = params.params;
1386
1387 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1388   // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1389   // See http://crbug.com/161576
1390   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1391                                                 print_params.document_cookie,
1392                                                 page_count));
1393 #endif  // !defined(OS_CHROMEOS)
1394
1395   if (print_params.preview_ui_id < 0) {
1396     // Printing for system dialog.
1397     int printed_count = params.pages.empty() ? page_count : params.pages.size();
1398 #if !defined(OS_CHROMEOS)
1399     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1400 #else
1401     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1402                          printed_count);
1403 #endif  // !defined(OS_CHROMEOS)
1404   }
1405
1406   if (!PrintPagesNative(prep_frame_view_->frame(), page_count)) {
1407     LOG(ERROR) << "Printing failed.";
1408     return DidFinishPrinting(FAIL_PRINT);
1409   }
1410 }
1411
1412 void PrintWebViewHelper::FinishFramePrinting() {
1413   prep_frame_view_.reset();
1414 }
1415
1416 #if defined(OS_MACOSX)
1417 bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1418                                           int page_count) {
1419   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1420   const PrintMsg_Print_Params& print_params = params.params;
1421
1422   PrintMsg_PrintPage_Params page_params;
1423   page_params.params = print_params;
1424   if (params.pages.empty()) {
1425     for (int i = 0; i < page_count; ++i) {
1426       page_params.page_number = i;
1427       PrintPageInternal(page_params, frame);
1428     }
1429   } else {
1430     for (size_t i = 0; i < params.pages.size(); ++i) {
1431       if (params.pages[i] >= page_count)
1432         break;
1433       page_params.page_number = params.pages[i];
1434       PrintPageInternal(page_params, frame);
1435     }
1436   }
1437   return true;
1438 }
1439
1440 #endif  // OS_MACOSX
1441
1442 // static - Not anonymous so that platform implementations can use it.
1443 void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1444     blink::WebFrame* frame,
1445     int page_index,
1446     const PrintMsg_Print_Params& page_params,
1447     bool ignore_css_margins,
1448     double* scale_factor,
1449     PageSizeMargins* page_layout_in_points) {
1450   PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1451       frame, page_index, page_params, ignore_css_margins,
1452       page_params.print_scaling_option ==
1453           blink::WebPrintScalingOptionFitToPrintableArea,
1454       scale_factor);
1455   CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1456 }
1457
1458 bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1459   PrintMsg_PrintPages_Params settings;
1460   Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1461                                                 &settings.params));
1462   // Check if the printer returned any settings, if the settings is empty, we
1463   // can safely assume there are no printer drivers configured. So we safely
1464   // terminate.
1465   bool result = true;
1466   if (!PrintMsg_Print_Params_IsValid(settings.params))
1467     result = false;
1468
1469   // Reset to default values.
1470   ignore_css_margins_ = false;
1471   settings.pages.clear();
1472
1473   settings.params.print_scaling_option = blink::WebPrintScalingOptionSourceSize;
1474   if (fit_to_paper_size) {
1475     settings.params.print_scaling_option =
1476         blink::WebPrintScalingOptionFitToPrintableArea;
1477   }
1478
1479   SetPrintPagesParams(settings);
1480   return result;
1481 }
1482
1483 bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1484                                                 const blink::WebNode& node,
1485                                                 int* number_of_pages) {
1486   DCHECK(frame);
1487   bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1488   if (!InitPrintSettings(fit_to_paper_size)) {
1489     notify_browser_of_print_failure_ = false;
1490     Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1491     return false;
1492   }
1493
1494   const PrintMsg_Print_Params& params = print_pages_params_->params;
1495   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1496   prepare.StartPrinting();
1497
1498   *number_of_pages = prepare.GetExpectedPageCount();
1499   return true;
1500 }
1501
1502 bool PrintWebViewHelper::SetOptionsFromPdfDocument(
1503     PrintHostMsg_SetOptionsFromDocument_Params* options) {
1504   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
1505   const blink::WebNode& source_node = print_preview_context_.source_node();
1506
1507   blink::WebPrintPresetOptions preset_options;
1508   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
1509                                                     &preset_options)) {
1510     return false;
1511   }
1512
1513   options->is_scaling_disabled = PDFShouldDisableScalingBasedOnPreset(
1514       preset_options, print_pages_params_->params);
1515   options->copies = preset_options.copies;
1516
1517   // TODO(thestig) This should be a straight pass-through, but print preview
1518   // does not currently support short-edge printing.
