components/printing/renderer/print_web_view_helper.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/printing/renderer/print_web_view_helper.h"
   6
   7 #include <string>
   8
   9 #include "base/auto_reset.h"
  10 #include "base/json/json_writer.h"
  11 #include "base/logging.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/metrics/histogram.h"
  14 #include "base/process/process_handle.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/stringprintf.h"
  17 #include "base/strings/utf_string_conversions.h"
  18 #include "components/printing/common/print_messages.h"
  19 #include "content/public/common/web_preferences.h"
  20 #include "content/public/renderer/render_frame.h"
  21 #include "content/public/renderer/render_thread.h"
  22 #include "content/public/renderer/render_view.h"
  23 #include "grit/components_resources.h"
  24 #include "net/base/escape.h"
  25 #include "printing/pdf_metafile_skia.h"
  26 #include "printing/units.h"
  27 #include "third_party/WebKit/public/platform/WebSize.h"
  28 #include "third_party/WebKit/public/platform/WebURLRequest.h"
  29 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  30 #include "third_party/WebKit/public/web/WebDocument.h"
  31 #include "third_party/WebKit/public/web/WebElement.h"
  32 #include "third_party/WebKit/public/web/WebFrameClient.h"
  33 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  34 #include "third_party/WebKit/public/web/WebPlugin.h"
  35 #include "third_party/WebKit/public/web/WebPluginDocument.h"
  36 #include "third_party/WebKit/public/web/WebPrintParams.h"
  37 #include "third_party/WebKit/public/web/WebPrintPresetOptions.h"
  38 #include "third_party/WebKit/public/web/WebPrintScalingOption.h"
  39 #include "third_party/WebKit/public/web/WebSandboxFlags.h"
  40 #include "third_party/WebKit/public/web/WebScriptSource.h"
  41 #include "third_party/WebKit/public/web/WebSettings.h"
  42 #include "third_party/WebKit/public/web/WebView.h"
  43 #include "third_party/WebKit/public/web/WebViewClient.h"
  44 #include "ui/base/resource/resource_bundle.h"
  45
  46 using content::WebPreferences;
  47
  48 namespace printing {
  49
  50 namespace {
  51
  52 enum PrintPreviewHelperEvents {
  53   PREVIEW_EVENT_REQUESTED,
  54   PREVIEW_EVENT_CACHE_HIT,  // Unused
  55   PREVIEW_EVENT_CREATE_DOCUMENT,
  56   PREVIEW_EVENT_NEW_SETTINGS,  // Unused
  57   PREVIEW_EVENT_MAX,
  58 };
  59
  60 const double kMinDpi = 1.0;
  61
  62 #if !defined(ENABLE_PRINT_PREVIEW)
  63 bool g_is_preview_enabled_ = false;
  64 #else
  65 bool g_is_preview_enabled_ = true;
  66
  67 const char kPageLoadScriptFormat[] =
  68     "document.open(); document.write(%s); document.close();";
  69
  70 const char kPageSetupScriptFormat[] = "setup(%s);";
  71
  72 void ExecuteScript(blink::WebFrame* frame,
  73                    const char* script_format,
  74                    const base::Value& parameters) {
  75   std::string json;
  76   base::JSONWriter::Write(&parameters, &json);
  77   std::string script = base::StringPrintf(script_format, json.c_str());
  78   frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
  79 }
  80 #endif  // !defined(ENABLE_PRINT_PREVIEW)
  81
  82 int GetDPI(const PrintMsg_Print_Params* print_params) {
  83 #if defined(OS_MACOSX)
  84   // On the Mac, the printable area is in points, don't do any scaling based
  85   // on dpi.
  86   return kPointsPerInch;
  87 #else
  88   return static_cast<int>(print_params->dpi);
  89 #endif  // defined(OS_MACOSX)
  90 }
  91
  92 bool PrintMsg_Print_Params_IsValid(const PrintMsg_Print_Params& params) {
  93   return !params.content_size.IsEmpty() && !params.page_size.IsEmpty() &&
  94          !params.printable_area.IsEmpty() && params.document_cookie &&
  95          params.desired_dpi && params.max_shrink && params.min_shrink &&
  96          params.dpi && (params.margin_top >= 0) && (params.margin_left >= 0) &&
  97          params.dpi > kMinDpi && params.document_cookie != 0;
  98 }
  99
 100 PrintMsg_Print_Params GetCssPrintParams(
 101     blink::WebFrame* frame,
 102     int page_index,
 103     const PrintMsg_Print_Params& page_params) {
 104   PrintMsg_Print_Params page_css_params = page_params;
 105   int dpi = GetDPI(&page_params);
 106
 107   blink::WebSize page_size_in_pixels(
 108       ConvertUnit(page_params.page_size.width(), dpi, kPixelsPerInch),
 109       ConvertUnit(page_params.page_size.height(), dpi, kPixelsPerInch));
 110   int margin_top_in_pixels =
 111       ConvertUnit(page_params.margin_top, dpi, kPixelsPerInch);
 112   int margin_right_in_pixels = ConvertUnit(
 113       page_params.page_size.width() -
 114       page_params.content_size.width() - page_params.margin_left,
 115       dpi, kPixelsPerInch);
 116   int margin_bottom_in_pixels = ConvertUnit(
 117       page_params.page_size.height() -
 118       page_params.content_size.height() - page_params.margin_top,
 119       dpi, kPixelsPerInch);
 120   int margin_left_in_pixels = ConvertUnit(
 121       page_params.margin_left,
 122       dpi, kPixelsPerInch);
 123
 124   blink::WebSize original_page_size_in_pixels = page_size_in_pixels;
 125
 126   if (frame) {
 127     frame->pageSizeAndMarginsInPixels(page_index,
 128                                       page_size_in_pixels,
 129                                       margin_top_in_pixels,
 130                                       margin_right_in_pixels,
 131                                       margin_bottom_in_pixels,
 132                                       margin_left_in_pixels);
 133   }
 134
 135   int new_content_width = page_size_in_pixels.width -
 136                           margin_left_in_pixels - margin_right_in_pixels;
 137   int new_content_height = page_size_in_pixels.height -
 138                            margin_top_in_pixels - margin_bottom_in_pixels;
 139
 140   // Invalid page size and/or margins. We just use the default setting.
 141   if (new_content_width < 1 || new_content_height < 1) {
 142     CHECK(frame != NULL);
 143     page_css_params = GetCssPrintParams(NULL, page_index, page_params);
 144     return page_css_params;
 145   }
 146
 147   page_css_params.content_size = gfx::Size(
 148       ConvertUnit(new_content_width, kPixelsPerInch, dpi),
 149       ConvertUnit(new_content_height, kPixelsPerInch, dpi));
 150
 151   if (original_page_size_in_pixels != page_size_in_pixels) {
 152     page_css_params.page_size = gfx::Size(
 153         ConvertUnit(page_size_in_pixels.width, kPixelsPerInch, dpi),
 154         ConvertUnit(page_size_in_pixels.height, kPixelsPerInch, dpi));
 155   } else {
 156     // Printing frame doesn't have any page size css. Pixels to dpi conversion
 157     // causes rounding off errors. Therefore use the default page size values
 158     // directly.
 159     page_css_params.page_size = page_params.page_size;
 160   }
 161
 162   page_css_params.margin_top =
 163       ConvertUnit(margin_top_in_pixels, kPixelsPerInch, dpi);
 164   page_css_params.margin_left =
 165       ConvertUnit(margin_left_in_pixels, kPixelsPerInch, dpi);
 166   return page_css_params;
 167 }
 168
 169 double FitPrintParamsToPage(const PrintMsg_Print_Params& page_params,
 170                             PrintMsg_Print_Params* params_to_fit) {
 171   double content_width =
 172       static_cast<double>(params_to_fit->content_size.width());
 173   double content_height =
 174       static_cast<double>(params_to_fit->content_size.height());
 175   int default_page_size_height = page_params.page_size.height();
 176   int default_page_size_width = page_params.page_size.width();
 177   int css_page_size_height = params_to_fit->page_size.height();
 178   int css_page_size_width = params_to_fit->page_size.width();
 179
 180   double scale_factor = 1.0f;
 181   if (page_params.page_size == params_to_fit->page_size)
 182     return scale_factor;
 183
 184   if (default_page_size_width < css_page_size_width ||
 185       default_page_size_height < css_page_size_height) {
 186     double ratio_width =
 187         static_cast<double>(default_page_size_width) / css_page_size_width;
 188     double ratio_height =
 189         static_cast<double>(default_page_size_height) / css_page_size_height;
 190     scale_factor = ratio_width < ratio_height ? ratio_width : ratio_height;
 191     content_width *= scale_factor;
 192     content_height *= scale_factor;
 193   }
 194   params_to_fit->margin_top = static_cast<int>(
 195       (default_page_size_height - css_page_size_height * scale_factor) / 2 +
 196       (params_to_fit->margin_top * scale_factor));
 197   params_to_fit->margin_left = static_cast<int>(
 198       (default_page_size_width - css_page_size_width * scale_factor) / 2 +
 199       (params_to_fit->margin_left * scale_factor));
 200   params_to_fit->content_size = gfx::Size(
 201       static_cast<int>(content_width), static_cast<int>(content_height));
 202   params_to_fit->page_size = page_params.page_size;
 203   return scale_factor;
 204 }
 205
 206 void CalculatePageLayoutFromPrintParams(
 207     const PrintMsg_Print_Params& params,
 208     PageSizeMargins* page_layout_in_points) {
 209   int dpi = GetDPI(&params);
 210   int content_width = params.content_size.width();
 211   int content_height = params.content_size.height();
 212
 213   int margin_bottom = params.page_size.height() -
 214                       content_height - params.margin_top;
 215   int margin_right = params.page_size.width() -
 216                       content_width - params.margin_left;
 217
 218   page_layout_in_points->content_width =
 219       ConvertUnit(content_width, dpi, kPointsPerInch);
 220   page_layout_in_points->content_height =
 221       ConvertUnit(content_height, dpi, kPointsPerInch);
 222   page_layout_in_points->margin_top =
 223       ConvertUnit(params.margin_top, dpi, kPointsPerInch);
 224   page_layout_in_points->margin_right =
 225       ConvertUnit(margin_right, dpi, kPointsPerInch);
 226   page_layout_in_points->margin_bottom =
 227       ConvertUnit(margin_bottom, dpi, kPointsPerInch);
 228   page_layout_in_points->margin_left =
 229       ConvertUnit(params.margin_left, dpi, kPointsPerInch);
 230 }
 231
 232 void EnsureOrientationMatches(const PrintMsg_Print_Params& css_params,
 233                               PrintMsg_Print_Params* page_params) {
 234   if ((page_params->page_size.width() > page_params->page_size.height()) ==
 235       (css_params.page_size.width() > css_params.page_size.height())) {
 236     return;
 237   }
 238
 239   // Swap the |width| and |height| values.
