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 = true;
  76
  77 const char kPageLoadScriptFormat[] =
  78     "document.open(); document.write(%s); document.close();";
  79
  80 const char kPageSetupScriptFormat[] = "setup(%s);";
  81
  82 void ExecuteScript(blink::WebFrame* frame,
  83                    const char* script_format,
  84                    const base::Value& parameters) {
  85   std::string json;
  86   base::JSONWriter::Write(parameters, &json);
  87   std::string script = base::StringPrintf(script_format, json.c_str());
  88   frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
  89 }
  90 #else
  91 bool g_is_preview_enabled = false;
  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   ~PrepareFrameAndViewForPrint() override;
 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  private:
 587   // blink::WebViewClient:
 588   void didStopLoading() override;
 589   // TODO(ojan): Remove this override and have this class use a non-null
 590   // layerTreeView.
 591   bool allowsBrokenNullLayerTreeView() const override;
 592
 593   // blink::WebFrameClient:
 594   blink::WebFrame* createChildFrame(
 595       blink::WebLocalFrame* parent,
 596       blink::WebTreeScopeType scope,
 597       const blink::WebString& name,
 598       blink::WebSandboxFlags sandboxFlags) override;
 599   void frameDetached(blink::WebFrame* frame, DetachType type) override;
 600
 601   void CallOnReady();
 602   void ResizeForPrinting();
 603   void RestoreSize();
 604   void CopySelection(const WebPreferences& preferences);
 605
 606   FrameReference frame_;
 607   blink::WebNode node_to_print_;
 608   bool owns_web_view_;
 609   blink::WebPrintParams web_print_params_;
 610   gfx::Size prev_view_size_;
 611   gfx::Size prev_scroll_offset_;
 612   int expected_pages_count_;
 613   base::Closure on_ready_;
 614   bool should_print_backgrounds_;
 615   bool should_print_selection_only_;
 616   bool is_printing_started_;
 617
 618   base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
 619
 620   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 621 };
 622
 623 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
 624     const PrintMsg_Print_Params& params,
 625     blink::WebLocalFrame* frame,
 626     const blink::WebNode& node,
 627     bool ignore_css_margins)
 628     : frame_(frame),
 629       node_to_print_(node),
 630       owns_web_view_(false),
 631       expected_pages_count_(0),
 632       should_print_backgrounds_(params.should_print_backgrounds),
 633       should_print_selection_only_(params.selection_only),
 634       is_printing_started_(false),
 635       weak_ptr_factory_(this) {
 636   PrintMsg_Print_Params print_params = params;
 637   if (!should_print_selection_only_ ||
 638       !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
 639     bool fit_to_page = ignore_css_margins &&
 640                        print_params.print_scaling_option ==
 641                            blink::WebPrintScalingOptionFitToPrintableArea;
 642     ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
 643     frame->printBegin(web_print_params_, node_to_print_);
 644     print_params = CalculatePrintParamsForCss(
 645         frame, 0, print_params, ignore_css_margins, fit_to_page, NULL);
 646     frame->printEnd();
 647   }
 648   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
 649 }
 650
 651 PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
 652   FinishPrinting();
 653 }
 654
 655 void PrepareFrameAndViewForPrint::ResizeForPrinting() {
 656   // Layout page according to printer page size. Since WebKit shrinks the
 657   // size of the page automatically (from 125% to 200%) we trick it to
 658   // think the page is 125% larger so the size of the page is correct for
 659   // minimum (default) scaling.
 660   // This is important for sites that try to fill the page.
 661   gfx::Size print_layout_size(web_print_params_.printContentArea.width,
 662                               web_print_params_.printContentArea.height);
 663   print_layout_size.set_height(
 664       static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
 665
 666   if (!frame())
 667     return;
 668   blink::WebView* web_view = frame_.view();
 669   // Backup size and offset.
 670   if (blink::WebFrame* web_frame = web_view->mainFrame())
 671     prev_scroll_offset_ = web_frame->scrollOffset();
 672   prev_view_size_ = web_view->size();
 673
 674   web_view->resize(print_layout_size);
 675 }
 676
 677 void PrepareFrameAndViewForPrint::StartPrinting() {
 678   ResizeForPrinting();
 679   blink::WebView* web_view = frame_.view();
 680   web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
 681   expected_pages_count_ =
 682       frame()->printBegin(web_print_params_, node_to_print_);
 683   is_printing_started_ = true;
 684 }
 685
 686 void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
 687     const WebPreferences& preferences,
 688     const base::Closure& on_ready) {
 689   on_ready_ = on_ready;
 690   if (should_print_selection_only_) {
 691     CopySelection(preferences);
 692   } else {
 693     // Call immediately, async call crashes scripting printing.
 694     CallOnReady();
 695   }
 696 }
 697
 698 void PrepareFrameAndViewForPrint::CopySelection(
 699     const WebPreferences& preferences) {
 700   ResizeForPrinting();
 701   std::string url_str = "data:text/html;charset=utf-8,";
 702   url_str.append(
 703       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
 704   RestoreSize();
 705   // Create a new WebView with the same settings as the current display one.
 706   // Except that we disable javascript (don't want any active content running
 707   // on the page).
 708   WebPreferences prefs = preferences;
 709   prefs.javascript_enabled = false;
 710
 711   blink::WebView* web_view = blink::WebView::create(this);
 712   owns_web_view_ = true;
 713   content::RenderView::ApplyWebPreferences(prefs, web_view);
 714   web_view->setMainFrame(
 715       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, this));
 716   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
 717   node_to_print_.reset();
 718
 719   // When loading is done this will call didStopLoading() and that will do the
 720   // actual printing.
 721   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 722 }
 723
 724 bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
 725   return true;
 726 }
 727
 728 void PrepareFrameAndViewForPrint::didStopLoading() {
 729   DCHECK(!on_ready_.is_null());
 730   // Don't call callback here, because it can delete |this| and WebView that is
 731   // called didStopLoading.
 732   base::ThreadTaskRunnerHandle::Get()->PostTask(
 733       FROM_HERE, base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
 734                             weak_ptr_factory_.GetWeakPtr()));
 735 }
 736
 737 blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
 738     blink::WebLocalFrame* parent,
 739     blink::WebTreeScopeType scope,
 740     const blink::WebString& name,
 741     blink::WebSandboxFlags sandboxFlags) {
 742   blink::WebFrame* frame = blink::WebLocalFrame::create(scope, this);
 743   parent->appendChild(frame);
 744   return frame;
 745 }
 746
 747 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame,
 748                                                 DetachType type) {
 749   DCHECK(type == DetachType::Remove);
 750   if (frame->parent())
 751     frame->parent()->removeChild(frame);
 752   frame->close();
 753 }
 754
 755 void PrepareFrameAndViewForPrint::CallOnReady() {
 756   return on_ready_.Run();  // Can delete |this|.
