ui/base/win/foreground_helper.cc

   1 // Copyright (c) 2012 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 "ui/base/win/foreground_helper.h"
   6
   7 #include "base/logging.h"
   8 #include "base/profiler/scoped_tracker.h"
   9 #include "ui/gfx/win/window_impl.h"
  10
  11 namespace ui {
  12
  13 // static
  14 HRESULT ForegroundHelper::SetForeground(HWND window) {
  15   DCHECK(::IsWindow(window));
  16   ForegroundHelper foreground_helper;
  17   return foreground_helper.ForegroundHotKey(window);
  18 }
  19
  20 HRESULT ForegroundHelper::ForegroundHotKey(HWND window) {
  21   // This implementation registers a hot key (F22) and then
  22   // triggers the hot key.  When receiving the hot key, we'll
  23   // be in the foreground and allowed to move the target window
  24   // into the foreground too.
  25
  26   set_window_style(WS_POPUP);
  27   Init(NULL, gfx::Rect());
  28
  29   static const int kHotKeyId = 0x0000baba;
  30   static const int kHotKeyWaitTimeout = 2000;
  31
  32   // Store the target window into our USERDATA for use in our
  33   // HotKey handler.
  34   window_ = window;
  35   RegisterHotKey(hwnd(), kHotKeyId, 0, VK_F22);
  36
  37   // If the calling thread is not yet a UI thread, call PeekMessage
  38   // to ensure creation of its message queue.
  39   MSG msg = {0};
  40   PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE);
  41
  42   // Send the Hotkey.
  43   INPUT hotkey = {0};
  44   hotkey.type = INPUT_KEYBOARD;
  45   hotkey.ki.wVk =  VK_F22;
  46   if (1 != SendInput(1, &hotkey, sizeof(hotkey))) {
  47     LOG(WARNING) << "Failed to send input; GetLastError(): " << GetLastError();
  48     return E_FAIL;
  49   }
  50
  51   // There are scenarios where the WM_HOTKEY is not dispatched by the
  52   // the corresponding foreground thread. To prevent us from indefinitely
  53   // waiting for the hotkey, we set a timer and exit the loop.
  54   SetTimer(hwnd(), kHotKeyId, kHotKeyWaitTimeout, NULL);
  55
  56   // Loop until we get the key or the timer fires.
  57   while (GetMessage(&msg, NULL, 0, 0)) {
  58     TranslateMessage(&msg);
  59     DispatchMessage(&msg);
  60
  61     if (WM_HOTKEY == msg.message)
  62       break;
  63     if (WM_TIMER == msg.message) {
  64       SetForegroundWindow(window);
  65       break;
  66     }
  67   }
  68
  69   UnregisterHotKey(hwnd(), kHotKeyId);
  70   KillTimer(hwnd(), kHotKeyId);
  71   DestroyWindow(hwnd());
  72
  73   return S_OK;
  74 }
  75
  76 // Handle the registered Hotkey being pressed.
  77 void ForegroundHelper::OnHotKey(int id, UINT vcode, UINT modifiers) {
  78   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
  79   tracked_objects::ScopedTracker tracking_profile(
  80       FROM_HERE_WITH_EXPLICIT_FUNCTION("440919 ForegroundHelper::OnHotKey"));
  81
  82   SetForegroundWindow(window_);
  83 }
  84
  85 }  // namespace ui