 240   page_params->page_size.SetSize(page_params->page_size.height(),
 241                                  page_params->page_size.width());
 242   page_params->content_size.SetSize(page_params->content_size.height(),
 243                                     page_params->content_size.width());
 244   page_params->printable_area.set_size(
 245       gfx::Size(page_params->printable_area.height(),
 246                 page_params->printable_area.width()));
 247 }
 248
 249 void ComputeWebKitPrintParamsInDesiredDpi(
 250     const PrintMsg_Print_Params& print_params,
 251     blink::WebPrintParams* webkit_print_params) {
 252   int dpi = GetDPI(&print_params);
 253   webkit_print_params->printerDPI = dpi;
 254   webkit_print_params->printScalingOption = print_params.print_scaling_option;
 255
 256   webkit_print_params->printContentArea.width =
 257       ConvertUnit(print_params.content_size.width(), dpi,
 258                   print_params.desired_dpi);
 259   webkit_print_params->printContentArea.height =
 260       ConvertUnit(print_params.content_size.height(), dpi,
 261                   print_params.desired_dpi);
 262
 263   webkit_print_params->printableArea.x =
 264       ConvertUnit(print_params.printable_area.x(), dpi,
 265                   print_params.desired_dpi);
 266   webkit_print_params->printableArea.y =
 267       ConvertUnit(print_params.printable_area.y(), dpi,
 268                   print_params.desired_dpi);
 269   webkit_print_params->printableArea.width =
 270       ConvertUnit(print_params.printable_area.width(), dpi,
 271                   print_params.desired_dpi);
 272   webkit_print_params->printableArea.height =
 273       ConvertUnit(print_params.printable_area.height(),
 274                   dpi, print_params.desired_dpi);
 275
 276   webkit_print_params->paperSize.width =
 277       ConvertUnit(print_params.page_size.width(), dpi,
 278                   print_params.desired_dpi);
 279   webkit_print_params->paperSize.height =
 280       ConvertUnit(print_params.page_size.height(), dpi,
 281                   print_params.desired_dpi);
 282 }
 283
 284 blink::WebPlugin* GetPlugin(const blink::WebFrame* frame) {
 285   return frame->document().isPluginDocument() ?
 286          frame->document().to<blink::WebPluginDocument>().plugin() : NULL;
 287 }
 288
 289 bool PrintingNodeOrPdfFrame(const blink::WebFrame* frame,
 290                             const blink::WebNode& node) {
 291   if (!node.isNull())
 292     return true;
 293   blink::WebPlugin* plugin = GetPlugin(frame);
 294   return plugin && plugin->supportsPaginatedPrint();
 295 }
 296
 297 bool PrintingFrameHasPageSizeStyle(blink::WebFrame* frame,
 298                                    int total_page_count) {
 299   if (!frame)
 300     return false;
 301   bool frame_has_custom_page_size_style = false;
 302   for (int i = 0; i < total_page_count; ++i) {
 303     if (frame->hasCustomPageSizeStyle(i)) {
 304       frame_has_custom_page_size_style = true;
 305       break;
 306     }
 307   }
 308   return frame_has_custom_page_size_style;
 309 }
 310
 311 MarginType GetMarginsForPdf(blink::WebFrame* frame,
 312                             const blink::WebNode& node) {
 313   if (frame->isPrintScalingDisabledForPlugin(node))
 314     return NO_MARGINS;
 315   else
 316     return PRINTABLE_AREA_MARGINS;
 317 }
 318
 319 bool FitToPageEnabled(const base::DictionaryValue& job_settings) {
 320   bool fit_to_paper_size = false;
 321   if (!job_settings.GetBoolean(kSettingFitToPageEnabled, &fit_to_paper_size)) {
 322     NOTREACHED();
 323   }
 324   return fit_to_paper_size;
 325 }
 326
 327 // Returns the print scaling option to retain/scale/crop the source page size
 328 // to fit the printable area of the paper.
 329 //
 330 // We retain the source page size when the current destination printer is
 331 // SAVE_AS_PDF.
 332 //
 333 // We crop the source page size to fit the printable area or we print only the
 334 // left top page contents when
 335 // (1) Source is PDF and the user has requested not to fit to printable area
 336 // via |job_settings|.
 337 // (2) Source is PDF. This is the first preview request and print scaling
 338 // option is disabled for initiator renderer plugin.
 339 //
 340 // In all other cases, we scale the source page to fit the printable area.
 341 blink::WebPrintScalingOption GetPrintScalingOption(
 342     blink::WebFrame* frame,
 343     const blink::WebNode& node,
 344     bool source_is_html,
 345     const base::DictionaryValue& job_settings,
 346     const PrintMsg_Print_Params& params) {
 347   if (params.print_to_pdf)
 348     return blink::WebPrintScalingOptionSourceSize;
 349
 350   if (!source_is_html) {
 351     if (!FitToPageEnabled(job_settings))
 352       return blink::WebPrintScalingOptionNone;
 353
 354     bool no_plugin_scaling = frame->isPrintScalingDisabledForPlugin(node);
 355
 356     if (params.is_first_request && no_plugin_scaling)
 357       return blink::WebPrintScalingOptionNone;
 358   }
 359   return blink::WebPrintScalingOptionFitToPrintableArea;
 360 }
 361
 362 PrintMsg_Print_Params CalculatePrintParamsForCss(
 363     blink::WebFrame* frame,
 364     int page_index,
 365     const PrintMsg_Print_Params& page_params,
 366     bool ignore_css_margins,
 367     bool fit_to_page,
 368     double* scale_factor) {
 369   PrintMsg_Print_Params css_params = GetCssPrintParams(frame, page_index,
 370                                                        page_params);
 371
 372   PrintMsg_Print_Params params = page_params;
 373   EnsureOrientationMatches(css_params, &params);
 374
 375   if (ignore_css_margins && fit_to_page)
 376     return params;
 377
 378   PrintMsg_Print_Params result_params = css_params;
 379   if (ignore_css_margins) {
 380     result_params.margin_top = params.margin_top;
 381     result_params.margin_left = params.margin_left;
 382
 383     DCHECK(!fit_to_page);
 384     // Since we are ignoring the margins, the css page size is no longer
 385     // valid.
 386     int default_margin_right = params.page_size.width() -
 387         params.content_size.width() - params.margin_left;
 388     int default_margin_bottom = params.page_size.height() -
 389         params.content_size.height() - params.margin_top;
 390     result_params.content_size = gfx::Size(
 391         result_params.page_size.width() - result_params.margin_left -
 392             default_margin_right,
 393         result_params.page_size.height() - result_params.margin_top -
 394             default_margin_bottom);
 395   }
 396
 397   if (fit_to_page) {
 398     double factor = FitPrintParamsToPage(params, &result_params);
 399     if (scale_factor)
 400       *scale_factor = factor;
 401   }
 402   return result_params;
 403 }
 404
 405 }  // namespace
 406
 407 FrameReference::FrameReference(blink::WebLocalFrame* frame) {
 408   Reset(frame);
 409 }
 410
 411 FrameReference::FrameReference() {
 412   Reset(NULL);
 413 }
 414
 415 FrameReference::~FrameReference() {
 416 }
 417
 418 void FrameReference::Reset(blink::WebLocalFrame* frame) {
 419   if (frame) {
 420     view_ = frame->view();
 421     frame_ = frame;
 422   } else {
 423     view_ = NULL;
 424     frame_ = NULL;
 425   }
 426 }
 427
 428 blink::WebLocalFrame* FrameReference::GetFrame() {
 429   if (view_ == NULL || frame_ == NULL)
 430     return NULL;
 431   for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
 432            frame = frame->traverseNext(false)) {
 433     if (frame == frame_)
 434       return frame_;
 435   }
 436   return NULL;
 437 }
 438
 439 blink::WebView* FrameReference::view() {
 440   return view_;
 441 }
 442
 443 #if defined(ENABLE_PRINT_PREVIEW)
 444 // static - Not anonymous so that platform implementations can use it.
