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
BHOLoader()23 BHOLoader::BHOLoader() : hooker_(new EventHooker()) {
24 }
25
~BHOLoader()26 BHOLoader::~BHOLoader() {
27 if (hooker_) {
28 delete hooker_;
29 hooker_ = NULL;
30 }
31 }
32
OnHookEvent(DWORD event,HWND window)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
StartHook()121 bool BHOLoader::StartHook() {
122 return hooker_->StartHook();
123 }
124
StopHook()125 void BHOLoader::StopHook() {
126 hooker_->StopHook();
127 }
128
GetInstance()129 BHOLoader* BHOLoader::GetInstance() {
130 static BHOLoader loader;
131 return &loader;
132 }
133