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