 445 void PrintWebViewHelper::PrintHeaderAndFooter(
 446     blink::WebCanvas* canvas,
 447     int page_number,
 448     int total_pages,
 449     const blink::WebFrame& source_frame,
 450     float webkit_scale_factor,
 451     const PageSizeMargins& page_layout,
 452     const PrintMsg_Print_Params& params) {
 453   SkAutoCanvasRestore auto_restore(canvas, true);
 454   canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);
 455
 456   blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
 457                                page_layout.content_width,
 458                            page_layout.margin_top + page_layout.margin_bottom +
 459                                page_layout.content_height);
 460
 461   blink::WebView* web_view = blink::WebView::create(NULL);
 462   web_view->settings()->setJavaScriptEnabled(true);
 463
 464   blink::WebLocalFrame* frame = blink::WebLocalFrame::create(NULL);
 465   web_view->setMainFrame(frame);
 466
 467   base::StringValue html(ResourceBundle::GetSharedInstance().GetLocalizedString(
 468       IDR_PRINT_PREVIEW_PAGE));
 469   // Load page with script to avoid async operations.
 470   ExecuteScript(frame, kPageLoadScriptFormat, html);
 471
 472   scoped_ptr<base::DictionaryValue> options(new base::DictionaryValue());
 473   options.reset(new base::DictionaryValue());
 474   options->SetDouble(kSettingHeaderFooterDate, base::Time::Now().ToJsTime());
 475   options->SetDouble("width", page_size.width);
 476   options->SetDouble("height", page_size.height);
 477   options->SetDouble("topMargin", page_layout.margin_top);
 478   options->SetDouble("bottomMargin", page_layout.margin_bottom);
 479   options->SetString("pageNumber",
 480                      base::StringPrintf("%d/%d", page_number, total_pages));
 481
 482   // Fallback to initiator URL and title if it's empty for printed frame.
 483   base::string16 url = source_frame.document().url().string();
 484   options->SetString("url", url.empty() ? params.url : url);
 485   base::string16 title = source_frame.document().title();
 486   options->SetString("title", title.empty() ? params.title : title);
 487
 488   ExecuteScript(frame, kPageSetupScriptFormat, *options);
 489
 490   blink::WebPrintParams webkit_params(page_size);
 491   webkit_params.printerDPI = GetDPI(&params);
 492
 493   frame->printBegin(webkit_params);
 494   frame->printPage(0, canvas);
 495   frame->printEnd();
 496
 497   web_view->close();
 498   frame->close();
 499 }
 500 #endif  // defined(ENABLE_PRINT_PREVIEW)
 501
 502 // static - Not anonymous so that platform implementations can use it.
 503 float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
 504                                             int page_number,
 505                                             const gfx::Rect& canvas_area,
 506                                             const gfx::Rect& content_area,
 507                                             double scale_factor,
 508                                             blink::WebCanvas* canvas) {
 509   SkAutoCanvasRestore auto_restore(canvas, true);
 510   canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
 511                     (content_area.y() - canvas_area.y()) / scale_factor);
 512   return frame->printPage(page_number, canvas);
 513 }
 514
 515 // Class that calls the Begin and End print functions on the frame and changes
 516 // the size of the view temporarily to support full page printing..
 517 class PrepareFrameAndViewForPrint : public blink::WebViewClient,
 518                                     public blink::WebFrameClient {
 519  public:
 520   PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
 521                               blink::WebLocalFrame* frame,
 522                               const blink::WebNode& node,
 523                               bool ignore_css_margins);
 524   virtual ~PrepareFrameAndViewForPrint();
 525
 526   // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
 527   // when completed.
 528   void CopySelectionIfNeeded(const WebPreferences& preferences,
 529                              const base::Closure& on_ready);
 530
 531   // Prepares frame for printing.
 532   void StartPrinting();
 533
 534   blink::WebLocalFrame* frame() {
 535     return frame_.GetFrame();
 536   }
 537
 538   const blink::WebNode& node() const {
 539     return node_to_print_;
 540   }
 541
 542   int GetExpectedPageCount() const {
 543     return expected_pages_count_;
 544   }
 545
 546   void FinishPrinting();
 547
 548   bool IsLoadingSelection() {
 549     // It's not selection if not |owns_web_view_|.
 550     return owns_web_view_ && frame() && frame()->isLoading();
 551   }
 552
 553   // TODO(ojan): Remove this override and have this class use a non-null
 554   // layerTreeView.
 555   // blink::WebViewClient override:
 556   virtual bool allowsBrokenNullLayerTreeView() const;
 557
 558  protected:
 559   // blink::WebViewClient override:
 560   virtual void didStopLoading();
 561
 562   // blink::WebFrameClient override:
 563   virtual blink::WebFrame* createChildFrame(
 564       blink::WebLocalFrame* parent,
 565       const blink::WebString& name,
 566       blink::WebSandboxFlags sandboxFlags);
 567   virtual void frameDetached(blink::WebFrame* frame);
 568
 569  private:
 570   void CallOnReady();
 571   void ResizeForPrinting();
 572   void RestoreSize();
 573   void CopySelection(const WebPreferences& preferences);
 574
 575   FrameReference frame_;
 576   blink::WebNode node_to_print_;
 577   bool owns_web_view_;
 578   blink::WebPrintParams web_print_params_;
 579   gfx::Size prev_view_size_;
 580   gfx::Size prev_scroll_offset_;
 581   int expected_pages_count_;
 582   base::Closure on_ready_;
 583   bool should_print_backgrounds_;
 584   bool should_print_selection_only_;
 585   bool is_printing_started_;
 586
 587   base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
 588
 589   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 590 };
 591
 592 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
 593     const PrintMsg_Print_Params& params,
 594     blink::WebLocalFrame* frame,
 595     const blink::WebNode& node,
 596     bool ignore_css_margins)
 597     : frame_(frame),
 598       node_to_print_(node),
 599       owns_web_view_(false),
 600       expected_pages_count_(0),
 601       should_print_backgrounds_(params.should_print_backgrounds),
 602       should_print_selection_only_(params.selection_only),
 603       is_printing_started_(false),
 604       weak_ptr_factory_(this) {
 605   PrintMsg_Print_Params print_params = params;
 606   if (!should_print_selection_only_ ||
 607       !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
 608     bool fit_to_page = ignore_css_margins &&
 609                        print_params.print_scaling_option ==
 610                             blink::WebPrintScalingOptionFitToPrintableArea;
 611     ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
 612     frame->printBegin(web_print_params_, node_to_print_);
 613     print_params = CalculatePrintParamsForCss(frame, 0, print_params,
 614                                               ignore_css_margins, fit_to_page,
 615                                               NULL);
 616     frame->printEnd();
 617   }
 618   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
 619 }
 620
 621 PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
 622   FinishPrinting();
 623 }
 624
 625 void PrepareFrameAndViewForPrint::ResizeForPrinting() {
 626   // Layout page according to printer page size. Since WebKit shrinks the
 627   // size of the page automatically (from 125% to 200%) we trick it to
 628   // think the page is 125% larger so the size of the page is correct for
 629   // minimum (default) scaling.
 630   // This is important for sites that try to fill the page.
 631   gfx::Size print_layout_size(web_print_params_.printContentArea.width,
 632                               web_print_params_.printContentArea.height);
 633   print_layout_size.set_height(
 634       static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
 635
 636   if (!frame())
 637     return;
 638   blink::WebView* web_view = frame_.view();
 639   // Backup size and offset.
 640   if (blink::WebFrame* web_frame = web_view->mainFrame())
 641     prev_scroll_offset_ = web_frame->scrollOffset();
 642   prev_view_size_ = web_view->size();
 643
 644   web_view->resize(print_layout_size);
 645 }
 646
 647
 648 void PrepareFrameAndViewForPrint::StartPrinting() {
 649   ResizeForPrinting();
 650   blink::WebView* web_view = frame_.view();
 651   web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
 652   expected_pages_count_ =
 653       frame()->printBegin(web_print_params_, node_to_print_);
 654   is_printing_started_ = true;
 655 }
 656
 657 void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
 658     const WebPreferences& preferences,
 659     const base::Closure& on_ready) {
 660   on_ready_ = on_ready;
 661   if (should_print_selection_only_) {
 662     CopySelection(preferences);
 663   } else {
 664     // Call immediately, async call crashes scripting printing.
