printing/image_win.cc

   1 // Copyright (c) 2011 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 "printing/image.h"
   6
   7 #include "printing/metafile.h"
   8 #include "skia/ext/platform_device.h"
   9 #include "ui/gfx/gdi_util.h"  // EMF support
  10 #include "ui/gfx/rect.h"
  11
  12 namespace {
  13
  14 // A simple class which temporarily overrides system settings.
  15 // The bitmap image rendered via the PlayEnhMetaFile() function depends on
  16 // some system settings.
  17 // As a workaround for such dependency, this class saves the system settings
  18 // and changes them. This class also restore the saved settings in its
  19 // destructor.
  20 class DisableFontSmoothing {
  21  public:
  22   explicit DisableFontSmoothing() : enable_again_(false) {
  23     BOOL enabled;
  24     if (SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &enabled, 0) &&
  25         enabled) {
  26       if (SystemParametersInfo(SPI_SETFONTSMOOTHING, FALSE, NULL, 0))
  27         enable_again_ = true;
  28     }
  29   }
  30
  31   ~DisableFontSmoothing() {
  32     if (enable_again_) {
  33       BOOL result = SystemParametersInfo(SPI_SETFONTSMOOTHING, TRUE, NULL, 0);
  34       DCHECK(result);
  35     }
  36   }
  37
  38  private:
  39   bool enable_again_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(DisableFontSmoothing);
  42 };
  43
  44 }  // namespace
  45
  46 namespace printing {
  47
  48 bool Image::LoadMetafile(const Metafile& metafile) {
  49     gfx::Rect rect(metafile.GetPageBounds(1));
  50   DisableFontSmoothing disable_in_this_scope;
  51
  52   // Create a temporary HDC and bitmap to retrieve the rendered data.
  53   HDC hdc = CreateCompatibleDC(NULL);
  54   BITMAPV4HEADER hdr;
  55   DCHECK_EQ(rect.x(), 0);
  56   DCHECK_EQ(rect.y(), 0);
  57   DCHECK_GE(rect.width(), 0);  // Metafile could be empty.
  58   DCHECK_GE(rect.height(), 0);
  59
  60   if (rect.width() < 1 || rect.height() < 1)
  61     return false;
  62
  63   size_ = rect.size();
  64   gfx::CreateBitmapV4Header(rect.width(), rect.height(), &hdr);
  65   void* bits;
  66   HBITMAP bitmap = CreateDIBSection(hdc,
  67                                     reinterpret_cast<BITMAPINFO*>(&hdr), 0,
  68                                     &bits, NULL, 0);
  69   DCHECK(bitmap);
  70   DCHECK(SelectObject(hdc, bitmap));
  71
  72   skia::InitializeDC(hdc);
  73
  74   bool success = metafile.Playback(hdc, NULL);
  75
  76   row_length_ = size_.width() * sizeof(uint32);
  77   size_t bytes = row_length_ * size_.height();
  78   DCHECK(bytes);
  79
  80   data_.resize(bytes);
  81   memcpy(&*data_.begin(), bits, bytes);
  82
  83   DeleteDC(hdc);
  84   DeleteObject(bitmap);
  85
  86   return success;
  87 }
  88
  89 }  // namespace printing