1// Copyright 2013 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// TODO(sgurun) copied from chrome/renderer. Remove after crbug.com/322276
6
7#include "android_webview/renderer/print_web_view_helper.h"
8
9#include <string>
10
11#include "android_webview/common/print_messages.h"
12#include "base/auto_reset.h"
13#include "base/command_line.h"
14#include "base/json/json_writer.h"
15#include "base/logging.h"
16#include "base/message_loop/message_loop.h"
17#include "base/metrics/histogram.h"
18#include "base/process/process_handle.h"
19#include "base/strings/string_number_conversions.h"
20#include "base/strings/stringprintf.h"
21#include "base/strings/utf_string_conversions.h"
22#include "content/public/renderer/render_thread.h"
23#include "content/public/renderer/render_view.h"
24#include "content/public/renderer/web_preferences.h"
25#include "net/base/escape.h"
26#include "printing/metafile.h"
27#include "printing/metafile_impl.h"
28#include "printing/units.h"
29#include "skia/ext/vector_platform_device_skia.h"
30#include "third_party/WebKit/public/platform/WebSize.h"
31#include "third_party/WebKit/public/platform/WebURLRequest.h"
32#include "third_party/WebKit/public/web/WebConsoleMessage.h"
33#include "third_party/WebKit/public/web/WebDocument.h"
34#include "third_party/WebKit/public/web/WebElement.h"
35#include "third_party/WebKit/public/web/WebFrameClient.h"
36#include "third_party/WebKit/public/web/WebLocalFrame.h"
37#include "third_party/WebKit/public/web/WebPlugin.h"
38#include "third_party/WebKit/public/web/WebPluginDocument.h"
39#include "third_party/WebKit/public/web/WebPrintParams.h"
40#include "third_party/WebKit/public/web/WebPrintScalingOption.h"
41#include "third_party/WebKit/public/web/WebScriptSource.h"
42#include "third_party/WebKit/public/web/WebSettings.h"
43#include "third_party/WebKit/public/web/WebView.h"
44#include "third_party/WebKit/public/web/WebViewClient.h"
45#include "ui/base/l10n/l10n_util.h"
46#include "ui/base/resource/resource_bundle.h"
47#include "webkit/common/webpreferences.h"
48
49// This code is copied from chrome/renderer/printing. Code is slightly
50// modified to run it with webview, and the modifications are marked
51// using OS_ANDROID.
52// TODO(sgurun): remove the code as part of componentization of printing.
53
54namespace printing {
55
56namespace {
57
58enum PrintPreviewHelperEvents {
59  PREVIEW_EVENT_REQUESTED,
60  PREVIEW_EVENT_CACHE_HIT,  // Unused
61  PREVIEW_EVENT_CREATE_DOCUMENT,
62  PREVIEW_EVENT_NEW_SETTINGS,  // Unused
63  PREVIEW_EVENT_MAX,
64};
65
66const double kMinDpi = 1.0;
67
68#if 0
69// TODO(sgurun) android_webview hack
70const char kPageLoadScriptFormat[] =
71    "document.open(); document.write(%s); document.close();";
72
73const char kPageSetupScriptFormat[] = "setup(%s);";
74
75void ExecuteScript(blink::WebFrame* frame,
76                   const char* script_format,
77                   const base::Value& parameters) {
78  std::string json;
79  base::JSONWriter::Write(&parameters, &json);
80  std::string script = base::StringPrintf(script_format, json.c_str());
81  frame->executeScript(blink::WebString(base::UTF8ToUTF16(script)));
82}
83#endif
84
85int GetDPI(const PrintMsg_Print_Params* print_params) {
86#if defined(OS_MACOSX)
87  // On the Mac, the printable area is in points, don't do any scaling based
88  // on dpi.
89  return kPointsPerInch;
90#else
91  return static_cast<int>(print_params->dpi);
92#endif  // defined(OS_MACOSX)
93}
94
95bool PrintMsg_Print_Params_IsValid(const PrintMsg_Print_Params& params) {
96  return !params.content_size.IsEmpty() && !params.page_size.IsEmpty() &&
97         !params.printable_area.IsEmpty() && params.document_cookie &&
98         params.desired_dpi && params.max_shrink && params.min_shrink &&
99         params.dpi && (params.margin_top >= 0) && (params.margin_left >= 0);
100}
101
102PrintMsg_Print_Params GetCssPrintParams(
103    blink::WebFrame* frame,
104    int page_index,
105    const PrintMsg_Print_Params& page_params) {
106  PrintMsg_Print_Params page_css_params = page_params;
107  int dpi = GetDPI(&page_params);
108
109  blink::WebSize page_size_in_pixels(
110      ConvertUnit(page_params.page_size.width(), dpi, kPixelsPerInch),
111      ConvertUnit(page_params.page_size.height(), dpi, kPixelsPerInch));
112  int margin_top_in_pixels =
113      ConvertUnit(page_params.margin_top, dpi, kPixelsPerInch);
114  int margin_right_in_pixels = ConvertUnit(
115      page_params.page_size.width() -
116      page_params.content_size.width() - page_params.margin_left,
117      dpi, kPixelsPerInch);
118  int margin_bottom_in_pixels = ConvertUnit(
119      page_params.page_size.height() -
120      page_params.content_size.height() - page_params.margin_top,
121      dpi, kPixelsPerInch);
122  int margin_left_in_pixels = ConvertUnit(
123      page_params.margin_left,
124      dpi, kPixelsPerInch);
125
126  blink::WebSize original_page_size_in_pixels = page_size_in_pixels;
127
128  if (frame) {
129    frame->pageSizeAndMarginsInPixels(page_index,
130                                      page_size_in_pixels,
131                                      margin_top_in_pixels,
132                                      margin_right_in_pixels,
133                                      margin_bottom_in_pixels,
134                                      margin_left_in_pixels);
135  }
136
137  int new_content_width = page_size_in_pixels.width -
138                          margin_left_in_pixels - margin_right_in_pixels;
139  int new_content_height = page_size_in_pixels.height -
140                           margin_top_in_pixels - margin_bottom_in_pixels;
141
142  // Invalid page size and/or margins. We just use the default setting.
143  if (new_content_width < 1 || new_content_height < 1) {
144    CHECK(frame != NULL);
145    page_css_params = GetCssPrintParams(NULL, page_index, page_params);
146    return page_css_params;
147  }
148
149  page_css_params.content_size = gfx::Size(
150      ConvertUnit(new_content_width, kPixelsPerInch, dpi),
151      ConvertUnit(new_content_height, kPixelsPerInch, dpi));
152
153  if (original_page_size_in_pixels != page_size_in_pixels) {
154    page_css_params.page_size = gfx::Size(
155        ConvertUnit(page_size_in_pixels.width, kPixelsPerInch, dpi),
156        ConvertUnit(page_size_in_pixels.height, kPixelsPerInch, dpi));
157  } else {
158    // Printing frame doesn't have any page size css. Pixels to dpi conversion
159    // causes rounding off errors. Therefore use the default page size values
160    // directly.
161    page_css_params.page_size = page_params.page_size;
162  }
163
164  page_css_params.margin_top =
165      ConvertUnit(margin_top_in_pixels, kPixelsPerInch, dpi);
166  page_css_params.margin_left =
167      ConvertUnit(margin_left_in_pixels, kPixelsPerInch, dpi);
168  return page_css_params;
169}
170
171double FitPrintParamsToPage(const PrintMsg_Print_Params& page_params,
172                            PrintMsg_Print_Params* params_to_fit) {
173  double content_width =
174      static_cast<double>(params_to_fit->content_size.width());
175  double content_height =
176      static_cast<double>(params_to_fit->content_size.height());
177  int default_page_size_height = page_params.page_size.height();
178  int default_page_size_width = page_params.page_size.width();
179  int css_page_size_height = params_to_fit->page_size.height();
180  int css_page_size_width = params_to_fit->page_size.width();
181
182  double scale_factor = 1.0f;
183  if (page_params.page_size == params_to_fit->page_size)
184    return scale_factor;
185
186  if (default_page_size_width < css_page_size_width ||
187      default_page_size_height < css_page_size_height) {
188    double ratio_width =
189        static_cast<double>(default_page_size_width) / css_page_size_width;
190    double ratio_height =
191        static_cast<double>(default_page_size_height) / css_page_size_height;
192    scale_factor = ratio_width < ratio_height ? ratio_width : ratio_height;
193    content_width *= scale_factor;
194    content_height *= scale_factor;
195  }
196  params_to_fit->margin_top = static_cast<int>(
197      (default_page_size_height - css_page_size_height * scale_factor) / 2 +
198      (params_to_fit->margin_top * scale_factor));
199  params_to_fit->margin_left = static_cast<int>(
200      (default_page_size_width - css_page_size_width * scale_factor) / 2 +
201      (params_to_fit->margin_left * scale_factor));
202  params_to_fit->content_size = gfx::Size(
203      static_cast<int>(content_width), static_cast<int>(content_height));
204  params_to_fit->page_size = page_params.page_size;
205  return scale_factor;
206}
207
208void CalculatePageLayoutFromPrintParams(
209    const PrintMsg_Print_Params& params,
210    PageSizeMargins* page_layout_in_points) {
211  int dpi = GetDPI(&params);
212  int content_width = params.content_size.width();
213  int content_height = params.content_size.height();
214
215  int margin_bottom = params.page_size.height() -
216                      content_height - params.margin_top;
217  int margin_right = params.page_size.width() -
218                      content_width - params.margin_left;
219
220  page_layout_in_points->content_width =
221      ConvertUnit(content_width, dpi, kPointsPerInch);
222  page_layout_in_points->content_height =
223      ConvertUnit(content_height, dpi, kPointsPerInch);
224  page_layout_in_points->margin_top =
225      ConvertUnit(params.margin_top, dpi, kPointsPerInch);
226  page_layout_in_points->margin_right =
227      ConvertUnit(margin_right, dpi, kPointsPerInch);
228  page_layout_in_points->margin_bottom =
229      ConvertUnit(margin_bottom, dpi, kPointsPerInch);
230  page_layout_in_points->margin_left =
231      ConvertUnit(params.margin_left, dpi, kPointsPerInch);
232}
233
234void EnsureOrientationMatches(const PrintMsg_Print_Params& css_params,
235                              PrintMsg_Print_Params* page_params) {
236  if ((page_params->page_size.width() > page_params->page_size.height()) ==
237      (css_params.page_size.width() > css_params.page_size.height())) {
238    return;
239  }
240
241  // Swap the |width| and |height| values.