 665     CallOnReady();
 666   }
 667 }
 668
 669 void PrepareFrameAndViewForPrint::CopySelection(
 670     const WebPreferences& preferences) {
 671   ResizeForPrinting();
 672   std::string url_str = "data:text/html;charset=utf-8,";
 673   url_str.append(
 674       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
 675   RestoreSize();
 676   // Create a new WebView with the same settings as the current display one.
 677   // Except that we disable javascript (don't want any active content running
 678   // on the page).
 679   WebPreferences prefs = preferences;
 680   prefs.javascript_enabled = false;
 681   prefs.java_enabled = false;
 682
 683   blink::WebView* web_view = blink::WebView::create(this);
 684   owns_web_view_ = true;
 685   content::RenderView::ApplyWebPreferences(prefs, web_view);
 686   web_view->setMainFrame(blink::WebLocalFrame::create(this));
 687   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
 688   node_to_print_.reset();
 689
 690   // When loading is done this will call didStopLoading() and that will do the
 691   // actual printing.
 692   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
 693 }
 694
 695 bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
 696   return true;
 697 }
 698
 699 void PrepareFrameAndViewForPrint::didStopLoading() {
 700   DCHECK(!on_ready_.is_null());
 701   // Don't call callback here, because it can delete |this| and WebView that is
 702   // called didStopLoading.
 703   base::MessageLoop::current()->PostTask(
 704       FROM_HERE,
 705       base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
 706                  weak_ptr_factory_.GetWeakPtr()));
 707 }
 708
 709 blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
 710     blink::WebLocalFrame* parent,
 711     const blink::WebString& name,
 712     blink::WebSandboxFlags sandboxFlags) {
 713   blink::WebFrame* frame = blink::WebLocalFrame::create(this);
 714   parent->appendChild(frame);
 715   return frame;
 716 }
 717
 718 void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame) {
 719   if (frame->parent())
 720     frame->parent()->removeChild(frame);
 721   frame->close();
 722 }
 723
 724 void PrepareFrameAndViewForPrint::CallOnReady() {
 725   return on_ready_.Run();  // Can delete |this|.
 726 }
 727
 728 void PrepareFrameAndViewForPrint::RestoreSize() {
 729   if (frame()) {
 730     blink::WebView* web_view = frame_.GetFrame()->view();
 731     web_view->resize(prev_view_size_);
 732     if (blink::WebFrame* web_frame = web_view->mainFrame())
 733       web_frame->setScrollOffset(prev_scroll_offset_);
 734   }
 735 }
 736
 737 void PrepareFrameAndViewForPrint::FinishPrinting() {
 738   blink::WebLocalFrame* frame = frame_.GetFrame();
 739   if (frame) {
 740     blink::WebView* web_view = frame->view();
 741     if (is_printing_started_) {
 742       is_printing_started_ = false;
 743       frame->printEnd();
 744       if (!owns_web_view_) {
 745         web_view->settings()->setShouldPrintBackgrounds(false);
 746         RestoreSize();
 747       }
 748     }
 749     if (owns_web_view_) {
 750       DCHECK(!frame->isLoading());
 751       owns_web_view_ = false;
 752       web_view->close();
 753     }
 754   }
 755   frame_.Reset(NULL);
 756   on_ready_.Reset();
 757 }
 758
 759 PrintWebViewHelper::PrintWebViewHelper(
 760     content::RenderView* render_view,
 761     scoped_ptr<Delegate> delegate)
 762     : content::RenderViewObserver(render_view),
 763       content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
 764       reset_prep_frame_view_(false),
 765       is_print_ready_metafile_sent_(false),
 766       ignore_css_margins_(false),
 767       is_scripted_printing_blocked_(false),
 768       notify_browser_of_print_failure_(true),
 769       print_for_preview_(false),
 770       delegate_(delegate.Pass()),
 771       print_node_in_progress_(false),
 772       is_loading_(false),
 773       is_scripted_preview_delayed_(false),
 774       weak_ptr_factory_(this) {
 775   if (!delegate_->IsPrintPreviewEnabled())
 776     DisablePreview();
 777 }
 778
 779 PrintWebViewHelper::~PrintWebViewHelper() {}
 780
 781 // static
 782 void PrintWebViewHelper::DisablePreview() {
 783   g_is_preview_enabled_ = false;
 784 }
 785
 786 bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(
 787     blink::WebFrame* frame, bool user_initiated) {
 788   // If preview is enabled, then the print dialog is tab modal, and the user
 789   // can always close the tab on a mis-behaving page (the system print dialog
 790   // is app modal). If the print was initiated through user action, don't
 791   // throttle. Or, if the command line flag to skip throttling has been set.
 792   return !is_scripted_printing_blocked_ &&
 793          (user_initiated || g_is_preview_enabled_ ||
 794           scripting_throttler_.IsAllowed(frame));
 795 }
 796
 797 void PrintWebViewHelper::DidStartLoading() {
 798   is_loading_ = true;
 799 }
 800
 801 void PrintWebViewHelper::DidStopLoading() {
 802   is_loading_ = false;
 803   if (!on_stop_loading_closure_.is_null()) {
 804     on_stop_loading_closure_.Run();
 805     on_stop_loading_closure_.Reset();
 806   }
 807 }
 808
 809 // Prints |frame| which called window.print().
 810 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
 811                                    bool user_initiated) {
 812   DCHECK(frame);
 813
 814   // Allow Prerendering to cancel this print request if necessary.
 815   if (delegate_->CancelPrerender(render_view(), routing_id()))
 816     return;
 817
 818   if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
 819     return;
 820
 821   if (delegate_->OverridePrint(frame))
 822     return;
 823
 824   if (!g_is_preview_enabled_) {
 825     Print(frame, blink::WebNode(), true);
 826   } else {
 827     print_preview_context_.InitWithFrame(frame);
 828     RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
 829   }
 830 }
 831
 832 bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
 833   bool handled = true;
 834   IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
 835 #if defined(ENABLE_BASIC_PRINTING)
 836     IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
 837     IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
 838 #endif  // ENABLE_BASIC_PRINTING
 839     IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
 840     IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
 841     IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
 842     IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
 843     IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
 844                         SetScriptedPrintBlocked)
 845     IPC_MESSAGE_UNHANDLED(handled = false)
 846     IPC_END_MESSAGE_MAP()
 847   return handled;
 848 }
 849
 850 void PrintWebViewHelper::OnPrintForPrintPreview(
 851     const base::DictionaryValue& job_settings) {
 852   // If still not finished with earlier print request simply ignore.
 853   if (prep_frame_view_)
 854     return;
 855
 856   if (!render_view()->GetWebView())
 857     return;
 858   blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
 859   if (!main_frame)
 860     return;
 861
 862   blink::WebDocument document = main_frame->document();
 863   // <object>/<iframe> with id="pdf-viewer" is created in
 864   // chrome/browser/resources/print_preview/print_preview.js
 865   blink::WebElement pdf_element = document.getElementById("pdf-viewer");
 866   if (pdf_element.isNull()) {
 867     NOTREACHED();
 868     return;
 869   }
 870
 871   // The out-of-process plugin element is nested within a frame. In tests, there
 872   // may not be an iframe containing the out-of-process plugin, so continue with
 873   // the element with ID "pdf-viewer" if it isn't an iframe.
 874   blink::WebLocalFrame* plugin_frame = pdf_element.document().frame();
 875   blink::WebElement plugin_element = pdf_element;
 876   if (delegate_->IsOutOfProcessPdfEnabled() &&
 877         pdf_element.hasHTMLTagName("iframe")) {
 878     plugin_frame = blink::WebLocalFrame::fromFrameOwnerElement(pdf_element);
 879     plugin_element = delegate_->GetPdfElement(plugin_frame);
 880     if (plugin_element.isNull()) {
 881       NOTREACHED();
 882       return;
 883     }
 884   }
 885
 886   // Set |print_for_preview_| flag and autoreset it to back to original
 887   // on return.
 888   base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
 889
 890   if (!UpdatePrintSettings(plugin_frame, plugin_element, job_settings)) {
 891     LOG(ERROR) << "UpdatePrintSettings failed";
 892     DidFinishPrinting(FAIL_PRINT);
 893     return;
 894   }
 895
 896   // Print page onto entire page not just printable area. Preview PDF already
 897   // has content in correct position taking into account page size and printable
 898   // area.
 899   // TODO(vitalybuka) : Make this consistent on all platform. This change
 900   // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
 901   // printable_area. Also we can't change printable_area deeper inside
 902   // RenderPagesForPrint for Windows, because it's used also by native
 903   // printing and it expects real printable_area value.
 904   // See http://crbug.com/123408
 905   PrintMsg_Print_Params& print_params = print_pages_params_->params;
 906   print_params.printable_area = gfx::Rect(print_params.page_size);
 907
 908   // Render Pages for printing.
