Add printing related source codes from chrome.

chromium_src/chrome/renderer/printing/print_web_view_helper.h

@@ -0,0 +1,457 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
+#define CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
+
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/shared_memory.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "content/public/renderer/render_view_observer.h"
+#include "content/public/renderer/render_view_observer_tracker.h"
+#include "printing/metafile_impl.h"
+#include "third_party/WebKit/public/platform/WebCanvas.h"
+#include "third_party/WebKit/public/web/WebNode.h"
+#include "third_party/WebKit/public/web/WebPrintParams.h"
+#include "ui/gfx/size.h"
+
+struct PrintMsg_Print_Params;
+struct PrintMsg_PrintPage_Params;
+struct PrintMsg_PrintPages_Params;
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace blink {
+class WebFrame;
+class WebView;
+}
+
+namespace printing {
+
+struct PageSizeMargins;
+class PrepareFrameAndViewForPrint;
+
+// Stores reference to frame using WebVew and unique name.
+// Workaround to modal dialog issue on Linux. crbug.com/236147.
+// If WebFrame someday supports WeakPtr, we should use it here.
+class FrameReference {
+ public:
+  explicit FrameReference(blink::WebLocalFrame* frame);
+  FrameReference();
+  ~FrameReference();
+
+  void Reset(blink::WebLocalFrame* frame);
+
+  blink::WebLocalFrame* GetFrame();
+  blink::WebView* view();
+
+ private:
+  blink::WebView* view_;
+  blink::WebLocalFrame* frame_;
+};
+
+// PrintWebViewHelper handles most of the printing grunt work for RenderView.
+// We plan on making print asynchronous and that will require copying the DOM
+// of the document and creating a new WebView with the contents.
+class PrintWebViewHelper
+    : public content::RenderViewObserver,
+      public content::RenderViewObserverTracker<PrintWebViewHelper> {
+ public:
+  explicit PrintWebViewHelper(content::RenderView* render_view);
+  virtual ~PrintWebViewHelper();
+
+  bool IsPrintingEnabled();
+
+  void PrintNode(const blink::WebNode& node);
+
+ private:
+  friend class PrintWebViewHelperTestBase;
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest,
+                           BlockScriptInitiatedPrinting);
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest,
+                           BlockScriptInitiatedPrintingFromPopup);
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, OnPrintPages);
+
+#if defined(OS_WIN) || defined(OS_MACOSX)
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, PrintLayoutTest);
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, PrintWithIframe);
+#endif  // defined(OS_WIN) || defined(OS_MACOSX)
+
+  enum PrintingResult {
+    OK,
+    FAIL_PRINT_INIT,
+    FAIL_PRINT,
+    FAIL_PREVIEW,
+  };
+
+  enum PrintPreviewErrorBuckets {
+    PREVIEW_ERROR_NONE,  // Always first.
+    PREVIEW_ERROR_BAD_SETTING,
+    PREVIEW_ERROR_METAFILE_COPY_FAILED,
+    PREVIEW_ERROR_METAFILE_INIT_FAILED,
+    PREVIEW_ERROR_ZERO_PAGES,
+    PREVIEW_ERROR_MAC_DRAFT_METAFILE_INIT_FAILED,
+    PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE,
+    PREVIEW_ERROR_UPDATING_PRINT_SETTINGS,
+    PREVIEW_ERROR_INVALID_PRINTER_SETTINGS,
+    PREVIEW_ERROR_LAST_ENUM  // Always last.
+  };
+
+  enum PrintPreviewRequestType {
+    PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME,
+    PRINT_PREVIEW_USER_INITIATED_SELECTION,
+    PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE,
+    PRINT_PREVIEW_SCRIPTED  // triggered by window.print().
+  };
+
+  // RenderViewObserver implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void PrintPage(blink::WebLocalFrame* frame,
+                         bool user_initiated) OVERRIDE;
+  virtual void DidStartLoading() OVERRIDE;
+  virtual void DidStopLoading() OVERRIDE;
+
+  // Message handlers ---------------------------------------------------------
+  void OnPrintPages();
+  void OnPrintForSystemDialog();
+  void OnInitiatePrintPreview(bool selection_only);
+  void OnPrintPreview(const base::DictionaryValue& settings);
+  void OnPrintForPrintPreview(const base::DictionaryValue& job_settings);
+  void OnPrintingDone(bool success);
+
+  // Get |page_size| and |content_area| information from
+  // |page_layout_in_points|.
+  void GetPageSizeAndContentAreaFromPageLayout(
+      const PageSizeMargins& page_layout_in_points,
+      gfx::Size* page_size,
+      gfx::Rect* content_area);
+
+  // Update |ignore_css_margins_| based on settings.
+  void UpdateFrameMarginsCssInfo(const base::DictionaryValue& settings);
+
+  // Returns true if the current destination printer is PRINT_TO_PDF.
+  bool IsPrintToPdfRequested(const base::DictionaryValue& settings);
+
+  // Prepare frame for creating preview document.
