chrome/renderer/printing/print_web_view_helper_win.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/renderer/printing/print_web_view_helper.h"
   6
   7 #include "base/logging.h"
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/metrics/histogram.h"
  10 #include "base/process/process_handle.h"
  11 #include "base/win/scoped_gdi_object.h"
  12 #include "base/win/scoped_hdc.h"
  13 #include "base/win/scoped_select_object.h"
  14 #include "chrome/common/print_messages.h"
  15 #include "printing/metafile.h"
  16 #include "printing/metafile_impl.h"
  17 #include "printing/metafile_skia_wrapper.h"
  18 #include "printing/page_size_margins.h"
  19 #include "printing/units.h"
  20 #include "skia/ext/platform_device.h"
  21 #include "skia/ext/refptr.h"
  22 #include "skia/ext/vector_canvas.h"
  23 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  24 #include "ui/gfx/gdi_util.h"
  25 #include "ui/gfx/point.h"
  26 #include "ui/gfx/rect.h"
  27 #include "ui/gfx/size.h"
  28
  29 namespace printing {
  30
  31 using blink::WebFrame;
  32
  33 void PrintWebViewHelper::PrintPageInternal(
  34     const PrintMsg_PrintPage_Params& params,
  35     const gfx::Size& canvas_size,
  36     WebFrame* frame) {
  37   // Generate a memory-based metafile. It will use the current screen's DPI.
  38   // Each metafile contains a single page.
  39   scoped_ptr<NativeMetafile> metafile(new NativeMetafile);
  40   metafile->Init();
  41   DCHECK(metafile->context());
  42   skia::InitializeDC(metafile->context());
  43
  44   int page_number = params.page_number;
  45
  46   // Calculate the dpi adjustment.
  47   // Browser will render context using desired_dpi, so we need to calculate
  48   // adjustment factor to play content on the printer DC later during the
  49   // actual printing.
  50   double actual_shrink = static_cast<float>(params.params.desired_dpi /
  51                                             params.params.dpi);
  52   gfx::Size page_size_in_dpi;
  53   gfx::Rect content_area_in_dpi;
  54
  55   // Render page for printing.
  56   RenderPage(params.params, page_number, frame, false, metafile.get(),
  57              &actual_shrink, &page_size_in_dpi, &content_area_in_dpi);
  58
  59   // Close the device context to retrieve the compiled metafile.
  60   if (!metafile->FinishDocument())
  61     NOTREACHED();
  62
  63   if (!params.params.supports_alpha_blend && metafile->IsAlphaBlendUsed()) {
  64     scoped_ptr<NativeMetafile> raster_metafile(
  65         metafile->RasterizeAlphaBlend());
  66     if (raster_metafile.get())
  67       metafile.swap(raster_metafile);
  68   }
  69
  70   // Get the size of the compiled metafile.
  71   uint32 buf_size = metafile->GetDataSize();
  72   DCHECK_GT(buf_size, 128u);
  73
  74   PrintHostMsg_DidPrintPage_Params page_params;
  75   page_params.data_size = buf_size;
  76   page_params.metafile_data_handle = NULL;
  77   page_params.page_number = page_number;
  78   page_params.document_cookie = params.params.document_cookie;
  79   page_params.actual_shrink = actual_shrink;
  80   page_params.page_size = page_size_in_dpi;
  81   page_params.content_area = content_area_in_dpi;
  82
  83   if (!CopyMetafileDataToSharedMem(metafile.get(),
  84                                    &(page_params.metafile_data_handle))) {
  85     page_params.data_size = 0;
  86   }
  87
  88   Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
  89 }
  90
  91 bool PrintWebViewHelper::RenderPreviewPage(
  92     int page_number,
  93     const PrintMsg_Print_Params& print_params) {
  94   // Calculate the dpi adjustment.
  95   double actual_shrink = static_cast<float>(print_params.desired_dpi /
  96                                             print_params.dpi);
  97   scoped_ptr<Metafile> draft_metafile;
  98   Metafile* initial_render_metafile = print_preview_context_.metafile();
  99
 100   if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
 101     draft_metafile.reset(new PreviewMetafile);
 102     initial_render_metafile = draft_metafile.get();
 103   }
 104
 105   base::TimeTicks begin_time = base::TimeTicks::Now();
 106   RenderPage(print_params, page_number, print_preview_context_.prepared_frame(),
 107              true, initial_render_metafile, &actual_shrink, NULL, NULL);
 108   print_preview_context_.RenderedPreviewPage(
 109       base::TimeTicks::Now() - begin_time);
 110
 111   if (draft_metafile.get()) {
 112     draft_metafile->FinishDocument();
 113   } else if (print_preview_context_.IsModifiable() &&
 114              print_preview_context_.generate_draft_pages()) {
 115     DCHECK(!draft_metafile.get());
 116     draft_metafile.reset(
 117         print_preview_context_.metafile()->GetMetafileForCurrentPage());
 118   }
 119   return PreviewPageRendered(page_number, draft_metafile.get());
 120 }
 121
 122 void PrintWebViewHelper::RenderPage(
 123     const PrintMsg_Print_Params& params, int page_number, WebFrame* frame,
 124     bool is_preview, Metafile* metafile, double* actual_shrink,
 125     gfx::Size* page_size_in_dpi, gfx::Rect* content_area_in_dpi) {
 126   PageSizeMargins page_layout_in_points;
 127   double css_scale_factor = 1.0f;
 128   ComputePageLayoutInPointsForCss(frame, page_number, params,
 129                                   ignore_css_margins_, &css_scale_factor,
 130                                   &page_layout_in_points);
 131   gfx::Size page_size;
 132   gfx::Rect content_area;
 133   GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
 134                                           &content_area);
 135   int dpi = static_cast<int>(params.dpi);
 136   // Calculate the actual page size and content area in dpi.