242  page_params->page_size.SetSize(page_params->page_size.height(),
243                                 page_params->page_size.width());
244  page_params->content_size.SetSize(page_params->content_size.height(),
245                                    page_params->content_size.width());
246  page_params->printable_area.set_size(
247      gfx::Size(page_params->printable_area.height(),
248                page_params->printable_area.width()));
249}
250
251void ComputeWebKitPrintParamsInDesiredDpi(
252    const PrintMsg_Print_Params& print_params,
253    blink::WebPrintParams* webkit_print_params) {
254  int dpi = GetDPI(&print_params);
255  webkit_print_params->printerDPI = dpi;
256  webkit_print_params->printScalingOption = print_params.print_scaling_option;
257
258  webkit_print_params->printContentArea.width =
259      ConvertUnit(print_params.content_size.width(), dpi,
260                  print_params.desired_dpi);
261  webkit_print_params->printContentArea.height =
262      ConvertUnit(print_params.content_size.height(), dpi,
263                  print_params.desired_dpi);
264
265  webkit_print_params->printableArea.x =
266      ConvertUnit(print_params.printable_area.x(), dpi,
267                  print_params.desired_dpi);
268  webkit_print_params->printableArea.y =
269      ConvertUnit(print_params.printable_area.y(), dpi,
270                  print_params.desired_dpi);
271  webkit_print_params->printableArea.width =
272      ConvertUnit(print_params.printable_area.width(), dpi,
273                  print_params.desired_dpi);
274  webkit_print_params->printableArea.height =
275      ConvertUnit(print_params.printable_area.height(),
276                  dpi, print_params.desired_dpi);
277
278  webkit_print_params->paperSize.width =
279      ConvertUnit(print_params.page_size.width(), dpi,
280                  print_params.desired_dpi);
281  webkit_print_params->paperSize.height =
282      ConvertUnit(print_params.page_size.height(), dpi,
283                  print_params.desired_dpi);
284}
285
286blink::WebPlugin* GetPlugin(const blink::WebFrame* frame) {
287  return frame->document().isPluginDocument() ?
288         frame->document().to<blink::WebPluginDocument>().plugin() : NULL;
289}
290
291bool PrintingNodeOrPdfFrame(const blink::WebFrame* frame,
292                            const blink::WebNode& node) {
293  if (!node.isNull())
294    return true;
295  blink::WebPlugin* plugin = GetPlugin(frame);
296  return plugin && plugin->supportsPaginatedPrint();
297}
298
299bool PrintingFrameHasPageSizeStyle(blink::WebFrame* frame,
300                                   int total_page_count) {
301  if (!frame)
302    return false;
303  bool frame_has_custom_page_size_style = false;
304  for (int i = 0; i < total_page_count; ++i) {
305    if (frame->hasCustomPageSizeStyle(i)) {
306      frame_has_custom_page_size_style = true;
307      break;
308    }
309  }
310  return frame_has_custom_page_size_style;
311}
312
313MarginType GetMarginsForPdf(blink::WebFrame* frame,
314                            const blink::WebNode& node) {
315  if (frame->isPrintScalingDisabledForPlugin(node))
316    return NO_MARGINS;
317  else
318    return PRINTABLE_AREA_MARGINS;
319}
320
321bool FitToPageEnabled(const base::DictionaryValue& job_settings) {
322  bool fit_to_paper_size = false;
323  if (!job_settings.GetBoolean(kSettingFitToPageEnabled, &fit_to_paper_size)) {
324    NOTREACHED();
325  }
326  return fit_to_paper_size;
327}
328
329PrintMsg_Print_Params CalculatePrintParamsForCss(
330    blink::WebFrame* frame,
331    int page_index,
332    const PrintMsg_Print_Params& page_params,
333    bool ignore_css_margins,
334    bool fit_to_page,
335    double* scale_factor) {
336  PrintMsg_Print_Params css_params = GetCssPrintParams(frame, page_index,
337                                                       page_params);
338
339  PrintMsg_Print_Params params = page_params;
340  EnsureOrientationMatches(css_params, &params);
341
342  if (ignore_css_margins && fit_to_page)
343    return params;
344
345  PrintMsg_Print_Params result_params = css_params;
346  if (ignore_css_margins) {
347    result_params.margin_top = params.margin_top;
348    result_params.margin_left = params.margin_left;
349
350    DCHECK(!fit_to_page);
351    // Since we are ignoring the margins, the css page size is no longer
352    // valid.
353    int default_margin_right = params.page_size.width() -
354        params.content_size.width() - params.margin_left;
355    int default_margin_bottom = params.page_size.height() -
356        params.content_size.height() - params.margin_top;
357    result_params.content_size = gfx::Size(
358        result_params.page_size.width() - result_params.margin_left -
359            default_margin_right,
360        result_params.page_size.height() - result_params.margin_top -
361            default_margin_bottom);
362  }
363
364  if (fit_to_page) {
365    double factor = FitPrintParamsToPage(params, &result_params);
366    if (scale_factor)
367      *scale_factor = factor;
368  }
369  return result_params;
370}
371
372bool IsPrintPreviewEnabled() {
373  return false;
374}
375
376bool IsPrintThrottlingDisabled() {
377  return true;
378}
379
380}  // namespace
381
382FrameReference::FrameReference(blink::WebLocalFrame* frame) {
383  Reset(frame);
384}
385
386FrameReference::FrameReference() {
387  Reset(NULL);
388}
389
390FrameReference::~FrameReference() {
391}
392
393void FrameReference::Reset(blink::WebLocalFrame* frame) {
394  if (frame) {
395    view_ = frame->view();
396    frame_ = frame;
397  } else {
398    view_ = NULL;
399    frame_ = NULL;
400  }
401}
402
403blink::WebLocalFrame* FrameReference::GetFrame() {
404  if (view_ == NULL || frame_ == NULL)
405    return NULL;
406  for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
407           frame = frame->traverseNext(false)) {
408    if (frame == frame_)
409      return frame_;
410  }
411  return NULL;
412}
413
414blink::WebView* FrameReference::view() {
415  return view_;
416}
417
418// static - Not anonymous so that platform implementations can use it.
419void PrintWebViewHelper::PrintHeaderAndFooter(
420    blink::WebCanvas* canvas,
421    int page_number,
422    int total_pages,
423    float webkit_scale_factor,
424    const PageSizeMargins& page_layout,
425    const base::DictionaryValue& header_footer_info,
426    const PrintMsg_Print_Params& params) {
427#if 0
428  // TODO(sgurun) android_webview hack
429  skia::VectorPlatformDeviceSkia* device =
430      static_cast<skia::VectorPlatformDeviceSkia*>(canvas->getTopDevice());
431  device->setDrawingArea(SkPDFDevice::kMargin_DrawingArea);
432
433  SkAutoCanvasRestore auto_restore(canvas, true);
434  canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);
435
436  blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
437                            page_layout.content_width,
438                            page_layout.margin_top + page_layout.margin_bottom +
439                            page_layout.content_height);
440
441  blink::WebView* web_view = blink::WebView::create(NULL);
442  web_view->settings()->setJavaScriptEnabled(true);
443  blink::WebFrame* frame = blink::WebLocalFrame::create(NULL)
444  web_view->setMainFrame(web_frame);
445
446  base::StringValue html(
447      ResourceBundle::GetSharedInstance().GetLocalizedString(
448          IDR_PRINT_PREVIEW_PAGE));
449  // Load page with script to avoid async operations.
450  ExecuteScript(frame, kPageLoadScriptFormat, html);
451
452  scoped_ptr<base::DictionaryValue> options(header_footer_info.DeepCopy());
453  options->SetDouble("width", page_size.width);
454  options->SetDouble("height", page_size.height);
455  options->SetDouble("topMargin", page_layout.margin_top);
456  options->SetDouble("bottomMargin", page_layout.margin_bottom);
457  options->SetString("pageNumber",
458                     base::StringPrintf("%d/%d", page_number, total_pages));
459
460  ExecuteScript(frame, kPageSetupScriptFormat, *options);
461
462  blink::WebPrintParams webkit_params(page_size);
463  webkit_params.printerDPI = GetDPI(&params);
464
465  frame->printBegin(webkit_params, WebKit::WebNode(), NULL);
466  frame->printPage(0, canvas);
467  frame->printEnd();
468
469  web_view->close();
470  frame->close();
471
472  device->setDrawingArea(SkPDFDevice::kContent_DrawingArea);
473#endif
474}
475
476// static - Not anonymous so that platform implementations can use it.
477float PrintWebViewHelper::RenderPageContent(blink::WebFrame* frame,
478                                            int page_number,
479                                            const gfx::Rect& canvas_area,
480                                            const gfx::Rect& content_area,
481                                            double scale_factor,
482                                            blink::WebCanvas* canvas) {
483  SkAutoCanvasRestore auto_restore(canvas, true);
484  if (content_area != canvas_area) {
485    canvas->translate((content_area.x() - canvas_area.x()) / scale_factor,
486                      (content_area.y() - canvas_area.y()) / scale_factor);
487    SkRect clip_rect(
488        SkRect::MakeXYWH(content_area.origin().x() / scale_factor,
489                         content_area.origin().y() / scale_factor,
490                         content_area.size().width() / scale_factor,
491                         content_area.size().height() / scale_factor));
492    SkIRect clip_int_rect;
493    clip_rect.roundOut(&clip_int_rect);
494    SkRegion clip_region(clip_int_rect);
495    canvas->setClipRegion(clip_region);
496  }
497  return frame->printPage(page_number, canvas);
498}
499
500// Class that calls the Begin and End print functions on the frame and changes
501// the size of the view temporarily to support full page printing..