 757 }
 758
 759 void PrepareFrameAndViewForPrint::RestoreSize() {
 760   if (frame()) {
 761     blink::WebView* web_view = frame_.GetFrame()->view();
 762     web_view->resize(prev_view_size_);
 763     if (blink::WebFrame* web_frame = web_view->mainFrame())
 764       web_frame->setScrollOffset(prev_scroll_offset_);
 765   }
 766 }
 767
 768 void PrepareFrameAndViewForPrint::FinishPrinting() {
 769   blink::WebLocalFrame* frame = frame_.GetFrame();
 770   if (frame) {
 771     blink::WebView* web_view = frame->view();
 772     if (is_printing_started_) {
 773       is_printing_started_ = false;
 774       frame->printEnd();
 775       if (!owns_web_view_) {
 776         web_view->settings()->setShouldPrintBackgrounds(false);
 777         RestoreSize();
 778       }
 779     }
 780     if (owns_web_view_) {
 781       DCHECK(!frame->isLoading());
 782       owns_web_view_ = false;
 783       web_view->close();
 784     }
 785   }
 786   frame_.Reset(NULL);
 787   on_ready_.Reset();
 788 }
 789
 790 bool PrintWebViewHelper::Delegate::IsAskPrintSettingsEnabled() {
 791   return true;
 792 }
 793
 794 bool PrintWebViewHelper::Delegate::IsScriptedPrintEnabled() {
 795   return true;
 796 }
 797
 798 PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view,
 799                                        scoped_ptr<Delegate> delegate)
 800     : content::RenderViewObserver(render_view),
 801       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
 802       reset_prep_frame_view_(false),
 803       is_print_ready_metafile_sent_(false),
 804       ignore_css_margins_(false),
 805       is_scripted_printing_blocked_(false),
 806       notify_browser_of_print_failure_(true),
 807       print_for_preview_(false),
 808       delegate_(delegate.Pass()),
 809       print_node_in_progress_(false),
 810       is_loading_(false),
 811       is_scripted_preview_delayed_(false),
 812       ipc_nesting_level_(0),
 813       weak_ptr_factory_(this) {
 814   if (!delegate_->IsPrintPreviewEnabled())
 815     DisablePreview();
 816 }
 817
 818 PrintWebViewHelper::~PrintWebViewHelper() {
 819 }
 820
 821 // static
 822 void PrintWebViewHelper::DisablePreview() {
 823   g_is_preview_enabled = false;
 824 }
 825
 826 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(blink::WebFrame* frame,
 827                                                        bool user_initiated) {
 828   if (!delegate_->IsScriptedPrintEnabled())
 829     return false;
 830
 831   // If preview is enabled, then the print dialog is tab modal, and the user
 832   // can always close the tab on a mis-behaving page (the system print dialog
 833   // is app modal). If the print was initiated through user action, don't
 834   // throttle. Or, if the command line flag to skip throttling has been set.
 835   return !is_scripted_printing_blocked_ &&
 836          (user_initiated || g_is_preview_enabled ||
 837           scripting_throttler_.IsAllowed(frame));
 838 }
 839
 840 void PrintWebViewHelper::DidStartLoading() {
 841   is_loading_ = true;
 842 }
 843
 844 void PrintWebViewHelper::DidStopLoading() {
 845   is_loading_ = false;
 846   if (!on_stop_loading_closure_.is_null()) {
 847     on_stop_loading_closure_.Run();
 848     on_stop_loading_closure_.Reset();
 849   }
 850 }
 851
 852 // Prints |frame| which called window.print().
 853 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
 854                                    bool user_initiated) {
 855   DCHECK(frame);
 856
 857   // Allow Prerendering to cancel this print request if necessary.
 858   if (delegate_->CancelPrerender(render_view(), routing_id()))
 859     return;
 860
 861   if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
 862     return;
 863
 864   if (delegate_->OverridePrint(frame))
 865     return;
 866
 867   if (!g_is_preview_enabled) {
 868     Print(frame, blink::WebNode(), true);
 869   } else {
 870     print_preview_context_.InitWithFrame(frame);
 871     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
 872   }
 873 }
 874
 875 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
 876   // The class is not designed to handle recursive messages. This is not
 877   // expected during regular flow. However, during rendering of content for
 878   // printing, lower level code may run nested message loop. E.g. PDF may has
 879   // script to show message box http://crbug.com/502562. In that moment browser
 880   // may receive updated printer capabilities and decide to restart print
 881   // preview generation. When this happened message handling function may
 882   // choose to ignore message or safely crash process.
 883   ++ipc_nesting_level_;
 884
 885   bool handled = true;
 886   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
 887 #if defined(ENABLE_BASIC_PRINTING)
 888     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
 889     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
 890 #endif  // ENABLE_BASIC_PRINTING
 891     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
 892     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
 893     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
 894     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
 895     IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
 896                         SetScriptedPrintBlocked)
 897     IPC_MESSAGE_UNHANDLED(handled = false)
 898   IPC_END_MESSAGE_MAP()
 899
 900   --ipc_nesting_level_;
 901   return handled;
 902 }
 903
 904 void PrintWebViewHelper::OnPrintForPrintPreview(
 905     const base::DictionaryValue& job_settings) {
 906   CHECK_LE(ipc_nesting_level_, 1);
 907   // If still not finished with earlier print request simply ignore.
 908   if (prep_frame_view_)
 909     return;
 910
 911   if (!render_view()->GetWebView())
 912     return;
 913   blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
 914   if (!main_frame)
 915     return;
 916
 917   blink::WebDocument document = main_frame->document();
 918   // <object>/<iframe> with id="pdf-viewer" is created in
 919   // chrome/browser/resources/print_preview/print_preview.js
 920   blink::WebElement pdf_element = document.getElementById("pdf-viewer");
 921   if (pdf_element.isNull()) {
 922     NOTREACHED();
 923     return;
 924   }
 925
 926   // The out-of-process plugin element is nested within a frame. In tests, there
 927   // may not be an iframe containing the out-of-process plugin, so continue with
 928   // the element with ID "pdf-viewer" if it isn't an iframe.
