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 "base/win/scoped_gdi_object.h"
   8 #include "base/win/scoped_hdc.h"
   9 #include "base/win/scoped_select_object.h"
  10 #include "printing/metafile.h"
  11 #include "skia/ext/platform_device.h"
  12 #include "ui/gfx/gdi_util.h"  // EMF support
  13 #include "ui/gfx/geometry/rect.h"
  14
  15
  16 namespace {
  17
  18 // A simple class which temporarily overrides system settings.
  19 // The bitmap image rendered via the PlayEnhMetaFile() function depends on
  20 // some system settings.
  21 // As a workaround for such dependency, this class saves the system settings
  22 // and changes them. This class also restore the saved settings in its
  23 // destructor.
  24 class DisableFontSmoothing {
  25  public:
  26   DisableFontSmoothing() : enable_again_(false) {
  27     BOOL enabled;
  28     if (SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &enabled, 0) &&
  29         enabled) {
  30       if (SystemParametersInfo(SPI_SETFONTSMOOTHING, FALSE, NULL, 0))
  31         enable_again_ = true;
  32     }
  33   }
  34
  35   ~DisableFontSmoothing() {
  36     if (enable_again_) {
  37       BOOL result = SystemParametersInfo(SPI_SETFONTSMOOTHING, TRUE, NULL, 0);
  38       DCHECK(result);
  39     }
  40   }
  41
  42  private:
  43   bool enable_again_;
  44
  45   DISALLOW_COPY_AND_ASSIGN(DisableFontSmoothing);
  46 };
  47
  48 }  // namespace
  49
  50 namespace printing {
  51
  52 bool Image::LoadMetafile(const Metafile& metafile) {
  53     gfx::Rect rect(metafile.GetPageBounds(1));
  54   DisableFontSmoothing disable_in_this_scope;
  55
  56   // Create a temporary HDC and bitmap to retrieve the rendered data.
  57   base::win::ScopedCreateDC hdc(::CreateCompatibleDC(NULL));
  58   BITMAPV4HEADER hdr;
  59   DCHECK_EQ(rect.x(), 0);
  60   DCHECK_EQ(rect.y(), 0);
  61   DCHECK_GE(rect.width(), 0);  // Metafile could be empty.
  62   DCHECK_GE(rect.height(), 0);
  63
  64   if (rect.width() < 1 || rect.height() < 1)
  65     return false;
  66
  67   size_ = rect.size();
  68   gfx::CreateBitmapV4Header(rect.width(), rect.height(), &hdr);
  69   unsigned char* bits = NULL;
  70   base::win::ScopedBitmap bitmap(
  71       ::CreateDIBSection(hdc.Get(), reinterpret_cast<BITMAPINFO*>(&hdr), 0,
  72                          reinterpret_cast<void**>(&bits), NULL, 0));
  73   DCHECK(bitmap);
  74   base::win::ScopedSelectObject select_object(hdc.Get(), bitmap);
  75
  76   skia::InitializeDC(hdc.Get());
  77
  78   bool success = metafile.Playback(hdc.Get(), NULL);
  79
  80   row_length_ = size_.width() * sizeof(uint32_t);
  81   size_t bytes = row_length_ * size_.height();
  82   DCHECK(bytes);
  83
  84   data_.assign(bits, bits + bytes);
  85
  86   return success;
  87 }
  88
  89 }  // namespace printing