chrome_frame/event_hooker.cc

   1 // Copyright (c) 2010 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_frame/event_hooker.h"
   6
   7 #include <crtdbg.h>
   8 #include "chrome_frame/bho_loader.h"
   9
  10 EXTERN_C IMAGE_DOS_HEADER __ImageBase;
  11
  12 EventHooker::EventHooker()
  13 : window_creation_hook_(NULL) {}
  14
  15 EventHooker::~EventHooker() {
  16   StopHook();
  17 }
  18
  19 bool EventHooker::StartHook() {
  20   if ((NULL != window_creation_hook_)) {
  21     return false;
  22   }
  23
  24   window_creation_hook_ = SetWinEventHook(EVENT_OBJECT_CREATE,
  25                                           EVENT_OBJECT_CREATE,
  26                                           reinterpret_cast<HMODULE>(
  27                                               &__ImageBase),
  28                                           WindowCreationHookProc,
  29                                           0,
  30                                           0,
  31                                           WINEVENT_INCONTEXT);
  32   if (NULL == window_creation_hook_) {
  33     return false;
  34   }
  35   return true;
  36 }
  37
  38 void EventHooker::StopHook() {
  39   if (NULL != window_creation_hook_) {
  40     UnhookWinEvent(window_creation_hook_);
  41     window_creation_hook_ = NULL;
  42   }
  43 }
  44
  45 VOID CALLBACK EventHooker::WindowCreationHookProc(HWINEVENTHOOK hook,
  46                                                   DWORD event,
  47                                                   HWND window,
  48                                                   LONG object_id,
  49                                                   LONG child_id,
  50                                                   DWORD event_tid,
  51                                                   DWORD event_time) {
  52   _ASSERTE((EVENT_OBJECT_CREATE == event) ||
  53            (EVENT_OBJECT_PARENTCHANGE == event));
  54   if (OBJID_WINDOW == object_id) {
  55     BHOLoader::GetInstance()->OnHookEvent(event, window);
  56   }
  57 }
  58