 929   blink::WebLocalFrame* plugin_frame = pdf_element.document().frame();
 930   blink::WebElement plugin_element = pdf_element;
 931   if (pdf_element.hasHTMLTagName("iframe")) {
 932     plugin_frame = blink::WebLocalFrame::fromFrameOwnerElement(pdf_element);
 933     plugin_element = delegate_->GetPdfElement(plugin_frame);
 934     if (plugin_element.isNull()) {
 935       NOTREACHED();
 936       return;
 937     }
 938   }
 939
 940   // Set |print_for_preview_| flag and autoreset it to back to original
 941   // on return.
 942   base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
 943
 944   if (!UpdatePrintSettings(plugin_frame, plugin_element, job_settings)) {
 945     LOG(ERROR) << "UpdatePrintSettings failed";
 946     DidFinishPrinting(FAIL_PRINT);
 947     return;
 948   }
 949
 950   // Print page onto entire page not just printable area. Preview PDF already
 951   // has content in correct position taking into account page size and printable
 952   // area.
 953   // TODO(vitalybuka) : Make this consistent on all platform. This change
 954   // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
 955   // printable_area. Also we can't change printable_area deeper inside
 956   // RenderPagesForPrint for Windows, because it's used also by native
 957   // printing and it expects real printable_area value.
 958   // See http://crbug.com/123408
 959   PrintMsg_Print_Params& print_params = print_pages_params_->params;
 960   print_params.printable_area = gfx::Rect(print_params.page_size);
 961
 962   // Render Pages for printing.
 963   if (!RenderPagesForPrint(plugin_frame, plugin_element)) {
 964     LOG(ERROR) << "RenderPagesForPrint failed";
 965     DidFinishPrinting(FAIL_PRINT);
 966   }
 967 }
 968
 969 bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
 970   DCHECK(frame);
 971   blink::WebView* webView = render_view()->GetWebView();
 972   DCHECK(webView);
 973   if (!webView)
 974     return false;
 975
 976   // If the user has selected text in the currently focused frame we print
 977   // only that frame (this makes print selection work for multiple frames).
 978   blink::WebLocalFrame* focusedFrame =
 979       webView->focusedFrame()->toWebLocalFrame();
 980   *frame = focusedFrame->hasSelection()
 981                ? focusedFrame
 982                : webView->mainFrame()->toWebLocalFrame();
 983   return true;
 984 }
 985
 986 #if defined(ENABLE_BASIC_PRINTING)
 987 void PrintWebViewHelper::OnPrintPages() {
 988   CHECK_LE(ipc_nesting_level_, 1);
 989   blink::WebLocalFrame* frame;
 990   if (!GetPrintFrame(&frame))
 991     return;
 992   // If we are printing a PDF extension frame, find the plugin node and print
 993   // that instead.
 994   auto plugin = delegate_->GetPdfElement(frame);
 995   Print(frame, plugin, false);
 996 }
 997
 998 void PrintWebViewHelper::OnPrintForSystemDialog() {
 999   CHECK_LE(ipc_nesting_level_, 1);
1000   blink::WebLocalFrame* frame = print_preview_context_.source_frame();
1001   if (!frame) {
1002     NOTREACHED();
1003     return;
1004   }
1005   Print(frame, print_preview_context_.source_node(), false);
1006 }
1007 #endif  // ENABLE_BASIC_PRINTING
1008
1009 void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
1010     const PageSizeMargins& page_layout_in_points,
1011     gfx::Size* page_size,
1012     gfx::Rect* content_area) {
1013   *page_size = gfx::Size(
1014       page_layout_in_points.content_width + page_layout_in_points.margin_right +
1015           page_layout_in_points.margin_left,
1016       page_layout_in_points.content_height + page_layout_in_points.margin_top +
1017           page_layout_in_points.margin_bottom);
1018   *content_area = gfx::Rect(page_layout_in_points.margin_left,
1019                             page_layout_in_points.margin_top,
1020                             page_layout_in_points.content_width,
1021                             page_layout_in_points.content_height);
1022 }
1023
1024 void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
1025     const base::DictionaryValue& settings) {
1026   int margins_type = 0;
1027   if (!settings.GetInteger(kSettingMarginsType, &margins_type))
1028     margins_type = DEFAULT_MARGINS;
1029   ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
1030 }
1031
1032 bool PrintWebViewHelper::IsPrintToPdfRequested(
1033     const base::DictionaryValue& job_settings) {
1034   bool print_to_pdf = false;
1035   if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
1036     NOTREACHED();
1037   return print_to_pdf;
1038 }
1039
1040 void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
1041   CHECK_LE(ipc_nesting_level_, 1);
1042
1043   print_preview_context_.OnPrintPreview();
1044
1045   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1046                             PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
1047
1048   if (!print_preview_context_.source_frame()) {
1049     DidFinishPrinting(FAIL_PREVIEW);
1050     return;
1051   }
1052
1053   if (!UpdatePrintSettings(print_preview_context_.source_frame(),
1054                            print_preview_context_.source_node(), settings)) {
1055     if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
1056       Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
1057           routing_id(), print_pages_params_
1058                             ? print_pages_params_->params.document_cookie
1059                             : 0));
1060       notify_browser_of_print_failure_ = false;  // Already sent.
1061     }
1062     DidFinishPrinting(FAIL_PREVIEW);
1063     return;
1064   }
1065
1066   // Set the options from document if we are previewing a pdf and send a
1067   // message to browser.
1068   if (print_pages_params_->params.is_first_request &&
1069       !print_preview_context_.IsModifiable()) {
1070     PrintHostMsg_SetOptionsFromDocument_Params options;
1071     if (SetOptionsFromPdfDocument(&options))
1072       Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), options));
1073   }
1074
1075   is_print_ready_metafile_sent_ = false;
1076
1077   // PDF printer device supports alpha blending.
1078   print_pages_params_->params.supports_alpha_blend = true;
1079
1080   bool generate_draft_pages = false;
1081   if (!settings.GetBoolean(kSettingGenerateDraftData, &generate_draft_pages)) {
1082     NOTREACHED();
1083   }
1084   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1085
1086   PrepareFrameForPreviewDocument();
1087 }
1088
1089 void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1090   reset_prep_frame_view_ = false;
1091
1092   if (!print_pages_params_ || CheckForCancel()) {
1093     DidFinishPrinting(FAIL_PREVIEW);
1094     return;
1095   }
1096
1097   // Don't reset loading frame or WebKit will fail assert. Just retry when
1098   // current selection is loaded.