 909   if (!RenderPagesForPrint(plugin_frame, plugin_element)) {
 910     LOG(ERROR) << "RenderPagesForPrint failed";
 911     DidFinishPrinting(FAIL_PRINT);
 912   }
 913 }
 914
 915 bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
 916   DCHECK(frame);
 917   blink::WebView* webView = render_view()->GetWebView();
 918   DCHECK(webView);
 919   if (!webView)
 920     return false;
 921
 922   // If the user has selected text in the currently focused frame we print
 923   // only that frame (this makes print selection work for multiple frames).
 924   blink::WebLocalFrame* focusedFrame =
 925       webView->focusedFrame()->toWebLocalFrame();
 926   *frame = focusedFrame->hasSelection()
 927                ? focusedFrame
 928                : webView->mainFrame()->toWebLocalFrame();
 929   return true;
 930 }
 931
 932 #if defined(ENABLE_BASIC_PRINTING)
 933 void PrintWebViewHelper::OnPrintPages() {
 934   blink::WebLocalFrame* frame;
 935   if (!GetPrintFrame(&frame))
 936     return;
 937   // If we are printing a PDF extension frame, find the plugin node and print
 938   // that instead.
 939   auto plugin = delegate_->GetPdfElement(frame);
 940   Print(frame, plugin, false);
 941 }
 942
 943 void PrintWebViewHelper::OnPrintForSystemDialog() {
 944   blink::WebLocalFrame* frame = print_preview_context_.source_frame();
 945   if (!frame) {
 946     NOTREACHED();
 947     return;
 948   }
 949   Print(frame, print_preview_context_.source_node(), false);
 950 }
 951 #endif  // ENABLE_BASIC_PRINTING
 952
 953 void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
 954     const PageSizeMargins& page_layout_in_points,
 955     gfx::Size* page_size,
 956     gfx::Rect* content_area) {
 957   *page_size = gfx::Size(
 958       page_layout_in_points.content_width +
 959           page_layout_in_points.margin_right +
 960           page_layout_in_points.margin_left,
 961       page_layout_in_points.content_height +
 962           page_layout_in_points.margin_top +
 963           page_layout_in_points.margin_bottom);
 964   *content_area = gfx::Rect(page_layout_in_points.margin_left,
 965                             page_layout_in_points.margin_top,
 966                             page_layout_in_points.content_width,
 967                             page_layout_in_points.content_height);
 968 }
 969
 970 void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
 971     const base::DictionaryValue& settings) {
 972   int margins_type = 0;
 973   if (!settings.GetInteger(kSettingMarginsType, &margins_type))
 974     margins_type = DEFAULT_MARGINS;
 975   ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
 976 }
 977
 978 bool PrintWebViewHelper::IsPrintToPdfRequested(
 979     const base::DictionaryValue& job_settings) {
 980   bool print_to_pdf = false;
 981   if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
 982     NOTREACHED();
 983   return print_to_pdf;
 984 }
 985
 986 void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
 987   print_preview_context_.OnPrintPreview();
 988
 989   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
 990                             PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
 991
 992   if (!print_preview_context_.source_frame()) {
 993     DidFinishPrinting(FAIL_PREVIEW);
 994     return;
 995   }
 996
 997   if (!UpdatePrintSettings(print_preview_context_.source_frame(),
 998                            print_preview_context_.source_node(), settings)) {
 999     if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
1000       Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
1001           routing_id(),
1002           print_pages_params_ ?
1003               print_pages_params_->params.document_cookie : 0));
1004       notify_browser_of_print_failure_ = false;  // Already sent.
1005     }
1006     DidFinishPrinting(FAIL_PREVIEW);
1007     return;
1008   }
1009
1010   // Set the options from document if we are previewing a pdf and send a
1011   // message to browser.
1012   if (print_pages_params_->params.is_first_request &&
1013       !print_preview_context_.IsModifiable()) {
1014     PrintHostMsg_SetOptionsFromDocument_Params params;
1015     SetOptionsFromDocument(params);
1016     Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), params));
1017   }
1018
1019   is_print_ready_metafile_sent_ = false;
1020
1021   // PDF printer device supports alpha blending.
1022   print_pages_params_->params.supports_alpha_blend = true;
1023
1024   bool generate_draft_pages = false;
1025   if (!settings.GetBoolean(kSettingGenerateDraftData,
1026                            &generate_draft_pages)) {
1027     NOTREACHED();
1028   }
1029   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1030
1031   PrepareFrameForPreviewDocument();
1032 }
1033
1034 void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1035   reset_prep_frame_view_ = false;
1036
1037   if (!print_pages_params_ || CheckForCancel()) {
1038     DidFinishPrinting(FAIL_PREVIEW);
1039     return;
1040   }
1041
1042   // Don't reset loading frame or WebKit will fail assert. Just retry when
1043   // current selection is loaded.
1044   if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1045     reset_prep_frame_view_ = true;
1046     return;
1047   }
1048
1049   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1050   prep_frame_view_.reset(
1051       new PrepareFrameAndViewForPrint(print_params,
1052                                       print_preview_context_.source_frame(),
1053                                       print_preview_context_.source_node(),
1054                                       ignore_css_margins_));
1055   prep_frame_view_->CopySelectionIfNeeded(
1056       render_view()->GetWebkitPreferences(),
1057       base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1058                  base::Unretained(this)));
1059 }
1060
1061 void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1062   if (reset_prep_frame_view_) {
1063     PrepareFrameForPreviewDocument();
1064     return;
1065   }
1066   DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1067 }
1068
1069 bool PrintWebViewHelper::CreatePreviewDocument() {
1070   if (!print_pages_params_ || CheckForCancel())
1071     return false;
1072
1073   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1074                             PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1075
1076   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1077   const std::vector<int>& pages = print_pages_params_->pages;
1078
1079   if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1080                                                     pages)) {
1081     return false;
1082   }
1083
1084   PageSizeMargins default_page_layout;
1085   ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1086                                   print_params, ignore_css_margins_, NULL,
1087                                   &default_page_layout);
1088
1089   bool has_page_size_style = PrintingFrameHasPageSizeStyle(
1090       print_preview_context_.prepared_frame(),
1091       print_preview_context_.total_page_count());
1092   int dpi = GetDPI(&print_params);
1093
1094   gfx::Rect printable_area_in_points(
1095       ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1096       ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1097       ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1098       ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1099
1100   // Margins: Send default page layout to browser process.
1101   Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1102                                                 default_page_layout,
1103                                                 printable_area_in_points,
1104                                                 has_page_size_style));
1105
1106   PrintHostMsg_DidGetPreviewPageCount_Params params;
1107   params.page_count = print_preview_context_.total_page_count();
1108   params.is_modifiable = print_preview_context_.IsModifiable();
1109   params.document_cookie = print_params.document_cookie;
1110   params.preview_request_id = print_params.preview_request_id;
1111   params.clear_preview_data = print_preview_context_.generate_draft_pages();
1112   Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1113   if (CheckForCancel())
1114     return false;
1115
1116   while (!print_preview_context_.IsFinalPageRendered()) {
1117     int page_number = print_preview_context_.GetNextPageNumber();
1118     DCHECK_GE(page_number, 0);
1119     if (!RenderPreviewPage(page_number, print_params))
1120       return false;
1121
1122     if (CheckForCancel())
1123       return false;
1124
1125     // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1126     // print_preview_context_.AllPagesRendered()) before calling
1127     // FinalizePrintReadyDocument() when printing a PDF because the plugin
1128     // code does not generate output until we call FinishPrinting().  We do not
1129     // generate draft pages for PDFs, so IsFinalPageRendered() and
1130     // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1131     // the loop.
1132     if (print_preview_context_.IsFinalPageRendered())
1133       print_preview_context_.AllPagesRendered();
1134
1135     if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1136       DCHECK(print_preview_context_.IsModifiable() ||
1137              print_preview_context_.IsFinalPageRendered());
1138       if (!FinalizePrintReadyDocument())
1139         return false;
1140     }
1141   }
1142   print_preview_context_.Finished();
1143   return true;
1144 }
1145
1146 bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1147   DCHECK(!is_print_ready_metafile_sent_);
1148   print_preview_context_.FinalizePrintReadyDocument();
1149
1150   // Get the size of the resulting metafile.
1151   PdfMetafileSkia* metafile = print_preview_context_.metafile();
1152   uint32 buf_size = metafile->GetDataSize();
1153   DCHECK_GT(buf_size, 0u);
1154
1155   PrintHostMsg_DidPreviewDocument_Params preview_params;
1156   preview_params.data_size = buf_size;
1157   preview_params.document_cookie = print_pages_params_->params.document_cookie;
1158   preview_params.expected_pages_count =
1159       print_preview_context_.total_page_count();
1160   preview_params.modifiable = print_preview_context_.IsModifiable();
1161   preview_params.preview_request_id =
1162       print_pages_params_->params.preview_request_id;
1163
1164   // Ask the browser to create the shared memory for us.