502class PrepareFrameAndViewForPrint : public blink::WebViewClient,
503                                    public blink::WebFrameClient {
504 public:
505  PrepareFrameAndViewForPrint(const PrintMsg_Print_Params& params,
506                              blink::WebLocalFrame* frame,
507                              const blink::WebNode& node,
508                              bool ignore_css_margins);
509  virtual ~PrepareFrameAndViewForPrint();
510
511  // Optional. Replaces |frame_| with selection if needed. Will call |on_ready|
512  // when completed.
513  void CopySelectionIfNeeded(const WebPreferences& preferences,
514                             const base::Closure& on_ready);
515
516  // Prepares frame for printing.
517  void StartPrinting();
518
519  blink::WebLocalFrame* frame() {
520    return frame_.GetFrame();
521  }
522
523  const blink::WebNode& node() const {
524    return node_to_print_;
525  }
526
527  int GetExpectedPageCount() const {
528    return expected_pages_count_;
529  }
530
531  gfx::Size GetPrintCanvasSize() const;
532
533  void FinishPrinting();
534
535  bool IsLoadingSelection() {
536    // It's not selection if not |owns_web_view_|.
537    return owns_web_view_ && frame() && frame()->isLoading();
538  }
539
540  // TODO(ojan): Remove this override and have this class use a non-null
541  // layerTreeView.
542  // blink::WebViewClient override:
543  virtual bool allowsBrokenNullLayerTreeView() const;
544
545 protected:
546  // blink::WebViewClient override:
547  virtual void didStopLoading();
548
549  // blink::WebFrameClient override:
550  virtual blink::WebFrame* createChildFrame(blink::WebLocalFrame* parent,
551                                            const blink::WebString& name);
552  virtual void frameDetached(blink::WebFrame* frame);
553
554 private:
555  void CallOnReady();
556  void ResizeForPrinting();
557  void RestoreSize();
558  void CopySelection(const WebPreferences& preferences);
559
560  base::WeakPtrFactory<PrepareFrameAndViewForPrint> weak_ptr_factory_;
561
562  FrameReference frame_;
563  blink::WebNode node_to_print_;
564  bool owns_web_view_;
565  blink::WebPrintParams web_print_params_;
566  gfx::Size prev_view_size_;
567  gfx::Size prev_scroll_offset_;
568  int expected_pages_count_;
569  base::Closure on_ready_;
570  bool should_print_backgrounds_;
571  bool should_print_selection_only_;
572  bool is_printing_started_;
573
574  DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
575};
576
577PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
578    const PrintMsg_Print_Params& params,
579    blink::WebLocalFrame* frame,
580    const blink::WebNode& node,
581    bool ignore_css_margins)
582    : weak_ptr_factory_(this),
583      frame_(frame),
584      node_to_print_(node),
585      owns_web_view_(false),
586      expected_pages_count_(0),
587      should_print_backgrounds_(params.should_print_backgrounds),
588      should_print_selection_only_(params.selection_only),
589      is_printing_started_(false) {
590  PrintMsg_Print_Params print_params = params;
591  if (!should_print_selection_only_ ||
592      !PrintingNodeOrPdfFrame(frame, node_to_print_)) {
593    bool fit_to_page = ignore_css_margins &&
594                       print_params.print_scaling_option ==
595                            blink::WebPrintScalingOptionFitToPrintableArea;
596    ComputeWebKitPrintParamsInDesiredDpi(params, &web_print_params_);
597    frame->printBegin(web_print_params_, node_to_print_);
598    print_params = CalculatePrintParamsForCss(frame, 0, print_params,
599                                              ignore_css_margins, fit_to_page,
600                                              NULL);
601    frame->printEnd();
602  }
603  ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
604}
605
606PrepareFrameAndViewForPrint::~PrepareFrameAndViewForPrint() {
607  FinishPrinting();
608}
609
610void PrepareFrameAndViewForPrint::ResizeForPrinting() {
611  // Layout page according to printer page size. Since WebKit shrinks the
612  // size of the page automatically (from 125% to 200%) we trick it to
613  // think the page is 125% larger so the size of the page is correct for
614  // minimum (default) scaling.
615  // This is important for sites that try to fill the page.
616  gfx::Size print_layout_size(web_print_params_.printContentArea.width,
617                              web_print_params_.printContentArea.height);
618  print_layout_size.set_height(
619      static_cast<int>(static_cast<double>(print_layout_size.height()) * 1.25));
620
621  if (!frame())
622    return;
623  blink::WebView* web_view = frame_.view();
624  // Backup size and offset.
625  if (blink::WebFrame* web_frame = web_view->mainFrame())
626    prev_scroll_offset_ = web_frame->scrollOffset();
627  prev_view_size_ = web_view->size();
628
629  web_view->resize(print_layout_size);
630}
631
632
633void PrepareFrameAndViewForPrint::StartPrinting() {
634  ResizeForPrinting();
635  blink::WebView* web_view = frame_.view();
636  web_view->settings()->setShouldPrintBackgrounds(should_print_backgrounds_);
637  expected_pages_count_ =
638      frame()->printBegin(web_print_params_, node_to_print_);
639  is_printing_started_ = true;
640}
641
642void PrepareFrameAndViewForPrint::CopySelectionIfNeeded(
643    const WebPreferences& preferences,
644    const base::Closure& on_ready) {
645  on_ready_ = on_ready;
646  if (should_print_selection_only_)
647    CopySelection(preferences);
648  else
649    didStopLoading();
650}
651
652void PrepareFrameAndViewForPrint::CopySelection(
653    const WebPreferences& preferences) {
654  ResizeForPrinting();
655  std::string url_str = "data:text/html;charset=utf-8,";
656  url_str.append(
657      net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
658  RestoreSize();
659  // Create a new WebView with the same settings as the current display one.
660  // Except that we disable javascript (don't want any active content running
661  // on the page).
662  WebPreferences prefs = preferences;
663  prefs.javascript_enabled = false;
664  prefs.java_enabled = false;
665
666  blink::WebView* web_view = blink::WebView::create(this);
667  owns_web_view_ = true;
668  content::ApplyWebPreferences(prefs, web_view);
669
670  web_view->setMainFrame(blink::WebLocalFrame::create(this));
671  frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
672  node_to_print_.reset();
673
674  // When loading is done this will call didStopLoading() and that will do the
675  // actual printing.
676  frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
677}
678
679bool PrepareFrameAndViewForPrint::allowsBrokenNullLayerTreeView() const {
680  return true;
681}
682
683void PrepareFrameAndViewForPrint::didStopLoading() {
684  DCHECK(!on_ready_.is_null());
685  // Don't call callback here, because it can delete |this| and WebView that is
686  // called didStopLoading.
687  base::MessageLoop::current()->PostTask(
688      FROM_HERE,
689      base::Bind(&PrepareFrameAndViewForPrint::CallOnReady,
690                 weak_ptr_factory_.GetWeakPtr()));
691}
692
693blink::WebFrame* PrepareFrameAndViewForPrint::createChildFrame(
694    blink::WebLocalFrame* parent,
695    const blink::WebString& name) {
696  blink::WebFrame* frame = blink::WebLocalFrame::create(this);
697  parent->appendChild(frame);
698  return frame;
699}
700
701void PrepareFrameAndViewForPrint::frameDetached(blink::WebFrame* frame) {
702  if (frame->parent())
703    frame->parent()->removeChild(frame);
704  frame->close();
705}
706
707void PrepareFrameAndViewForPrint::CallOnReady() {
708  return on_ready_.Run();  // Can delete |this|.
709}
710
711gfx::Size PrepareFrameAndViewForPrint::GetPrintCanvasSize() const {
712  DCHECK(is_printing_started_);
713  return gfx::Size(web_print_params_.printContentArea.width,
714                   web_print_params_.printContentArea.height);
715}
716
717void PrepareFrameAndViewForPrint::RestoreSize() {
718  if (frame()) {
719    blink::WebView* web_view = frame_.GetFrame()->view();
720    web_view->resize(prev_view_size_);
721    if (blink::WebFrame* web_frame = web_view->mainFrame())
722      web_frame->setScrollOffset(prev_scroll_offset_);
723  }
724}
725
726void PrepareFrameAndViewForPrint::FinishPrinting() {
727  blink::WebFrame* frame = frame_.GetFrame();
728  if (frame) {
729    blink::WebView* web_view = frame->view();
730    if (is_printing_started_) {
731      is_printing_started_ = false;
732      frame->printEnd();
733      if (!owns_web_view_) {
734        web_view->settings()->setShouldPrintBackgrounds(false);
735        RestoreSize();
736      }
737    }
738    if (owns_web_view_) {
739      DCHECK(!frame->isLoading());
740      owns_web_view_ = false;
741      web_view->close();
742    }
743  }
744  frame_.Reset(NULL);
745  on_ready_.Reset();
746}
747
748PrintWebViewHelper::PrintWebViewHelper(content::RenderView* render_view)
749    : content::RenderViewObserver(render_view),
750      content::RenderViewObserverTracker<PrintWebViewHelper>(render_view),
751      reset_prep_frame_view_(false),
752      is_preview_enabled_(IsPrintPreviewEnabled()),
753      is_scripted_print_throttling_disabled_(IsPrintThrottlingDisabled()),
754      is_print_ready_metafile_sent_(false),
755      ignore_css_margins_(false),
756      user_cancelled_scripted_print_count_(0),
757      is_scripted_printing_blocked_(false),
758      notify_browser_of_print_failure_(true),
759      print_for_preview_(false),
760      print_node_in_progress_(false),
761      is_loading_(false),
762      is_scripted_preview_delayed_(false),
763      weak_ptr_factory_(this) {
764  // TODO(sgurun) enable window.print() for webview crbug.com/322303
765  SetScriptedPrintBlocked(true);
766}
767
768PrintWebViewHelper::~PrintWebViewHelper() {}
769
770bool PrintWebViewHelper::IsScriptInitiatedPrintAllowed(
771    blink::WebFrame* frame, bool user_initiated) {
772#if defined(OS_ANDROID)
773  return false;
774#endif  // defined(OS_ANDROID)
775  if (is_scripted_printing_blocked_)
776    return false;
777  // If preview is enabled, then the print dialog is tab modal, and the user
778  // can always close the tab on a mis-behaving page (the system print dialog
779  // is app modal). If the print was initiated through user action, don't
780  // throttle. Or, if the command line flag to skip throttling has been set.
