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::WebFrame* frame) {
 289   return frame->document().isPluginDocument()
 290              ? frame->document().to<blink::WebPluginDocument>().plugin()
 291              : NULL;
 292 }
 293
 294 bool PrintingNodeOrPdfFrame(const blink::WebFrame* 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   // Fallback to initiator URL and title if it's empty for printed frame.
 524   base::string16 url = source_frame.document().url().string();
 525   options->SetString("url", url.empty() ? params.url : url);
 526   base::string16 title = source_frame.document().title();
 527   options->SetString("title", title.empty() ? params.title : title);
 528
 529   ExecuteScript(frame, kPageSetupScriptFormat, *options);
 530
 531   blink::WebPrintParams webkit_params(page_size);
 532   webkit_params.printerDPI = GetDPI(&params);
 533
 534   frame->printBegin(webkit_params);
 535   frame->printPage(0, canvas);
 536   frame->printEnd();
 537
 538   web_view->close();
 539   frame->close();
 540 }
 541 #endif  // defined(ENABLE_PRINT_PREVIEW)
 542
 543 // static - Not anonymous so that platform implementations can use it.
 544 float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
 545                                             int page_number,
 546                                             const gfx::Rect& canvas_area,
 547                                             const gfx::Rect& content_area,
 548                                             double scale_factor,
 549                                             blink::WebCanvas* canvas) {
 550   SkAutoCanvasRestore auto_restore(canvas, true);
 551   canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
 552                     (content_area.y() - canvas_area.y()) / scale_factor);
 553   return frame->printPage(page_number, canvas);
 554 }
 555
 556 // Class that calls the Begin and End print functions on the frame and changes
 557 // the size of the view temporarily to support full page printing..
 558 class PrepareFrameAndViewForPrint : public blink::WebViewClient,
 559                                     public blink::WebFrameClient {
 560  public:
 561   PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
 562                               blink::WebLocalFrame* frame,
 563                               const blink::WebNode& node,
 564                               bool ignore_css_margins);
 565   virtual ~PrepareFrameAndViewForPrint();
 566
 567   // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
 568   // when completed.
 569   void CopySelectionIfNeeded(const WebPreferences& preferences,
 570                              const base::Closure& on_ready);
 571
 572   // Prepares frame for printing.
 573   void StartPrinting();
 574
 575   blink::WebLocalFrame* frame() { return frame_.GetFrame(); }
 576
 577   const blink::WebNode& node() const { return node_to_print_; }
 578
 579   int GetExpectedPageCount() const { return expected_pages_count_; }
 580
 581   void FinishPrinting();
 582
 583   bool IsLoadingSelection() {
 584     // It's not selection if not |owns_web_view_|.
 585     return owns_web_view_ && frame() && frame()->isLoading();
 586   }
 587
 588   // TODO(ojan): Remove this override and have this class use a non-null
 589   // layerTreeView.
 590   // blink::WebViewClient override:
 591   virtual bool allowsBrokenNullLayerTreeView() const;
 592
 593  protected:
 594   // blink::WebViewClient override:
 595   virtual void didStopLoading();
 596
 597   // blink::WebFrameClient override:
 598   virtual blink::WebFrame* createChildFrame(
 599       blink::WebLocalFrame* parent,
 600       blink::WebTreeScopeType scope,
 601       const blink::WebString& name,
 602       blink::WebSandboxFlags sandboxFlags);
 603   // TODO(lfg): Remove this method once the blink patch lands.
 604   virtual void frameDetached(blink::WebFrame* frame);
 605   virtual void frameDetached(blink::WebFrame* frame, DetachType type);
 606
 607  private:
 608   void CallOnReady();
 609   void ResizeForPrinting();
 610   void RestoreSize();
 611   void CopySelection(const WebPreferences& preferences);
 612
 613   FrameReference frame_;
 614   blink::WebNode node_to_print_;
 615   bool owns_web_view_;
 616   blink::WebPrintParams web_print_params_;
 617   gfx::Size prev_view_size_;
 618   gfx::Size prev_scroll_offset_;
 619   int expected_pages_count_;
 620   base::Closure on_ready_;
 621   bool should_print_backgrounds_;
 622   bool should_print_selection_only_;
 623   bool is_printing_started_;
 624
 625   base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
 626
 627   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 628 };
 629
 630 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
 631     const PrintMsg_Print_Params& params,
 632     blink::WebLocalFrame* frame,
 633     const blink::WebNode& node,
 634     bool ignore_css_margins)
 635     : frame_(frame),
 636       node_to_print_(node),
 637       owns_web_view_(false),
 638       expected_pages_count_(0),
 639       should_print_backgrounds_(params.should_print_backgrounds),
 640       should_print_selection_only_(params.selection_only),
 641       is_printing_started_(false),
 642       weak_ptr_factory_(this) {
 643   PrintMsg_Print_Params print_params = params;
 644   if (!should_print_selection_only_ ||
 645       !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
 646     bool fit_to_page = ignore_css_margins &&
 647                        print_params.print_scaling_option ==
 648                            blink::WebPrintScalingOptionFitToPrintableArea;
 649     ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
 650     frame->printBegin(web_print_params_, node_to_print_);
 651     print_params = CalculatePrintParamsForCss(
 652         frame, 0, print_params, ignore_css_margins, fit_to_page, NULL);
 653     frame->printEnd();
 654   }
 655   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
 656 }
 657
 658 PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
 659   FinishPrinting();
 660 }
 661
 662 void PrepareFrameAndViewForPrint::ResizeForPrinting() {
 663   // Layout page according to printer page size. Since WebKit shrinks the
 664   // size of the page automatically (from 125% to 200%) we trick it to
 665   // think the page is 125% larger so the size of the page is correct for
 666   // minimum (default) scaling.
 667   // This is important for sites that try to fill the page.
 668   gfx::Size print_layout_size(web_print_params_.printContentArea.width,
 669                               web_print_params_.printContentArea.height);
 670   print_layout_size.set_height(
 671       static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
 672
 673   if (!frame())
 674     return;
 675   blink::WebView* web_view = frame_.view();
 676   // Backup size and offset.
 677   if (blink::WebFrame* web_frame = web_view->mainFrame())
 678     prev_scroll_offset_ = web_frame->scrollOffset();
 679   prev_view_size_ = web_view->size();
 680
 681   web_view->resize(print_layout_size);
 682 }
 683
 684 void PrepareFrameAndViewForPrint::StartPrinting() {
 685   ResizeForPrinting();
 686   blink::WebView* web_view = frame_.view();
 687   web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
 688   expected_pages_count_ =
 689       frame()->printBegin(web_print_params_, node_to_print_);
 690   is_printing_started_ = true;
 691 }
 692
 693 void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
 694     const WebPreferences& preferences,
 695     const base::Closure& on_ready) {
 696   on_ready_ = on_ready;
 697   if (should_print_selection_only_) {
 698     CopySelection(preferences);
 699   } else {
 700     // Call immediately, async call crashes scripting printing.