1519   switch (preset_options.duplexMode) {
1520     case blink::WebSimplex:
1521       options->duplex = SIMPLEX;
1522       break;
1523     case blink::WebLongEdge:
1524       options->duplex = LONG_EDGE;
1525       break;
1526     default:
1527       options->duplex = UNKNOWN_DUPLEX_MODE;
1528       break;
1529   }
1530   return true;
1531 }
1532
1533 bool PrintWebViewHelper::UpdatePrintSettings(
1534     blink::WebLocalFrame* frame,
1535     const blink::WebNode& node,
1536     const base::DictionaryValue& passed_job_settings) {
1537   const base::DictionaryValue* job_settings = &passed_job_settings;
1538   base::DictionaryValue modified_job_settings;
1539   if (job_settings->empty()) {
1540     if (!print_for_preview_)
1541       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1542     return false;
1543   }
1544
1545   bool source_is_html = true;
1546   if (print_for_preview_) {
1547     if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1548       NOTREACHED();
1549     }
1550   } else {
1551     source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1552   }
1553
1554   if (print_for_preview_ || !source_is_html) {
1555     modified_job_settings.MergeDictionary(job_settings);
1556     modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1557     modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1558     job_settings = &modified_job_settings;
1559   }
1560
1561   // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1562   // possible.
1563   int cookie =
1564       print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1565   PrintMsg_PrintPages_Params settings;
1566   bool canceled = false;
1567   Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
1568                                             &settings, &canceled));
1569   if (canceled) {
1570     notify_browser_of_print_failure_ = false;
1571     return false;
1572   }
1573
1574   if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1575     NOTREACHED();
1576     print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1577     return false;
1578   }
1579
1580   if (!print_for_preview_) {
1581     // Validate expected print preview settings.
1582     if (!job_settings->GetInteger(kPreviewRequestID,
1583                                   &settings.params.preview_request_id) ||
1584         !job_settings->GetBoolean(kIsFirstRequest,
1585                                   &settings.params.is_first_request)) {
1586       NOTREACHED();
1587       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1588       return false;
1589     }
1590
1591     settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1592     UpdateFrameMarginsCssInfo(*job_settings);
1593     settings.params.print_scaling_option = GetPrintScalingOption(
1594         frame, node, source_is_html, *job_settings, settings.params);
1595   }
1596
1597   SetPrintPagesParams(settings);
1598
1599   if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1600     if (!print_for_preview_)
1601       print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1602     else
1603       Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1604
1605     return false;
1606   }
1607
1608   return true;
1609 }
1610
1611 bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebLocalFrame* frame,
1612                                                   const blink::WebNode& node,
1613                                                   int expected_pages_count,
1614                                                   bool is_scripted) {
1615   PrintHostMsg_ScriptedPrint_Params params;
1616   PrintMsg_PrintPages_Params print_settings;
1617
1618   params.cookie = print_pages_params_->params.document_cookie;
1619   params.has_selection = frame->hasSelection();
1620   params.expected_pages_count = expected_pages_count;
1621   MarginType margin_type = DEFAULT_MARGINS;
1622   if (PrintingNodeOrPdfFrame(frame, node)) {
1623     margin_type =
1624         GetMarginsForPdf(frame, node, print_pages_params_->params);
1625   }
1626   params.margin_type = margin_type;
1627   params.is_scripted = is_scripted;
1628
1629   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1630
1631   // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1632   // value before and restore it afterwards.
1633   blink::WebPrintScalingOption scaling_option =
1634       print_pages_params_->params.print_scaling_option;
1635
1636   print_pages_params_.reset();
1637   IPC::SyncMessage* msg =
1638       new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1639   msg->EnableMessagePumping();
1640   Send(msg);
1641   print_settings.params.print_scaling_option = scaling_option;
1642   SetPrintPagesParams(print_settings);
1643   return (print_settings.params.dpi && print_settings.params.document_cookie);
1644 }
1645
1646 bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1647                                              const blink::WebNode& node) {
1648   if (!frame || prep_frame_view_)
1649     return false;
1650   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1651   const PrintMsg_Print_Params& print_params = params.params;
1652   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1653       print_params, frame, node, ignore_css_margins_));
1654   DCHECK(!print_pages_params_->params.selection_only ||
1655          print_pages_params_->pages.empty());
1656   prep_frame_view_->CopySelectionIfNeeded(
1657       render_view()->GetWebkitPreferences(),
1658       base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1659                  base::Unretained(this)));
1660   return true;
1661 }
1662
1663 #if defined(OS_POSIX)
1664 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1665     PdfMetafileSkia* metafile,
1666     base::SharedMemoryHandle* shared_mem_handle) {
1667   uint32 buf_size = metafile->GetDataSize();
1668   scoped_ptr<base::SharedMemory> shared_buf(
1669       content::RenderThread::Get()
1670           ->HostAllocateSharedMemoryBuffer(buf_size)
1671           .release());
1672
1673   if (shared_buf) {
1674     if (shared_buf->Map(buf_size)) {
1675       metafile->GetData(shared_buf->memory(), buf_size);
1676       return shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1677                                        shared_mem_handle);
1678     }
1679   }
1680   return false;
1681 }
1682 #endif  // defined(OS_POSIX)
1683
1684 void PrintWebViewHelper::ShowScriptedPrintPreview() {
1685   if (is_scripted_preview_delayed_) {
1686     is_scripted_preview_delayed_ = false;
1687     Send(new PrintHostMsg_ShowScriptedPrintPreview(
1688         routing_id(), print_preview_context_.IsModifiable()));
1689   }
1690 }
1691
1692 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1693   const bool is_modifiable = print_preview_context_.IsModifiable();
1694   const bool has_selection = print_preview_context_.HasSelection();
1695   PrintHostMsg_RequestPrintPreview_Params params;
1696   params.is_modifiable = is_modifiable;
1697   params.has_selection = has_selection;
1698   switch (type) {
1699     case PRINT_PREVIEW_SCRIPTED: {
1700       // Shows scripted print preview in two stages.