781  if (!is_scripted_print_throttling_disabled_ &&
782      !is_preview_enabled_ &&
783      !user_initiated)
784    return !IsScriptInitiatedPrintTooFrequent(frame);
785  return true;
786}
787
788void PrintWebViewHelper::DidStartLoading() {
789  is_loading_ = true;
790}
791
792void PrintWebViewHelper::DidStopLoading() {
793  is_loading_ = false;
794  ShowScriptedPrintPreview();
795}
796
797// Prints |frame| which called window.print().
798void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
799                                   bool user_initiated) {
800  DCHECK(frame);
801
802#if !defined(OS_ANDROID)
803  // TODO(sgurun) android_webview hack
804  // Allow Prerendering to cancel this print request if necessary.
805  if (prerender::PrerenderHelper::IsPrerendering(render_view())) {
806    Send(new ChromeViewHostMsg_CancelPrerenderForPrinting(routing_id()));
807    return;
808  }
809#endif  // !defined(OS_ANDROID)
810
811  if (!IsScriptInitiatedPrintAllowed(frame, user_initiated))
812    return;
813  IncrementScriptedPrintCount();
814
815  if (is_preview_enabled_) {
816    print_preview_context_.InitWithFrame(frame);
817    RequestPrintPreview(PRINT_PREVIEW_SCRIPTED);
818  } else {
819    Print(frame, blink::WebNode());
820  }
821}
822
823bool PrintWebViewHelper::OnMessageReceived(const IPC::Message& message) {
824  bool handled = true;
825  IPC_BEGIN_MESSAGE_MAP(PrintWebViewHelper, message)
826    IPC_MESSAGE_HANDLER(PrintMsg_PrintPages, OnPrintPages)
827    IPC_MESSAGE_HANDLER(PrintMsg_PrintForSystemDialog, OnPrintForSystemDialog)
828    IPC_MESSAGE_HANDLER(PrintMsg_InitiatePrintPreview, OnInitiatePrintPreview)
829    IPC_MESSAGE_HANDLER(PrintMsg_PrintPreview, OnPrintPreview)
830    IPC_MESSAGE_HANDLER(PrintMsg_PrintForPrintPreview, OnPrintForPrintPreview)
831    IPC_MESSAGE_HANDLER(PrintMsg_PrintingDone, OnPrintingDone)
832    IPC_MESSAGE_HANDLER(PrintMsg_ResetScriptedPrintCount,
833                        ResetScriptedPrintCount)
834    IPC_MESSAGE_HANDLER(PrintMsg_SetScriptedPrintingBlocked,
835                        SetScriptedPrintBlocked)
836    IPC_MESSAGE_UNHANDLED(handled = false)
837    IPC_END_MESSAGE_MAP()
838  return handled;
839}
840
841void PrintWebViewHelper::OnPrintForPrintPreview(
842    const base::DictionaryValue& job_settings) {
843  DCHECK(is_preview_enabled_);
844  // If still not finished with earlier print request simply ignore.
845  if (prep_frame_view_)
846    return;
847
848  if (!render_view()->GetWebView())
849    return;
850  blink::WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
851  if (!main_frame)
852    return;
853
854  blink::WebDocument document = main_frame->document();
855  // <object> with id="pdf-viewer" is created in
856  // chrome/browser/resources/print_preview/print_preview.js
857  blink::WebElement pdf_element = document.getElementById("pdf-viewer");
858  if (pdf_element.isNull()) {
859    NOTREACHED();
860    return;
861  }
862
863  // Set |print_for_preview_| flag and autoreset it to back to original
864  // on return.
865  base::AutoReset<bool> set_printing_flag(&print_for_preview_, true);
866
867  blink::WebLocalFrame* pdf_frame = pdf_element.document().frame();
868  if (!UpdatePrintSettings(pdf_frame, pdf_element, job_settings)) {
869    LOG(ERROR) << "UpdatePrintSettings failed";
870    DidFinishPrinting(FAIL_PRINT);
871    return;
872  }
873
874  // Print page onto entire page not just printable area. Preview PDF already
875  // has content in correct position taking into account page size and printable
876  // area.
877  // TODO(vitalybuka) : Make this consistent on all platform. This change
878  // affects Windows only. On Linux and OSX RenderPagesForPrint does not use
879  // printable_area. Also we can't change printable_area deeper inside
880  // RenderPagesForPrint for Windows, because it's used also by native
881  // printing and it expects real printable_area value.
882  // See http://crbug.com/123408
883  PrintMsg_Print_Params& print_params = print_pages_params_->params;
884  print_params.printable_area = gfx::Rect(print_params.page_size);
885
886  // Render Pages for printing.
887  if (!RenderPagesForPrint(pdf_frame, pdf_element)) {
888    LOG(ERROR) << "RenderPagesForPrint failed";
889    DidFinishPrinting(FAIL_PRINT);
890  }
891}
892
893bool PrintWebViewHelper::GetPrintFrame(blink::WebLocalFrame** frame) {
894  DCHECK(frame);
895  blink::WebView* webView = render_view()->GetWebView();
896  DCHECK(webView);
897  if (!webView)
898    return false;
899
900  // If the user has selected text in the currently focused frame we print
901  // only that frame (this makes print selection work for multiple frames).
902  blink::WebLocalFrame* focusedFrame =
903      webView->focusedFrame()->toWebLocalFrame();
904  *frame = focusedFrame->hasSelection()
905               ? focusedFrame
906               : webView->mainFrame()->toWebLocalFrame();
907  return true;
908}
909
910void PrintWebViewHelper::OnPrintPages() {
911  blink::WebLocalFrame* frame;
912  if (GetPrintFrame(&frame))
913    Print(frame, blink::WebNode());
914}
915
916void PrintWebViewHelper::OnPrintForSystemDialog() {
917  blink::WebLocalFrame* frame = print_preview_context_.source_frame();
918  if (!frame) {
919    NOTREACHED();
920    return;
921  }
922
923  Print(frame, print_preview_context_.source_node());
924}
925
926void PrintWebViewHelper::GetPageSizeAndContentAreaFromPageLayout(
927    const PageSizeMargins& page_layout_in_points,
928    gfx::Size* page_size,
929    gfx::Rect* content_area) {
930  *page_size = gfx::Size(
931      page_layout_in_points.content_width +
932          page_layout_in_points.margin_right +
933          page_layout_in_points.margin_left,
934      page_layout_in_points.content_height +
935          page_layout_in_points.margin_top +
936          page_layout_in_points.margin_bottom);
937  *content_area = gfx::Rect(page_layout_in_points.margin_left,
938                            page_layout_in_points.margin_top,
939                            page_layout_in_points.content_width,
940                            page_layout_in_points.content_height);
941}
942
943void PrintWebViewHelper::UpdateFrameMarginsCssInfo(
944    const base::DictionaryValue& settings) {
945  int margins_type = 0;
946  if (!settings.GetInteger(kSettingMarginsType, &margins_type))
947    margins_type = DEFAULT_MARGINS;
948  ignore_css_margins_ = (margins_type != DEFAULT_MARGINS);
949}
950
951bool PrintWebViewHelper::IsPrintToPdfRequested(
952    const base::DictionaryValue& job_settings) {
953  bool print_to_pdf = false;
954  if (!job_settings.GetBoolean(kSettingPrintToPDF, &print_to_pdf))
955    NOTREACHED();
956  return print_to_pdf;
957}
958
959blink::WebPrintScalingOption PrintWebViewHelper::GetPrintScalingOption(
960    bool source_is_html, const base::DictionaryValue& job_settings,
961    const PrintMsg_Print_Params& params) {
962  DCHECK(!print_for_preview_);
963
964  if (params.print_to_pdf)
965    return blink::WebPrintScalingOptionSourceSize;
966
967  if (!source_is_html) {
968    if (!FitToPageEnabled(job_settings))
969      return blink::WebPrintScalingOptionNone;
970
971    bool no_plugin_scaling =
972        print_preview_context_.source_frame()->isPrintScalingDisabledForPlugin(
973            print_preview_context_.source_node());
974
975    if (params.is_first_request && no_plugin_scaling)
976      return blink::WebPrintScalingOptionNone;
977  }
978  return blink::WebPrintScalingOptionFitToPrintableArea;
979}
980
981void PrintWebViewHelper::OnPrintPreview(const base::DictionaryValue& settings) {
982  DCHECK(is_preview_enabled_);
983  print_preview_context_.OnPrintPreview();
984
985  UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
986                            PREVIEW_EVENT_REQUESTED, PREVIEW_EVENT_MAX);
987
988  if (!UpdatePrintSettings(print_preview_context_.source_frame(),
989                           print_preview_context_.source_node(), settings)) {
990    if (print_preview_context_.last_error() != PREVIEW_ERROR_BAD_SETTING) {
991      Send(new PrintHostMsg_PrintPreviewInvalidPrinterSettings(
992          routing_id(), print_pages_params_->params.document_cookie));
993      notify_browser_of_print_failure_ = false;  // Already sent.
994    }
995    DidFinishPrinting(FAIL_PREVIEW);
996    return;
997  }
998
999  // If we are previewing a pdf and the print scaling is disabled, send a
1000  // message to browser.
1001  if (print_pages_params_->params.is_first_request &&
1002      !print_preview_context_.IsModifiable() &&
1003      print_preview_context_.source_frame()->isPrintScalingDisabledForPlugin(
1004          print_preview_context_.source_node())) {
1005    Send(new PrintHostMsg_PrintPreviewScalingDisabled(routing_id()));
1006  }
1007
1008  is_print_ready_metafile_sent_ = false;
1009
1010  // PDF printer device supports alpha blending.