1099   if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1100     reset_prep_frame_view_ = true;
1101     return;
1102   }
1103
1104   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1105   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1106       print_params, print_preview_context_.source_frame(),
1107       print_preview_context_.source_node(), ignore_css_margins_));
1108   prep_frame_view_->CopySelectionIfNeeded(
1109       render_view()->GetWebkitPreferences(),
1110       base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1111                  base::Unretained(this)));
1112 }
1113
1114 void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1115   if (reset_prep_frame_view_) {
1116     PrepareFrameForPreviewDocument();
1117     return;
1118   }
1119   DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1120 }
1121
1122 bool PrintWebViewHelper::CreatePreviewDocument() {
1123   if (!print_pages_params_ || CheckForCancel())
1124     return false;
1125
1126   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1127                             PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1128
1129   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1130   const std::vector<int>& pages = print_pages_params_->pages;
1131
1132   if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1133                                                     pages)) {
1134     return false;
1135   }
1136
1137   PageSizeMargins default_page_layout;
1138   ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1139                                   print_params, ignore_css_margins_, NULL,
1140                                   &default_page_layout);
1141
1142   bool has_page_size_style =
1143       PrintingFrameHasPageSizeStyle(print_preview_context_.prepared_frame(),
1144                                     print_preview_context_.total_page_count());
1145   int dpi = GetDPI(&print_params);
1146
1147   gfx::Rect printable_area_in_points(
1148       ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1149       ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1150       ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1151       ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1152
1153   // Margins: Send default page layout to browser process.
1154   Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1155                                                 default_page_layout,
1156                                                 printable_area_in_points,
1157                                                 has_page_size_style));
1158
1159   PrintHostMsg_DidGetPreviewPageCount_Params params;
1160   params.page_count = print_preview_context_.total_page_count();
1161   params.is_modifiable = print_preview_context_.IsModifiable();
1162   params.document_cookie = print_params.document_cookie;
1163   params.preview_request_id = print_params.preview_request_id;
1164   params.clear_preview_data = print_preview_context_.generate_draft_pages();
1165   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1166   if (CheckForCancel())
1167     return false;
1168
1169   while (!print_preview_context_.IsFinalPageRendered()) {
1170     int page_number = print_preview_context_.GetNextPageNumber();
1171     DCHECK_GE(page_number, 0);
1172     if (!RenderPreviewPage(page_number, print_params))
1173       return false;
1174
1175     if (CheckForCancel())
1176       return false;
1177
1178     // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1179     // print_preview_context_.AllPagesRendered()) before calling
1180     // FinalizePrintReadyDocument() when printing a PDF because the plugin
1181     // code does not generate output until we call FinishPrinting().  We do not
1182     // generate draft pages for PDFs, so IsFinalPageRendered() and
1183     // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1184     // the loop.
1185     if (print_preview_context_.IsFinalPageRendered())
1186       print_preview_context_.AllPagesRendered();
1187
1188     if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1189       DCHECK(print_preview_context_.IsModifiable() ||
1190              print_preview_context_.IsFinalPageRendered());
1191       if (!FinalizePrintReadyDocument())
1192         return false;
1193     }
1194   }
1195   print_preview_context_.Finished();
1196   return true;
1197 }
1198
1199 bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1200   DCHECK(!is_print_ready_metafile_sent_);
1201   print_preview_context_.FinalizePrintReadyDocument();
1202
1203   PdfMetafileSkia* metafile = print_preview_context_.metafile();
1204   PrintHostMsg_DidPreviewDocument_Params preview_params;
1205
1206   // Ask the browser to create the shared memory for us.
1207   if (!CopyMetafileDataToSharedMem(*metafile,
1208                                    &(preview_params.metafile_data_handle))) {
1209     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1210     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1211     return false;
1212   }
1213
1214   preview_params.data_size = metafile->GetDataSize();
1215   preview_params.document_cookie = print_pages_params_->params.document_cookie;
1216   preview_params.expected_pages_count =
1217       print_preview_context_.total_page_count();
1218   preview_params.modifiable = print_preview_context_.IsModifiable();
1219   preview_params.preview_request_id =
1220       print_pages_params_->params.preview_request_id;
1221
1222   is_print_ready_metafile_sent_ = true;
1223
1224   Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1225   return true;
1226 }
1227
1228 void PrintWebViewHelper::OnPrintingDone(bool success) {
1229   CHECK_LE(ipc_nesting_level_, 1);
1230   notify_browser_of_print_failure_ = false;
1231   if (!success)
1232     LOG(ERROR) << "Failure in OnPrintingDone";
1233   DidFinishPrinting(success ? OK : FAIL_PRINT);
1234 }
1235
1236 void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1237   is_scripted_printing_blocked_ = blocked;
1238 }
1239
1240 void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1241   CHECK_LE(ipc_nesting_level_, 1);
1242   blink::WebLocalFrame* frame = NULL;
1243   GetPrintFrame(&frame);
1244   DCHECK(frame);
1245   // If we are printing a PDF extension frame, find the plugin node and print
1246   // that instead.
1247   auto plugin = delegate_->GetPdfElement(frame);
1248   if (!plugin.isNull()) {
1249     PrintNode(plugin);
1250     return;
1251   }
1252   print_preview_context_.InitWithFrame(frame);
1253   RequestPrintPreview(selection_only
1254                           ? PRINT_PREVIEW_USER_INITIATED_SELECTION
1255                           : PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1256 }
1257
1258 bool PrintWebViewHelper::IsPrintingEnabled() {
1259   bool result = false;
1260   Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1261   return result;
1262 }
1263
1264 void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1265   if (node.isNull() || !node.document().frame()) {
1266     // This can occur when the context menu refers to an invalid WebNode.
1267     // See http://crbug.com/100890#c17 for a repro case.
1268     return;
1269   }
1270
1271   if (print_node_in_progress_) {
1272     // This can happen as a result of processing sync messages when printing
1273     // from ppapi plugins. It's a rare case, so its OK to just fail here.
1274     // See http://crbug.com/159165.
1275     return;
1276   }
1277
1278   print_node_in_progress_ = true;
1279
1280   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1281   // its |context_menu_node_|.