+  void PrepareFrameForPreviewDocument();
+
+  // Continue creating preview document.
+  void OnFramePreparedForPreviewDocument();
+
+  // Initialize the print preview document.
+  bool CreatePreviewDocument();
+
+  // Renders a print preview page. |page_number| is 0-based.
+  // Returns true if print preview should continue, false on failure.
+  bool RenderPreviewPage(int page_number,
+                         const PrintMsg_Print_Params& print_params);
+
+  // Finalize the print ready preview document.
+  bool FinalizePrintReadyDocument();
+
+  // Enable/Disable window.print calls.  If |blocked| is true window.print
+  // calls will silently fail.  Call with |blocked| set to false to reenable.
+  void SetScriptedPrintBlocked(bool blocked);
+
+  // Main printing code -------------------------------------------------------
+
+  void Print(blink::WebLocalFrame* frame, const blink::WebNode& node);
+
+  // Notification when printing is done - signal tear-down/free resources.
+  void DidFinishPrinting(PrintingResult result);
+
+  // Print Settings -----------------------------------------------------------
+
+  // Initialize print page settings with default settings.
+  // Used only for native printing workflow.
+  bool InitPrintSettings(bool fit_to_paper_size);
+
+  // Calculate number of pages in source document.
+  bool CalculateNumberOfPages(blink::WebLocalFrame* frame,
+                              const blink::WebNode& node,
+                              int* number_of_pages);
+
+  // Update the current print settings with new |passed_job_settings|.
+  // |passed_job_settings| dictionary contains print job details such as printer
+  // name, number of copies, page range, etc.
+  bool UpdatePrintSettings(blink::WebLocalFrame* frame,
+                           const blink::WebNode& node,
+                           const base::DictionaryValue& passed_job_settings);
+
+  // Get final print settings from the user.
+  // Return false if the user cancels or on error.
+  bool GetPrintSettingsFromUser(blink::WebFrame* frame,
+                                const blink::WebNode& node,
+                                int expected_pages_count);
+
+  // Page Printing / Rendering ------------------------------------------------
+
+  void OnFramePreparedForPrintPages();
+  void PrintPages();
+  bool PrintPagesNative(blink::WebFrame* frame,
+                        int page_count,
+                        const gfx::Size& canvas_size);
+  void FinishFramePrinting();
+
+  // Prints the page listed in |params|.
+#if defined(OS_LINUX) || defined(OS_ANDROID)
+  void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
+                         const gfx::Size& canvas_size,
+                         blink::WebFrame* frame,
+                         Metafile* metafile);
+#else
+  void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
+                         const gfx::Size& canvas_size,
+                         blink::WebFrame* frame);
+#endif
+
+  // Render the frame for printing.
+  bool RenderPagesForPrint(blink::WebLocalFrame* frame,
+                           const blink::WebNode& node);
+
+  // Platform specific helper function for rendering page(s) to |metafile|.
+#if defined(OS_WIN)
+  void RenderPage(const PrintMsg_Print_Params& params,
+                  int page_number,
+                  blink::WebFrame* frame,
+                  bool is_preview,
+                  Metafile* metafile,
+                  double* scale_factor,
+                  gfx::Size* page_size_in_dpi,
+                  gfx::Rect* content_area_in_dpi);
+#elif defined(OS_MACOSX)
+  void RenderPage(const PrintMsg_Print_Params& params,
+                  int page_number,
+                  blink::WebFrame* frame,
+                  bool is_preview,
+                  Metafile* metafile,
+                  gfx::Size* page_size,
+                  gfx::Rect* content_rect);
+#endif  // defined(OS_WIN)
+
+  // Renders page contents from |frame| to |content_area| of |canvas|.
+  // |page_number| is zero-based.
+  // When method is called, canvas should be setup to draw to |canvas_area|
+  // with |scale_factor|.
+  static float RenderPageContent(blink::WebFrame* frame,
+                                 int page_number,
+                                 const gfx::Rect& canvas_area,
+                                 const gfx::Rect& content_area,
+                                 double scale_factor,
+                                 blink::WebCanvas* canvas);
+
+  // Helper methods -----------------------------------------------------------
+
+  bool CopyMetafileDataToSharedMem(Metafile* metafile,
+                                   base::SharedMemoryHandle* shared_mem_handle);
+
+  // Helper method to get page layout in points and fit to page if needed.
+  static void ComputePageLayoutInPointsForCss(
+      blink::WebFrame* frame,
+      int page_index,
+      const PrintMsg_Print_Params& default_params,
+      bool ignore_css_margins,
+      double* scale_factor,
+      PageSizeMargins* page_layout_in_points);
+
+  // Given the |device| and |canvas| to draw on, prints the appropriate headers
+  // and footers using strings from |header_footer_info| on to the canvas.