 701     CallOnReady();
 702   }
 703 }
 704
 705 void PrepareFrameAndViewForPrint::CopySelection(
 706     const WebPreferences& preferences) {
 707   ResizeForPrinting();
 708   std::string url_str = "data:text/html;charset=utf-8,";
 709   url_str.append(
 710       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
 711   RestoreSize();
 712   // Create a new WebView with the same settings as the current display one.
 713   // Except that we disable javascript (don't want any active content running
 714   // on the page).
 715   WebPreferences prefs = preferences;
 716   prefs.javascript_enabled = false;
 717   prefs.java_enabled = false;
 718
 719   blink::WebView* web_view = blink::WebView::create(this);
 720   owns_web_view_ = true;
 721   content::RenderView::ApplyWebPreferences(prefs, web_view);
 722   web_view->setMainFrame(
 723       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, this));
 724   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
 725   node_to_print_.reset();
 726
 727   // When loading is done this will call didStopLoading() and that will do the
 728   // actual printing.
 729   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 730 }
 731
 732 bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
 733   return true;
 734 }
 735
 736 void PrepareFrameAndViewForPrint::didStopLoading() {
 737   DCHECK(!on_ready_.is_null());
 738   // Don't call callback here, because it can delete |this| and WebView that is
 739   // called didStopLoading.
 740   base::ThreadTaskRunnerHandle::Get()->PostTask(
 741       FROM_HERE, base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
 742                             weak_ptr_factory_.GetWeakPtr()));
 743 }
 744
 745 blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
 746     blink::WebLocalFrame* parent,
 747     blink::WebTreeScopeType scope,
 748     const blink::WebString& name,
 749     blink::WebSandboxFlags sandboxFlags) {
 750   blink::WebFrame* frame = blink::WebLocalFrame::create(scope, this);
 751   parent->appendChild(frame);
 752   return frame;
 753 }
 754
 755 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame) {
 756   frameDetached(frame, DetachType::Remove);
 757 }
 758
 759 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame,
 760                                                 DetachType type) {
 761   DCHECK(type == DetachType::Remove);
 762   if (frame->parent())
 763     frame->parent()->removeChild(frame);
 764   frame->close();
 765 }
 766
 767 void PrepareFrameAndViewForPrint::CallOnReady() {
 768   return on_ready_.Run();  // Can delete |this|.
 769 }
 770
 771 void PrepareFrameAndViewForPrint::RestoreSize() {
 772   if (frame()) {
 773     blink::WebView* web_view = frame_.GetFrame()->view();
 774     web_view->resize(prev_view_size_);
 775     if (blink::WebFrame* web_frame = web_view->mainFrame())
 776       web_frame->setScrollOffset(prev_scroll_offset_);
 777   }
 778 }
 779
 780 void PrepareFrameAndViewForPrint::FinishPrinting() {
 781   blink::WebLocalFrame* frame = frame_.GetFrame();
 782   if (frame) {
 783     blink::WebView* web_view = frame->view();
 784     if (is_printing_started_) {
 785       is_printing_started_ = false;
 786       frame->printEnd();
 787       if (!owns_web_view_) {
 788         web_view->settings()->setShouldPrintBackgrounds(false);
 789         RestoreSize();
 790       }
 791     }
 792     if (owns_web_view_) {
 793       DCHECK(!frame->isLoading());
 794       owns_web_view_ = false;
 795       web_view->close();
 796     }
 797   }
 798   frame_.Reset(NULL);
 799   on_ready_.Reset();
 800 }
 801
 802 bool PrintWebViewHelper::Delegate::IsAskPrintSettingsEnabled() {
 803   return true;
 804 }
 805
 806 bool PrintWebViewHelper::Delegate::IsScriptedPrintEnabled() {
 807   return true;
 808 }
 809
 810 PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view,
 811                                        scoped_ptr<Delegate> delegate)
 812     : content::RenderViewObserver(render_view),
 813       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
 814       reset_prep_frame_view_(false),
 815       is_print_ready_metafile_sent_(false),
 816       ignore_css_margins_(false),
 817       is_scripted_printing_blocked_(false),
 818       notify_browser_of_print_failure_(true),
 819       print_for_preview_(false),
 820       delegate_(delegate.Pass()),
 821       print_node_in_progress_(false),
 822       is_loading_(false),
 823       is_scripted_preview_delayed_(false),
 824       weak_ptr_factory_(this) {
 825   if (!delegate_->IsPrintPreviewEnabled())
 826     DisablePreview();
 827 }
 828
 829 PrintWebViewHelper::~PrintWebViewHelper() {
 830 }
 831
 832 // static
 833 void PrintWebViewHelper::DisablePreview() {
 834   g_is_preview_enabled_ = false;
 835 }
 836
 837 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(blink::WebFrame* frame,
 838                                                        bool user_initiated) {
 839   if (!delegate_->IsScriptedPrintEnabled())
 840     return false;
 841
 842   // If preview is enabled, then the print dialog is tab modal, and the user
 843   // can always close the tab on a mis-behaving page (the system print dialog
 844   // is app modal). If the print was initiated through user action, don't
 845   // throttle. Or, if the command line flag to skip throttling has been set.
 846   return !is_scripted_printing_blocked_ &&
 847          (user_initiated || g_is_preview_enabled_ ||
 848           scripting_throttler_.IsAllowed(frame));
 849 }
 850
 851 void PrintWebViewHelper::DidStartLoading() {
 852   is_loading_ = true;
 853 }
 854
 855 void PrintWebViewHelper::DidStopLoading() {
 856   is_loading_ = false;
 857   if (!on_stop_loading_closure_.is_null()) {
 858     on_stop_loading_closure_.Run();
 859     on_stop_loading_closure_.Reset();
 860   }
 861 }
 862
 863 // Prints |frame| which called window.print().
 864 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
 865                                    bool user_initiated) {
 866   DCHECK(frame);
 867
 868   // Allow Prerendering to cancel this print request if necessary.