1165   if (!CopyMetafileDataToSharedMem(metafile,
1166                                    &(preview_params.metafile_data_handle))) {
1167     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1168     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1169     return false;
1170   }
1171   is_print_ready_metafile_sent_ = true;
1172
1173   Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1174   return true;
1175 }
1176
1177 void PrintWebViewHelper::OnPrintingDone(bool success) {
1178   notify_browser_of_print_failure_ = false;
1179   if (!success)
1180     LOG(ERROR) << "Failure in OnPrintingDone";
1181   DidFinishPrinting(success ? OK : FAIL_PRINT);
1182 }
1183
1184 void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1185   is_scripted_printing_blocked_ = blocked;
1186 }
1187
1188 void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1189   blink::WebLocalFrame* frame = NULL;
1190   GetPrintFrame(&frame);
1191   DCHECK(frame);
1192   // If we are printing a PDF extension frame, find the plugin node and print
1193   // that instead.
1194   auto plugin = delegate_->GetPdfElement(frame);
1195   if (!plugin.isNull()) {
1196     PrintNode(plugin);
1197     return;
1198   }
1199   print_preview_context_.InitWithFrame(frame);
1200   RequestPrintPreview(selection_only ?
1201                       PRINT_PREVIEW_USER_INITIATED_SELECTION :
1202                       PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1203 }
1204
1205 bool PrintWebViewHelper::IsPrintingEnabled() {
1206   bool result = false;
1207   Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1208   return result;
1209 }
1210
1211 void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1212   if (node.isNull() || !node.document().frame()) {
1213     // This can occur when the context menu refers to an invalid WebNode.
1214     // See http://crbug.com/100890#c17 for a repro case.
1215     return;
1216   }
1217
1218   if (print_node_in_progress_) {
1219     // This can happen as a result of processing sync messages when printing
1220     // from ppapi plugins. It's a rare case, so its OK to just fail here.
1221     // See http://crbug.com/159165.
1222     return;
1223   }
1224
1225   print_node_in_progress_ = true;
1226
1227   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1228   // its |context_menu_node_|.
1229   if (!g_is_preview_enabled_) {
1230     blink::WebNode duplicate_node(node);
1231     Print(duplicate_node.document().frame(), duplicate_node, false);
1232   } else {
1233     print_preview_context_.InitWithNode(node);
1234     RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1235   }
1236
1237   print_node_in_progress_ = false;
1238 }
1239
1240 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1241                                const blink::WebNode& node,
1242                                bool is_scripted) {
1243   // If still not finished with earlier print request simply ignore.
1244   if (prep_frame_view_)
1245     return;
1246
1247   FrameReference frame_ref(frame);
1248
1249   int expected_page_count = 0;
1250   if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1251     DidFinishPrinting(FAIL_PRINT_INIT);
1252     return;  // Failed to init print page settings.
1253   }
1254
1255   // Some full screen plugins can say they don't want to print.
1256   if (!expected_page_count) {
1257     DidFinishPrinting(FAIL_PRINT);
1258     return;
1259   }
1260
1261   // Ask the browser to show UI to retrieve the final print settings.
1262   if (!GetPrintSettingsFromUser(frame_ref.GetFrame(), node,
1263                                 expected_page_count,
1264                                 is_scripted)) {
1265     DidFinishPrinting(OK);  // Release resources and fail silently.
1266     return;
1267   }
1268
1269   // Render Pages for printing.
1270   if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1271     LOG(ERROR) << "RenderPagesForPrint failed";
1272     DidFinishPrinting(FAIL_PRINT);
1273   }
1274   scripting_throttler_.Reset();
1275 }
1276
1277 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1278   switch (result) {
1279     case OK:
1280       break;
1281
1282     case FAIL_PRINT_INIT:
1283       DCHECK(!notify_browser_of_print_failure_);
1284       break;
1285
1286     case FAIL_PRINT:
1287       if (notify_browser_of_print_failure_ && print_pages_params_) {
1288         int cookie = print_pages_params_->params.document_cookie;
1289         Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1290       }
1291       break;
1292
1293     case FAIL_PREVIEW:
1294       int cookie = print_pages_params_ ?
1295           print_pages_params_->params.document_cookie : 0;
1296       if (notify_browser_of_print_failure_) {
1297         LOG(ERROR) << "CreatePreviewDocument failed";
1298         Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1299       } else {
1300         Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1301       }
1302       print_preview_context_.Failed(notify_browser_of_print_failure_);
1303       break;
1304   }
1305   prep_frame_view_.reset();
1306   print_pages_params_.reset();
1307   notify_browser_of_print_failure_ = true;
1308 }
1309
1310 void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1311   PrintPages();
1312   FinishFramePrinting();
1313 }
1314
1315 void PrintWebViewHelper::PrintPages() {
1316   if (!prep_frame_view_)  // Printing is already canceled or failed.
1317     return;
1318   prep_frame_view_->StartPrinting();
1319
1320   int page_count = prep_frame_view_->GetExpectedPageCount();
1321   if (!page_count) {
1322     LOG(ERROR) << "Can't print 0 pages.";
1323     return DidFinishPrinting(FAIL_PRINT);
1324   }
1325
1326   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1327   const PrintMsg_Print_Params& print_params = params.params;
1328
1329 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1330   // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1331   // See http://crbug.com/161576
1332   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1333                                                 print_params.document_cookie,
1334                                                 page_count));
1335 #endif  // !defined(OS_CHROMEOS)
1336
1337   if (print_params.preview_ui_id < 0) {
1338     // Printing for system dialog.
1339     int printed_count = params.pages.empty() ? page_count : params.pages.size();
1340 #if !defined(OS_CHROMEOS)
1341     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1342 #else
1343     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1344                          printed_count);
1345 #endif  // !defined(OS_CHROMEOS)
1346   }
1347
1348
1349   if (!PrintPagesNative(prep_frame_view_->frame(), page_count)) {
1350     LOG(ERROR) << "Printing failed.";
1351     return DidFinishPrinting(FAIL_PRINT);
1352   }
1353 }
1354
1355 void PrintWebViewHelper::FinishFramePrinting() {
1356   prep_frame_view_.reset();
1357 }
1358
1359 #if defined(OS_MACOSX)
1360 bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1361                                           int page_count) {
1362   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1363   const PrintMsg_Print_Params& print_params = params.params;
1364
1365   PrintMsg_PrintPage_Params page_params;
1366   page_params.params = print_params;
1367   if (params.pages.empty()) {
1368     for (int i = 0; i < page_count; ++i) {
1369       page_params.page_number = i;
1370       PrintPageInternal(page_params, frame);
1371     }
1372   } else {
1373     for (size_t i = 0; i < params.pages.size(); ++i) {
1374       if (params.pages[i] >= page_count)
1375         break;
1376       page_params.page_number = params.pages[i];
1377       PrintPageInternal(page_params, frame);
1378     }
1379   }
1380   return true;
1381 }
1382
1383 #endif  // OS_MACOSX
1384
1385 // static - Not anonymous so that platform implementations can use it.
1386 void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1387     blink::WebFrame* frame,
1388     int page_index,
1389     const PrintMsg_Print_Params& page_params,
1390     bool ignore_css_margins,
1391     double* scale_factor,
1392     PageSizeMargins* page_layout_in_points) {
1393   PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1394       frame, page_index, page_params, ignore_css_margins,
1395       page_params.print_scaling_option ==
1396           blink::WebPrintScalingOptionFitToPrintableArea,
1397       scale_factor);
1398   CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1399 }
1400
1401 bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1402   PrintMsg_PrintPages_Params settings;
1403   Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1404                                                 &settings.params));
1405   // Check if the printer returned any settings, if the settings is empty, we
1406   // can safely assume there are no printer drivers configured. So we safely
1407   // terminate.
1408   bool result = true;
1409   if (!PrintMsg_Print_Params_IsValid(settings.params))
1410     result = false;
1411
1412   // Reset to default values.
1413   ignore_css_margins_ = false;
1414   settings.pages.clear();
1415
1416   settings.params.print_scaling_option =
1417       blink::WebPrintScalingOptionSourceSize;
1418   if (fit_to_paper_size) {
1419     settings.params.print_scaling_option =
1420         blink::WebPrintScalingOptionFitToPrintableArea;
1421   }
1422
1423   SetPrintPagesParams(settings);
1424   return result;
1425 }
1426
1427 bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1428                                                 const blink::WebNode& node,
1429                                                 int* number_of_pages) {
1430   DCHECK(frame);
1431   bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1432   if (!InitPrintSettings(fit_to_paper_size)) {
1433     notify_browser_of_print_failure_ = false;
1434     Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1435     return false;
1436   }
1437
1438   const PrintMsg_Print_Params& params = print_pages_params_->params;
1439   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1440   prepare.StartPrinting();
1441
1442   *number_of_pages = prepare.GetExpectedPageCount();
1443   return true;
1444 }
1445
1446 void PrintWebViewHelper::SetOptionsFromDocument(
1447     PrintHostMsg_SetOptionsFromDocument_Params& params) {
1448   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
1449   const blink::WebNode& source_node = print_preview_context_.source_node();
1450
1451   blink::WebPrintPresetOptions preset_options;
1452   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
1453                                                     &preset_options)) {
1454     return;
1455   }
1456
1457   params.is_scaling_disabled = preset_options.isScalingDisabled;
1458   params.copies = preset_options.copies;
1459 }
1460
1461 bool PrintWebViewHelper::UpdatePrintSettings(
1462     blink::WebLocalFrame* frame,
1463     const blink::WebNode& node,
1464     const base::DictionaryValue& passed_job_settings) {
1465   const base::DictionaryValue* job_settings = &passed_job_settings;
1466   base::DictionaryValue modified_job_settings;
1467   if (job_settings->empty()) {
1468     if (!print_for_preview_)
1469       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1470     return false;
1471   }
1472
1473   bool source_is_html = true;
1474   if (print_for_preview_) {
1475     if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1476       NOTREACHED();
1477     }
1478   } else {
1479     source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1480   }
1481
1482   if (print_for_preview_ || !source_is_html) {
1483     modified_job_settings.MergeDictionary(job_settings);
1484     modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1485     modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1486     job_settings = &modified_job_settings;
1487   }
1488
1489   // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1490   // possible.