+  static void PrintHeaderAndFooter(
+      blink::WebCanvas* canvas,
+      int page_number,
+      int total_pages,
+      float webkit_scale_factor,
+      const PageSizeMargins& page_layout_in_points,
+      const base::DictionaryValue& header_footer_info,
+      const PrintMsg_Print_Params& params);
+
+  bool GetPrintFrame(blink::WebLocalFrame** frame);
+
+  // Script Initiated Printing ------------------------------------------------
+
+  // Return true if script initiated printing is currently
+  // allowed. |user_initiated| should be true when a user event triggered the
+  // script, most likely by pressing a print button on the page.
+  bool IsScriptInitiatedPrintAllowed(blink::WebFrame* frame,
+                                     bool user_initiated);
+
+  // Returns true if script initiated printing occurs too often.
+  bool IsScriptInitiatedPrintTooFrequent(blink::WebFrame* frame);
+
+  // Reset the counter for script initiated printing.
+  // Scripted printing will be allowed to continue.
+  void ResetScriptedPrintCount();
+
+  // Increment the counter for script initiated printing.
+  // Scripted printing will be blocked for a limited amount of time.
+  void IncrementScriptedPrintCount();
+
+  // Shows scripted print preview when options from plugin are availible.
+  void ShowScriptedPrintPreview();
+
+  void RequestPrintPreview(PrintPreviewRequestType type);
+
+  // Checks whether print preview should continue or not.
+  // Returns true if cancelling, false if continuing.
+  bool CheckForCancel();
+
+  // Notifies the browser a print preview page has been rendered.
+  // |page_number| is 0-based.
+  // For a valid |page_number| with modifiable content,
+  // |metafile| is the rendered page. Otherwise |metafile| is NULL.
+  // Returns true if print preview should continue, false on failure.
+  bool PreviewPageRendered(int page_number, Metafile* metafile);
+
+  // WebView used only to print the selection.
+  scoped_ptr<PrepareFrameAndViewForPrint> prep_frame_view_;
+  bool reset_prep_frame_view_;
+
+  scoped_ptr<PrintMsg_PrintPages_Params> print_pages_params_;
+  bool is_preview_enabled_;
+  bool is_scripted_print_throttling_disabled_;
+  bool is_print_ready_metafile_sent_;
+  bool ignore_css_margins_;
+
+  // Used for scripted initiated printing blocking.
+  base::Time last_cancelled_script_print_;
+  int user_cancelled_scripted_print_count_;
+  bool is_scripted_printing_blocked_;
+
+  // Let the browser process know of a printing failure. Only set to false when
+  // the failure came from the browser in the first place.
+  bool notify_browser_of_print_failure_;
+
+  // True, when printing from print preview.
+  bool print_for_preview_;
+
+  // Strings generated by the browser process to be printed as headers and
+  // footers if requested by the user.
+  scoped_ptr<base::DictionaryValue> header_footer_info_;
+
+  // Keeps track of the state of print preview between messages.
+  // TODO(vitalybuka): Create PrintPreviewContext when needed and delete after
+  // use. Now it's interaction with various messages is confusing.
+  class PrintPreviewContext {
+   public:
+    PrintPreviewContext();
+    ~PrintPreviewContext();
+
+    // Initializes the print preview context. Need to be called to set
+    // the |web_frame| / |web_node| to generate the print preview for.
+    void InitWithFrame(blink::WebLocalFrame* web_frame);
+    void InitWithNode(const blink::WebNode& web_node);
+
+    // Does bookkeeping at the beginning of print preview.
+    void OnPrintPreview();
+
+    // Create the print preview document. |pages| is empty to print all pages.
+    // Takes ownership of |prepared_frame|.
+    bool CreatePreviewDocument(PrepareFrameAndViewForPrint* prepared_frame,
+                               const std::vector<int>& pages);
+
+    // Called after a page gets rendered. |page_time| is how long the
+    // rendering took.
+    void RenderedPreviewPage(const base::TimeDelta& page_time);
+
+    // Updates the print preview context when the required pages are rendered.
+    void AllPagesRendered();
+
+    // Finalizes the print ready preview document.
+    void FinalizePrintReadyDocument();
+
+    // Cleanup after print preview finishes.
+    void Finished();
+
+    // Cleanup after print preview fails.
+    void Failed(bool report_error);
+
+    // Helper functions
+    int GetNextPageNumber();
+    bool IsRendering() const;
+    bool IsModifiable();
+    bool HasSelection();
+    bool IsLastPageOfPrintReadyMetafile() const;
+    bool IsFinalPageRendered() const;
+
+    // Setters
+    void set_generate_draft_pages(bool generate_draft_pages);
+    void set_error(enum PrintPreviewErrorBuckets error);
+
+    // Getters
+    // Original frame for which preview was requested.
+    blink::WebLocalFrame* source_frame();
+    // Original node for which preview was requested.
+    const blink::WebNode& source_node() const;
+
+    // Frame to be use to render preview. May be the same as source_frame(), or
+    // generated from it, e.g. copy of selected block.
+    blink::WebLocalFrame* prepared_frame();
+    // Node to be use to render preview. May be the same as source_node(), or
+    // generated from it, e.g. copy of selected block.
