taskbar_decorator_win.cc revision 4e180b6a0b4720a9b8e9e959a882386f690f08ff 
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
25namespace chrome {
26
27namespace {
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.
36void 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
90void 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
114