1701       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1702       //    pumping messages here.
1703       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1704       //    document has been loaded.
1705       is_scripted_preview_delayed_ = true;
1706       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1707         // Wait for DidStopLoading. Plugins may not know the correct
1708         // |is_modifiable| value until they are fully loaded, which occurs when
1709         // DidStopLoading() is called. Defer showing the preview until then.
1710         on_stop_loading_closure_ =
1711             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1712                        base::Unretained(this));
1713       } else {
1714         base::ThreadTaskRunnerHandle::Get()->PostTask(
1715             FROM_HERE, base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1716                                   weak_ptr_factory_.GetWeakPtr()));
1717       }
1718       IPC::SyncMessage* msg =
1719           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1720       msg->EnableMessagePumping();
1721       Send(msg);
1722       is_scripted_preview_delayed_ = false;
1723       return;
1724     }
1725     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1726       // Wait for DidStopLoading. Continuing with this function while
1727       // |is_loading_| is true will cause print preview to hang when try to
1728       // print a PDF document.
1729       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1730         on_stop_loading_closure_ =
1731             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1732                        base::Unretained(this), type);
1733         return;
1734       }
1735
1736       break;
1737     }
1738     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1739       DCHECK(has_selection);
1740       DCHECK(!GetPlugin(print_preview_context_.source_frame()));
1741       params.selection_only = has_selection;
1742       break;
1743     }
1744     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1745       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1746         on_stop_loading_closure_ =
1747             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1748                        base::Unretained(this), type);
1749         return;
1750       }
1751
1752       params.webnode_only = true;
1753       break;
1754     }
1755     default: {
1756       NOTREACHED();
1757       return;
1758     }
1759   }
1760   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1761 }
1762
1763 bool PrintWebViewHelper::CheckForCancel() {
1764   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1765   bool cancel = false;
1766   Send(new PrintHostMsg_CheckForCancel(routing_id(),
1767                                        print_params.preview_ui_id,
1768                                        print_params.preview_request_id,
1769                                        &cancel));
1770   if (cancel)
1771     notify_browser_of_print_failure_ = false;
1772   return cancel;
1773 }
1774
1775 bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1776                                              PdfMetafileSkia* metafile) {
1777   DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1778
1779   // For non-modifiable files, |metafile| should be NULL, so do not bother
1780   // sending a message. If we don't generate draft metafiles, |metafile| is
1781   // NULL.
1782   if (!print_preview_context_.IsModifiable() ||
1783       !print_preview_context_.generate_draft_pages()) {
1784     DCHECK(!metafile);
1785     return true;
1786   }
1787
1788   if (!metafile) {
1789     NOTREACHED();
1790     print_preview_context_.set_error(
1791         PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1792     return false;
1793   }
1794
1795   PrintHostMsg_DidPreviewPage_Params preview_page_params;
1796   // Get the size of the resulting metafile.