 869   if (delegate_->CancelPrerender(render_view(), routing_id()))
 870     return;
 871
 872   if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
 873     return;
 874
 875   if (delegate_->OverridePrint(frame))
 876     return;
 877
 878   if (!g_is_preview_enabled_) {
 879     Print(frame, blink::WebNode(), true);
 880   } else {
 881     print_preview_context_.InitWithFrame(frame);
 882     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
 883   }
 884 }
 885
 886 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
 887   bool handled = true;
 888   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
 889 #if defined(ENABLE_BASIC_PRINTING)
 890     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
 891     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
 892 #endif  // ENABLE_BASIC_PRINTING
 893     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
 894     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
 895     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
 896     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
 897     IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
 898                         SetScriptedPrintBlocked)
 899     IPC_MESSAGE_UNHANDLED(handled = false)
 900     IPC_END_MESSAGE_MAP()
 901   return handled;
 902 }
 903
 904 void PrintWebViewHelper::OnPrintForPrintPreview(
 905     const base::DictionaryValue& job_settings) {
 906   // If still not finished with earlier print request simply ignore.
 907   if (prep_frame_view_)
 908     return;
 909
 910   if (!render_view()->GetWebView())
 911     return;
 912   blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
 913   if (!main_frame)
 914     return;
 915
 916   blink::WebDocument document = main_frame->document();
 917   // <object>/<iframe> with id="pdf-viewer" is created in
 918   // chrome/browser/resources/print_preview/print_preview.js
 919   blink::WebElement pdf_element = document.getElementById("pdf-viewer");
 920   if (pdf_element.isNull()) {
 921     NOTREACHED();
 922     return;
 923   }
 924
 925   // The out-of-process plugin element is nested within a frame. In tests, there
 926   // may not be an iframe containing the out-of-process plugin, so continue with
 927   // the element with ID "pdf-viewer" if it isn't an iframe.
 928   blink::WebLocalFrame* plugin_frame = pdf_element.document().frame();
 929   blink::WebElement plugin_element = pdf_element;
 930   if (pdf_element.hasHTMLTagName("iframe")) {
 931     plugin_frame = blink::WebLocalFrame::fromFrameOwnerElement(pdf_element);
 932     plugin_element = delegate_->GetPdfElement(plugin_frame);
 933     if (plugin_element.isNull()) {
 934       NOTREACHED();
 935       return;
 936     }
 937   }
 938
 939   // Set |print_for_preview_| flag and autoreset it to back to original
 940   // on return.
 941   base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
 942
 943   if (!UpdatePrintSettings(plugin_frame, plugin_element, job_settings)) {
 944     LOG(ERROR) << "UpdatePrintSettings failed";
 945     DidFinishPrinting(FAIL_PRINT);
 946     return;
 947   }
 948
 949   // Print page onto entire page not just printable area. Preview PDF already
 950   // has content in correct position taking into account page size and printable
 951   // area.
 952   // TODO(vitalybuka) : Make this consistent on all platform. This change
 953   // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
 954   // printable_area. Also we can't change printable_area deeper inside
 955   // RenderPagesForPrint for Windows, because it's used also by native
 956   // printing and it expects real printable_area value.
 957   // See http://crbug.com/123408
 958   PrintMsg_Print_Params& print_params = print_pages_params_->params;
 959   print_params.printable_area = gfx::Rect(print_params.page_size);
 960
 961   // Render Pages for printing.
 962   if (!RenderPagesForPrint(plugin_frame, plugin_element)) {
 963     LOG(ERROR) << "RenderPagesForPrint failed";
 964     DidFinishPrinting(FAIL_PRINT);
 965   }
 966 }
 967
 968 bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
 969   DCHECK(frame);
 970   blink::WebView* webView = render_view()->GetWebView();
 971   DCHECK(webView);
 972   if (!webView)
 973     return false;
 974
 975   // If the user has selected text in the currently focused frame we print
 976   // only that frame (this makes print selection work for multiple frames).
 977   blink::WebLocalFrame* focusedFrame =
 978       webView->focusedFrame()->toWebLocalFrame();
 979   *frame = focusedFrame->hasSelection()
 980                ? focusedFrame
 981                : webView->mainFrame()->toWebLocalFrame();
 982   return true;
 983 }
 984
 985 #if defined(ENABLE_BASIC_PRINTING)
 986 void PrintWebViewHelper::OnPrintPages() {
 987   blink::WebLocalFrame* frame;
 988   if (!GetPrintFrame(&frame))
 989     return;
 990   // If we are printing a PDF extension frame, find the plugin node and print
 991   // that instead.
 992   auto plugin = delegate_->GetPdfElement(frame);
 993   Print(frame, plugin, false);
 994 }
 995
 996 void PrintWebViewHelper::OnPrintForSystemDialog() {
 997   blink::WebLocalFrame* frame = print_preview_context_.source_frame();
 998   if (!frame) {
 999     NOTREACHED();
1000     return;
1001   }
1002   Print(frame, print_preview_context_.source_node(), false);
1003 }
1004 #endif  // ENABLE_BASIC_PRINTING
1005
1006 void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
1007     const PageSizeMargins& page_layout_in_points,
1008     gfx::Size* page_size,
1009     gfx::Rect* content_area) {
1010   *page_size = gfx::Size(
1011       page_layout_in_points.content_width + page_layout_in_points.margin_right +
1012           page_layout_in_points.margin_left,
1013       page_layout_in_points.content_height + page_layout_in_points.margin_top +
1014           page_layout_in_points.margin_bottom);
1015   *content_area = gfx::Rect(page_layout_in_points.margin_left,
1016                             page_layout_in_points.margin_top,
1017                             page_layout_in_points.content_width,
1018                             page_layout_in_points.content_height);
1019 }
1020
1021 void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
1022     const base::DictionaryValue& settings) {
1023   int margins_type = 0;
1024   if (!settings.GetInteger(kSettingMarginsType, &margins_type))
1025     margins_type = DEFAULT_MARGINS;
1026   ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
1027 }
1028
1029 bool PrintWebViewHelper::IsPrintToPdfRequested(
1030     const base::DictionaryValue& job_settings) {
1031   bool print_to_pdf = false;
1032   if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
1033     NOTREACHED();
1034   return print_to_pdf;
1035 }
1036
1037 void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
1038   print_preview_context_.OnPrintPreview();
1039
1040   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1041                             PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
1042
1043   if (!print_preview_context_.source_frame()) {
1044     DidFinishPrinting(FAIL_PREVIEW);
1045     return;
1046   }
1047
1048   if (!UpdatePrintSettings(print_preview_context_.source_frame(),
1049                            print_preview_context_.source_node(), settings)) {
1050     if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
1051       Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
1052           routing_id(), print_pages_params_
1053                             ? print_pages_params_->params.document_cookie
1054                             : 0));
1055       notify_browser_of_print_failure_ = false;  // Already sent.
1056     }
1057     DidFinishPrinting(FAIL_PREVIEW);
1058     return;
1059   }
1060
1061   // Set the options from document if we are previewing a pdf and send a
1062   // message to browser.