+    const blink::WebNode& prepared_node() const;
+
+    int total_page_count() const;
+    bool generate_draft_pages() const;
+    PreviewMetafile* metafile();
+    gfx::Size GetPrintCanvasSize() const;
+    int last_error() const;
+
+   private:
+    enum State {
+      UNINITIALIZED,  // Not ready to render.
+      INITIALIZED,    // Ready to render.
+      RENDERING,      // Rendering.
+      DONE            // Finished rendering.
+    };
+
+    // Reset some of the internal rendering context.
+    void ClearContext();
+
+    // Specifies what to render for print preview.
+    FrameReference source_frame_;
+    blink::WebNode source_node_;
+
+    scoped_ptr<PrepareFrameAndViewForPrint> prep_frame_view_;
+    scoped_ptr<PreviewMetafile> metafile_;
+
+    // Total page count in the renderer.
+    int total_page_count_;
+
+    // The current page to render.
+    int current_page_index_;
+
+    // List of page indices that need to be rendered.
+    std::vector<int> pages_to_render_;
+
+    // True, when draft pages needs to be generated.
+    bool generate_draft_pages_;
+
+    // Specifies the total number of pages in the print ready metafile.
+    int print_ready_metafile_page_count_;
+
+    base::TimeDelta document_render_time_;
+    base::TimeTicks begin_time_;
+
+    enum PrintPreviewErrorBuckets error_;
+
+    State state_;
+  };
+
+  bool print_node_in_progress_;
+  PrintPreviewContext print_preview_context_;
+  bool is_loading_;
+  bool is_scripted_preview_delayed_;
+  base::WeakPtrFactory<PrintWebViewHelper> weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
+};
+
+}  // namespace printing
+
+#endif  // CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_

chromium_src/chrome/renderer/printing/print_web_view_helper_linux.cc

@@ -0,0 +1,198 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/renderer/printing/print_web_view_helper.h"
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/common/print_messages.h"
+#include "content/public/renderer/render_thread.h"
+#include "printing/metafile.h"
+#include "printing/metafile_impl.h"
+#include "printing/metafile_skia_wrapper.h"
+#include "printing/page_size_margins.h"
+#include "skia/ext/platform_device.h"
+#include "skia/ext/vector_canvas.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
+#include "base/process/process_handle.h"
+#else
+#include "base/file_descriptor_posix.h"
+#endif  // !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
+
+namespace printing {
+
+using blink::WebFrame;
+
+bool PrintWebViewHelper::RenderPreviewPage(
+    int page_number,
+    const PrintMsg_Print_Params& print_params) {
+  PrintMsg_PrintPage_Params page_params;
+  page_params.params = print_params;
+  page_params.page_number = page_number;
+  scoped_ptr<Metafile> draft_metafile;
+  Metafile* initial_render_metafile = print_preview_context_.metafile();
+  if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
+    draft_metafile.reset(new PreviewMetafile);
+    initial_render_metafile = draft_metafile.get();
+  }
+
+  base::TimeTicks begin_time = base::TimeTicks::Now();
+  PrintPageInternal(page_params,
+                    print_preview_context_.GetPrintCanvasSize(),
+                    print_preview_context_.prepared_frame(),
+                    initial_render_metafile);
+  print_preview_context_.RenderedPreviewPage(
+      base::TimeTicks::Now() - begin_time);
+  if (draft_metafile.get()) {
+    draft_metafile->FinishDocument();
+  } else if (print_preview_context_.IsModifiable() &&
+             print_preview_context_.generate_draft_pages()) {
+    DCHECK(!draft_metafile.get());
+    draft_metafile.reset(
+        print_preview_context_.metafile()->GetMetafileForCurrentPage());
+  }
+  return PreviewPageRendered(page_number, draft_metafile.get());
+}
+
+bool PrintWebViewHelper::PrintPagesNative(blink::WebFrame* frame,
+                                          int page_count,
+                                          const gfx::Size& canvas_size) {
+  NativeMetafile metafile;
+  if (!metafile.Init())
+    return false;
+
+  const PrintMsg_PrintPages_Params& params = *print_pages_params_;
+  std::vector<int> printed_pages;
+
+  if (params.pages.empty()) {
+    for (int i = 0; i < page_count; ++i) {
+      printed_pages.push_back(i);
+    }
+  } else {
+    // TODO(vitalybuka): redesign to make more code cross platform.
+    for (size_t i = 0; i < params.pages.size(); ++i) {
+      if (params.pages[i] >= 0 && params.pages[i] < page_count) {
+        printed_pages.push_back(params.pages[i]);
+      }
+    }
+  }
+
+  if (printed_pages.empty())
+    return false;
+
+  PrintMsg_PrintPage_Params page_params;
+  page_params.params = params.params;
+  for (size_t i = 0; i < printed_pages.size(); ++i) {
+    page_params.page_number = printed_pages[i];
+    PrintPageInternal(page_params, canvas_size, frame, &metafile);
+  }
+
+  // blink::printEnd() for PDF should be called before metafile is closed.
