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      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/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   explicit 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, reinterpret_cast<BITMAPINFO*>(&hdr), 0,
     72                          reinterpret_cast<void**>(&bits), NULL, 0));
     73   DCHECK(bitmap);
     74   base::win::ScopedSelectObject select_object(hdc, bitmap);
     75 
     76   skia::InitializeDC(hdc);
     77 
     78   bool success = metafile.Playback(hdc, NULL);
     79 
     80   row_length_ = size_.width() * sizeof(uint32);
     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
     90