1063   if (print_pages_params_->params.is_first_request &&
1064       !print_preview_context_.IsModifiable()) {
1065     PrintHostMsg_SetOptionsFromDocument_Params options;
1066     if (SetOptionsFromPdfDocument(&options))
1067       Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), options));
1068   }
1069
1070   is_print_ready_metafile_sent_ = false;
1071
1072   // PDF printer device supports alpha blending.
1073   print_pages_params_->params.supports_alpha_blend = true;
1074
1075   bool generate_draft_pages = false;
1076   if (!settings.GetBoolean(kSettingGenerateDraftData, &generate_draft_pages)) {
1077     NOTREACHED();
1078   }
1079   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1080
1081   PrepareFrameForPreviewDocument();
1082 }
1083
1084 void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1085   reset_prep_frame_view_ = false;
1086
1087   if (!print_pages_params_ || CheckForCancel()) {
1088     DidFinishPrinting(FAIL_PREVIEW);
1089     return;
1090   }
1091
1092   // Don't reset loading frame or WebKit will fail assert. Just retry when
1093   // current selection is loaded.
1094   if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1095     reset_prep_frame_view_ = true;
1096     return;
1097   }
1098
1099   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1100   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1101       print_params, print_preview_context_.source_frame(),
1102       print_preview_context_.source_node(), ignore_css_margins_));
1103   prep_frame_view_->CopySelectionIfNeeded(
1104       render_view()->GetWebkitPreferences(),
1105       base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1106                  base::Unretained(this)));
1107 }
1108
1109 void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1110   if (reset_prep_frame_view_) {
1111     PrepareFrameForPreviewDocument();
1112     return;
1113   }
1114   DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1115 }
1116
1117 bool PrintWebViewHelper::CreatePreviewDocument() {
1118   if (!print_pages_params_ || CheckForCancel())
1119     return false;
1120
1121   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1122                             PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1123
1124   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1125   const std::vector<int>& pages = print_pages_params_->pages;
1126
1127   if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1128                                                     pages)) {
1129     return false;
1130   }
1131
1132   PageSizeMargins default_page_layout;
1133   ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1134                                   print_params, ignore_css_margins_, NULL,
1135                                   &default_page_layout);
1136
1137   bool has_page_size_style =
1138       PrintingFrameHasPageSizeStyle(print_preview_context_.prepared_frame(),
1139                                     print_preview_context_.total_page_count());
1140   int dpi = GetDPI(&print_params);
1141
1142   gfx::Rect printable_area_in_points(
1143       ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1144       ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1145       ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1146       ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1147
1148   // Margins: Send default page layout to browser process.
1149   Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1150                                                 default_page_layout,
1151                                                 printable_area_in_points,
1152                                                 has_page_size_style));
1153
1154   PrintHostMsg_DidGetPreviewPageCount_Params params;
1155   params.page_count = print_preview_context_.total_page_count();
1156   params.is_modifiable = print_preview_context_.IsModifiable();
1157   params.document_cookie = print_params.document_cookie;
1158   params.preview_request_id = print_params.preview_request_id;
1159   params.clear_preview_data = print_preview_context_.generate_draft_pages();
1160   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1161   if (CheckForCancel())
1162     return false;
1163
1164   while (!print_preview_context_.IsFinalPageRendered()) {
1165     int page_number = print_preview_context_.GetNextPageNumber();
1166     DCHECK_GE(page_number, 0);
1167     if (!RenderPreviewPage(page_number, print_params))
1168       return false;
1169
1170     if (CheckForCancel())
1171       return false;
1172
1173     // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1174     // print_preview_context_.AllPagesRendered()) before calling
1175     // FinalizePrintReadyDocument() when printing a PDF because the plugin
1176     // code does not generate output until we call FinishPrinting().  We do not
1177     // generate draft pages for PDFs, so IsFinalPageRendered() and
1178     // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1179     // the loop.
1180     if (print_preview_context_.IsFinalPageRendered())
1181       print_preview_context_.AllPagesRendered();
1182
1183     if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1184       DCHECK(print_preview_context_.IsModifiable() ||
1185              print_preview_context_.IsFinalPageRendered());
1186       if (!FinalizePrintReadyDocument())
1187         return false;
1188     }
1189   }
1190   print_preview_context_.Finished();
1191   return true;
1192 }
1193
1194 bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1195   DCHECK(!is_print_ready_metafile_sent_);
1196   print_preview_context_.FinalizePrintReadyDocument();
1197
1198   // Get the size of the resulting metafile.
1199   PdfMetafileSkia* metafile = print_preview_context_.metafile();
1200   uint32 buf_size = metafile->GetDataSize();
1201   DCHECK_GT(buf_size, 0u);
1202
1203   PrintHostMsg_DidPreviewDocument_Params preview_params;
1204   preview_params.data_size = buf_size;
1205   preview_params.document_cookie = print_pages_params_->params.document_cookie;
1206   preview_params.expected_pages_count =
1207       print_preview_context_.total_page_count();
1208   preview_params.modifiable = print_preview_context_.IsModifiable();
1209   preview_params.preview_request_id =
1210       print_pages_params_->params.preview_request_id;
1211
1212   // Ask the browser to create the shared memory for us.
1213   if (!CopyMetafileDataToSharedMem(metafile,
1214                                    &(preview_params.metafile_data_handle))) {
1215     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1216     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1217     return false;
1218   }
1219   is_print_ready_metafile_sent_ = true;
1220
1221   Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1222   return true;
1223 }
1224
1225 void PrintWebViewHelper::OnPrintingDone(bool success) {
1226   notify_browser_of_print_failure_ = false;
1227   if (!success)
1228     LOG(ERROR) << "Failure in OnPrintingDone";
1229   DidFinishPrinting(success ? OK : FAIL_PRINT);
1230 }
1231
1232 void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1233   is_scripted_printing_blocked_ = blocked;
1234 }
1235
1236 void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1237   blink::WebLocalFrame* frame = NULL;
1238   GetPrintFrame(&frame);
1239   DCHECK(frame);
1240   // If we are printing a PDF extension frame, find the plugin node and print
1241   // that instead.
1242   auto plugin = delegate_->GetPdfElement(frame);
1243   if (!plugin.isNull()) {
1244     PrintNode(plugin);
1245     return;
1246   }
1247   print_preview_context_.InitWithFrame(frame);
1248   RequestPrintPreview(selection_only
1249                           ? PRINT_PREVIEW_USER_INITIATED_SELECTION
1250                           : PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1251 }
1252
1253 bool PrintWebViewHelper::IsPrintingEnabled() {
1254   bool result = false;
1255   Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1256   return result;
1257 }
1258
1259 void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1260   if (node.isNull() || !node.document().frame()) {
1261     // This can occur when the context menu refers to an invalid WebNode.