1797   uint32 buf_size = metafile->GetDataSize();
1798   DCHECK_GT(buf_size, 0u);
1799   if (!CopyMetafileDataToSharedMem(
1800           metafile, &(preview_page_params.metafile_data_handle))) {
1801     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1802     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1803     return false;
1804   }
1805   preview_page_params.data_size = buf_size;
1806   preview_page_params.page_number = page_number;
1807   preview_page_params.preview_request_id =
1808       print_pages_params_->params.preview_request_id;
1809
1810   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1811   return true;
1812 }
1813
1814 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1815     : total_page_count_(0),
1816       current_page_index_(0),
1817       generate_draft_pages_(true),
1818       print_ready_metafile_page_count_(0),
1819       error_(PREVIEW_ERROR_NONE),
1820       state_(UNINITIALIZED) {
1821 }
1822
1823 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1824 }
1825
1826 void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1827     blink::WebLocalFrame* web_frame) {
1828   DCHECK(web_frame);
1829   DCHECK(!IsRendering());
1830   state_ = INITIALIZED;
1831   source_frame_.Reset(web_frame);
1832   source_node_.reset();
1833 }
1834
1835 void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1836     const blink::WebNode& web_node) {
1837   DCHECK(!web_node.isNull());
1838   DCHECK(web_node.document().frame());
1839   DCHECK(!IsRendering());
1840   state_ = INITIALIZED;
1841   source_frame_.Reset(web_node.document().frame());
1842   source_node_ = web_node;
1843 }
1844
1845 void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1846   DCHECK_EQ(INITIALIZED, state_);
1847   ClearContext();
1848 }
1849
1850 bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1851     PrepareFrameAndViewForPrint* prepared_frame,
1852     const std::vector<int>& pages) {
1853   DCHECK_EQ(INITIALIZED, state_);
1854   state_ = RENDERING;
1855
1856   // Need to make sure old object gets destroyed first.
1857   prep_frame_view_.reset(prepared_frame);
1858   prep_frame_view_->StartPrinting();
1859
1860   total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1861   if (total_page_count_ == 0) {
1862     LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1863     set_error(PREVIEW_ERROR_ZERO_PAGES);
1864     return false;
1865   }
1866
1867   metafile_.reset(new PdfMetafileSkia);
1868   if (!metafile_->Init()) {
1869     set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1870     LOG(ERROR) << "PdfMetafileSkia Init failed";
1871     return false;
1872   }
1873
1874   current_page_index_ = 0;
1875   pages_to_render_ = pages;
1876   // Sort and make unique.
1877   std::sort(pages_to_render_.begin(), pages_to_render_.end());
1878   pages_to_render_.resize(
1879       std::unique(pages_to_render_.begin(), pages_to_render_.end()) -
1880       pages_to_render_.begin());
1881   // Remove invalid pages.
1882   pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1883                                            pages_to_render_.end(),
1884                                            total_page_count_) -
1885                           pages_to_render_.begin());
1886   print_ready_metafile_page_count_ = pages_to_render_.size();
1887   if (pages_to_render_.empty()) {
1888     print_ready_metafile_page_count_ = total_page_count_;
1889     // Render all pages.
1890     for (int i = 0; i < total_page_count_; ++i)
1891       pages_to_render_.push_back(i);
1892   } else if (generate_draft_pages_) {
1893     int pages_index = 0;
1894     for (int i = 0; i < total_page_count_; ++i) {
1895       if (pages_index < print_ready_metafile_page_count_ &&
1896           i == pages_to_render_[pages_index]) {
1897         pages_index++;
1898         continue;
1899       }
1900       pages_to_render_.push_back(i);
1901     }
1902   }
1903
1904   document_render_time_ = base::TimeDelta();
1905   begin_time_ = base::TimeTicks::Now();
1906
1907   return true;
1908 }
1909
1910 void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1911     const base::TimeDelta& page_time) {
1912   DCHECK_EQ(RENDERING, state_);
1913   document_render_time_ += page_time;
1914   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1915 }
1916
1917 void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1918   DCHECK_EQ(RENDERING, state_);
1919   state_ = DONE;
1920   prep_frame_view_->FinishPrinting();
1921 }
1922
1923 void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1924   DCHECK(IsRendering());
1925
1926   base::TimeTicks begin_time = base::TimeTicks::Now();
1927   metafile_->FinishDocument();
1928
1929   if (print_ready_metafile_page_count_ <= 0) {
1930     NOTREACHED();
1931     return;
1932   }
1933
1934   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1935                              document_render_time_);
1936   base::TimeDelta total_time =
1937       (base::TimeTicks::Now() - begin_time) + document_render_time_;
1938   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1939                              total_time);
1940   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1941                              total_time / pages_to_render_.size());
1942 }
1943
1944 void PrintWebViewHelper::PrintPreviewContext::Finished() {
1945   DCHECK_EQ(DONE, state_);
1946   state_ = INITIALIZED;
1947   ClearContext();
1948 }
1949
1950 void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1951   DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1952   state_ = INITIALIZED;
1953   if (report_error) {
1954     DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1955     UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1956                               PREVIEW_ERROR_LAST_ENUM);
1957   }
1958   ClearContext();
1959 }
1960
1961 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1962   DCHECK_EQ(RENDERING, state_);
1963   if (IsFinalPageRendered())
1964     return -1;
1965   return pages_to_render_[current_page_index_++];
1966 }
1967
1968 bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1969   return state_ == RENDERING || state_ == DONE;
1970 }
1971
1972 bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1973   // The only kind of node we can print right now is a PDF node.
