src/chrome/browser/ui/views/frame/taskbar_decorator_win.cc

   1 // Copyright (c) 2013 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/browser/ui/views/frame/taskbar_decorator.h"
   6
   7 #include <shobjidl.h>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/win/scoped_comptr.h"
  12 #include "base/win/scoped_gdi_object.h"
  13 #include "base/win/windows_version.h"
  14 #include "chrome/browser/profiles/profile_avatar_icon_util.h"
  15 #include "chrome/browser/ui/host_desktop.h"
  16 #include "content/public/browser/browser_thread.h"
  17 #include "skia/ext/image_operations.h"
  18 #include "skia/ext/platform_canvas.h"
  19 #include "ui/gfx/icon_util.h"
  20 #include "ui/gfx/image/image.h"
  21 #include "ui/views/win/hwnd_util.h"
  22
  23 namespace chrome {
  24
  25 namespace {
  26
  27 // Responsible for invoking TaskbarList::SetOverlayIcon(). The call to
  28 // TaskbarList::SetOverlayIcon() runs a nested message loop that proves
  29 // problematic when called on the UI thread. Additionally it seems the call may
  30 // take a while to complete. For this reason we call it on a worker thread.
  31 //
  32 // Docs for TaskbarList::SetOverlayIcon() say it does nothing if the HWND is not
  33 // valid.
  34 void SetOverlayIcon(HWND hwnd, scoped_ptr<SkBitmap> bitmap) {
  35   base::win::ScopedComPtr<ITaskbarList3> taskbar;
  36   HRESULT result = taskbar.CreateInstance(CLSID_TaskbarList, NULL,
  37                                           CLSCTX_INPROC_SERVER);
  38   if (FAILED(result) || FAILED(taskbar->HrInit()))
  39     return;
  40
  41   base::win::ScopedGDIObject<HICON> icon;
  42   if (bitmap.get()) {
  43     DCHECK_GE(bitmap.get()->width(), bitmap.get()->height());
  44     // Maintain aspect ratio on resize.
  45     const int kOverlayIconSize = 16;
  46     int resized_height =
  47         bitmap.get()->height() * kOverlayIconSize / bitmap.get()->width();
  48     DCHECK_GE(kOverlayIconSize, resized_height);
  49     // Since the target size is so small, we use our best resizer.
  50     SkBitmap sk_icon = skia::ImageOperations::Resize(
  51         *bitmap.get(),
  52         skia::ImageOperations::RESIZE_LANCZOS3,
  53         kOverlayIconSize, resized_height);
  54
  55     // Paint the resized icon onto a 16x16 canvas otherwise Windows will badly
  56     // hammer it to 16x16.
  57     SkBitmap offscreen_bitmap;
  58     offscreen_bitmap.allocN32Pixels(kOverlayIconSize, kOverlayIconSize);
  59     SkCanvas offscreen_canvas(offscreen_bitmap);
  60     offscreen_canvas.clear(SK_ColorTRANSPARENT);
  61     offscreen_canvas.drawBitmap(sk_icon, 0, kOverlayIconSize - resized_height);
  62     icon.Set(IconUtil::CreateHICONFromSkBitmap(offscreen_bitmap));
  63     if (!icon.Get())
  64       return;
  65   }
  66   taskbar->SetOverlayIcon(hwnd, icon, L"");
  67 }
  68
  69 }  // namespace
  70
  71 void DrawTaskbarDecoration(gfx::NativeWindow window, const gfx::Image* image) {
  72   // HOST_DESKTOP_TYPE_ASH doesn't use the taskbar.
  73   if (base::win::GetVersion() < base::win::VERSION_WIN7 ||
  74       chrome::GetHostDesktopTypeForNativeWindow(window) !=
  75       chrome::HOST_DESKTOP_TYPE_NATIVE)
  76     return;
  77
  78   HWND hwnd = views::HWNDForNativeWindow(window);
  79
  80   // SetOverlayIcon() does nothing if the window is not visible so testing here
  81   // avoids all the wasted effort of the image resizing.
  82   if (!::IsWindowVisible(hwnd))
  83     return;
  84
  85   // Copy the image since we're going to use it on a separate thread and
  86   // gfx::Image isn't thread safe.
  87   scoped_ptr<SkBitmap> bitmap;
  88   if (image) {
  89     bitmap.reset(new SkBitmap(
  90         profiles::GetAvatarIconAsSquare(*image->ToSkBitmap(), 1)));
  91   }
  92   content::BrowserThread::GetBlockingPool()->PostWorkerTaskWithShutdownBehavior(
  93       FROM_HERE, base::Bind(&SetOverlayIcon, hwnd, Passed(&bitmap)),
  94       base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
  95 }
  96
  97 }  // namespace chrome