1262     // See http://crbug.com/100890#c17 for a repro case.
1263     return;
1264   }
1265
1266   if (print_node_in_progress_) {
1267     // This can happen as a result of processing sync messages when printing
1268     // from ppapi plugins. It's a rare case, so its OK to just fail here.
1269     // See http://crbug.com/159165.
1270     return;
1271   }
1272
1273   print_node_in_progress_ = true;
1274
1275   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1276   // its |context_menu_node_|.
1277   if (!g_is_preview_enabled_) {
1278     blink::WebNode duplicate_node(node);
1279     Print(duplicate_node.document().frame(), duplicate_node, false);
1280   } else {
1281     print_preview_context_.InitWithNode(node);
1282     RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1283   }
1284
1285   print_node_in_progress_ = false;
1286 }
1287
1288 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1289                                const blink::WebNode& node,
1290                                bool is_scripted) {
1291   // If still not finished with earlier print request simply ignore.
1292   if (prep_frame_view_)
1293     return;
1294
1295   FrameReference frame_ref(frame);
1296
1297   int expected_page_count = 0;
1298   if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1299     DidFinishPrinting(FAIL_PRINT_INIT);
1300     return;  // Failed to init print page settings.
1301   }
1302
1303   // Some full screen plugins can say they don't want to print.
1304   if (!expected_page_count) {
1305     DidFinishPrinting(FAIL_PRINT);
1306     return;
1307   }
1308
1309   // Ask the browser to show UI to retrieve the final print settings.
1310   if (delegate_->IsAskPrintSettingsEnabled() &&
1311       !GetPrintSettingsFromUser(frame_ref.GetFrame(), node, expected_page_count,
1312                                 is_scripted)) {
1313     DidFinishPrinting(OK);  // Release resources and fail silently.
1314     return;
1315   }
1316
1317   // Render Pages for printing.
1318   if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1319     LOG(ERROR) << "RenderPagesForPrint failed";
1320     DidFinishPrinting(FAIL_PRINT);
1321   }
1322   scripting_throttler_.Reset();
1323 }
1324
1325 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1326   switch (result) {
1327     case OK:
1328       break;
1329
1330     case FAIL_PRINT_INIT:
1331       DCHECK(!notify_browser_of_print_failure_);
1332       break;
1333
1334     case FAIL_PRINT:
1335       if (notify_browser_of_print_failure_ && print_pages_params_) {
1336         int cookie = print_pages_params_->params.document_cookie;
1337         Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1338       }
1339       break;
1340
1341     case FAIL_PREVIEW:
1342       int cookie =
1343           print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1344       if (notify_browser_of_print_failure_) {
1345         LOG(ERROR) << "CreatePreviewDocument failed";
1346         Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1347       } else {
1348         Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1349       }
1350       print_preview_context_.Failed(notify_browser_of_print_failure_);
1351       break;
1352   }
1353   prep_frame_view_.reset();
1354   print_pages_params_.reset();
1355   notify_browser_of_print_failure_ = true;
1356 }
1357
1358 void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1359   PrintPages();
1360   FinishFramePrinting();
1361 }
1362
1363 void PrintWebViewHelper::PrintPages() {
1364   if (!prep_frame_view_)  // Printing is already canceled or failed.
1365     return;
1366   prep_frame_view_->StartPrinting();
1367
1368   int page_count = prep_frame_view_->GetExpectedPageCount();
1369   if (!page_count) {
1370     LOG(ERROR) << "Can't print 0 pages.";
1371     return DidFinishPrinting(FAIL_PRINT);
1372   }
1373
1374   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1375   const PrintMsg_Print_Params& print_params = params.params;
1376
1377 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1378   // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1379   // See http://crbug.com/161576
1380   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1381                                                 print_params.document_cookie,
1382                                                 page_count));
1383 #endif  // !defined(OS_CHROMEOS)
1384
1385   if (print_params.preview_ui_id < 0) {
1386     // Printing for system dialog.
1387     int printed_count = params.pages.empty() ? page_count : params.pages.size();
1388 #if !defined(OS_CHROMEOS)
1389     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1390 #else
1391     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1392                          printed_count);
1393 #endif  // !defined(OS_CHROMEOS)
1394   }
1395
1396   if (!PrintPagesNative(prep_frame_view_->frame(), page_count)) {
1397     LOG(ERROR) << "Printing failed.";
1398     return DidFinishPrinting(FAIL_PRINT);
1399   }
1400 }
1401
1402 void PrintWebViewHelper::FinishFramePrinting() {
1403   prep_frame_view_.reset();
1404 }
1405
1406 #if defined(OS_MACOSX)
1407 bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1408                                           int page_count) {
1409   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1410   const PrintMsg_Print_Params& print_params = params.params;
1411
1412   PrintMsg_PrintPage_Params page_params;
1413   page_params.params = print_params;
1414   if (params.pages.empty()) {
1415     for (int i = 0; i < page_count; ++i) {
1416       page_params.page_number = i;
1417       PrintPageInternal(page_params, frame);
1418     }
1419   } else {
1420     for (size_t i = 0; i < params.pages.size(); ++i) {
1421       if (params.pages[i] >= page_count)
1422         break;
1423       page_params.page_number = params.pages[i];
1424       PrintPageInternal(page_params, frame);
1425     }
1426   }
1427   return true;
1428 }
1429
1430 #endif  // OS_MACOSX
1431
1432 // static - Not anonymous so that platform implementations can use it.
1433 void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1434     blink::WebFrame* frame,
1435     int page_index,
1436     const PrintMsg_Print_Params& page_params,
1437     bool ignore_css_margins,
1438     double* scale_factor,
1439     PageSizeMargins* page_layout_in_points) {
1440   PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1441       frame, page_index, page_params, ignore_css_margins,
1442       page_params.print_scaling_option ==
1443           blink::WebPrintScalingOptionFitToPrintableArea,
1444       scale_factor);
1445   CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1446 }
1447
1448 bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1449   PrintMsg_PrintPages_Params settings;
1450   Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1451                                                 &settings.params));
1452   // Check if the printer returned any settings, if the settings is empty, we
1453   // can safely assume there are no printer drivers configured. So we safely
1454   // terminate.
1455   bool result = true;
1456   if (!PrintMsg_Print_Params_IsValid(settings.params))
1457     result = false;
1458
1459   // Reset to default values.