+  FinishFramePrinting();
+
+  metafile.FinishDocument();
+
+  // Get the size of the resulting metafile.
+  uint32 buf_size = metafile.GetDataSize();
+  DCHECK_GT(buf_size, 0u);
+
+#if defined(OS_CHROMEOS) || defined(OS_ANDROID)
+  int sequence_number = -1;
+  base::FileDescriptor fd;
+
+  // Ask the browser to open a file for us.
+  Send(new PrintHostMsg_AllocateTempFileForPrinting(routing_id(),
+                                                    &fd,
+                                                    &sequence_number));
+  if (!metafile.SaveToFD(fd))
+    return false;
+
+  // Tell the browser we've finished writing the file.
+  Send(new PrintHostMsg_TempFileForPrintingWritten(routing_id(),
+                                                   sequence_number));
+  return true;
+#else
+  PrintHostMsg_DidPrintPage_Params printed_page_params;
+  printed_page_params.data_size = 0;
+  printed_page_params.document_cookie = params.params.document_cookie;
+
+  {
+    scoped_ptr<base::SharedMemory> shared_mem(
+        content::RenderThread::Get()->HostAllocateSharedMemoryBuffer(
+            buf_size).release());
+    if (!shared_mem.get()) {
+      NOTREACHED() << "AllocateSharedMemoryBuffer failed";
+      return false;
+    }
+
+    if (!shared_mem->Map(buf_size)) {
+      NOTREACHED() << "Map failed";
+      return false;
+    }
+    metafile.GetData(shared_mem->memory(), buf_size);
+    printed_page_params.data_size = buf_size;
+    shared_mem->GiveToProcess(base::GetCurrentProcessHandle(),
+                              &(printed_page_params.metafile_data_handle));
+  }
+
+  for (size_t i = 0; i < printed_pages.size(); ++i) {
+    printed_page_params.page_number = printed_pages[i];
+    Send(new PrintHostMsg_DidPrintPage(routing_id(), printed_page_params));
+    // Send the rest of the pages with an invalid metafile handle.
+    printed_page_params.metafile_data_handle.fd = -1;
+  }
+  return true;
+#endif  // defined(OS_CHROMEOS)
+}
+
+void PrintWebViewHelper::PrintPageInternal(
+    const PrintMsg_PrintPage_Params& params,
+    const gfx::Size& canvas_size,
+    WebFrame* frame,
+    Metafile* metafile) {
+  PageSizeMargins page_layout_in_points;
+  double scale_factor = 1.0f;
+  ComputePageLayoutInPointsForCss(frame, params.page_number, params.params,
+                                  ignore_css_margins_, &scale_factor,
+                                  &page_layout_in_points);
+  gfx::Size page_size;
+  gfx::Rect content_area;
+  GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
+                                          &content_area);
+  gfx::Rect canvas_area =
+      params.params.display_header_footer ? gfx::Rect(page_size) : content_area;
+
+  SkBaseDevice* device = metafile->StartPageForVectorCanvas(page_size,
+                                                            canvas_area,
+                                                            scale_factor);
+  if (!device)
+    return;
+
+  // The printPage method take a reference to the canvas we pass down, so it
+  // can't be a stack object.
+  skia::RefPtr<skia::VectorCanvas> canvas =
+      skia::AdoptRef(new skia::VectorCanvas(device));
+  MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
+  skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
+
+  if (params.params.display_header_footer) {
+    // |page_number| is 0-based, so 1 is added.
+    // TODO(vitalybuka) : why does it work only with 1.25?
+    PrintHeaderAndFooter(canvas.get(), params.page_number + 1,
+                         print_preview_context_.total_page_count(),
+                         scale_factor / 1.25,
+                         page_layout_in_points, *header_footer_info_,
+                         params.params);
+  }
+  RenderPageContent(frame, params.page_number, canvas_area, content_area,
+                    scale_factor, canvas.get());
+
+  // Done printing. Close the device context to retrieve the compiled metafile.