1011  print_pages_params_->params.supports_alpha_blend = true;
1012
1013  bool generate_draft_pages = false;
1014  if (!settings.GetBoolean(kSettingGenerateDraftData,
1015                           &generate_draft_pages)) {
1016    NOTREACHED();
1017  }
1018  print_preview_context_.set_generate_draft_pages(generate_draft_pages);
1019
1020  PrepareFrameForPreviewDocument();
1021}
1022
1023void PrintWebViewHelper::PrepareFrameForPreviewDocument() {
1024  reset_prep_frame_view_ = false;
1025
1026  if (!print_pages_params_ || CheckForCancel()) {
1027    DidFinishPrinting(FAIL_PREVIEW);
1028    return;
1029  }
1030
1031  // Don't reset loading frame or WebKit will fail assert. Just retry when
1032  // current selection is loaded.
1033  if (prep_frame_view_ && prep_frame_view_->IsLoadingSelection()) {
1034    reset_prep_frame_view_ = true;
1035    return;
1036  }
1037
1038  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1039  prep_frame_view_.reset(
1040      new PrepareFrameAndViewForPrint(print_params,
1041                                      print_preview_context_.source_frame(),
1042                                      print_preview_context_.source_node(),
1043                                      ignore_css_margins_));
1044  prep_frame_view_->CopySelectionIfNeeded(
1045      render_view()->GetWebkitPreferences(),
1046      base::Bind(&PrintWebViewHelper::OnFramePreparedForPreviewDocument,
1047                 base::Unretained(this)));
1048}
1049
1050void PrintWebViewHelper::OnFramePreparedForPreviewDocument() {
1051  if (reset_prep_frame_view_) {
1052    PrepareFrameForPreviewDocument();
1053    return;
1054  }
1055  DidFinishPrinting(CreatePreviewDocument() ? OK : FAIL_PREVIEW);
1056}
1057
1058bool PrintWebViewHelper::CreatePreviewDocument() {
1059  if (!print_pages_params_ || CheckForCancel())
1060    return false;
1061
1062  UMA_HISTOGRAM_ENUMERATION("PrintPreview.PreviewEvent",
1063                            PREVIEW_EVENT_CREATE_DOCUMENT, PREVIEW_EVENT_MAX);
1064
1065  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1066  const std::vector<int>& pages = print_pages_params_->pages;
1067
1068  if (!print_preview_context_.CreatePreviewDocument(prep_frame_view_.release(),
1069                                                    pages)) {
1070    return false;
1071  }
1072
1073  PageSizeMargins default_page_layout;
1074  ComputePageLayoutInPointsForCss(print_preview_context_.prepared_frame(), 0,
1075                                  print_params, ignore_css_margins_, NULL,
1076                                  &default_page_layout);
1077
1078  bool has_page_size_style = PrintingFrameHasPageSizeStyle(
1079      print_preview_context_.prepared_frame(),
1080      print_preview_context_.total_page_count());
1081  int dpi = GetDPI(&print_params);
1082
1083  gfx::Rect printable_area_in_points(
1084      ConvertUnit(print_params.printable_area.x(), dpi, kPointsPerInch),
1085      ConvertUnit(print_params.printable_area.y(), dpi, kPointsPerInch),
1086      ConvertUnit(print_params.printable_area.width(), dpi, kPointsPerInch),
1087      ConvertUnit(print_params.printable_area.height(), dpi, kPointsPerInch));
1088
1089  // Margins: Send default page layout to browser process.
1090  Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
1091                                                default_page_layout,
1092                                                printable_area_in_points,
1093                                                has_page_size_style));
1094
1095  PrintHostMsg_DidGetPreviewPageCount_Params params;
1096  params.page_count = print_preview_context_.total_page_count();
1097  params.is_modifiable = print_preview_context_.IsModifiable();
1098  params.document_cookie = print_params.document_cookie;
1099  params.preview_request_id = print_params.preview_request_id;
1100  params.clear_preview_data = print_preview_context_.generate_draft_pages();
1101  Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), params));
1102  if (CheckForCancel())
1103    return false;
1104
1105  while (!print_preview_context_.IsFinalPageRendered()) {
1106    int page_number = print_preview_context_.GetNextPageNumber();
1107    DCHECK_GE(page_number, 0);
1108    if (!RenderPreviewPage(page_number, print_params))
1109      return false;
1110
1111    if (CheckForCancel())
1112      return false;
1113
1114    // We must call PrepareFrameAndViewForPrint::FinishPrinting() (by way of
1115    // print_preview_context_.AllPagesRendered()) before calling
1116    // FinalizePrintReadyDocument() when printing a PDF because the plugin
1117    // code does not generate output until we call FinishPrinting().  We do not
1118    // generate draft pages for PDFs, so IsFinalPageRendered() and
1119    // IsLastPageOfPrintReadyMetafile() will be true in the same iteration of
1120    // the loop.
1121    if (print_preview_context_.IsFinalPageRendered())
1122      print_preview_context_.AllPagesRendered();
1123
1124    if (print_preview_context_.IsLastPageOfPrintReadyMetafile()) {
1125      DCHECK(print_preview_context_.IsModifiable() ||
1126             print_preview_context_.IsFinalPageRendered());
1127      if (!FinalizePrintReadyDocument())
1128        return false;
1129    }
1130  }
1131  print_preview_context_.Finished();
1132  return true;
1133}
1134
1135bool PrintWebViewHelper::FinalizePrintReadyDocument() {
1136  DCHECK(!is_print_ready_metafile_sent_);
1137  print_preview_context_.FinalizePrintReadyDocument();
1138
1139  // Get the size of the resulting metafile.
1140  PreviewMetafile* metafile = print_preview_context_.metafile();
1141  uint32 buf_size = metafile->GetDataSize();
1142  DCHECK_GT(buf_size, 0u);
1143
1144  PrintHostMsg_DidPreviewDocument_Params preview_params;
1145  preview_params.reuse_existing_data = false;
1146  preview_params.data_size = buf_size;
1147  preview_params.document_cookie = print_pages_params_->params.document_cookie;
1148  preview_params.expected_pages_count =
1149      print_preview_context_.total_page_count();
1150  preview_params.modifiable = print_preview_context_.IsModifiable();
1151  preview_params.preview_request_id =
1152      print_pages_params_->params.preview_request_id;
1153
1154  // Ask the browser to create the shared memory for us.
1155  if (!CopyMetafileDataToSharedMem(metafile,
1156                                   &(preview_params.metafile_data_handle))) {
1157    LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1158    print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1159    return false;
1160  }
1161  is_print_ready_metafile_sent_ = true;
1162
1163  Send(new PrintHostMsg_MetafileReadyForPrinting(routing_id(), preview_params));
1164  return true;
1165}
1166
1167void PrintWebViewHelper::OnPrintingDone(bool success) {
1168  notify_browser_of_print_failure_ = false;
1169  if (!success)
1170    LOG(ERROR) << "Failure in OnPrintingDone";
1171  DidFinishPrinting(success ? OK : FAIL_PRINT);
1172}
1173
1174void PrintWebViewHelper::SetScriptedPrintBlocked(bool blocked) {
1175  is_scripted_printing_blocked_ = blocked;
1176}
1177
1178void PrintWebViewHelper::OnInitiatePrintPreview(bool selection_only) {
1179  DCHECK(is_preview_enabled_);
1180  blink::WebLocalFrame* frame = NULL;
1181  GetPrintFrame(&frame);
1182  DCHECK(frame);
1183  print_preview_context_.InitWithFrame(frame);
1184  RequestPrintPreview(selection_only ?
1185                      PRINT_PREVIEW_USER_INITIATED_SELECTION :
1186                      PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME);
1187}
1188
1189bool PrintWebViewHelper::IsPrintingEnabled() {
1190  bool result = false;
1191  Send(new PrintHostMsg_IsPrintingEnabled(routing_id(), &result));
1192  return result;
1193}
1194
1195void PrintWebViewHelper::PrintNode(const blink::WebNode& node) {
1196  if (node.isNull() || !node.document().frame()) {
1197    // This can occur when the context menu refers to an invalid WebNode.
1198    // See http://crbug.com/100890#c17 for a repro case.
1199    return;
1200  }
1201
1202  if (print_node_in_progress_) {
1203    // This can happen as a result of processing sync messages when printing
1204    // from ppapi plugins. It's a rare case, so its OK to just fail here.
1205    // See http://crbug.com/159165.
1206    return;
1207  }
1208
1209  print_node_in_progress_ = true;
1210
1211  // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
1212  // its |context_menu_node_|.
1213  if (is_preview_enabled_) {
1214    print_preview_context_.InitWithNode(node);
1215    RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
1216  } else {
1217    blink::WebNode duplicate_node(node);
1218    Print(duplicate_node.document().frame(), duplicate_node);
1219  }
1220
1221  print_node_in_progress_ = false;
1222}
1223
1224void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
1225                               const blink::WebNode& node) {
1226  // If still not finished with earlier print request simply ignore.
1227  if (prep_frame_view_)
1228    return;
1229
1230  FrameReference frame_ref(frame);
1231
1232  int expected_page_count = 0;
1233  if (!CalculateNumberOfPages(frame, node, &expected_page_count)) {
1234    DidFinishPrinting(FAIL_PRINT_INIT);
1235    return;  // Failed to init print page settings.
1236  }
1237
1238  // Some full screen plugins can say they don't want to print.
1239  if (!expected_page_count) {
1240    DidFinishPrinting(FAIL_PRINT);
1241    return;
1242  }
1243
1244#if !defined(OS_ANDROID)
1245  // TODO(sgurun) android_webview hack
1246  // Ask the browser to show UI to retrieve the final print settings.
1247  if (!GetPrintSettingsFromUser(frame_ref.GetFrame(), node,
1248                                expected_page_count)) {
1249    DidFinishPrinting(OK);  // Release resources and fail silently.
1250    return;
1251  }
1252#endif  // !defined(OS_ANDROID)
1253
1254  // Render Pages for printing.