 137   if (page_size_in_dpi) {
 138     *page_size_in_dpi = gfx::Size(
 139         static_cast<int>(ConvertUnitDouble(page_size.width(), kPointsPerInch,
 140                                            dpi)),
 141         static_cast<int>(ConvertUnitDouble(page_size.height(), kPointsPerInch,
 142                                            dpi)));
 143   }
 144
 145   if (content_area_in_dpi) {
 146     *content_area_in_dpi = gfx::Rect(
 147         static_cast<int>(ConvertUnitDouble(content_area.x(), kPointsPerInch,
 148                                            dpi)),
 149         static_cast<int>(ConvertUnitDouble(content_area.y(), kPointsPerInch,
 150                                            dpi)),
 151         static_cast<int>(ConvertUnitDouble(content_area.width(), kPointsPerInch,
 152                                            dpi)),
 153         static_cast<int>(ConvertUnitDouble(content_area.height(),
 154                                            kPointsPerInch, dpi)));
 155   }
 156
 157   if (!is_preview) {
 158     // Since WebKit extends the page width depending on the magical scale factor
 159     // we make sure the canvas covers the worst case scenario (x2.0 currently).
 160     // PrintContext will then set the correct clipping region.
 161     page_size = gfx::Size(
 162         static_cast<int>(page_layout_in_points.content_width *
 163                          params.max_shrink),
 164         static_cast<int>(page_layout_in_points.content_height *
 165                          params.max_shrink));
 166   }
 167
 168   float webkit_page_shrink_factor = frame->getPrintPageShrink(page_number);
 169   float scale_factor = css_scale_factor * webkit_page_shrink_factor;
 170
 171   gfx::Rect canvas_area =
 172       params.display_header_footer ? gfx::Rect(page_size) : content_area;
 173
 174   SkBaseDevice* device = metafile->StartPageForVectorCanvas(
 175       page_size, canvas_area, scale_factor);
 176   DCHECK(device);
 177   // The printPage method may take a reference to the canvas we pass down, so it
 178   // can't be a stack object.
 179   skia::RefPtr<skia::VectorCanvas> canvas =
 180       skia::AdoptRef(new skia::VectorCanvas(device));
 181
 182   if (is_preview) {
 183     MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
 184     skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
 185     skia::SetIsPreviewMetafile(*canvas, is_preview);
 186   }
 187
 188   if (params.display_header_footer) {
 189     // |page_number| is 0-based, so 1 is added.
 190     PrintHeaderAndFooter(canvas.get(), page_number + 1,
 191         print_preview_context_.total_page_count(), scale_factor,
 192         page_layout_in_points, *header_footer_info_, params);
 193   }
 194
 195   float webkit_scale_factor = RenderPageContent(frame, page_number, canvas_area,
 196                                                 content_area, scale_factor,
 197                                                 canvas.get());
 198
 199   if (*actual_shrink <= 0 || webkit_scale_factor <= 0) {
 200     NOTREACHED() << "Printing page " << page_number << " failed.";
 201   } else {
 202     // While rendering certain plugins (PDF) to metafile, we might need to
 203     // set custom scale factor. Update |actual_shrink| with custom scale
 204     // if it is set on canvas.
 205     // TODO(gene): We should revisit this solution for the next versions.
 206     // Consider creating metafile of the right size (or resizable)
 207     // https://code.google.com/p/chromium/issues/detail?id=126037
 208     if (!MetafileSkiaWrapper::GetCustomScaleOnCanvas(
 209             *canvas, actual_shrink)) {
 210       // Update the dpi adjustment with the "page |actual_shrink|" calculated in
 211       // webkit.
 212       *actual_shrink /= (webkit_scale_factor * css_scale_factor);
 213     }
 214   }
 215
 216   bool result = metafile->FinishPage();
 217   DCHECK(result);
 218 }
 219
 220 bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
 221     Metafile* metafile, base::SharedMemoryHandle* shared_mem_handle) {
 222   uint32 buf_size = metafile->GetDataSize();
 223   base::SharedMemory shared_buf;
 224   if (buf_size >= kMetafileMaxSize) {
 225     NOTREACHED() << "Buffer too large: " << buf_size;
 226     return false;
 227   }
 228
 229   // Allocate a shared memory buffer to hold the generated metafile data.
 230   if (!shared_buf.CreateAndMapAnonymous(buf_size)) {
 231     NOTREACHED() << "Buffer allocation failed";
 232     return false;
 233   }
 234
 235   // Copy the bits into shared memory.
 236   if (!metafile->GetData(shared_buf.memory(), buf_size)) {
 237     NOTREACHED() << "GetData() failed";
 238     shared_buf.Unmap();
 239     return false;
 240   }
 241   shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), shared_mem_handle);
 242   shared_buf.Unmap();
 243
 244   Send(new PrintHostMsg_DuplicateSection(routing_id(), *shared_mem_handle,
 245                                          shared_mem_handle));
 246   return true;
 247 }
 248
 249 }  // namespace printing