1460   ignore_css_margins_ = false;
1461   settings.pages.clear();
1462
1463   settings.params.print_scaling_option = blink::WebPrintScalingOptionSourceSize;
1464   if (fit_to_paper_size) {
1465     settings.params.print_scaling_option =
1466         blink::WebPrintScalingOptionFitToPrintableArea;
1467   }
1468
1469   SetPrintPagesParams(settings);
1470   return result;
1471 }
1472
1473 bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1474                                                 const blink::WebNode& node,
1475                                                 int* number_of_pages) {
1476   DCHECK(frame);
1477   bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1478   if (!InitPrintSettings(fit_to_paper_size)) {
1479     notify_browser_of_print_failure_ = false;
1480     Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1481     return false;
1482   }
1483
1484   const PrintMsg_Print_Params& params = print_pages_params_->params;
1485   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1486   prepare.StartPrinting();
1487
1488   *number_of_pages = prepare.GetExpectedPageCount();
1489   return true;
1490 }
1491
1492 bool PrintWebViewHelper::SetOptionsFromPdfDocument(
1493     PrintHostMsg_SetOptionsFromDocument_Params* options) {
1494   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
1495   const blink::WebNode& source_node = print_preview_context_.source_node();
1496
1497   blink::WebPrintPresetOptions preset_options;
1498   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
1499                                                     &preset_options)) {
1500     return false;
1501   }
1502
1503   options->is_scaling_disabled = PDFShouldDisableScalingBasedOnPreset(
1504       preset_options, print_pages_params_->params);
1505   options->copies = preset_options.copies;
1506
1507   // TODO(thestig) This should be a straight pass-through, but print preview
1508   // does not currently support short-edge printing.
1509   switch (preset_options.duplexMode) {
1510     case blink::WebSimplex:
1511       options->duplex = SIMPLEX;
1512       break;
1513     case blink::WebLongEdge:
1514       options->duplex = LONG_EDGE;
1515       break;
1516     default:
1517       options->duplex = UNKNOWN_DUPLEX_MODE;
1518       break;
1519   }
1520   return true;
1521 }
1522
1523 bool PrintWebViewHelper::UpdatePrintSettings(
1524     blink::WebLocalFrame* frame,
1525     const blink::WebNode& node,
1526     const base::DictionaryValue& passed_job_settings) {
1527   const base::DictionaryValue* job_settings = &passed_job_settings;
1528   base::DictionaryValue modified_job_settings;
1529   if (job_settings->empty()) {
1530     if (!print_for_preview_)
1531       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1532     return false;
1533   }
1534
1535   bool source_is_html = true;
1536   if (print_for_preview_) {
1537     if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1538       NOTREACHED();
1539     }
1540   } else {
1541     source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1542   }
1543
1544   if (print_for_preview_ || !source_is_html) {
1545     modified_job_settings.MergeDictionary(job_settings);
1546     modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1547     modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1548     job_settings = &modified_job_settings;
1549   }
1550
1551   // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1552   // possible.
1553   int cookie =
1554       print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1555   PrintMsg_PrintPages_Params settings;
1556   bool canceled = false;
1557   Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
1558                                             &settings, &canceled));
1559   if (canceled) {
1560     notify_browser_of_print_failure_ = false;
1561     return false;
1562   }
1563
1564   if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1565     NOTREACHED();
1566     print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1567     return false;
1568   }
1569
1570   if (!print_for_preview_) {
1571     // Validate expected print preview settings.
1572     if (!job_settings->GetInteger(kPreviewRequestID,
1573                                   &settings.params.preview_request_id) ||
1574         !job_settings->GetBoolean(kIsFirstRequest,
1575                                   &settings.params.is_first_request)) {
1576       NOTREACHED();
1577       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1578       return false;
1579     }
1580
1581     settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1582     UpdateFrameMarginsCssInfo(*job_settings);
1583     settings.params.print_scaling_option = GetPrintScalingOption(
1584         frame, node, source_is_html, *job_settings, settings.params);
1585   }
1586
1587   SetPrintPagesParams(settings);
1588
1589   if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1590     if (!print_for_preview_)
1591       print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1592     else
1593       Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1594
1595     return false;
1596   }
1597
1598   return true;
1599 }
1600
1601 bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebLocalFrame* frame,
1602                                                   const blink::WebNode& node,
1603                                                   int expected_pages_count,
1604                                                   bool is_scripted) {
1605   PrintHostMsg_ScriptedPrint_Params params;
1606   PrintMsg_PrintPages_Params print_settings;
1607
1608   params.cookie = print_pages_params_->params.document_cookie;
1609   params.has_selection = frame->hasSelection();
1610   params.expected_pages_count = expected_pages_count;
1611   MarginType margin_type = DEFAULT_MARGINS;
1612   if (PrintingNodeOrPdfFrame(frame, node)) {
1613     margin_type =
1614         GetMarginsForPdf(frame, node, print_pages_params_->params);
1615   }
1616   params.margin_type = margin_type;
1617   params.is_scripted = is_scripted;
1618
1619   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1620
1621   // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1622   // value before and restore it afterwards.
1623   blink::WebPrintScalingOption scaling_option =
1624       print_pages_params_->params.print_scaling_option;
1625
1626   print_pages_params_.reset();
1627   IPC::SyncMessage* msg =
1628       new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1629   msg->EnableMessagePumping();
1630   Send(msg);
1631   print_settings.params.print_scaling_option = scaling_option;
1632   SetPrintPagesParams(print_settings);
1633   return (print_settings.params.dpi && print_settings.params.document_cookie);
1634 }
1635
1636 bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1637                                              const blink::WebNode& node) {
1638   if (!frame || prep_frame_view_)
1639     return false;
1640   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1641   const PrintMsg_Print_Params& print_params = params.params;
1642   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1643       print_params, frame, node, ignore_css_margins_));
1644   DCHECK(!print_pages_params_->params.selection_only ||
1645          print_pages_params_->pages.empty());
1646   prep_frame_view_->CopySelectionIfNeeded(
1647       render_view()->GetWebkitPreferences(),
1648       base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1649                  base::Unretained(this)));
1650   return true;
1651 }
1652
1653 #if defined(OS_POSIX)
1654 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1655     PdfMetafileSkia* metafile,
1656     base::SharedMemoryHandle* shared_mem_handle) {
1657   uint32 buf_size = metafile->GetDataSize();
1658   scoped_ptr<base::SharedMemory> shared_buf(
1659       content::RenderThread::Get()
1660           ->HostAllocateSharedMemoryBuffer(buf_size)
1661           .release());
1662
1663   if (shared_buf) {
1664     if (shared_buf->Map(buf_size)) {
1665       metafile->GetData(shared_buf->memory(), buf_size);
1666       return shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1667                                        shared_mem_handle);
1668     }
1669   }
1670   return false;
1671 }
1672 #endif  // defined(OS_POSIX)
1673
1674 void PrintWebViewHelper::ShowScriptedPrintPreview() {
1675   if (is_scripted_preview_delayed_) {
1676     is_scripted_preview_delayed_ = false;
1677     Send(new PrintHostMsg_ShowScriptedPrintPreview(
1678         routing_id(), print_preview_context_.IsModifiable()));
1679   }
1680 }
1681
1682 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1683   const bool is_modifiable = print_preview_context_.IsModifiable();
1684   const bool has_selection = print_preview_context_.HasSelection();
1685   PrintHostMsg_RequestPrintPreview_Params params;
1686   params.is_modifiable = is_modifiable;
1687   params.has_selection = has_selection;
1688   switch (type) {
1689     case PRINT_PREVIEW_SCRIPTED: {
1690       // Shows scripted print preview in two stages.