1255  if (!RenderPagesForPrint(frame_ref.GetFrame(), node)) {
1256    LOG(ERROR) << "RenderPagesForPrint failed";
1257    DidFinishPrinting(FAIL_PRINT);
1258  }
1259  ResetScriptedPrintCount();
1260}
1261
1262void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
1263  switch (result) {
1264    case OK:
1265      break;
1266
1267    case FAIL_PRINT_INIT:
1268      DCHECK(!notify_browser_of_print_failure_);
1269      break;
1270
1271    case FAIL_PRINT:
1272      if (notify_browser_of_print_failure_ && print_pages_params_.get()) {
1273        int cookie = print_pages_params_->params.document_cookie;
1274        Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
1275      }
1276      break;
1277
1278    case FAIL_PREVIEW:
1279      DCHECK(is_preview_enabled_);
1280      int cookie = print_pages_params_.get() ?
1281          print_pages_params_->params.document_cookie : 0;
1282      if (notify_browser_of_print_failure_) {
1283        LOG(ERROR) << "CreatePreviewDocument failed";
1284        Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
1285      } else {
1286        Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
1287      }
1288      print_preview_context_.Failed(notify_browser_of_print_failure_);
1289      break;
1290  }
1291
1292  prep_frame_view_.reset();
1293  print_pages_params_.reset();
1294  notify_browser_of_print_failure_ = true;
1295}
1296
1297void PrintWebViewHelper::OnFramePreparedForPrintPages() {
1298  PrintPages();
1299  FinishFramePrinting();
1300}
1301
1302void PrintWebViewHelper::PrintPages() {
1303  if (!prep_frame_view_)  // Printing is already canceled or failed.
1304    return;
1305  prep_frame_view_->StartPrinting();
1306
1307  int page_count = prep_frame_view_->GetExpectedPageCount();
1308  if (!page_count) {
1309    LOG(ERROR) << "Can't print 0 pages.";
1310    return DidFinishPrinting(FAIL_PRINT);
1311  }
1312
1313  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1314  const PrintMsg_Print_Params& print_params = params.params;
1315
1316#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
1317  // TODO(vitalybuka): should be page_count or valid pages from params.pages.
1318  // See http://crbug.com/161576
1319  Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
1320                                                print_params.document_cookie,
1321                                                page_count));
1322#endif  // !defined(OS_CHROMEOS)
1323
1324  if (print_params.preview_ui_id < 0) {
1325    // Printing for system dialog.
1326    int printed_count = params.pages.empty() ? page_count : params.pages.size();
1327#if !defined(OS_CHROMEOS)
1328    UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.SystemDialog", printed_count);
1329#else
1330    UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.PrintToCloudPrintWebDialog",
1331                         printed_count);
1332#endif  // !defined(OS_CHROMEOS)
1333  }
1334
1335
1336  if (!PrintPagesNative(prep_frame_view_->frame(), page_count,
1337                        prep_frame_view_->GetPrintCanvasSize())) {
1338    LOG(ERROR) << "Printing failed.";
1339    return DidFinishPrinting(FAIL_PRINT);
1340  }
1341}
1342
1343void PrintWebViewHelper::FinishFramePrinting() {
1344  prep_frame_view_.reset();
1345}
1346
1347#if defined(OS_MACOSX) || defined(OS_WIN)
1348bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
1349                                          int page_count,
1350                                          const gfx::Size& canvas_size) {
1351  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1352  const PrintMsg_Print_Params& print_params = params.params;
1353
1354  PrintMsg_PrintPage_Params page_params;
1355  page_params.params = print_params;
1356  if (params.pages.empty()) {
1357    for (int i = 0; i < page_count; ++i) {
1358      page_params.page_number = i;
1359      PrintPageInternal(page_params, canvas_size, frame);
1360    }
1361  } else {
1362    for (size_t i = 0; i < params.pages.size(); ++i) {
1363      if (params.pages[i] >= page_count)
1364        break;
1365      page_params.page_number = params.pages[i];
1366      PrintPageInternal(page_params, canvas_size, frame);
1367    }
1368  }
1369  return true;
1370}
1371
1372#endif  // OS_MACOSX || OS_WIN
1373
1374// static - Not anonymous so that platform implementations can use it.
1375void PrintWebViewHelper::ComputePageLayoutInPointsForCss(
1376    blink::WebFrame* frame,
1377    int page_index,
1378    const PrintMsg_Print_Params& page_params,
1379    bool ignore_css_margins,
1380    double* scale_factor,
1381    PageSizeMargins* page_layout_in_points) {
1382  PrintMsg_Print_Params params = CalculatePrintParamsForCss(
1383      frame, page_index, page_params, ignore_css_margins,
1384      page_params.print_scaling_option ==
1385          blink::WebPrintScalingOptionFitToPrintableArea,
1386      scale_factor);
1387  CalculatePageLayoutFromPrintParams(params, page_layout_in_points);
1388}
1389
1390bool PrintWebViewHelper::InitPrintSettings(bool fit_to_paper_size) {
1391  PrintMsg_PrintPages_Params settings;
1392  Send(new PrintHostMsg_GetDefaultPrintSettings(routing_id(),
1393                                                &settings.params));
1394  // Check if the printer returned any settings, if the settings is empty, we
1395  // can safely assume there are no printer drivers configured. So we safely
1396  // terminate.
1397  bool result = true;
1398  if (!PrintMsg_Print_Params_IsValid(settings.params))
1399    result = false;
1400
1401  if (result &&
1402      (settings.params.dpi < kMinDpi || settings.params.document_cookie == 0)) {
1403    // Invalid print page settings.
1404    NOTREACHED();
1405    result = false;
1406  }
1407
1408  // Reset to default values.
1409  ignore_css_margins_ = false;
1410  settings.pages.clear();
1411
1412  settings.params.print_scaling_option =
1413      blink::WebPrintScalingOptionSourceSize;
1414  if (fit_to_paper_size) {
1415    settings.params.print_scaling_option =
1416        blink::WebPrintScalingOptionFitToPrintableArea;
1417  }
1418
1419  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
1420  return result;
1421}
1422
1423bool PrintWebViewHelper::CalculateNumberOfPages(blink::WebLocalFrame* frame,
1424                                                const blink::WebNode& node,
1425                                                int* number_of_pages) {
1426  DCHECK(frame);
1427  bool fit_to_paper_size = !(PrintingNodeOrPdfFrame(frame, node));
1428  if (!InitPrintSettings(fit_to_paper_size)) {
1429    notify_browser_of_print_failure_ = false;
1430#if !defined(OS_ANDROID)
1431    // TODO(sgurun) android_webview hack
1432    render_view()->RunModalAlertDialog(
1433        frame,
1434        l10n_util::GetStringUTF16(IDS_PRINT_INVALID_PRINTER_SETTINGS));
1435#endif  //  !defined(OS_ANDROID)
1436    return false;
1437  }
1438
1439  const PrintMsg_Print_Params& params = print_pages_params_->params;
1440  PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
1441  prepare.StartPrinting();
1442
1443  Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
1444                                             params.document_cookie));
1445  *number_of_pages = prepare.GetExpectedPageCount();
1446  return true;
1447}
1448
1449bool PrintWebViewHelper::UpdatePrintSettings(
1450    blink::WebLocalFrame* frame,
1451    const blink::WebNode& node,
1452    const base::DictionaryValue& passed_job_settings) {
1453  DCHECK(is_preview_enabled_);
1454  const base::DictionaryValue* job_settings = &passed_job_settings;
1455  base::DictionaryValue modified_job_settings;
1456  if (job_settings->empty()) {
1457    if (!print_for_preview_)
1458      print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1459    return false;
1460  }
1461
1462  bool source_is_html = true;
1463  if (print_for_preview_) {
1464    if (!job_settings->GetBoolean(kSettingPreviewModifiable, &source_is_html)) {
1465      NOTREACHED();
1466    }
1467  } else {
1468    source_is_html = !PrintingNodeOrPdfFrame(frame, node);
1469  }
1470
1471  if (print_for_preview_ || !source_is_html) {
1472    modified_job_settings.MergeDictionary(job_settings);
1473    modified_job_settings.SetBoolean(kSettingHeaderFooterEnabled, false);
1474    modified_job_settings.SetInteger(kSettingMarginsType, NO_MARGINS);
1475    job_settings = &modified_job_settings;
1476  }
1477
1478  // Send the cookie so that UpdatePrintSettings can reuse PrinterQuery when
1479  // possible.
1480  int cookie = print_pages_params_.get() ?
1481      print_pages_params_->params.document_cookie : 0;
1482  PrintMsg_PrintPages_Params settings;
1483  Send(new PrintHostMsg_UpdatePrintSettings(routing_id(), cookie, *job_settings,
1484                                            &settings));
1485  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
1486
1487  if (!PrintMsg_Print_Params_IsValid(settings.params)) {
1488    if (!print_for_preview_) {
1489      print_preview_context_.set_error(PREVIEW_ERROR_INVALID_PRINTER_SETTINGS);
1490    } else {
1491#if !defined(OS_ANDROID)
1492      // TODO(sgurun) android_webview hack
1493      // PrintForPrintPreview
1494      blink::WebFrame* print_frame = NULL;
1495      // This may not be the right frame, but the alert will be modal,
1496      // therefore it works well enough.
1497      GetPrintFrame(&print_frame);
1498      if (print_frame) {
1499        render_view()->RunModalAlertDialog(
1500            print_frame,
1501            l10n_util::GetStringUTF16(
1502                IDS_PRINT_INVALID_PRINTER_SETTINGS));
1503      }
1504#endif  // !defined(OS_ANDROID)
1505    }
1506    return false;
1507  }
1508
1509  if (settings.params.dpi < kMinDpi || !settings.params.document_cookie) {
1510    print_preview_context_.set_error(PREVIEW_ERROR_UPDATING_PRINT_SETTINGS);
1511    return false;
1512  }
1513
1514  if (!job_settings->GetInteger(kPreviewUIID, &settings.params.preview_ui_id)) {
1515    NOTREACHED();
1516    print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1517    return false;
1518  }
1519
1520  if (!print_for_preview_) {
1521    // Validate expected print preview settings.