1282   if (!g_is_preview_enabled) {
1283     blink::WebNode duplicate_node(node);
1284     Print(duplicate_node.document().frame(), duplicate_node, false);
1285   } else {
1286     print_preview_context_.InitWithNode(node);
1287     RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1288   }
1289
1290   print_node_in_progress_ = false;
1291 }
1292
1293 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1294                                const blink::WebNode& node,
1295                                bool is_scripted) {
1296   // If still not finished with earlier print request simply ignore.
1297   if (prep_frame_view_)
1298     return;
1299
1300   FrameReference frame_ref(frame);
1301
1302   int expected_page_count = 0;
1303   if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1304     DidFinishPrinting(FAIL_PRINT_INIT);
1305     return;  // Failed to init print page settings.
1306   }
1307
1308   // Some full screen plugins can say they don't want to print.
1309   if (!expected_page_count) {
1310     DidFinishPrinting(FAIL_PRINT);
1311     return;
1312   }
1313
1314   // Ask the browser to show UI to retrieve the final print settings.
1315   if (delegate_->IsAskPrintSettingsEnabled() &&
1316       !GetPrintSettingsFromUser(frame_ref.GetFrame(), node, expected_page_count,
1317                                 is_scripted)) {
1318     DidFinishPrinting(OK);  // Release resources and fail silently.
1319     return;
1320   }
1321
1322   // Render Pages for printing.
1323   if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1324     LOG(ERROR) << "RenderPagesForPrint failed";
1325     DidFinishPrinting(FAIL_PRINT);
1326   }
1327   scripting_throttler_.Reset();
1328 }
1329
1330 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1331   switch (result) {
1332     case OK:
1333       break;
1334
1335     case FAIL_PRINT_INIT:
1336       DCHECK(!notify_browser_of_print_failure_);
1337       break;
1338
1339     case FAIL_PRINT:
1340       if (notify_browser_of_print_failure_ && print_pages_params_) {
1341         int cookie = print_pages_params_->params.document_cookie;
1342         Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1343       }
1344       break;
1345
1346     case FAIL_PREVIEW:
1347       int cookie =
1348           print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1349       if (notify_browser_of_print_failure_) {
1350         LOG(ERROR) << "CreatePreviewDocument failed";
1351         Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1352       } else {
1353         Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1354       }
1355       print_preview_context_.Failed(notify_browser_of_print_failure_);
1356       break;
1357   }
1358   prep_frame_view_.reset();
1359   print_pages_params_.reset();
1360   notify_browser_of_print_failure_ = true;
1361 }
1362
1363 void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1364   PrintPages();
1365   FinishFramePrinting();
1366 }
1367
1368 void PrintWebViewHelper::PrintPages() {
1369   if (!prep_frame_view_)  // Printing is already canceled or failed.
1370     return;
1371   prep_frame_view_->StartPrinting();
1372
1373   int page_count = prep_frame_view_->GetExpectedPageCount();
1374   if (!page_count) {
1375     LOG(ERROR) << "Can't print 0 pages.";
1376     return DidFinishPrinting(FAIL_PRINT);
1377   }
1378
1379   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1380   const PrintMsg_Print_Params& print_params = params.params;
1381
1382 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1383   // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1384   // See http://crbug.com/161576
1385   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1386                                                 print_params.document_cookie,
1387                                                 page_count));
1388 #endif  // !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1389
1390   if (print_params.preview_ui_id < 0) {
1391     // Printing for system dialog.
1392     int printed_count = params.pages.empty() ? page_count : params.pages.size();
1393 #if defined(OS_CHROMEOS)
1394     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1395                          printed_count);
1396 #else
1397     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1398 #endif  // defined(OS_CHROMEOS)
1399   }
1400
1401   if (!PrintPagesNative(prep_frame_view_->frame(), page_count)) {
1402     LOG(ERROR) << "Printing failed.";
1403     return DidFinishPrinting(FAIL_PRINT);
1404   }
1405 }
1406
1407 void PrintWebViewHelper::FinishFramePrinting() {
1408   prep_frame_view_.reset();
1409 }
1410
1411 #if defined(OS_MACOSX)
1412 bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1413                                           int page_count) {
1414   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1415   const PrintMsg_Print_Params& print_params = params.params;
1416
1417   PrintMsg_PrintPage_Params page_params;
1418   page_params.params = print_params;
1419   if (params.pages.empty()) {
1420     for (int i = 0; i < page_count; ++i) {
1421       page_params.page_number = i;
1422       PrintPageInternal(page_params, frame);
1423     }
1424   } else {
1425     for (size_t i = 0; i < params.pages.size(); ++i) {
1426       if (params.pages[i] >= page_count)
1427         break;
1428       page_params.page_number = params.pages[i];
1429       PrintPageInternal(page_params, frame);
1430     }
1431   }
1432   return true;
1433 }
1434
1435 #endif  // OS_MACOSX
1436
1437 // static - Not anonymous so that platform implementations can use it.
1438 void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1439     blink::WebFrame* frame,
1440     int page_index,
1441     const PrintMsg_Print_Params& page_params,
1442     bool ignore_css_margins,
1443     double* scale_factor,
1444     PageSizeMargins* page_layout_in_points) {
1445   PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1446       frame, page_index, page_params, ignore_css_margins,
1447       page_params.print_scaling_option ==
1448           blink::WebPrintScalingOptionFitToPrintableArea,
1449       scale_factor);
1450   CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1451 }
1452
1453 bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1454   PrintMsg_PrintPages_Params settings;
1455   Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1456                                                 &settings.params));
1457   // Check if the printer returned any settings, if the settings is empty, we
1458   // can safely assume there are no printer drivers configured. So we safely
1459   // terminate.
1460   bool result = true;
1461   if (!PrintMsg_Print_Params_IsValid(settings.params))
1462     result = false;
1463
1464   // Reset to default values.