1691       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1692       //    pumping messages here.
1693       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1694       //    document has been loaded.
1695       is_scripted_preview_delayed_ = true;
1696       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1697         // Wait for DidStopLoading. Plugins may not know the correct
1698         // |is_modifiable| value until they are fully loaded, which occurs when
1699         // DidStopLoading() is called. Defer showing the preview until then.
1700         on_stop_loading_closure_ =
1701             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1702                        base::Unretained(this));
1703       } else {
1704         base::ThreadTaskRunnerHandle::Get()->PostTask(
1705             FROM_HERE, base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1706                                   weak_ptr_factory_.GetWeakPtr()));
1707       }
1708       IPC::SyncMessage* msg =
1709           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1710       msg->EnableMessagePumping();
1711       Send(msg);
1712       is_scripted_preview_delayed_ = false;
1713       return;
1714     }
1715     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1716       // Wait for DidStopLoading. Continuing with this function while
1717       // |is_loading_| is true will cause print preview to hang when try to
1718       // print a PDF document.
1719       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1720         on_stop_loading_closure_ =
1721             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1722                        base::Unretained(this), type);
1723         return;
1724       }
1725
1726       break;
1727     }
1728     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1729       DCHECK(has_selection);
1730       DCHECK(!GetPlugin(print_preview_context_.source_frame()));
1731       params.selection_only = has_selection;
1732       break;
1733     }
1734     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1735       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1736         on_stop_loading_closure_ =
1737             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1738                        base::Unretained(this), type);
1739         return;
1740       }
1741
1742       params.webnode_only = true;
1743       break;
1744     }
1745     default: {
1746       NOTREACHED();
1747       return;
1748     }
1749   }
1750   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1751 }
1752
1753 bool PrintWebViewHelper::CheckForCancel() {
1754   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1755   bool cancel = false;
1756   Send(new PrintHostMsg_CheckForCancel(routing_id(),
1757                                        print_params.preview_ui_id,
1758                                        print_params.preview_request_id,
1759                                        &cancel));
1760   if (cancel)
1761     notify_browser_of_print_failure_ = false;
1762   return cancel;
1763 }
1764
1765 bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1766                                              PdfMetafileSkia* metafile) {
1767   DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1768
1769   // For non-modifiable files, |metafile| should be NULL, so do not bother
1770   // sending a message. If we don't generate draft metafiles, |metafile| is
1771   // NULL.
1772   if (!print_preview_context_.IsModifiable() ||
1773       !print_preview_context_.generate_draft_pages()) {
1774     DCHECK(!metafile);
1775     return true;
1776   }
1777
1778   if (!metafile) {
1779     NOTREACHED();
1780     print_preview_context_.set_error(
1781         PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1782     return false;
1783   }
1784
1785   PrintHostMsg_DidPreviewPage_Params preview_page_params;
1786   // Get the size of the resulting metafile.
1787   uint32 buf_size = metafile->GetDataSize();
1788   DCHECK_GT(buf_size, 0u);
1789   if (!CopyMetafileDataToSharedMem(
1790           metafile, &(preview_page_params.metafile_data_handle))) {
1791     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1792     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1793     return false;
1794   }
1795   preview_page_params.data_size = buf_size;
1796   preview_page_params.page_number = page_number;
1797   preview_page_params.preview_request_id =
1798       print_pages_params_->params.preview_request_id;
1799
1800   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1801   return true;
1802 }
1803
1804 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1805     : total_page_count_(0),
1806       current_page_index_(0),
1807       generate_draft_pages_(true),
1808       print_ready_metafile_page_count_(0),
1809       error_(PREVIEW_ERROR_NONE),
1810       state_(UNINITIALIZED) {
1811 }
1812
1813 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1814 }
1815
1816 void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1817     blink::WebLocalFrame* web_frame) {
1818   DCHECK(web_frame);
1819   DCHECK(!IsRendering());
1820   state_ = INITIALIZED;
1821   source_frame_.Reset(web_frame);
1822   source_node_.reset();
1823 }
1824
1825 void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1826     const blink::WebNode& web_node) {
1827   DCHECK(!web_node.isNull());
1828   DCHECK(web_node.document().frame());
1829   DCHECK(!IsRendering());
1830   state_ = INITIALIZED;
1831   source_frame_.Reset(web_node.document().frame());
1832   source_node_ = web_node;
1833 }
1834
1835 void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1836   DCHECK_EQ(INITIALIZED, state_);
1837   ClearContext();
1838 }
1839
1840 bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1841     PrepareFrameAndViewForPrint* prepared_frame,
1842     const std::vector<int>& pages) {
1843   DCHECK_EQ(INITIALIZED, state_);
1844   state_ = RENDERING;
1845
1846   // Need to make sure old object gets destroyed first.
1847   prep_frame_view_.reset(prepared_frame);
1848   prep_frame_view_->StartPrinting();
1849
1850   total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1851   if (total_page_count_ == 0) {
1852     LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1853     set_error(PREVIEW_ERROR_ZERO_PAGES);
1854     return false;
1855   }
1856
1857   metafile_.reset(new PdfMetafileSkia);
1858   if (!metafile_->Init()) {
1859     set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1860     LOG(ERROR) << "PdfMetafileSkia Init failed";
1861     return false;
1862   }
1863
1864   current_page_index_ = 0;
1865   pages_to_render_ = pages;
1866   // Sort and make unique.
1867   std::sort(pages_to_render_.begin(), pages_to_render_.end());
1868   pages_to_render_.resize(
1869       std::unique(pages_to_render_.begin(), pages_to_render_.end()) -
1870       pages_to_render_.begin());
1871   // Remove invalid pages.