1491   int cookie = print_pages_params_ ?
1492       print_pages_params_->params.document_cookie : 0;
1493   PrintMsg_PrintPages_Params settings;
1494   bool canceled = false;
1495   Send(new PrintHostMsg_UpdatePrintSettings(
1496       routing_id(), cookie, *job_settings, &settings, &canceled));
1497   if (canceled) {
1498     notify_browser_of_print_failure_ = false;
1499     return false;
1500   }
1501
1502   if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1503     NOTREACHED();
1504     print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1505     return false;
1506   }
1507
1508   if (!print_for_preview_) {
1509     // Validate expected print preview settings.
1510     if (!job_settings->GetInteger(kPreviewRequestID,
1511                                   &settings.params.preview_request_id) ||
1512         !job_settings->GetBoolean(kIsFirstRequest,
1513                                   &settings.params.is_first_request)) {
1514       NOTREACHED();
1515       print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1516       return false;
1517     }
1518
1519     settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1520     UpdateFrameMarginsCssInfo(*job_settings);
1521     settings.params.print_scaling_option = GetPrintScalingOption(
1522         frame, node, source_is_html, *job_settings, settings.params);
1523   }
1524
1525   SetPrintPagesParams(settings);
1526
1527   if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1528     if (!print_for_preview_)
1529       print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1530     else
1531       Send(new PrintHostMsg_ShowInvalidPrinterSettingsError(routing_id()));
1532
1533     return false;
1534   }
1535
1536   return true;
1537 }
1538
1539 bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebFrame* frame,
1540                                                   const blink::WebNode& node,
1541                                                   int expected_pages_count,
1542                                                   bool is_scripted) {
1543   PrintHostMsg_ScriptedPrint_Params params;
1544   PrintMsg_PrintPages_Params print_settings;
1545
1546   params.cookie = print_pages_params_->params.document_cookie;
1547   params.has_selection = frame->hasSelection();
1548   params.expected_pages_count = expected_pages_count;
1549   MarginType margin_type = DEFAULT_MARGINS;
1550   if (PrintingNodeOrPdfFrame(frame, node))
1551     margin_type = GetMarginsForPdf(frame, node);
1552   params.margin_type = margin_type;
1553   params.is_scripted = is_scripted;
1554
1555   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1556
1557   // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1558   // value before and restore it afterwards.
1559   blink::WebPrintScalingOption scaling_option =
1560       print_pages_params_->params.print_scaling_option;
1561
1562   print_pages_params_.reset();
1563   IPC::SyncMessage* msg =
1564       new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1565   msg->EnableMessagePumping();
1566   Send(msg);
1567   print_settings.params.print_scaling_option = scaling_option;
1568   SetPrintPagesParams(print_settings);
1569   return (print_settings.params.dpi && print_settings.params.document_cookie);
1570 }
1571
1572 bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1573                                              const blink::WebNode& node) {
1574   if (!frame || prep_frame_view_)
1575     return false;
1576   const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1577   const PrintMsg_Print_Params& print_params = params.params;
1578   prep_frame_view_.reset(new PrepareFrameAndViewForPrint(
1579       print_params, frame, node, ignore_css_margins_));
1580   DCHECK(!print_pages_params_->params.selection_only ||
1581          print_pages_params_->pages.empty());
1582   prep_frame_view_->CopySelectionIfNeeded(
1583       render_view()->GetWebkitPreferences(),
1584       base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1585                  base::Unretained(this)));
1586   return true;
1587 }
1588
1589 #if defined(OS_POSIX)
1590 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1591     PdfMetafileSkia* metafile,
1592     base::SharedMemoryHandle* shared_mem_handle) {
1593   uint32 buf_size = metafile->GetDataSize();
1594   scoped_ptr<base::SharedMemory> shared_buf(
1595       content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(
1596           buf_size).release());
1597
1598   if (shared_buf) {
1599     if (shared_buf->Map(buf_size)) {
1600       metafile->GetData(shared_buf->memory(), buf_size);
1601       return shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1602                                        shared_mem_handle);
1603     }
1604   }
1605   return false;
1606 }
1607 #endif  // defined(OS_POSIX)
1608
1609 void PrintWebViewHelper::ShowScriptedPrintPreview() {
1610   if (is_scripted_preview_delayed_) {
1611     is_scripted_preview_delayed_ = false;
1612     Send(new PrintHostMsg_ShowScriptedPrintPreview(routing_id(),
1613             print_preview_context_.IsModifiable()));
1614   }
1615 }
1616
1617 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1618   const bool is_modifiable = print_preview_context_.IsModifiable();
1619   const bool has_selection = print_preview_context_.HasSelection();
1620   PrintHostMsg_RequestPrintPreview_Params params;
1621   params.is_modifiable = is_modifiable;
1622   params.has_selection = has_selection;
1623   switch (type) {
1624     case PRINT_PREVIEW_SCRIPTED: {
1625       // Shows scripted print preview in two stages.
1626       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1627       //    pumping messages here.
1628       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1629       //    document has been loaded.
1630       is_scripted_preview_delayed_ = true;
1631       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1632         // Wait for DidStopLoading. Plugins may not know the correct
1633         // |is_modifiable| value until they are fully loaded, which occurs when
1634         // DidStopLoading() is called. Defer showing the preview until then.
1635         on_stop_loading_closure_ =
1636             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1637                        base::Unretained(this));
1638       } else {
1639         base::MessageLoop::current()->PostTask(
1640             FROM_HERE,
1641             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1642                        weak_ptr_factory_.GetWeakPtr()));
1643       }
1644       IPC::SyncMessage* msg =
1645           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1646       msg->EnableMessagePumping();
1647       Send(msg);
1648       is_scripted_preview_delayed_ = false;
1649       return;
1650     }
1651     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1652       // Wait for DidStopLoading. Continuing with this function while
1653       // |is_loading_| is true will cause print preview to hang when try to
1654       // print a PDF document.
1655       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1656         on_stop_loading_closure_ =
1657             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1658                        base::Unretained(this),
1659                        type);
1660         return;
1661       }
1662
1663       break;
1664     }
1665     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1666       DCHECK(has_selection);
1667       DCHECK(!GetPlugin(print_preview_context_.source_frame()));
1668       params.selection_only = has_selection;
1669       break;
1670     }
1671     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1672       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1673         on_stop_loading_closure_ =
1674             base::Bind(&PrintWebViewHelper::RequestPrintPreview,
1675                        base::Unretained(this),
1676                        type);
1677         return;
1678       }
1679
1680       params.webnode_only = true;
1681       break;
1682     }
1683     default: {
1684       NOTREACHED();
1685       return;
1686     }
1687   }
1688   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1689 }
1690
1691 bool PrintWebViewHelper::CheckForCancel() {
1692   const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1693   bool cancel = false;
1694   Send(new PrintHostMsg_CheckForCancel(routing_id(),
1695                                        print_params.preview_ui_id,
1696                                        print_params.preview_request_id,
1697                                        &cancel));
1698   if (cancel)
1699     notify_browser_of_print_failure_ = false;
1700   return cancel;
1701 }
1702
1703 bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1704                                              PdfMetafileSkia* metafile) {
1705   DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1706
1707   // For non-modifiable files, |metafile| should be NULL, so do not bother
1708   // sending a message. If we don't generate draft metafiles, |metafile| is
1709   // NULL.
1710   if (!print_preview_context_.IsModifiable() ||
1711       !print_preview_context_.generate_draft_pages()) {
1712     DCHECK(!metafile);
1713     return true;
1714   }
1715
1716   if (!metafile) {
1717     NOTREACHED();
1718     print_preview_context_.set_error(
1719         PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1720     return false;
1721   }
1722
1723   PrintHostMsg_DidPreviewPage_Params preview_page_params;
1724   // Get the size of the resulting metafile.