1522    if (!job_settings->GetInteger(kPreviewRequestID,
1523                                  &settings.params.preview_request_id) ||
1524        !job_settings->GetBoolean(kIsFirstRequest,
1525                                  &settings.params.is_first_request)) {
1526      NOTREACHED();
1527      print_preview_context_.set_error(PREVIEW_ERROR_BAD_SETTING);
1528      return false;
1529    }
1530
1531    settings.params.print_to_pdf = IsPrintToPdfRequested(*job_settings);
1532    UpdateFrameMarginsCssInfo(*job_settings);
1533    settings.params.print_scaling_option = GetPrintScalingOption(
1534        source_is_html, *job_settings, settings.params);
1535
1536    // Header/Footer: Set |header_footer_info_|.
1537    if (settings.params.display_header_footer) {
1538      header_footer_info_.reset(new base::DictionaryValue());
1539      header_footer_info_->SetDouble(kSettingHeaderFooterDate,
1540                                     base::Time::Now().ToJsTime());
1541      header_footer_info_->SetString(kSettingHeaderFooterURL,
1542                                     settings.params.url);
1543      header_footer_info_->SetString(kSettingHeaderFooterTitle,
1544                                     settings.params.title);
1545    }
1546  }
1547
1548  print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
1549  Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
1550                                             settings.params.document_cookie));
1551
1552  return true;
1553}
1554
1555bool PrintWebViewHelper::GetPrintSettingsFromUser(blink::WebFrame* frame,
1556                                                  const blink::WebNode& node,
1557                                                  int expected_pages_count) {
1558  PrintHostMsg_ScriptedPrint_Params params;
1559  PrintMsg_PrintPages_Params print_settings;
1560
1561  params.cookie = print_pages_params_->params.document_cookie;
1562  params.has_selection = frame->hasSelection();
1563  params.expected_pages_count = expected_pages_count;
1564  MarginType margin_type = DEFAULT_MARGINS;
1565  if (PrintingNodeOrPdfFrame(frame, node))
1566    margin_type = GetMarginsForPdf(frame, node);
1567  params.margin_type = margin_type;
1568
1569  Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
1570
1571  // PrintHostMsg_ScriptedPrint will reset print_scaling_option, so we save the
1572  // value before and restore it afterwards.
1573  blink::WebPrintScalingOption scaling_option =
1574      print_pages_params_->params.print_scaling_option;
1575
1576  print_pages_params_.reset();
1577  IPC::SyncMessage* msg =
1578      new PrintHostMsg_ScriptedPrint(routing_id(), params, &print_settings);
1579  msg->EnableMessagePumping();
1580  Send(msg);
1581  print_pages_params_.reset(new PrintMsg_PrintPages_Params(print_settings));
1582
1583  print_pages_params_->params.print_scaling_option = scaling_option;
1584  return (print_settings.params.dpi && print_settings.params.document_cookie);
1585}
1586
1587bool PrintWebViewHelper::RenderPagesForPrint(blink::WebLocalFrame* frame,
1588                                             const blink::WebNode& node) {
1589  if (!frame || prep_frame_view_)
1590    return false;
1591  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
1592  const PrintMsg_Print_Params& print_params = params.params;
1593  prep_frame_view_.reset(
1594      new PrepareFrameAndViewForPrint(print_params, frame, node,
1595                                      ignore_css_margins_));
1596  DCHECK(!print_pages_params_->params.selection_only ||
1597         print_pages_params_->pages.empty());
1598  prep_frame_view_->CopySelectionIfNeeded(
1599      render_view()->GetWebkitPreferences(),
1600      base::Bind(&PrintWebViewHelper::OnFramePreparedForPrintPages,
1601                 base::Unretained(this)));
1602  return true;
1603}
1604
1605#if defined(OS_POSIX)
1606bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
1607    Metafile* metafile,
1608    base::SharedMemoryHandle* shared_mem_handle) {
1609  uint32 buf_size = metafile->GetDataSize();
1610  scoped_ptr<base::SharedMemory> shared_buf(
1611      content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(
1612          buf_size).release());
1613
1614  if (shared_buf.get()) {
1615    if (shared_buf->Map(buf_size)) {
1616      metafile->GetData(shared_buf->memory(), buf_size);
1617      shared_buf->GiveToProcess(base::GetCurrentProcessHandle(),
1618                                shared_mem_handle);
1619      return true;
1620    }
1621  }
1622  NOTREACHED();
1623  return false;
1624}
1625#endif  // defined(OS_POSIX)
1626
1627bool PrintWebViewHelper::IsScriptInitiatedPrintTooFrequent(
1628    blink::WebFrame* frame) {
1629  const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
1630  const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 32;
1631  bool too_frequent = false;
1632
1633  // Check if there is script repeatedly trying to print and ignore it if too
1634  // frequent.  The first 3 times, we use a constant wait time, but if this
1635  // gets excessive, we switch to exponential wait time. So for a page that
1636  // calls print() in a loop the user will need to cancel the print dialog
1637  // after: [2, 2, 2, 4, 8, 16, 32, 32, ...] seconds.
1638  // This gives the user time to navigate from the page.
1639  if (user_cancelled_scripted_print_count_ > 0) {
1640    base::TimeDelta diff = base::Time::Now() - last_cancelled_script_print_;
1641    int min_wait_seconds = kMinSecondsToIgnoreJavascriptInitiatedPrint;
1642    if (user_cancelled_scripted_print_count_ > 3) {
1643      min_wait_seconds = std::min(
1644          kMinSecondsToIgnoreJavascriptInitiatedPrint <<
1645              (user_cancelled_scripted_print_count_ - 3),
1646          kMaxSecondsToIgnoreJavascriptInitiatedPrint);
1647    }
1648    if (diff.InSeconds() < min_wait_seconds) {
1649      too_frequent = true;
1650    }
1651  }
1652
1653  if (!too_frequent)
1654    return false;
1655
1656  blink::WebString message(
1657      blink::WebString::fromUTF8("Ignoring too frequent calls to print()."));
1658  frame->addMessageToConsole(
1659      blink::WebConsoleMessage(
1660          blink::WebConsoleMessage::LevelWarning, message));
1661  return true;
1662}
1663
1664void PrintWebViewHelper::ResetScriptedPrintCount() {
1665  // Reset cancel counter on successful print.
1666  user_cancelled_scripted_print_count_ = 0;
1667}
1668
1669void PrintWebViewHelper::IncrementScriptedPrintCount() {
1670  ++user_cancelled_scripted_print_count_;
1671  last_cancelled_script_print_ = base::Time::Now();
1672}
1673
1674void PrintWebViewHelper::ShowScriptedPrintPreview() {
1675  if (is_scripted_preview_delayed_) {
1676    is_scripted_preview_delayed_ = false;
1677    Send(new PrintHostMsg_ShowScriptedPrintPreview(routing_id(),
1678            print_preview_context_.IsModifiable()));
1679  }
1680}
1681
1682void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
1683  const bool is_modifiable = print_preview_context_.IsModifiable();
1684  const bool has_selection = print_preview_context_.HasSelection();
1685  PrintHostMsg_RequestPrintPreview_Params params;
1686  params.is_modifiable = is_modifiable;
1687  params.has_selection = has_selection;
1688  switch (type) {
1689    case PRINT_PREVIEW_SCRIPTED: {
1690      // Shows scripted print preview in two stages.
1691      // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
1692      //    pumping messages here.
1693      // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
1694      //    document has been loaded.
1695      is_scripted_preview_delayed_ = true;
1696      if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
1697        // Wait for DidStopLoading. Plugins may not know the correct
1698        // |is_modifiable| value until they are fully loaded, which occurs when
1699        // DidStopLoading() is called. Defer showing the preview until then.
1700      } else {
1701        base::MessageLoop::current()->PostTask(
1702            FROM_HERE,
1703            base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
1704                       weak_ptr_factory_.GetWeakPtr()));
1705      }
1706      IPC::SyncMessage* msg =
1707          new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
1708      msg->EnableMessagePumping();
1709      Send(msg);
1710      is_scripted_preview_delayed_ = false;
1711      return;
1712    }
1713    case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
1714      break;
1715    }
1716    case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
1717      DCHECK(has_selection);
1718      params.selection_only = has_selection;
1719      break;
1720    }
1721    case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
1722      params.webnode_only = true;
1723      break;
1724    }
1725    default: {
1726      NOTREACHED();
1727      return;
1728    }
1729  }
1730  Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
1731}
1732
1733bool PrintWebViewHelper::CheckForCancel() {
1734  const PrintMsg_Print_Params& print_params = print_pages_params_->params;
1735  bool cancel = false;
1736  Send(new PrintHostMsg_CheckForCancel(routing_id(),
1737                                       print_params.preview_ui_id,
1738                                       print_params.preview_request_id,
1739                                       &cancel));
1740  if (cancel)
1741    notify_browser_of_print_failure_ = false;
1742  return cancel;
1743}
1744
1745bool PrintWebViewHelper::PreviewPageRendered(int page_number,
1746                                             Metafile* metafile) {
1747  DCHECK_GE(page_number, FIRST_PAGE_INDEX);
1748
1749  // For non-modifiable files, |metafile| should be NULL, so do not bother
1750  // sending a message. If we don't generate draft metafiles, |metafile| is
1751  // NULL.
1752  if (!print_preview_context_.IsModifiable() ||
1753      !print_preview_context_.generate_draft_pages()) {
1754    DCHECK(!metafile);
1755    return true;
1756  }
1757
1758  if (!metafile) {
1759    NOTREACHED();
1760    print_preview_context_.set_error(
1761        PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE);
1762    return false;
1763  }
1764
1765  PrintHostMsg_DidPreviewPage_Params preview_page_params;
1766  // Get the size of the resulting metafile.
