1/*
2 * Copyright (C) 2008, 2009, 2010 Apple Inc. All Rights Reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "AccessibilityController.h"
28
29#include "AccessibilityUIElement.h"
30#include "DumpRenderTree.h"
31#include "FrameLoadDelegate.h"
32#include <JavaScriptCore/Assertions.h>
33#include <JavaScriptCore/JSRetainPtr.h>
34#include <JavaScriptCore/JSStringRef.h>
35#include <WebCore/COMPtr.h>
36#include <WebKit/WebKit.h>
37#include <oleacc.h>
38#include <string>
39
40using namespace std;
41
42AccessibilityController::AccessibilityController()
43    : m_focusEventHook(0)
44    , m_scrollingStartEventHook(0)
45    , m_valueChangeEventHook(0)
46    , m_allEventsHook(0)
47{
48}
49
50AccessibilityController::~AccessibilityController()
51{
52    setLogFocusEvents(false);
53    setLogValueChangeEvents(false);
54
55    if (m_allEventsHook)
56        UnhookWinEvent(m_allEventsHook);
57
58    for (HashMap<PlatformUIElement, JSObjectRef>::iterator it = m_notificationListeners.begin(); it != m_notificationListeners.end(); ++it)
59        JSValueUnprotect(frame->globalContext(), it->second);
60}
61
62AccessibilityUIElement AccessibilityController::elementAtPoint(int x, int y)
63{
64    // FIXME: implement
65    return 0;
66}
67
68AccessibilityUIElement AccessibilityController::focusedElement()
69{
70    COMPtr<IAccessible> rootAccessible = rootElement().platformUIElement();
71
72    VARIANT vFocus;
73    if (FAILED(rootAccessible->get_accFocus(&vFocus)))
74        return 0;
75
76    if (V_VT(&vFocus) == VT_I4) {
77        ASSERT(V_I4(&vFocus) == CHILDID_SELF);
78        // The root accessible object is the focused object.
79        return rootAccessible;
80    }
81
82    ASSERT(V_VT(&vFocus) == VT_DISPATCH);
83    // We have an IDispatch; query for IAccessible.
84    return COMPtr<IAccessible>(Query, V_DISPATCH(&vFocus));
85}
86
87AccessibilityUIElement AccessibilityController::rootElement()
88{
89    COMPtr<IWebView> view;
90    if (FAILED(frame->webView(&view)))
91        return 0;
92
93    COMPtr<IWebViewPrivate> viewPrivate(Query, view);
94    if (!viewPrivate)
95        return 0;
96
97    HWND webViewWindow;
98    if (FAILED(viewPrivate->viewWindow((OLE_HANDLE*)&webViewWindow)))
99        return 0;
100
101    // Get the root accessible object by querying for the accessible object for the
102    // WebView's window.
103    COMPtr<IAccessible> rootAccessible;
104    if (FAILED(AccessibleObjectFromWindow(webViewWindow, static_cast<DWORD>(OBJID_CLIENT), __uuidof(IAccessible), reinterpret_cast<void**>(&rootAccessible))))
105        return 0;
106
107    return rootAccessible;
108}
109
110static void CALLBACK logEventProc(HWINEVENTHOOK, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD, DWORD)
111{
112    // Get the accessible object for this event.
113    COMPtr<IAccessible> parentObject;
114
115    VARIANT vChild;
116    VariantInit(&vChild);
117
118    HRESULT hr = AccessibleObjectFromEvent(hwnd, idObject, idChild, &parentObject, &vChild);
119    ASSERT(SUCCEEDED(hr));
120
121    // Get the name of the focused element, and log it to stdout.
122    BSTR nameBSTR;
123    hr = parentObject->get_accName(vChild, &nameBSTR);
124    ASSERT(SUCCEEDED(hr));
125    wstring name(nameBSTR, ::SysStringLen(nameBSTR));
126    SysFreeString(nameBSTR);
127
128    switch (event) {
129        case EVENT_OBJECT_FOCUS:
130            printf("Received focus event for object '%S'.\n", name.c_str());
131            break;
132
133        case EVENT_OBJECT_VALUECHANGE: {
134            BSTR valueBSTR;
135            hr = parentObject->get_accValue(vChild, &valueBSTR);
136            ASSERT(SUCCEEDED(hr));
137            wstring value(valueBSTR, ::SysStringLen(valueBSTR));
138            SysFreeString(valueBSTR);
139
140            printf("Received value change event for object '%S', value '%S'.\n", name.c_str(), value.c_str());
141            break;
142        }
143
144        case EVENT_SYSTEM_SCROLLINGSTART:
145            printf("Received scrolling start event for object '%S'.\n", name.c_str());
146            break;
147
148        default:
149            printf("Received unknown event for object '%S'.\n", name.c_str());
150            break;
151    }
152
153    VariantClear(&vChild);
154}
155
156void AccessibilityController::setLogFocusEvents(bool logFocusEvents)
157{
158    if (!!m_focusEventHook == logFocusEvents)
159        return;
160
161    if (!logFocusEvents) {
162        UnhookWinEvent(m_focusEventHook);
163        m_focusEventHook = 0;
164        return;
165    }
166
167    // Ensure that accessibility is initialized for the WebView by querying for
168    // the root accessible object.