1725   uint32 buf_size = metafile->GetDataSize();
1726   DCHECK_GT(buf_size, 0u);
1727   if (!CopyMetafileDataToSharedMem(
1728       metafile, &(preview_page_params.metafile_data_handle))) {
1729     LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1730     print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1731     return false;
1732   }
1733   preview_page_params.data_size = buf_size;
1734   preview_page_params.page_number = page_number;
1735   preview_page_params.preview_request_id =
1736       print_pages_params_->params.preview_request_id;
1737
1738   Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1739   return true;
1740 }
1741
1742 PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1743     : total_page_count_(0),
1744       current_page_index_(0),
1745       generate_draft_pages_(true),
1746       print_ready_metafile_page_count_(0),
1747       error_(PREVIEW_ERROR_NONE),
1748       state_(UNINITIALIZED) {
1749 }
1750
1751 PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1752 }
1753
1754 void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1755     blink::WebLocalFrame* web_frame) {
1756   DCHECK(web_frame);
1757   DCHECK(!IsRendering());
1758   state_ = INITIALIZED;
1759   source_frame_.Reset(web_frame);
1760   source_node_.reset();
1761 }
1762
1763 void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1764     const blink::WebNode& web_node) {
1765   DCHECK(!web_node.isNull());
1766   DCHECK(web_node.document().frame());
1767   DCHECK(!IsRendering());
1768   state_ = INITIALIZED;
1769   source_frame_.Reset(web_node.document().frame());
1770   source_node_ = web_node;
1771 }
1772
1773 void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1774   DCHECK_EQ(INITIALIZED, state_);
1775   ClearContext();
1776 }
1777
1778 bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1779     PrepareFrameAndViewForPrint* prepared_frame,
1780     const std::vector<int>& pages) {
1781   DCHECK_EQ(INITIALIZED, state_);
1782   state_ = RENDERING;
1783
1784   // Need to make sure old object gets destroyed first.
1785   prep_frame_view_.reset(prepared_frame);
1786   prep_frame_view_->StartPrinting();
1787
1788   total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1789   if (total_page_count_ == 0) {
1790     LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1791     set_error(PREVIEW_ERROR_ZERO_PAGES);
1792     return false;
1793   }
1794
1795   metafile_.reset(new PdfMetafileSkia);
1796   if (!metafile_->Init()) {
1797     set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1798     LOG(ERROR) << "PdfMetafileSkia Init failed";
1799     return false;
1800   }
1801
1802   current_page_index_ = 0;
1803   pages_to_render_ = pages;
1804   // Sort and make unique.
1805   std::sort(pages_to_render_.begin(), pages_to_render_.end());
1806   pages_to_render_.resize(std::unique(pages_to_render_.begin(),
1807                                       pages_to_render_.end()) -
1808                           pages_to_render_.begin());
1809   // Remove invalid pages.
1810   pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1811                                            pages_to_render_.end(),
1812                                            total_page_count_) -
1813                           pages_to_render_.begin());
1814   print_ready_metafile_page_count_ = pages_to_render_.size();
1815   if (pages_to_render_.empty()) {
1816     print_ready_metafile_page_count_ = total_page_count_;
1817     // Render all pages.
1818     for (int i = 0; i < total_page_count_; ++i)
1819       pages_to_render_.push_back(i);
1820   } else if (generate_draft_pages_) {
1821     int pages_index = 0;
1822     for (int i = 0; i < total_page_count_; ++i) {
1823       if (pages_index < print_ready_metafile_page_count_ &&
1824           i == pages_to_render_[pages_index]) {
1825         pages_index++;
1826         continue;
1827       }
1828       pages_to_render_.push_back(i);
1829     }
1830   }
1831
1832   document_render_time_ = base::TimeDelta();
1833   begin_time_ = base::TimeTicks::Now();
1834
1835   return true;
1836 }
1837
1838 void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1839     const base::TimeDelta& page_time) {
1840   DCHECK_EQ(RENDERING, state_);
1841   document_render_time_ += page_time;
1842   UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1843 }
1844
1845 void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1846   DCHECK_EQ(RENDERING, state_);
1847   state_ = DONE;
1848   prep_frame_view_->FinishPrinting();
1849 }
1850
1851 void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1852   DCHECK(IsRendering());
1853
1854   base::TimeTicks begin_time = base::TimeTicks::Now();
1855   metafile_->FinishDocument();
1856
1857   if (print_ready_metafile_page_count_ <= 0) {
1858     NOTREACHED();
1859     return;
1860   }
1861
1862   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1863                              document_render_time_);
1864   base::TimeDelta total_time = (base::TimeTicks::Now() - begin_time) +
1865                                document_render_time_;
1866   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1867                              total_time);
1868   UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1869                              total_time / pages_to_render_.size());
1870 }
1871
1872 void PrintWebViewHelper::PrintPreviewContext::Finished() {
1873   DCHECK_EQ(DONE, state_);
1874   state_ = INITIALIZED;
1875   ClearContext();
1876 }
1877
1878 void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1879   DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1880   state_ = INITIALIZED;
1881   if (report_error) {
1882     DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1883     UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1884                               PREVIEW_ERROR_LAST_ENUM);
1885   }
1886   ClearContext();
1887 }
1888
1889 int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1890   DCHECK_EQ(RENDERING, state_);
1891   if (IsFinalPageRendered())
1892     return -1;
1893   return pages_to_render_[current_page_index_++];
1894 }
1895
1896 bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1897   return state_ == RENDERING || state_ == DONE;
1898 }
1899
1900 bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1901   // The only kind of node we can print right now is a PDF node.
1902   return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1903 }
1904
1905 bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1906   return IsModifiable() && source_frame()->hasSelection();
1907 }
1908
1909 bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1910     const {
1911   DCHECK(IsRendering());
1912   return current_page_index_ == print_ready_metafile_page_count_;
1913 }
1914
1915 bool  PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1916   DCHECK(IsRendering());
1917   return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1918 }
1919
1920 void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1921     bool generate_draft_pages) {
1922   DCHECK_EQ(INITIALIZED, state_);
1923   generate_draft_pages_ = generate_draft_pages;
1924 }
1925
1926 void PrintWebViewHelper::PrintPreviewContext::set_error(
1927     enum PrintPreviewErrorBuckets error) {
1928   error_ = error;
1929 }
1930
1931 blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
1932   DCHECK(state_ != UNINITIALIZED);
1933   return source_frame_.GetFrame();
1934 }
1935
1936 const blink::WebNode&
1937     PrintWebViewHelper::PrintPreviewContext::source_node() const {
1938   DCHECK(state_ != UNINITIALIZED);
1939   return source_node_;
1940 }
1941
1942 blink::WebLocalFrame*
1943 PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
1944   DCHECK(state_ != UNINITIALIZED);
1945   return prep_frame_view_->frame();
1946 }
1947
1948 const blink::WebNode&
1949     PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
1950   DCHECK(state_ != UNINITIALIZED);
1951   return prep_frame_view_->node();
1952 }
1953
1954 int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
1955   DCHECK(state_ != UNINITIALIZED);
1956   return total_page_count_;
1957 }
1958
1959 bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
1960   return generate_draft_pages_;
1961 }
1962
1963 PdfMetafileSkia* PrintWebViewHelper::PrintPreviewContext::metafile() {
1964   DCHECK(IsRendering());
1965   return metafile_.get();
1966 }
1967
1968 int PrintWebViewHelper::PrintPreviewContext::last_error() const {
1969   return error_;
1970 }
1971
1972 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
1973   prep_frame_view_.reset();
1974   metafile_.reset();
1975   pages_to_render_.clear();
1976   error_ = PREVIEW_ERROR_NONE;
1977 }
1978
1979 void PrintWebViewHelper::SetPrintPagesParams(
1980     const PrintMsg_PrintPages_Params& settings) {
1981   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
1982   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
1983                                              settings.params.document_cookie));
1984 }
1985
1986 PrintWebViewHelper::ScriptingThrottler::ScriptingThrottler() : count_(0) {
1987 }
1988
1989 bool PrintWebViewHelper::ScriptingThrottler::IsAllowed(blink::WebFrame* frame) {
1990   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
1991   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
1992   bool too_frequent = false;
1993
1994   // Check if there is script repeatedly trying to print and ignore it if too
1995   // frequent.  The first 3 times, we use a constant wait time, but if this
1996   // gets excessive, we switch to exponential wait time. So for a page that
1997   // calls print() in a loop the user will need to cancel the print dialog
1998   // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
1999   // This gives the user time to navigate from the page.
2000   if (count_ > 0) {
2001     base::TimeDelta diff = base::Time::Now() - last_print_;
2002     int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
2003     if (count_ > 3) {
2004       min_wait_seconds =
2005           std::min(kMinSecondsToIgnoreJavascriptInitiatedPrint << (count_ - 3),
2006                    kMaxSecondsToIgnoreJavascriptInitiatedPrint);
2007     }
2008     if (diff.InSeconds() < min_wait_seconds) {
2009       too_frequent = true;
2010     }
2011   }
2012
2013   if (!too_frequent) {
2014     ++count_;
2015     last_print_ = base::Time::Now();
2016     return true;
2017   }
2018
2019   blink::WebString message(
2020       blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
2021   frame->addMessageToConsole(blink::WebConsoleMessage(
2022       blink::WebConsoleMessage::LevelWarning, message));
2023   return false;
2024 }
2025
2026 void PrintWebViewHelper::ScriptingThrottler::Reset() {
2027   // Reset counter on successful print.
2028   count_ = 0;
2029 }
2030
2031 }  // namespace printing