1767  uint32 buf_size = metafile->GetDataSize();
1768  DCHECK_GT(buf_size, 0u);
1769  if (!CopyMetafileDataToSharedMem(
1770      metafile, &(preview_page_params.metafile_data_handle))) {
1771    LOG(ERROR) << "CopyMetafileDataToSharedMem failed";
1772    print_preview_context_.set_error(PREVIEW_ERROR_METAFILE_COPY_FAILED);
1773    return false;
1774  }
1775  preview_page_params.data_size = buf_size;
1776  preview_page_params.page_number = page_number;
1777  preview_page_params.preview_request_id =
1778      print_pages_params_->params.preview_request_id;
1779
1780  Send(new PrintHostMsg_DidPreviewPage(routing_id(), preview_page_params));
1781  return true;
1782}
1783
1784PrintWebViewHelper::PrintPreviewContext::PrintPreviewContext()
1785    : total_page_count_(0),
1786      current_page_index_(0),
1787      generate_draft_pages_(true),
1788      print_ready_metafile_page_count_(0),
1789      error_(PREVIEW_ERROR_NONE),
1790      state_(UNINITIALIZED) {
1791}
1792
1793PrintWebViewHelper::PrintPreviewContext::~PrintPreviewContext() {
1794}
1795
1796void PrintWebViewHelper::PrintPreviewContext::InitWithFrame(
1797    blink::WebLocalFrame* web_frame) {
1798  DCHECK(web_frame);
1799  DCHECK(!IsRendering());
1800  state_ = INITIALIZED;
1801  source_frame_.Reset(web_frame);
1802  source_node_.reset();
1803}
1804
1805void PrintWebViewHelper::PrintPreviewContext::InitWithNode(
1806    const blink::WebNode& web_node) {
1807  DCHECK(!web_node.isNull());
1808  DCHECK(web_node.document().frame());
1809  DCHECK(!IsRendering());
1810  state_ = INITIALIZED;
1811  source_frame_.Reset(web_node.document().frame());
1812  source_node_ = web_node;
1813}
1814
1815void PrintWebViewHelper::PrintPreviewContext::OnPrintPreview() {
1816  DCHECK_EQ(INITIALIZED, state_);
1817  ClearContext();
1818}
1819
1820bool PrintWebViewHelper::PrintPreviewContext::CreatePreviewDocument(
1821    PrepareFrameAndViewForPrint* prepared_frame,
1822    const std::vector<int>& pages) {
1823  DCHECK_EQ(INITIALIZED, state_);
1824  state_ = RENDERING;
1825
1826  // Need to make sure old object gets destroyed first.
1827  prep_frame_view_.reset(prepared_frame);
1828  prep_frame_view_->StartPrinting();
1829
1830  total_page_count_ = prep_frame_view_->GetExpectedPageCount();
1831  if (total_page_count_ == 0) {
1832    LOG(ERROR) << "CreatePreviewDocument got 0 page count";
1833    set_error(PREVIEW_ERROR_ZERO_PAGES);
1834    return false;
1835  }
1836
1837  metafile_.reset(new PreviewMetafile);
1838  if (!metafile_->Init()) {
1839    set_error(PREVIEW_ERROR_METAFILE_INIT_FAILED);
1840    LOG(ERROR) << "PreviewMetafile Init failed";
1841    return false;
1842  }
1843
1844  current_page_index_ = 0;
1845  pages_to_render_ = pages;
1846  // Sort and make unique.
1847  std::sort(pages_to_render_.begin(), pages_to_render_.end());
1848  pages_to_render_.resize(std::unique(pages_to_render_.begin(),
1849                                      pages_to_render_.end()) -
1850                          pages_to_render_.begin());
1851  // Remove invalid pages.
1852  pages_to_render_.resize(std::lower_bound(pages_to_render_.begin(),
1853                                           pages_to_render_.end(),
1854                                           total_page_count_) -
1855                          pages_to_render_.begin());
1856  print_ready_metafile_page_count_ = pages_to_render_.size();
1857  if (pages_to_render_.empty()) {
1858    print_ready_metafile_page_count_ = total_page_count_;
1859    // Render all pages.
1860    for (int i = 0; i < total_page_count_; ++i)
1861      pages_to_render_.push_back(i);
1862  } else if (generate_draft_pages_) {
1863    int pages_index = 0;
1864    for (int i = 0; i < total_page_count_; ++i) {
1865      if (pages_index < print_ready_metafile_page_count_ &&
1866          i == pages_to_render_[pages_index]) {
1867        pages_index++;
1868        continue;
1869      }
1870      pages_to_render_.push_back(i);
1871    }
1872  }
1873
1874  document_render_time_ = base::TimeDelta();
1875  begin_time_ = base::TimeTicks::Now();
1876
1877  return true;
1878}
1879
1880void PrintWebViewHelper::PrintPreviewContext::RenderedPreviewPage(
1881    const base::TimeDelta& page_time) {
1882  DCHECK_EQ(RENDERING, state_);
1883  document_render_time_ += page_time;
1884  UMA_HISTOGRAM_TIMES("PrintPreview.RenderPDFPageTime", page_time);
1885}
1886
1887void PrintWebViewHelper::PrintPreviewContext::AllPagesRendered() {
1888  DCHECK_EQ(RENDERING, state_);
1889  state_ = DONE;
1890  prep_frame_view_->FinishPrinting();
1891}
1892
1893void PrintWebViewHelper::PrintPreviewContext::FinalizePrintReadyDocument() {
1894  DCHECK(IsRendering());
1895
1896  base::TimeTicks begin_time = base::TimeTicks::Now();
1897  metafile_->FinishDocument();
1898
1899  if (print_ready_metafile_page_count_ <= 0) {
1900    NOTREACHED();
1901    return;
1902  }
1903
1904  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderToPDFTime",
1905                             document_render_time_);
1906  base::TimeDelta total_time = (base::TimeTicks::Now() - begin_time) +
1907                               document_render_time_;
1908  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTime",
1909                             total_time);
1910  UMA_HISTOGRAM_MEDIUM_TIMES("PrintPreview.RenderAndGeneratePDFTimeAvgPerPage",
1911                             total_time / pages_to_render_.size());
1912}
1913
1914void PrintWebViewHelper::PrintPreviewContext::Finished() {
1915  DCHECK_EQ(DONE, state_);
1916  state_ = INITIALIZED;
1917  ClearContext();
1918}
1919
1920void PrintWebViewHelper::PrintPreviewContext::Failed(bool report_error) {
1921  DCHECK(state_ == INITIALIZED || state_ == RENDERING);
1922  state_ = INITIALIZED;
1923  if (report_error) {
1924    DCHECK_NE(PREVIEW_ERROR_NONE, error_);
1925    UMA_HISTOGRAM_ENUMERATION("PrintPreview.RendererError", error_,
1926                              PREVIEW_ERROR_LAST_ENUM);
1927  }
1928  ClearContext();
1929}
1930
1931int PrintWebViewHelper::PrintPreviewContext::GetNextPageNumber() {
1932  DCHECK_EQ(RENDERING, state_);
1933  if (IsFinalPageRendered())
1934    return -1;
1935  return pages_to_render_[current_page_index_++];
1936}
1937
1938bool PrintWebViewHelper::PrintPreviewContext::IsRendering() const {
1939  return state_ == RENDERING || state_ == DONE;
1940}
1941
1942bool PrintWebViewHelper::PrintPreviewContext::IsModifiable() {
1943  // The only kind of node we can print right now is a PDF node.
1944  return !PrintingNodeOrPdfFrame(source_frame(), source_node_);
1945}
1946
1947bool PrintWebViewHelper::PrintPreviewContext::HasSelection() {
1948  return IsModifiable() && source_frame()->hasSelection();
1949}
1950
1951bool PrintWebViewHelper::PrintPreviewContext::IsLastPageOfPrintReadyMetafile()
1952    const {
1953  DCHECK(IsRendering());
1954  return current_page_index_ == print_ready_metafile_page_count_;
1955}
1956
1957bool  PrintWebViewHelper::PrintPreviewContext::IsFinalPageRendered() const {
1958  DCHECK(IsRendering());
1959  return static_cast<size_t>(current_page_index_) == pages_to_render_.size();
1960}
1961
1962void PrintWebViewHelper::PrintPreviewContext::set_generate_draft_pages(
1963    bool generate_draft_pages) {
1964  DCHECK_EQ(INITIALIZED, state_);
1965  generate_draft_pages_ = generate_draft_pages;
1966}
1967
1968void PrintWebViewHelper::PrintPreviewContext::set_error(
1969    enum PrintPreviewErrorBuckets error) {
1970  error_ = error;
1971}
1972
1973blink::WebLocalFrame* PrintWebViewHelper::PrintPreviewContext::source_frame() {
1974  DCHECK(state_ != UNINITIALIZED);
1975  return source_frame_.GetFrame();
1976}
1977
1978const blink::WebNode&
1979    PrintWebViewHelper::PrintPreviewContext::source_node() const {
1980  DCHECK(state_ != UNINITIALIZED);
1981  return source_node_;
1982}
1983
1984blink::WebLocalFrame*
1985PrintWebViewHelper::PrintPreviewContext::prepared_frame() {
1986  DCHECK(state_ != UNINITIALIZED);
1987  return prep_frame_view_->frame();
1988}
1989
1990const blink::WebNode&
1991    PrintWebViewHelper::PrintPreviewContext::prepared_node() const {
1992  DCHECK(state_ != UNINITIALIZED);
1993  return prep_frame_view_->node();
1994}
1995
1996int PrintWebViewHelper::PrintPreviewContext::total_page_count() const {
1997  DCHECK(state_ != UNINITIALIZED);
1998  return total_page_count_;
1999}
2000
2001bool PrintWebViewHelper::PrintPreviewContext::generate_draft_pages() const {
2002  return generate_draft_pages_;
2003}
2004
2005PreviewMetafile* PrintWebViewHelper::PrintPreviewContext::metafile() {
2006  DCHECK(IsRendering());
2007  return metafile_.get();
2008}
2009
2010int PrintWebViewHelper::PrintPreviewContext::last_error() const {
2011  return error_;
2012}
2013
2014gfx::Size PrintWebViewHelper::PrintPreviewContext::GetPrintCanvasSize() const {
2015  DCHECK(IsRendering());
2016  return prep_frame_view_->GetPrintCanvasSize();
2017}
2018
2019void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
2020  prep_frame_view_.reset();
2021  metafile_.reset();
2022  pages_to_render_.clear();
2023  error_ = PREVIEW_ERROR_NONE;
2024}
2025
2026}  // namespace printing
2027