+  if (!metafile->FinishPage())
+    NOTREACHED() << "metafile failed";
+}
+
+}  // namespace printing

chromium_src/chrome/renderer/printing/print_web_view_helper_mac.mm

@@ -0,0 +1,147 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/renderer/printing/print_web_view_helper.h"
+
+#import <AppKit/AppKit.h>
+
+#include "base/logging.h"
+#include "base/mac/scoped_nsautorelease_pool.h"
+#include "base/metrics/histogram.h"
+#include "chrome/common/print_messages.h"
+#include "printing/metafile.h"
+#include "printing/metafile_impl.h"
+#include "printing/metafile_skia_wrapper.h"
+#include "printing/page_size_margins.h"
+#include "skia/ext/platform_device.h"
+#include "skia/ext/vector_canvas.h"
+#include "third_party/WebKit/public/platform/WebCanvas.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+
+namespace printing {
+
+using blink::WebFrame;
+
+void PrintWebViewHelper::PrintPageInternal(
+    const PrintMsg_PrintPage_Params& params,
+    const gfx::Size& canvas_size,
+    WebFrame* frame) {
+  NativeMetafile metafile;
+  if (!metafile.Init())
+    return;
+
+  int page_number = params.page_number;
+  gfx::Size page_size_in_dpi;
+  gfx::Rect content_area_in_dpi;
+  RenderPage(print_pages_params_->params, page_number, frame, false, &metafile,
+             &page_size_in_dpi, &content_area_in_dpi);
+  metafile.FinishDocument();
+
+  PrintHostMsg_DidPrintPage_Params page_params;
+  page_params.data_size = metafile.GetDataSize();
+  page_params.page_number = page_number;
+  page_params.document_cookie = params.params.document_cookie;
+  page_params.page_size = page_size_in_dpi;
+  page_params.content_area = content_area_in_dpi;
+
+  // Ask the browser to create the shared memory for us.
+  if (!CopyMetafileDataToSharedMem(&metafile,
+                                   &(page_params.metafile_data_handle))) {
+    page_params.data_size = 0;
+  }
+
+  Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
+}
+
+bool PrintWebViewHelper::RenderPreviewPage(
+    int page_number,
+    const PrintMsg_Print_Params& print_params) {
+  PrintMsg_Print_Params printParams = print_params;
+  scoped_ptr<Metafile> draft_metafile;
+  Metafile* initial_render_metafile = print_preview_context_.metafile();
+
+  bool render_to_draft = print_preview_context_.IsModifiable() &&
+                         is_print_ready_metafile_sent_;
+
+  if (render_to_draft) {
+    draft_metafile.reset(new PreviewMetafile());
+    if (!draft_metafile->Init()) {
+      print_preview_context_.set_error(
+          PREVIEW_ERROR_MAC_DRAFT_METAFILE_INIT_FAILED);
+      LOG(ERROR) << "Draft PreviewMetafile Init failed";
+      return false;
+    }
+    initial_render_metafile = draft_metafile.get();
+  }
+
+  base::TimeTicks begin_time = base::TimeTicks::Now();
+  gfx::Size page_size;
+  RenderPage(printParams, page_number, print_preview_context_.prepared_frame(),
+             true, initial_render_metafile, &page_size, NULL);
+  print_preview_context_.RenderedPreviewPage(
+      base::TimeTicks::Now() - begin_time);
+
+  if (draft_metafile.get()) {
+    draft_metafile->FinishDocument();
+  } else {
+    if (print_preview_context_.IsModifiable() &&
+        print_preview_context_.generate_draft_pages()) {
+      DCHECK(!draft_metafile.get());
+      draft_metafile.reset(
+          print_preview_context_.metafile()->GetMetafileForCurrentPage());
+    }
+  }
+  return PreviewPageRendered(page_number, draft_metafile.get());
+}
+
+void PrintWebViewHelper::RenderPage(
+    const PrintMsg_Print_Params& params, int page_number, WebFrame* frame,
+    bool is_preview, Metafile* metafile, gfx::Size* page_size,
+    gfx::Rect* content_rect) {
+  double scale_factor = 1.0f;
+  double webkit_shrink_factor = frame->getPrintPageShrink(page_number);
+  PageSizeMargins page_layout_in_points;
+  gfx::Rect content_area;
+
+  ComputePageLayoutInPointsForCss(frame, page_number, params,
+                                  ignore_css_margins_, &scale_factor,
+                                  &page_layout_in_points);
+  GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, page_size,
+                                          &content_area);
+  if (content_rect)
+    *content_rect = content_area;
+
+  scale_factor *= webkit_shrink_factor;
+
+  gfx::Rect canvas_area =
+      params.display_header_footer ? gfx::Rect(*page_size) : content_area;
+
+  {
+    SkBaseDevice* device = metafile->StartPageForVectorCanvas(
+        *page_size, canvas_area, scale_factor);
+    if (!device)
+      return;
+
+    skia::RefPtr<skia::VectorCanvas> canvas =
+        skia::AdoptRef(new skia::VectorCanvas(device));
+    blink::WebCanvas* canvas_ptr = canvas.get();
+    MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
+    skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
+    skia::SetIsPreviewMetafile(*canvas, is_preview);
+
+    if (print_pages_params_->params.display_header_footer) {
+      PrintHeaderAndFooter(canvas_ptr, page_number + 1,
+                           print_preview_context_.total_page_count(),
+                           scale_factor, page_layout_in_points,
+                           *header_footer_info_, params);
+    }
+    RenderPageContent(frame, page_number, canvas_area, content_area,
+                      scale_factor, canvas_ptr);
+  }
+
+  // Done printing. Close the device context to retrieve the compiled metafile.
