Moves the notification icon out of the status area overflow.

chrome/browser/ui/views/status_icons/status_tray_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/ui/views/status_icons/status_tray_win.h"
 
 #include <commctrl.h>
 
+#include "base/bind.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread.h"
 #include "base/win/wrapped_window_proc.h"
 #include "chrome/browser/ui/views/status_icons/status_icon_win.h"
+#include "chrome/browser/ui/views/status_icons/status_tray_state_changer_win.h"
 #include "chrome/common/chrome_constants.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/win/hwnd_util.h"
 
 static const UINT kStatusIconMessage = WM_APP + 1;
 
 namespace {
 // |kBaseIconId| is 2 to avoid conflicts with plugins that hard-code id 1.
 const UINT kBaseIconId = 2;
 
 UINT ReservedIconId(StatusTray::StatusIconType type) {
   return kBaseIconId + static_cast<UINT>(type);
 }
 }  // namespace
 
+// Default implementation for StatusTrayStateChanger that communicates to
+// Exporer.exe via COM.  It spawns a background thread with a fresh COM
+// apartment and requests that the visibility be increased unless the user
+// has explicitly set the icon to be hidden.
+class StatusTrayStateChangerProxyImpl : public StatusTrayStateChangerProxy,
+                                        public base::NonThreadSafe {
+ public:
+  StatusTrayStateChangerProxyImpl()
+      : pending_requests_(0),
+        worker_thread_("StatusIconCOMWorkerThread"),
+        weak_factory_(this) {
+    worker_thread_.init_com_with_mta(false);
+  }
+
+  virtual void EnqueueChange(UINT icon_id, HWND window) OVERRIDE {
+    DCHECK(CalledOnValidThread());
+    if (pending_requests_ == 0)
+      worker_thread_.Start();
+
+    ++pending_requests_;
+    worker_thread_.message_loop_proxy()->PostTaskAndReply(
+        FROM_HERE,
+        base::Bind(
+            &StatusTrayStateChangerProxyImpl::EnqueueChangeOnWorkerThread,
+            icon_id,
+            window),
+        base::Bind(&StatusTrayStateChangerProxyImpl::ChangeDone,
+                   weak_factory_.GetWeakPtr()));
+  }
+
+ private:
+  // Must be called only on |worker_thread_|, to ensure the correct COM
+  // apartment.
+  static void EnqueueChangeOnWorkerThread(UINT icon_id, HWND window) {
+    // It appears that IUnknowns are coincidentally compatible with
+    // scoped_refptr.  Normally I wouldn't depend on that but it seems that
+    // base::win::IUnknownImpl itself depends on that coincidence so it's
+    // already being assumed elsewhere.
+    scoped_refptr<StatusTrayStateChangerWin> status_tray_state_changer(
+        new StatusTrayStateChangerWin(icon_id, window));
+    status_tray_state_changer->EnsureTrayIconVisible();
+  }
+
+  // Called on UI thread.
+  void ChangeDone() {
+    DCHECK(CalledOnValidThread());
+    DCHECK_GT(pending_requests_, 0);
+
+    if (--pending_requests_ == 0)
+      worker_thread_.Stop();
+  }
+
+ private:
+  int pending_requests_;
+  base::Thread worker_thread_;
+  base::WeakPtrFactory<StatusTrayStateChangerProxyImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(StatusTrayStateChangerProxyImpl);
+};
+
 StatusTrayWin::StatusTrayWin()
     : next_icon_id_(1),
       atom_(0),
       instance_(NULL),
       window_(NULL) {
   // Register our window class
   WNDCLASSEX window_class;
   base::win::InitializeWindowClass(
       chrome::kStatusTrayWindowClass,
       &base::win::WrappedWindowProc<StatusTrayWin::WndProcStatic>,
@@ skipping 10 matching lines @@
   // Create an offscreen window for handling messages for the status icons. We
   // create a hidden WS_POPUP window instead of an HWND_MESSAGE window, because
   // only top-level windows such as popups can receive broadcast messages like
   // "TaskbarCreated".
   window_ = CreateWindow(MAKEINTATOM(atom_),
                          0, WS_POPUP, 0, 0, 0, 0, 0, 0, instance_, 0);
   gfx::CheckWindowCreated(window_);
   gfx::SetWindowUserData(window_, this);
 }
 
+StatusTrayWin::~StatusTrayWin() {
+  if (window_)
+    DestroyWindow(window_);
+
+  if (atom_)
+    UnregisterClass(MAKEINTATOM(atom_), instance_);
+}
+
+void StatusTrayWin::UpdateIconVisibilityInBackground(
+    StatusIconWin* status_icon) {
+  if (!state_changer_proxy_.get())
+    state_changer_proxy_.reset(new StatusTrayStateChangerProxyImpl);
+
+  state_changer_proxy_->EnqueueChange(status_icon->icon_id(),
+                                      status_icon->window());
+}
+
 LRESULT CALLBACK StatusTrayWin::WndProcStatic(HWND hwnd,
                                               UINT message,
                                               WPARAM wparam,
                                               LPARAM lparam) {
   StatusTrayWin* msg_wnd = reinterpret_cast<StatusTrayWin*>(
       GetWindowLongPtr(hwnd, GWLP_USERDATA));
   if (msg_wnd)
     return msg_wnd->WndProc(hwnd, message, wparam, lparam);
   else
     return ::DefWindowProc(hwnd, message, wparam, lparam);
@@ skipping 43 matching lines @@
         // HandleClickEvent() method.
         gfx::Point cursor_pos(
             gfx::Screen::GetNativeScreen()->GetCursorScreenPoint());
         win_icon->HandleClickEvent(cursor_pos, lparam == WM_LBUTTONDOWN);
         return TRUE;
     }
   }
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }
 
-StatusTrayWin::~StatusTrayWin() {
-  if (window_)
-    DestroyWindow(window_);
-
-  if (atom_)
-    UnregisterClass(MAKEINTATOM(atom_), instance_);
-}
-
 StatusIcon* StatusTrayWin::CreatePlatformStatusIcon(
     StatusTray::StatusIconType type,
     const gfx::ImageSkia& image,
     const base::string16& tool_tip) {
   UINT next_icon_id;
   if (type == StatusTray::OTHER_ICON)
     next_icon_id = NextIconId();
   else
     next_icon_id = ReservedIconId(type);
 
   StatusIcon* icon =
-      new StatusIconWin(next_icon_id, window_, kStatusIconMessage);
+      new StatusIconWin(this, next_icon_id, window_, kStatusIconMessage);
 
   icon->SetImage(image);
   icon->SetToolTip(tool_tip);
   return icon;
 }
 
 UINT StatusTrayWin::NextIconId() {
   UINT icon_id = next_icon_id_++;
   return kBaseIconId + static_cast<UINT>(NAMED_STATUS_ICON_COUNT) + icon_id;
 }
 
+void StatusTrayWin::SetStatusTrayStateChangerProxyForTest(
+    scoped_ptr<StatusTrayStateChangerProxy> proxy) {
+  state_changer_proxy_ = proxy.Pass();
+}
+
 StatusTray* StatusTray::Create() {
   return new StatusTrayWin();
 }