1465   ignore_css_margins_ = false;
1466   settings.pages.clear();
1467
1468   settings.params.print_scaling_option = blink::WebPrintScalingOptionSourceSize;
1469   if (fit_to_paper_size) {
1470     settings.params.print_scaling_option =
1471         blink::WebPrintScalingOptionFitToPrintableArea;
1472   }
1473
1474   SetPrintPagesParams(settings);
1475   return result;
1476 }
1477
1478 bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1479                                                 const blink::WebNode& node,
1480                                                 int* number_of_pages) {
1481   DCHECK(frame);
1482   bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1483   if (!InitPrintSettings(fit_to_paper_size)) {
1484     notify_browser_of_print_failure_ = false;
1485     Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1486     return false;
1487   }
1488
1489   const PrintMsg_Print_Params& params = print_pages_params_->params;
1490   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1491   prepare.StartPrinting();
1492
1493   *number_of_pages = prepare.GetExpectedPageCount();
1494   return true;
1495 }
1496
1497 bool PrintWebViewHelper::SetOptionsFromPdfDocument(
1498     PrintHostMsg_SetOptionsFromDocument_Params* options) {
1499   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
1500   const blink::WebNode& source_node = print_preview_context_.source_node();
1501
1502   blink::WebPrintPresetOptions preset_options;
1503   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
1504                                                     &preset_options)) {
1505     return false;
1506   }
1507
1508   options->is_scaling_disabled = PDFShouldDisableScalingBasedOnPreset(
1509       preset_options, print_pages_params_->params);
1510   options->copies = preset_options.copies;
1511
1512   // TODO(thestig) This should be a straight pass-through, but print preview
1513   // does not currently support short-edge printing.
1514   switch (preset_options.duplexMode) {
1515     case blink::WebSimplex:
1516       options->duplex = SIMPLEX;
1517       break;
1518     case blink::WebLongEdge:
1519       options->duplex = LONG_EDGE;
1520       break;
1521     default:
1522       options->duplex = UNKNOWN_DUPLEX_MODE;
1523       break;
1524   }
1525   return true;
1526 }
1527
1528 bool PrintWebViewHelper::UpdatePrintSettings(
1529     blink::WebLocalFrame* frame,
1530     const blink::WebNode& node,
1531     const base::DictionaryValue& passed_job_settings) {
1532   const base::DictionaryValue* job_settings = &passed_job_settings;
1533   base::DictionaryValue modified_job_settings;
1534   if (job_settings->empty()) {
1535     if (!print_for_preview_)
1536       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1537     return false;
1538   }
1539
1540   bool source_is_html = true;
1541   if (print_for_preview_) {
1542     if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1543       NOTREACHED();
1544     }
1545   } else {
1546     source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1547   }
1548
1549   if (print_for_preview_ || !source_is_html) {
1550     modified_job_settings.MergeDictionary(job_settings);
1551     modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1552     modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1553     job_settings = &modified_job_settings;
1554   }
1555
1556   // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1557   // possible.
1558   int cookie =
1559       print_pages_params_ ? print_pages_params_->params.document_cookie : 0;
1560   PrintMsg_PrintPages_Params settings;
1561   bool canceled = false;
1562   Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
1563                                             &settings, &canceled));
1564   if (canceled) {
1565     notify_browser_of_print_failure_ = false;
1566     return false;
1567   }
1568
1569   if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1570     NOTREACHED();
1571     print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1572     return false;
1573   }
1574
1575   if (!print_for_preview_) {
1576     // Validate expected print preview settings.
1577     if (!job_settings->GetInteger(kPreviewRequestID,
1578                                   &settings.params.preview_request_id) ||
1579         !job_settings->GetBoolean(kIsFirstRequest,
1580                                   &settings.params.is_first_request)) {
1581       NOTREACHED();
1582       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1583       return false;
1584     }
1585
1586     settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1587     UpdateFrameMarginsCssInfo(*job_settings);
1588     settings.params.print_scaling_option = GetPrintScalingOption(
1589         frame, node, source_is_html, *job_settings, settings.params);
1590   }
1591
1592   SetPrintPagesParams(settings);
1593
1594   if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1595     if (!print_for_preview_)
1596       print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1597     else
1598       Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1599
1600     return false;
1601   }
1602
1603   return true;
1604 }
1605
1606 bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebLocalFrame* frame,
1607                                                   const blink::WebNode& node,
1608                                                   int expected_pages_count,
1609                                                   bool is_scripted) {
1610   PrintHostMsg_ScriptedPrint_Params params;
1611   PrintMsg_PrintPages_Params print_settings;
1612
1613   params.cookie = print_pages_params_->params.document_cookie;
1614   params.has_selection = frame->hasSelection();
1615   params.expected_pages_count = expected_pages_count;
1616   MarginType margin_type = DEFAULT_MARGINS;
1617   if (PrintingNodeOrPdfFrame(frame, node)) {
1618     margin_type =
1619         GetMarginsForPdf(frame, node, print_pages_params_->params);
1620   }
1621   params.margin_type = margin_type;
1622   params.is_scripted = is_scripted;
1623
1624   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1625
1626   // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1627   // value before and restore it afterwards.
1628   blink::WebPrintScalingOption scaling_option =
1629       print_pages_params_->params.print_scaling_option;
1630
1631   print_pages_params_.reset();
1632   IPC::SyncMessage* msg =
1633       new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1634   msg->EnableMessagePumping();
1635   Send(msg);
1636   print_settings.params.print_scaling_option = scaling_option;
1637   SetPrintPagesParams(print_settings);
1638   return (print_settings.params.dpi && print_settings.params.document_cookie);
1639 }
1640
1641 bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1642                                              const blink::WebNode& node) {
1643   if (!frame || prep_frame_view_)
1644     return false;
1645   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1646   const PrintMsg_Print_Params& print_params = params.params;
1647   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1648       print_params, frame, node, ignore_css_margins_));
1649   DCHECK(!print_pages_params_->params.selection_only ||
1650          print_pages_params_->pages.empty());
1651   prep_frame_view_->CopySelectionIfNeeded(
1652       render_view()->GetWebkitPreferences(),
1653       base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1654                  base::Unretained(this)));
1655   return true;
1656 }
1657
1658 #if defined(OS_POSIX)
1659 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1660     const PdfMetafileSkia& metafile,
1661     base::SharedMemoryHandle* shared_mem_handle) {
1662   uint32_t buf_size = metafile.GetDataSize();
1663   if (buf_size == 0)
1664     return false;
1665
1666   scoped_ptr<base::SharedMemory> shared_buf(
1667       content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(buf_size));
1668   if (!shared_buf)
1669     return false;
1670
1671   if (!shared_buf->Map(buf_size))
1672     return false;
1673
1674   if (!metafile.GetData(shared_buf->memory(), buf_size))
1675     return false;
1676
1677   return shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1678                                    shared_mem_handle);
1679 }
1680 #endif  // defined(OS_POSIX)
1681
1682 void PrintWebViewHelper::ShowScriptedPrintPreview() {
1683   if (is_scripted_preview_delayed_) {
1684     is_scripted_preview_delayed_ = false;
1685     Send(new PrintHostMsg_ShowScriptedPrintPreview(
1686         routing_id(), print_preview_context_.IsModifiable()));
1687   }
1688 }
1689
1690 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1691   const bool is_modifiable = print_preview_context_.IsModifiable();
1692   const bool has_selection = print_preview_context_.HasSelection();
1693   PrintHostMsg_RequestPrintPreview_Params params;
1694   params.is_modifiable = is_modifiable;
1695   params.has_selection = has_selection;
1696   switch (type) {
1697     case PRINT_PREVIEW_SCRIPTED: {
1698       // Shows scripted print preview in two stages.
