Add avatar decoration to the windows7 taskbar

chrome/browser/ui/views/avatar_menu_button.cc

 // Copyright (c) 2011 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/ui/views/avatar_menu_button.h"
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/profile_menu_model.h"
 #include "chrome/browser/ui/views/avatar_menu_bubble_view.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "ui/gfx/canvas_skia.h"
 #include "views/widget/widget.h"
 
+
+#if defined(OS_WIN)
+#include <shobjidl.h>
+#include "base/win/scoped_comptr.h"
+#include "base/win/windows_version.h"
+#include "skia/ext/image_operations.h"
+#include "ui/gfx/icon_util.h"
+#endif
+
 static inline int Round(double x) {
   return static_cast<int>(x + 0.5);
 }
 
+// The Windows 7 taskbar supports dynamic overlays and effects, we use this
+// to ovelay the avatar icon there. The overlay only applies if the taskbar
+// is in "default large icon mode". This function is a best effort deal so
+// we bail out silently at any error condition.
+// See http://msdn.microsoft.com/en-us/library/dd391696(VS.85).aspx for
+// more information.
+void DrawTaskBarDecoration(const Browser* browser, const SkBitmap& avatar) {
+#if defined(OS_WIN)
+  if (base::win::GetVersion() < base::win::VERSION_WIN7)
+    return;
+
+  base::win::ScopedComPtr<ITaskbarList3> taskbar;
+  HRESULT result = taskbar.CreateInstance(CLSID_TaskbarList, NULL,

[Peter Kasting, 2011/08/31 16:59:46]

Nit: Shorter:

  if (FAILED(taskbar.CreateInstance(...)) ||
      FAILED(taskbar->HrInit()))
    return;

+                                          CLSCTX_INPROC_SERVER);
+  if (FAILED(result))
+    return;
+  result = taskbar->HrInit();
+  if (FAILED(result))
+    return;
+  BrowserWindow* bw = browser->window();

[Peter Kasting, 2011/08/31 16:59:46]

Nit: Do we really need to check window() and GetNativeHandle()?  Seems like they
should be guaranteed to be non-NULL if we only call this when painting the
button?

+  if (!bw)
+    return;
+  gfx::NativeWindow window = bw->GetNativeHandle();
+  if (!window)
+    return;
+  // Since the target size is so small, we use our best resizer.
+  SkBitmap sk_icon = skia::ImageOperations::Resize(
+      avatar,
+      skia::ImageOperations::RESIZE_LANCZOS3,
+      16, 16);
+  HICON icon = IconUtil::CreateHICONFromSkBitmap(sk_icon);
+  if (!icon)
+    return;
+  taskbar->SetOverlayIcon(window, icon, L"");
+  ::DestroyIcon(icon);

[Peter Kasting, 2011/08/31 16:59:46]

Nit: I think you can get away without :: here

+#endif
+}
+
 AvatarMenuButton::AvatarMenuButton(Browser* browser, bool has_menu)
     : MenuButton(NULL, std::wstring(), this, false),
       browser_(browser),
-      has_menu_(has_menu) {
+      has_menu_(has_menu),
+      first_time_(true) {
   // In RTL mode, the avatar icon should be looking the opposite direction.
   EnableCanvasFlippingForRTLUI(true);
 }
 
 AvatarMenuButton::~AvatarMenuButton() {}
 
 void AvatarMenuButton::OnPaint(gfx::Canvas* canvas) {
   const SkBitmap& icon = GetImageToPaint();
   if (icon.isNull())
     return;
@@ skipping 11 matching lines @@
   // Round here so that we minimize the aspect ratio drift.
   int dst_height = Round(icon.height() * scale);
   // Round rather than truncating, so that for odd heights we select an extra
   // pixel below the image center rather than above.  This is because the
   // incognito image has shadows at the top that make the apparent center below
   // the real center.
   int dst_y = Round((height() - dst_height) / 2.0);
 
   canvas->DrawBitmapInt(icon, 0, 0, icon.width(), icon.height(),
       dst_x, dst_y, dst_width, dst_height, false);
+
+  if (first_time_) {

[Peter Kasting, 2011/08/31 16:59:46]

Nit: Sounds like this variable should be named |should_draw_taskbar_decoration_|
or similar.

+    // Drawing the taskbar decoration uses lanczos resizing so we really
+    // want to do it only once.
+    DrawTaskBarDecoration(browser_, icon);
+    first_time_ = false;
+  }
 }
 
 bool AvatarMenuButton::HitTest(const gfx::Point& point) const {
   if (!has_menu_)
     return false;
   return views::MenuButton::HitTest(point);
 }
 
 // views::ViewMenuDelegate implementation
 void AvatarMenuButton::RunMenu(views::View* source, const gfx::Point& pt) {
   if (!has_menu_)
     return;
 
   BrowserView* browser_view = BrowserView::GetBrowserViewForNativeWindow(
       browser_->window()->GetNativeHandle());
 
   gfx::Point origin;
   views::View::ConvertPointToScreen(this, &origin);
   gfx::Rect bounds(0, 0, width(), height());
   bounds.set_origin(origin);
 
   AvatarMenuBubbleView* bubble_view = new AvatarMenuBubbleView(browser_);
   // Bubble::Show() takes ownership of the view.
   Bubble::Show(browser_view->GetWidget(), bounds,
                views::BubbleBorder::TOP_LEFT,
                bubble_view, bubble_view);
 }