chrome/browser/icon_loader_win.cc

// 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/browser/icon_loader.h"

#include <windows.h>
#include <shellapi.h>

#include "base/bind.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_loop.h"
#include "base/task_scheduler/post_task.h"
#include "base/threading/thread.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/display/win/dpi.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/icon_util.h"
#include "ui/gfx/image/image_skia.h"

// static
IconLoader::IconGroup IconLoader::GroupForFilepath(
    const base::FilePath& file_path) {
  if (file_path.MatchesExtension(L".exe") ||
      file_path.MatchesExtension(L".dll") ||
      file_path.MatchesExtension(L".ico")) {
    return file_path.value();
  }

  return file_path.Extension();
}

// static
scoped_refptr<base::TaskRunner> IconLoader::GetReadIconTaskRunner() {
  // Technically speaking, only a thread with COM is needed, not one that has
  // a COM STA. However, this is what is available for now.
  return base::CreateCOMSTATaskRunnerWithTraits(traits());
}

void IconLoader::ReadIcon() {
  int size = 0;
  switch (icon_size_) {
    case IconLoader::SMALL:
      size = SHGFI_SMALLICON;
      break;
    case IconLoader::NORMAL:
      size = 0;
      break;
    case IconLoader::LARGE:
      size = SHGFI_LARGEICON;
      break;
    default:
      NOTREACHED();
  }

  std::unique_ptr<gfx::Image> image;

  SHFILEINFO file_info = { 0 };
  if (SHGetFileInfo(group_.c_str(), FILE_ATTRIBUTE_NORMAL, &file_info,
                     sizeof(SHFILEINFO),
                     SHGFI_ICON | size | SHGFI_USEFILEATTRIBUTES)) {
    std::unique_ptr<SkBitmap> bitmap(
        IconUtil::CreateSkBitmapFromHICON(file_info.hIcon));
    if (bitmap.get()) {
      gfx::ImageSkia image_skia(gfx::ImageSkiaRep(*bitmap,
                                                  display::win::GetDPIScale()));
      image_skia.MakeThreadSafe();
      image = base::MakeUnique<gfx::Image>(image_skia);
      DestroyIcon(file_info.hIcon);
    }
  }

  target_task_runner_->PostTask(
      FROM_HERE, base::Bind(callback_, base::Passed(&image), group_));
  delete this;
}