1699       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1700       //    pumping messages here.
1701       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1702       //    document has been loaded.
1703       is_scripted_preview_delayed_ = true;
1704       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1705         // Wait for DidStopLoading. Plugins may not know the correct
1706         // |is_modifiable| value until they are fully loaded, which occurs when
1707         // DidStopLoading() is called. Defer showing the preview until then.
1708         on_stop_loading_closure_ =
1709             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1710                        base::Unretained(this));
1711       } else {
1712         base::ThreadTaskRunnerHandle::Get()->PostTask(
1713             FROM_HERE, base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1714                                   weak_ptr_factory_.GetWeakPtr()));
1715       }
1716       IPC::SyncMessage* msg =
1717           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1718       msg->EnableMessagePumping();
1719       Send(msg);
1720       is_scripted_preview_delayed_ = false;
1721       return;
1722     }
1723     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1724       // Wait for DidStopLoading. Continuing with this function while
1725       // |is_loading_| is true will cause print preview to hang when try to
1726       // print a PDF document.
1727       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1728         on_stop_loading_closure_ =
1729             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1730                        base::Unretained(this), type);
1731         return;
1732       }
1733
1734       break;
1735     }
1736     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1737       DCHECK(has_selection);
1738       DCHECK(!GetPlugin(print_preview_context_.source_frame()));
1739       params.selection_only = has_selection;
1740       break;
1741     }
1742     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1743       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1744         on_stop_loading_closure_ =
1745             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1746                        base::Unretained(this), type);
1747         return;
1748       }
1749
1750       params.webnode_only = true;
1751       break;
1752     }
1753     default: {
1754       NOTREACHED();
1755       return;
1756     }
1757   }
1758   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1759 }
1760
1761 bool PrintWebViewHelper::CheckForCancel() {
1762   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1763   bool cancel = false;
1764   Send(new PrintHostMsg_CheckForCancel(routing_id(),
1765                                        print_params.preview_ui_id,
1766                                        print_params.preview_request_id,
1767                                        &cancel));
1768   if (cancel)
1769     notify_browser_of_print_failure_ = false;
1770   return cancel;
1771 }
1772
1773 bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1774                                              PdfMetafileSkia* metafile) {
1775   DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1776
1777   // For non-modifiable files, |metafile| should be NULL, so do not bother
1778   // sending a message. If we don't generate draft metafiles, |metafile| is
1779   // NULL.
1780   if (!print_preview_context_.IsModifiable() ||
1781       !print_preview_context_.generate_draft_pages()) {
1782     DCHECK(!metafile);
1783     return true;
1784   }
1785
1786   if (!metafile) {
1787     NOTREACHED();
1788     print_preview_context_.set_error(
1789         PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1790     return false;
1791   }
1792
1793   PrintHostMsg_DidPreviewPage_Params preview_page_params;
1794   // Get the size of the resulting metafile.
1795   if (!CopyMetafileDataToSharedMem(
1796           *metafile, &(preview_page_params.metafile_data_handle))) {
1797     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1798     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1799     return false;
1800   }
1801   preview_page_params.data_size = metafile->GetDataSize();
1802   preview_page_params.page_number = page_number;
1803   preview_page_params.preview_request_id =
1804       print_pages_params_->params.preview_request_id;
1805
1806   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1807   return true;
1808 }
1809
1810 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1811     : total_page_count_(0),
1812       current_page_index_(0),
1813       generate_draft_pages_(true),
1814       print_ready_metafile_page_count_(0),
1815       error_(PREVIEW_ERROR_NONE),
1816       state_(UNINITIALIZED) {
1817 }
1818
1819 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1820 }
1821
1822 void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1823     blink::WebLocalFrame* web_frame) {
1824   DCHECK(web_frame);
1825   DCHECK(!IsRendering());
1826   state_ = INITIALIZED;
1827   source_frame_.Reset(web_frame);
1828   source_node_.reset();
1829 }
1830
1831 void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1832     const blink::WebNode& web_node) {
1833   DCHECK(!web_node.isNull());
1834   DCHECK(web_node.document().frame());
1835   DCHECK(!IsRendering());
1836   state_ = INITIALIZED;
1837   source_frame_.Reset(web_node.document().frame());
1838   source_node_ = web_node;
1839 }
1840
1841 void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1842   DCHECK_EQ(INITIALIZED, state_);
1843   ClearContext();
1844 }
1845
1846 bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1847     PrepareFrameAndViewForPrint* prepared_frame,
1848     const std::vector<int>& pages) {
1849   DCHECK_EQ(INITIALIZED, state_);
1850   state_ = RENDERING;
1851
1852   // Need to make sure old object gets destroyed first.
1853   prep_frame_view_.reset(prepared_frame);
1854   prep_frame_view_->StartPrinting();
1855
1856   total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1857   if (total_page_count_ == 0) {
1858     LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1859     set_error(PREVIEW_ERROR_ZERO_PAGES);
1860     return false;
1861   }
1862
1863   metafile_.reset(new PdfMetafileSkia);
1864   if (!metafile_->Init()) {
1865     set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1866     LOG(ERROR) << "PdfMetafileSkia Init failed";
1867     return false;
1868   }
1869
1870   current_page_index_ = 0;
1871   pages_to_render_ = pages;
1872   // Sort and make unique.
1873   std::sort(pages_to_render_.begin(), pages_to_render_.end());
1874   pages_to_render_.resize(
1875       std::unique(pages_to_render_.begin(), pages_to_render_.end()) -
1876       pages_to_render_.begin());
1877   // Remove invalid pages.
1878   pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1879                                            pages_to_render_.end(),
1880                                            total_page_count_) -
1881                           pages_to_render_.begin());
1882   print_ready_metafile_page_count_ = pages_to_render_.size();
1883   if (pages_to_render_.empty()) {
1884     print_ready_metafile_page_count_ = total_page_count_;
1885     // Render all pages.
