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/threading/worker_pool.h"
  12 #include "base/win/scoped_com_initializer.h"
  13 #include "base/win/scoped_comptr.h"
  14 #include "base/win/scoped_gdi_object.h"
  15 #include "base/win/windows_version.h"
  16 #include "chrome/browser/profiles/profile_info_util.h"
  17 #include "chrome/browser/ui/host_desktop.h"
  18 #include "skia/ext/image_operations.h"
  19 #include "skia/ext/platform_canvas.h"
  20 #include "third_party/skia/include/core/SkRect.h"
  21 #include "ui/gfx/icon_util.h"
  22 #include "ui/gfx/image/image.h"
  23 #include "ui/views/win/hwnd_util.h"
  24
  25 namespace chrome {
  26
  27 namespace {
  28
  29 // Responsible for invoking TaskbarList::SetOverlayIcon(). The call to
  30 // TaskbarList::SetOverlayIcon() runs a nested message loop that proves
  31 // problematic when called on the UI thread. Additionally it seems the call may
  32 // take a while to complete. For this reason we call it on a worker thread.
  33 //
  34 // Docs for TaskbarList::SetOverlayIcon() say it does nothing if the HWND is not
  35 // valid.
  36 void SetOverlayIcon(HWND hwnd, scoped_ptr<SkBitmap> bitmap) {
  37   base::win::ScopedCOMInitializer com_initializer;
  38   base::win::ScopedComPtr<ITaskbarList3> taskbar;
  39   HRESULT result = taskbar.CreateInstance(CLSID_TaskbarList, NULL,
  40                                           CLSCTX_INPROC_SERVER);
  41   if (FAILED(result) || FAILED(taskbar->HrInit()))
  42     return;
  43
  44   base::win::ScopedGDIObject<HICON> icon;
  45   if (bitmap.get()) {
  46     const SkBitmap* source_bitmap = NULL;
  47     SkBitmap squarer_bitmap;
  48     if ((bitmap->width() == profiles::kAvatarIconWidth) &&
  49         (bitmap->height() == profiles::kAvatarIconHeight)) {
  50       // Shave a couple of columns so the bitmap is more square. So when
  51       // resized to a square aspect ratio it looks pretty.
  52       int x = 2;
  53       bitmap->extractSubset(&squarer_bitmap, SkIRect::MakeXYWH(x, 0,
  54           profiles::kAvatarIconWidth - x * 2, profiles::kAvatarIconHeight));
  55       source_bitmap = &squarer_bitmap;
  56     } else {
  57       // The image's size has changed. Resize what we have.
  58       source_bitmap = bitmap.get();
  59     }
  60
  61     // Maintain aspect ratio on resize. It is assumed that the image is wider
  62     // than it is tall.
  63     const size_t kOverlayIconSize = 16;
  64     size_t resized_height =
  65         source_bitmap->height() * kOverlayIconSize / source_bitmap->width();
  66     DCHECK_GE(kOverlayIconSize, resized_height);
  67     // Since the target size is so small, we use our best resizer.
  68     SkBitmap sk_icon = skia::ImageOperations::Resize(
  69         *source_bitmap,
  70         skia::ImageOperations::RESIZE_LANCZOS3,
  71         kOverlayIconSize, resized_height);
  72
  73     // Paint the resized icon onto a 16x16 canvas otherwise Windows will badly
  74     // hammer it to 16x16.
  75     scoped_ptr<SkCanvas> offscreen_canvas(
  76         skia::CreateBitmapCanvas(kOverlayIconSize, kOverlayIconSize, false));
  77     DCHECK(offscreen_canvas);
  78     offscreen_canvas->drawBitmap(sk_icon, 0, kOverlayIconSize - resized_height);
  79
  80     icon.Set(IconUtil::CreateHICONFromSkBitmap(
  81         offscreen_canvas->getDevice()->accessBitmap(false)));
  82     if (!icon.Get())
  83       return;
  84   }
  85   taskbar->SetOverlayIcon(hwnd, icon, L"");
  86 }
  87
  88 }  // namespace
  89
  90 void DrawTaskbarDecoration(gfx::NativeWindow window, const gfx::Image* image) {
  91   // HOST_DESKTOP_TYPE_ASH doesn't use the taskbar.
  92   if (base::win::GetVersion() < base::win::VERSION_WIN7 ||
  93       chrome::GetHostDesktopTypeForNativeWindow(window) !=
  94       chrome::HOST_DESKTOP_TYPE_NATIVE)
  95     return;
  96
  97   HWND hwnd = views::HWNDForNativeWindow(window);
  98
  99   // SetOverlayIcon() does nothing if the window is not visible so testing here
 100   // avoids all the wasted effort of the image resizing.
 101   if (!::IsWindowVisible(hwnd))
 102     return;
 103
 104   // Copy the image since we're going to use it on a separate thread and
 105   // gfx::Image isn't thread safe.
 106   scoped_ptr<SkBitmap> bitmap(
 107       image ? new SkBitmap(*image->ToSkBitmap()) : NULL);
 108   // TaskbarList::SetOverlayIcon() may take a while, so we use slow here.
 109   base::WorkerPool::PostTask(
 110       FROM_HERE, base::Bind(&SetOverlayIcon, hwnd, Passed(&bitmap)), true);
 111 }
 112
 113 }  // namespace chrome