1974   return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1975 }
1976
1977 bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1978   return IsModifiable() && source_frame()->hasSelection();
1979 }
1980
1981 bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1982     const {
1983   DCHECK(IsRendering());
1984   return current_page_index_ == print_ready_metafile_page_count_;
1985 }
1986
1987 bool PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1988   DCHECK(IsRendering());
1989   return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1990 }
1991
1992 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1993     bool generate_draft_pages) {
1994   DCHECK_EQ(INITIALIZED, state_);
1995   generate_draft_pages_ = generate_draft_pages;
1996 }
1997
1998 void PrintWebViewHelper::PrintPreviewContext::set_error(
1999     enum PrintPreviewErrorBuckets error) {
2000   error_ = error;
2001 }
2002
2003 blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
2004   DCHECK(state_ != UNINITIALIZED);
2005   return source_frame_.GetFrame();
2006 }
2007
2008 const blink::WebNode&
2009     PrintWebViewHelper::PrintPreviewContext::source_node() const {
2010   DCHECK(state_ != UNINITIALIZED);
2011   return source_node_;
2012 }
2013
2014 blink::WebLocalFrame*
2015 PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
2016   DCHECK(state_ != UNINITIALIZED);
2017   return prep_frame_view_->frame();
2018 }
2019
2020 const blink::WebNode&
2021     PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
2022   DCHECK(state_ != UNINITIALIZED);
2023   return prep_frame_view_->node();
2024 }
2025
2026 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
2027   DCHECK(state_ != UNINITIALIZED);
2028   return total_page_count_;
2029 }
2030
2031 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
2032   return generate_draft_pages_;
2033 }
2034
2035 PdfMetafileSkia* PrintWebViewHelper::PrintPreviewContext::metafile() {
2036   DCHECK(IsRendering());
2037   return metafile_.get();
2038 }
2039
2040 int PrintWebViewHelper::PrintPreviewContext::last_error() const {
2041   return error_;
2042 }
2043
2044 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
2045   prep_frame_view_.reset();
2046   metafile_.reset();
2047   pages_to_render_.clear();
2048   error_ = PREVIEW_ERROR_NONE;
2049 }
2050
2051 void PrintWebViewHelper::SetPrintPagesParams(
2052     const PrintMsg_PrintPages_Params& settings) {
2053   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
2054   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
2055                                              settings.params.document_cookie));
2056 }
2057
2058 PrintWebViewHelper::ScriptingThrottler::ScriptingThrottler() : count_(0) {
2059 }
2060
2061 bool PrintWebViewHelper::ScriptingThrottler::IsAllowed(blink::WebFrame* frame) {
2062   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
2063   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
2064   bool too_frequent = false;
2065
2066   // Check if there is script repeatedly trying to print and ignore it if too
2067   // frequent.  The first 3 times, we use a constant wait time, but if this
2068   // gets excessive, we switch to exponential wait time. So for a page that
2069   // calls print() in a loop the user will need to cancel the print dialog
2070   // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
2071   // This gives the user time to navigate from the page.
2072   if (count_ > 0) {
2073     base::TimeDelta diff = base::Time::Now() - last_print_;
2074     int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
2075     if (count_ > 3) {
2076       min_wait_seconds =
2077           std::min(kMinSecondsToIgnoreJavascriptInitiatedPrint << (count_ - 3),
2078                    kMaxSecondsToIgnoreJavascriptInitiatedPrint);
2079     }
2080     if (diff.InSeconds() < min_wait_seconds) {
2081       too_frequent = true;
2082     }
2083   }
2084
2085   if (!too_frequent) {
2086     ++count_;
2087     last_print_ = base::Time::Now();
2088     return true;
2089   }
2090
2091   blink::WebString message(
2092       blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
2093   frame->addMessageToConsole(blink::WebConsoleMessage(
2094       blink::WebConsoleMessage::LevelWarning, message));
2095   return false;
2096 }
2097
2098 void PrintWebViewHelper::ScriptingThrottler::Reset() {
2099   // Reset counter on successful print.
2100   count_ = 0;
2101 }
2102
2103 }  // namespace printing