+  metafile->FinishPage();
+}
+
+}  // namespace printing

chromium_src/chrome/renderer/printing/print_web_view_helper_win.cc

@@ -0,0 +1,249 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/renderer/printing/print_web_view_helper.h"
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
+#include "base/process/process_handle.h"
+#include "base/win/scoped_gdi_object.h"
+#include "base/win/scoped_hdc.h"
+#include "base/win/scoped_select_object.h"
+#include "chrome/common/print_messages.h"
+#include "printing/metafile.h"
+#include "printing/metafile_impl.h"
+#include "printing/metafile_skia_wrapper.h"
+#include "printing/page_size_margins.h"
+#include "printing/units.h"
+#include "skia/ext/platform_device.h"
+#include "skia/ext/refptr.h"
+#include "skia/ext/vector_canvas.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "ui/gfx/gdi_util.h"
+#include "ui/gfx/point.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/size.h"
+
+namespace printing {
+
+using blink::WebFrame;
+
+void PrintWebViewHelper::PrintPageInternal(
+    const PrintMsg_PrintPage_Params& params,
+    const gfx::Size& canvas_size,
+    WebFrame* frame) {
+  // Generate a memory-based metafile. It will use the current screen's DPI.
+  // Each metafile contains a single page.
+  scoped_ptr<NativeMetafile> metafile(new NativeMetafile);
+  metafile->Init();
+  DCHECK(metafile->context());
+  skia::InitializeDC(metafile->context());
+
+  int page_number = params.page_number;
+
+  // Calculate the dpi adjustment.
+  // Browser will render context using desired_dpi, so we need to calculate
+  // adjustment factor to play content on the printer DC later during the
+  // actual printing.
+  double actual_shrink = static_cast<float>(params.params.desired_dpi /
+                                            params.params.dpi);
+  gfx::Size page_size_in_dpi;
+  gfx::Rect content_area_in_dpi;
+
+  // Render page for printing.
+  RenderPage(params.params, page_number, frame, false, metafile.get(),
+             &actual_shrink, &page_size_in_dpi, &content_area_in_dpi);
+
+  // Close the device context to retrieve the compiled metafile.
+  if (!metafile->FinishDocument())
+    NOTREACHED();
+
+  if (!params.params.supports_alpha_blend && metafile->IsAlphaBlendUsed()) {
+    scoped_ptr<NativeMetafile> raster_metafile(
+        metafile->RasterizeAlphaBlend());
+    if (raster_metafile.get())
+      metafile.swap(raster_metafile);
+  }
+
+  // Get the size of the compiled metafile.
+  uint32 buf_size = metafile->GetDataSize();
+  DCHECK_GT(buf_size, 128u);
+
+  PrintHostMsg_DidPrintPage_Params page_params;
+  page_params.data_size = buf_size;
+  page_params.metafile_data_handle = NULL;
+  page_params.page_number = page_number;
+  page_params.document_cookie = params.params.document_cookie;
+  page_params.actual_shrink = actual_shrink;
+  page_params.page_size = page_size_in_dpi;
+  page_params.content_area = content_area_in_dpi;
+
+  if (!CopyMetafileDataToSharedMem(metafile.get(),
+                                   &(page_params.metafile_data_handle))) {
+    page_params.data_size = 0;
+  }
+
+  Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
+}
+
+bool PrintWebViewHelper::RenderPreviewPage(
+    int page_number,
+    const PrintMsg_Print_Params& print_params) {
+  // Calculate the dpi adjustment.
+  double actual_shrink = static_cast<float>(print_params.desired_dpi /
+                                            print_params.dpi);
+  scoped_ptr<Metafile> draft_metafile;
+  Metafile* initial_render_metafile = print_preview_context_.metafile();
+
+  if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
+    draft_metafile.reset(new PreviewMetafile);
+    initial_render_metafile = draft_metafile.get();
+  }
+
+  base::TimeTicks begin_time = base::TimeTicks::Now();
+  RenderPage(print_params, page_number, print_preview_context_.prepared_frame(),
+             true, initial_render_metafile, &actual_shrink, NULL, NULL);
+  print_preview_context_.RenderedPreviewPage(
+      base::TimeTicks::Now() - begin_time);
+
+  if (draft_metafile.get()) {
+    draft_metafile->FinishDocument();
+  } else if (print_preview_context_.IsModifiable() &&
+             print_preview_context_.generate_draft_pages()) {
+    DCHECK(!draft_metafile.get());
+    draft_metafile.reset(
+        print_preview_context_.metafile()->GetMetafileForCurrentPage());
+  }
+  return PreviewPageRendered(page_number, draft_metafile.get());
+}
+
+void PrintWebViewHelper::RenderPage(
+    const PrintMsg_Print_Params& params, int page_number, WebFrame* frame,
+    bool is_preview, Metafile* metafile, double* actual_shrink,
+    gfx::Size* page_size_in_dpi, gfx::Rect* content_area_in_dpi) {
+  PageSizeMargins page_layout_in_points;
+  double css_scale_factor = 1.0f;
+  ComputePageLayoutInPointsForCss(frame, page_number, params,
+                                  ignore_css_margins_, &css_scale_factor,
+                                  &page_layout_in_points);
+  gfx::Size page_size;
+  gfx::Rect content_area;
+  GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
+                                          &content_area);
+  int dpi = static_cast<int>(params.dpi);
+  // Calculate the actual page size and content area in dpi.