169    rootElement();
170
171    m_focusEventHook = SetWinEventHook(EVENT_OBJECT_FOCUS, EVENT_OBJECT_FOCUS, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);
172
173    ASSERT(m_focusEventHook);
174}
175
176void AccessibilityController::setLogValueChangeEvents(bool logValueChangeEvents)
177{
178    if (!!m_valueChangeEventHook == logValueChangeEvents)
179        return;
180
181    if (!logValueChangeEvents) {
182        UnhookWinEvent(m_valueChangeEventHook);
183        m_valueChangeEventHook = 0;
184        return;
185    }
186
187    // Ensure that accessibility is initialized for the WebView by querying for
188    // the root accessible object.
189    rootElement();
190
191    m_valueChangeEventHook = SetWinEventHook(EVENT_OBJECT_VALUECHANGE, EVENT_OBJECT_VALUECHANGE, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);
192
193    ASSERT(m_valueChangeEventHook);
194}
195
196void AccessibilityController::setLogScrollingStartEvents(bool logScrollingStartEvents)
197{
198    if (!!m_scrollingStartEventHook == logScrollingStartEvents)
199        return;
200
201    if (!logScrollingStartEvents) {
202        UnhookWinEvent(m_scrollingStartEventHook);
203        m_scrollingStartEventHook = 0;
204        return;
205    }
206
207    // Ensure that accessibility is initialized for the WebView by querying for
208    // the root accessible object.
209    rootElement();
210
211    m_scrollingStartEventHook = SetWinEventHook(EVENT_SYSTEM_SCROLLINGSTART, EVENT_SYSTEM_SCROLLINGSTART, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);
212
213    ASSERT(m_scrollingStartEventHook);
214}
215
216void AccessibilityController::setLogAccessibilityEvents(bool)
217{
218}
219
220static string stringEvent(DWORD event)
221{
222    switch(event) {
223        case EVENT_OBJECT_VALUECHANGE:
224            return "value change event";
225        default:
226            return "unknown event";
227    }
228}
229
230static void CALLBACK notificationListenerProc(HWINEVENTHOOK, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD, DWORD)
231{
232    // Get the accessible object for this event.
233    COMPtr<IAccessible> parentObject;
234
235    VARIANT vChild;
236    VariantInit(&vChild);
237
238    HRESULT hr = AccessibleObjectFromEvent(hwnd, idObject, idChild, &parentObject, &vChild);
239    if (FAILED(hr) || !parentObject)
240        return;
241
242    COMPtr<IDispatch> childDispatch;
243    if (FAILED(parentObject->get_accChild(vChild, &childDispatch))) {
244        VariantClear(&vChild);
245        return;
246    }
247
248    COMPtr<IAccessible> childAccessible(Query, childDispatch);
249
250    sharedFrameLoadDelegate->accessibilityController()->notificationReceived(childAccessible, stringEvent(event));
251
252    VariantClear(&vChild);
253}
254
255static COMPtr<IAccessibleComparable> comparableObject(const COMPtr<IServiceProvider>& serviceProvider)
256{
257    COMPtr<IAccessibleComparable> comparable;
258    serviceProvider->QueryService(SID_AccessibleComparable, __uuidof(IAccessibleComparable), reinterpret_cast<void**>(&comparable));
259    return comparable;
260}
261
262void AccessibilityController::notificationReceived(PlatformUIElement element, const string& eventName)
263{
264    for (HashMap<PlatformUIElement, JSObjectRef>::iterator it = m_notificationListeners.begin(); it != m_notificationListeners.end(); ++it) {
265        COMPtr<IServiceProvider> thisServiceProvider(Query, it->first);
266        if (!thisServiceProvider)
267            continue;
268
269        COMPtr<IAccessibleComparable> thisComparable = comparableObject(thisServiceProvider);
270        if (!thisComparable)
271            continue;
272
273        COMPtr<IServiceProvider> elementServiceProvider(Query, element);
274        if (!elementServiceProvider)
275            continue;
276
277        COMPtr<IAccessibleComparable> elementComparable = comparableObject(elementServiceProvider);
278        if (!elementComparable)
279            continue;
280
281        BOOL isSame = FALSE;
282        thisComparable->isSameObject(elementComparable.get(), &isSame);
283        if (!isSame)
284            continue;
285
286        JSRetainPtr<JSStringRef> jsNotification(Adopt, JSStringCreateWithUTF8CString(eventName.c_str()));
287        JSValueRef argument = JSValueMakeString(frame->globalContext(), jsNotification.get());
288        JSObjectCallAsFunction(frame->globalContext(), it->second, NULL, 1, &argument, NULL);
289    }
290}
291
292void AccessibilityController::addNotificationListener(PlatformUIElement element, JSObjectRef functionCallback)
293{
294    if (!m_allEventsHook)
295        m_allEventsHook = SetWinEventHook(EVENT_MIN, EVENT_MAX, GetModuleHandle(0), notificationListenerProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);
296
297    JSValueProtect(frame->globalContext(), functionCallback);
298    m_notificationListeners.add(element, functionCallback);
299}
300