chrome_frame/bho_loader.cc

   1 // Copyright (c) 2011 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/bho_loader.h"
   6
   7 #include <atlbase.h>
   8 #include <atlcomcli.h>
   9 #include <exdisp.h>
  10
  11 #include "chrome_frame/chrome_frame_helper_util.h"
  12 #include "chrome_frame/chrome_tab.h"
  13 #include "chrome_frame/event_hooker.h"
  14
  15
  16 // Describes the window class we look for.
  17 const wchar_t kStatusBarWindowClass[] = L"msctls_statusbar32";
  18
  19 // On IE9, the status bar is disabled by default, so we look for an
  20 // AsyncBoundaryLayer window instead.
  21 const wchar_t kAsyncBoundaryDnWindow[] = L"asynclayerboundarydn\0";
  22
  23 BHOLoader::BHOLoader() : hooker_(new EventHooker()) {
  24 }
  25
  26 BHOLoader::~BHOLoader() {
  27   if (hooker_) {
  28     delete hooker_;
  29     hooker_ = NULL;
  30   }
  31 }
  32
  33 void BHOLoader::OnHookEvent(DWORD event, HWND window) {
  34   // Step 1: Make sure that we are in a process named iexplore.exe.
  35   if (IsNamedProcess(L"iexplore.exe")) {
  36     if (!IsWindowOfClass(window, kStatusBarWindowClass) &&
  37         !IsWindowOfClass(window, kAsyncBoundaryDnWindow)) {
  38       return;
  39     } else {
  40       // We have the right sort of window, check to make sure it was created
  41       // on the current thread.
  42       DWORD thread_id = GetWindowThreadProcessId(window, NULL);
  43       _ASSERTE(thread_id == GetCurrentThreadId());
  44     }
  45
  46     // Step 2: Check to see if the window is of the right class.
  47     HWND browser_hwnd = NULL;
  48     if (IsWindowOfClass(window, kStatusBarWindowClass)) {
  49       // For IE8 and under, IE loads BHOs in the WM_CREATE handler of the tab
  50       // window approximately after it creates the status bar window. To be as
  51       // close to IE as possible in our simulation on BHO loading, we watch for
  52       // the status bar to be created and do our simulated BHO loading at that
  53       // time.
  54       browser_hwnd = GetParent(window);
  55     } else if (IsWindowOfClass(window, kAsyncBoundaryDnWindow)) {
  56       // For IE9, the status bar is disabled by default, so we look for an
  57       // AsyncBoundaryWindow to be created. When we find that, look for a
  58       // child window owned by the current thread named "tabwindowclass".
  59       // That will be our browser window.
  60       browser_hwnd = RecurseFindWindow(NULL, L"tabwindowclass", NULL,
  61                                        GetCurrentThreadId(),
  62                                        GetCurrentProcessId());
  63       _ASSERTE(NULL != browser_hwnd);
  64     }
  65
  66     if (browser_hwnd != NULL) {
  67       // Step 3:
  68       // Parent window of status bar window is the web browser window. Try to
  69       // get its IWebBrowser2 interface
  70       CComPtr<IWebBrowser2> browser;
  71       UtilGetWebBrowserObjectFromWindow(browser_hwnd, __uuidof(browser),
  72                                         reinterpret_cast<void**>(&browser));
  73       if (browser) {
  74         if (IsSystemLevelChromeFrameInstalled()) {
  75           // We're in the right place, but a system-level installation has
  76           // appeared. We should leave now.
  77           return;
  78         }
  79
  80         // Figure out if we're already in the property map.
  81         wchar_t bho_clsid_as_string[MAX_PATH] = {0};
  82         StringFromGUID2(CLSID_ChromeFrameBHO, bho_clsid_as_string,
  83                         ARRAYSIZE(bho_clsid_as_string));
  84         CComBSTR bho_clsid_as_string_bstr(bho_clsid_as_string);
  85
  86         CComVariant existing_bho;
  87         HRESULT hr = browser->GetProperty(bho_clsid_as_string_bstr,
  88                                           &existing_bho);
  89
  90         if (V_VT(&existing_bho) != VT_DISPATCH &&
  91             V_VT(&existing_bho) != VT_UNKNOWN) {
  92           // Step 4:
  93           // We have the IWebBrowser2 interface. Now create the BHO instance
  94           CComPtr<IObjectWithSite> bho_object;
  95           hr =  bho_object.CoCreateInstance(CLSID_ChromeFrameBHO,
  96                                             NULL,
  97                                             CLSCTX_INPROC_SERVER);
  98
  99           _ASSERTE(bho_object);
 100           if (SUCCEEDED(hr) && bho_object) {
 101             // Step 5:
 102             // Initialize the BHO by calling SetSite and passing it IWebBrowser2
 103             hr = bho_object->SetSite(browser);
 104             _ASSERTE(bho_object);
 105             if (SUCCEEDED(hr)) {
 106               // Step 6:
 107               // Now add the BHO to the collection of automation objects. This
 108               // will ensure that BHO will be accessible from the web pages as
 109               // any other BHO. Importantly, it will make sure that our BHO
 110               // will be cleaned up at the right time along with other BHOs.
 111               CComVariant object_variant(bho_object);
 112               browser->PutProperty(bho_clsid_as_string_bstr, object_variant);
 113             }
 114           }
 115         }
 116       }
 117     }
 118   }
 119 }
 120
 121 bool BHOLoader::StartHook() {
 122   return hooker_->StartHook();
 123 }
 124
 125 void BHOLoader::StopHook() {
 126   hooker_->StopHook();
 127 }
 128
 129 BHOLoader* BHOLoader::GetInstance() {
 130   static BHOLoader loader;
 131   return &loader;
 132 }