+  if (page_size_in_dpi) {
+    *page_size_in_dpi = gfx::Size(
+        static_cast<int>(ConvertUnitDouble(page_size.width(), kPointsPerInch,
+                                           dpi)),
+        static_cast<int>(ConvertUnitDouble(page_size.height(), kPointsPerInch,
+                                           dpi)));
+  }
+
+  if (content_area_in_dpi) {
+    *content_area_in_dpi = gfx::Rect(
+        static_cast<int>(ConvertUnitDouble(content_area.x(), kPointsPerInch,
+                                           dpi)),
+        static_cast<int>(ConvertUnitDouble(content_area.y(), kPointsPerInch,
+                                           dpi)),
+        static_cast<int>(ConvertUnitDouble(content_area.width(), kPointsPerInch,
+                                           dpi)),
+        static_cast<int>(ConvertUnitDouble(content_area.height(),
+                                           kPointsPerInch, dpi)));
+  }
+
+  if (!is_preview) {
+    // Since WebKit extends the page width depending on the magical scale factor
+    // we make sure the canvas covers the worst case scenario (x2.0 currently).
+    // PrintContext will then set the correct clipping region.
+    page_size = gfx::Size(
+        static_cast<int>(page_layout_in_points.content_width *
+                         params.max_shrink),
+        static_cast<int>(page_layout_in_points.content_height *
+                         params.max_shrink));
+  }
+
+  float webkit_page_shrink_factor = frame->getPrintPageShrink(page_number);
+  float scale_factor = css_scale_factor * webkit_page_shrink_factor;
+
+  gfx::Rect canvas_area =
+      params.display_header_footer ? gfx::Rect(page_size) : content_area;
+
+  SkBaseDevice* device = metafile->StartPageForVectorCanvas(
+      page_size, canvas_area, scale_factor);
+  DCHECK(device);
+  // The printPage method may take a reference to the canvas we pass down, so it
+  // can't be a stack object.
+  skia::RefPtr<skia::VectorCanvas> canvas =
+      skia::AdoptRef(new skia::VectorCanvas(device));
+
+  if (is_preview) {
+    MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
+    skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
+    skia::SetIsPreviewMetafile(*canvas, is_preview);
+  }
+
+  if (params.display_header_footer) {
+    // |page_number| is 0-based, so 1 is added.
+    PrintHeaderAndFooter(canvas.get(), page_number + 1,
+        print_preview_context_.total_page_count(), scale_factor,
+        page_layout_in_points, *header_footer_info_, params);
+  }
+
+  float webkit_scale_factor = RenderPageContent(frame, page_number, canvas_area,
+                                                content_area, scale_factor,
+                                                canvas.get());
+
+  if (*actual_shrink <= 0 || webkit_scale_factor <= 0) {
+    NOTREACHED() << "Printing page " << page_number << " failed.";
+  } else {
+    // While rendering certain plugins (PDF) to metafile, we might need to
+    // set custom scale factor. Update |actual_shrink| with custom scale
+    // if it is set on canvas.
+    // TODO(gene): We should revisit this solution for the next versions.
+    // Consider creating metafile of the right size (or resizable)
+    // https://code.google.com/p/chromium/issues/detail?id=126037
+    if (!MetafileSkiaWrapper::GetCustomScaleOnCanvas(
+            *canvas, actual_shrink)) {
+      // Update the dpi adjustment with the "page |actual_shrink|" calculated in
+      // webkit.
+      *actual_shrink /= (webkit_scale_factor * css_scale_factor);
+    }
+  }
+
+  bool result = metafile->FinishPage();
+  DCHECK(result);
+}
+
+bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
+    Metafile* metafile, base::SharedMemoryHandle* shared_mem_handle) {
+  uint32 buf_size = metafile->GetDataSize();
+  base::SharedMemory shared_buf;
+  if (buf_size >= kMetafileMaxSize) {
+    NOTREACHED() << "Buffer too large: " << buf_size;
+    return false;
+  }
+
+  // Allocate a shared memory buffer to hold the generated metafile data.
+  if (!shared_buf.CreateAndMapAnonymous(buf_size)) {
+    NOTREACHED() << "Buffer allocation failed";
+    return false;
+  }
+
+  // Copy the bits into shared memory.
+  if (!metafile->GetData(shared_buf.memory(), buf_size)) {
+    NOTREACHED() << "GetData() failed";
+    shared_buf.Unmap();
+    return false;
+  }
+  shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), shared_mem_handle);
+  shared_buf.Unmap();
+
+  Send(new PrintHostMsg_DuplicateSection(routing_id(), *shared_mem_handle,
+                                         shared_mem_handle));
+  return true;
+}
+
+}  // namespace printing