1886     for (int i = 0; i < total_page_count_; ++i)
1887       pages_to_render_.push_back(i);
1888   } else if (generate_draft_pages_) {
1889     int pages_index = 0;
1890     for (int i = 0; i < total_page_count_; ++i) {
1891       if (pages_index < print_ready_metafile_page_count_ &&
1892           i == pages_to_render_[pages_index]) {
1893         pages_index++;
1894         continue;
1895       }
1896       pages_to_render_.push_back(i);
1897     }
1898   }
1899
1900   document_render_time_ = base::TimeDelta();
1901   begin_time_ = base::TimeTicks::Now();
1902
1903   return true;
1904 }
1905
1906 void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1907     const base::TimeDelta& page_time) {
1908   DCHECK_EQ(RENDERING, state_);
1909   document_render_time_ += page_time;
1910   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1911 }
1912
1913 void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1914   DCHECK_EQ(RENDERING, state_);
1915   state_ = DONE;
1916   prep_frame_view_->FinishPrinting();
1917 }
1918
1919 void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1920   DCHECK(IsRendering());
1921
1922   base::TimeTicks begin_time = base::TimeTicks::Now();
1923   metafile_->FinishDocument();
1924
1925   if (print_ready_metafile_page_count_ <= 0) {
1926     NOTREACHED();
1927     return;
1928   }
1929
1930   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1931                              document_render_time_);
1932   base::TimeDelta total_time =
1933       (base::TimeTicks::Now() - begin_time) + document_render_time_;
1934   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1935                              total_time);
1936   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1937                              total_time / pages_to_render_.size());
1938 }
1939
1940 void PrintWebViewHelper::PrintPreviewContext::Finished() {
1941   DCHECK_EQ(DONE, state_);
1942   state_ = INITIALIZED;
1943   ClearContext();
1944 }
1945
1946 void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1947   DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1948   state_ = INITIALIZED;
1949   if (report_error) {
1950     DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1951     UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1952                               PREVIEW_ERROR_LAST_ENUM);
1953   }
1954   ClearContext();
1955 }
1956
1957 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1958   DCHECK_EQ(RENDERING, state_);
1959   if (IsFinalPageRendered())
1960     return -1;
1961   return pages_to_render_[current_page_index_++];
1962 }
1963
1964 bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1965   return state_ == RENDERING || state_ == DONE;
1966 }
1967
1968 bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1969   // The only kind of node we can print right now is a PDF node.
1970   return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1971 }
1972
1973 bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1974   return IsModifiable() && source_frame()->hasSelection();
1975 }
1976
1977 bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1978     const {
1979   DCHECK(IsRendering());
1980   return current_page_index_ == print_ready_metafile_page_count_;
1981 }
1982
1983 bool PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1984   DCHECK(IsRendering());
1985   return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1986 }
1987
1988 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1989     bool generate_draft_pages) {
1990   DCHECK_EQ(INITIALIZED, state_);
1991   generate_draft_pages_ = generate_draft_pages;
1992 }
1993
1994 void PrintWebViewHelper::PrintPreviewContext::set_error(
1995     enum PrintPreviewErrorBuckets error) {
1996   error_ = error;
1997 }
1998
1999 blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
2000   DCHECK(state_ != UNINITIALIZED);
2001   return source_frame_.GetFrame();
2002 }
2003
2004 const blink::WebNode&
2005     PrintWebViewHelper::PrintPreviewContext::source_node() const {
2006   DCHECK(state_ != UNINITIALIZED);
2007   return source_node_;
2008 }
2009
2010 blink::WebLocalFrame*
2011 PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
2012   DCHECK(state_ != UNINITIALIZED);
2013   return prep_frame_view_->frame();
2014 }
2015
2016 const blink::WebNode&
2017     PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
2018   DCHECK(state_ != UNINITIALIZED);
2019   return prep_frame_view_->node();
2020 }
2021
2022 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
2023   DCHECK(state_ != UNINITIALIZED);
2024   return total_page_count_;
2025 }
2026
2027 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
2028   return generate_draft_pages_;
2029 }
2030
2031 PdfMetafileSkia* PrintWebViewHelper::PrintPreviewContext::metafile() {
2032   DCHECK(IsRendering());
2033   return metafile_.get();
2034 }
2035
2036 int PrintWebViewHelper::PrintPreviewContext::last_error() const {
2037   return error_;
2038 }
2039
2040 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
2041   prep_frame_view_.reset();
2042   metafile_.reset();
2043   pages_to_render_.clear();
2044   error_ = PREVIEW_ERROR_NONE;
2045 }
2046
2047 void PrintWebViewHelper::SetPrintPagesParams(
2048     const PrintMsg_PrintPages_Params& settings) {
2049   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
2050   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
2051                                              settings.params.document_cookie));
2052 }
2053
2054 PrintWebViewHelper::ScriptingThrottler::ScriptingThrottler() : count_(0) {
2055 }
2056
2057 bool PrintWebViewHelper::ScriptingThrottler::IsAllowed(blink::WebFrame* frame) {
2058   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
2059   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
2060   bool too_frequent = false;
2061
2062   // Check if there is script repeatedly trying to print and ignore it if too
2063   // frequent.  The first 3 times, we use a constant wait time, but if this
2064   // gets excessive, we switch to exponential wait time. So for a page that
2065   // calls print() in a loop the user will need to cancel the print dialog
2066   // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
2067   // This gives the user time to navigate from the page.
2068   if (count_ > 0) {
2069     base::TimeDelta diff = base::Time::Now() - last_print_;
2070     int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
2071     if (count_ > 3) {
2072       min_wait_seconds =
2073           std::min(kMinSecondsToIgnoreJavascriptInitiatedPrint << (count_ - 3),
2074                    kMaxSecondsToIgnoreJavascriptInitiatedPrint);
2075     }
2076     if (diff.InSeconds() < min_wait_seconds) {
2077       too_frequent = true;
2078     }
2079   }
2080
2081   if (!too_frequent) {
2082     ++count_;
2083     last_print_ = base::Time::Now();
2084     return true;
2085   }
2086
2087   blink::WebString message(
2088       blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
2089   frame->addMessageToConsole(blink::WebConsoleMessage(
2090       blink::WebConsoleMessage::LevelWarning, message));
2091   return false;
2092 }
2093
2094 void PrintWebViewHelper::ScriptingThrottler::Reset() {
2095   // Reset counter on successful print.
2096   count_ = 0;
2097 }
2098
2099 }  // namespace printing