1872   pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1873                                            pages_to_render_.end(),
1874                                            total_page_count_) -
1875                           pages_to_render_.begin());
1876   print_ready_metafile_page_count_ = pages_to_render_.size();
1877   if (pages_to_render_.empty()) {
1878     print_ready_metafile_page_count_ = total_page_count_;
1879     // Render all pages.
1880     for (int i = 0; i < total_page_count_; ++i)
1881       pages_to_render_.push_back(i);
1882   } else if (generate_draft_pages_) {
1883     int pages_index = 0;
1884     for (int i = 0; i < total_page_count_; ++i) {
1885       if (pages_index < print_ready_metafile_page_count_ &&
1886           i == pages_to_render_[pages_index]) {
1887         pages_index++;
1888         continue;
1889       }
1890       pages_to_render_.push_back(i);
1891     }
1892   }
1893
1894   document_render_time_ = base::TimeDelta();
1895   begin_time_ = base::TimeTicks::Now();
1896
1897   return true;
1898 }
1899
1900 void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1901     const base::TimeDelta& page_time) {
1902   DCHECK_EQ(RENDERING, state_);
1903   document_render_time_ += page_time;
1904   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1905 }
1906
1907 void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1908   DCHECK_EQ(RENDERING, state_);
1909   state_ = DONE;
1910   prep_frame_view_->FinishPrinting();
1911 }
1912
1913 void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1914   DCHECK(IsRendering());
1915
1916   base::TimeTicks begin_time = base::TimeTicks::Now();
1917   metafile_->FinishDocument();
1918
1919   if (print_ready_metafile_page_count_ <= 0) {
1920     NOTREACHED();
1921     return;
1922   }
1923
1924   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1925                              document_render_time_);
1926   base::TimeDelta total_time =
1927       (base::TimeTicks::Now() - begin_time) + document_render_time_;
1928   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1929                              total_time);
1930   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1931                              total_time / pages_to_render_.size());
1932 }
1933
1934 void PrintWebViewHelper::PrintPreviewContext::Finished() {
1935   DCHECK_EQ(DONE, state_);
1936   state_ = INITIALIZED;
1937   ClearContext();
1938 }
1939
1940 void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1941   DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1942   state_ = INITIALIZED;
1943   if (report_error) {
1944     DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1945     UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1946                               PREVIEW_ERROR_LAST_ENUM);
1947   }
1948   ClearContext();
1949 }
1950
1951 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1952   DCHECK_EQ(RENDERING, state_);
1953   if (IsFinalPageRendered())
1954     return -1;
1955   return pages_to_render_[current_page_index_++];
1956 }
1957
1958 bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1959   return state_ == RENDERING || state_ == DONE;
1960 }
1961
1962 bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1963   // The only kind of node we can print right now is a PDF node.
1964   return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1965 }
1966
1967 bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1968   return IsModifiable() && source_frame()->hasSelection();
1969 }
1970
1971 bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1972     const {
1973   DCHECK(IsRendering());
1974   return current_page_index_ == print_ready_metafile_page_count_;
1975 }
1976
1977 bool PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1978   DCHECK(IsRendering());
1979   return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1980 }
1981
1982 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1983     bool generate_draft_pages) {
1984   DCHECK_EQ(INITIALIZED, state_);
1985   generate_draft_pages_ = generate_draft_pages;
1986 }
1987
1988 void PrintWebViewHelper::PrintPreviewContext::set_error(
1989     enum PrintPreviewErrorBuckets error) {
1990   error_ = error;
1991 }
1992
1993 blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
1994   DCHECK(state_ != UNINITIALIZED);
1995   return source_frame_.GetFrame();
1996 }
1997
1998 const blink::WebNode&
1999     PrintWebViewHelper::PrintPreviewContext::source_node() const {
2000   DCHECK(state_ != UNINITIALIZED);
2001   return source_node_;
2002 }
2003
2004 blink::WebLocalFrame*
2005 PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
2006   DCHECK(state_ != UNINITIALIZED);
2007   return prep_frame_view_->frame();
2008 }
2009
2010 const blink::WebNode&
2011     PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
2012   DCHECK(state_ != UNINITIALIZED);
2013   return prep_frame_view_->node();
2014 }
2015
2016 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
2017   DCHECK(state_ != UNINITIALIZED);
2018   return total_page_count_;
2019 }
2020
2021 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
2022   return generate_draft_pages_;
2023 }
2024
2025 PdfMetafileSkia* PrintWebViewHelper::PrintPreviewContext::metafile() {
2026   DCHECK(IsRendering());
2027   return metafile_.get();
2028 }
2029
2030 int PrintWebViewHelper::PrintPreviewContext::last_error() const {
2031   return error_;
2032 }
2033
2034 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
2035   prep_frame_view_.reset();
2036   metafile_.reset();
2037   pages_to_render_.clear();
2038   error_ = PREVIEW_ERROR_NONE;
2039 }
2040
2041 void PrintWebViewHelper::SetPrintPagesParams(
2042     const PrintMsg_PrintPages_Params& settings) {
2043   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
2044   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
2045                                              settings.params.document_cookie));
2046 }
2047
2048 PrintWebViewHelper::ScriptingThrottler::ScriptingThrottler() : count_(0) {
2049 }
2050
2051 bool PrintWebViewHelper::ScriptingThrottler::IsAllowed(blink::WebFrame* frame) {
2052   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
2053   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
2054   bool too_frequent = false;
2055
2056   // Check if there is script repeatedly trying to print and ignore it if too
2057   // frequent.  The first 3 times, we use a constant wait time, but if this
2058   // gets excessive, we switch to exponential wait time. So for a page that
2059   // calls print() in a loop the user will need to cancel the print dialog
2060   // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
2061   // This gives the user time to navigate from the page.
2062   if (count_ > 0) {
2063     base::TimeDelta diff = base::Time::Now() - last_print_;
2064     int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
2065     if (count_ > 3) {
2066       min_wait_seconds =
2067           std::min(kMinSecondsToIgnoreJavascriptInitiatedPrint << (count_ - 3),
2068                    kMaxSecondsToIgnoreJavascriptInitiatedPrint);
2069     }
2070     if (diff.InSeconds() < min_wait_seconds) {
2071       too_frequent = true;
2072     }
2073   }
2074
2075   if (!too_frequent) {
2076     ++count_;
2077     last_print_ = base::Time::Now();
2078     return true;
2079   }
2080
2081   blink::WebString message(
2082       blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
2083   frame->addMessageToConsole(blink::WebConsoleMessage(
2084       blink::WebConsoleMessage::LevelWarning, message));
2085   return false;
2086 }
2087
2088 void PrintWebViewHelper::ScriptingThrottler::Reset() {
2089   // Reset counter on successful print.
2090   count_ = 0;
2091 }
2092
2093 }  // namespace printing