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
27 #include "config.h"
28 #include "AXObjectCache.h"
29
30 #include "AccessibilityObject.h"
31 #include "Chrome.h"
32 #include "Document.h"
33 #include "Page.h"
34 #include "RenderObject.h"
35
36 using namespace std;
37
38 namespace WebCore {
39
detachWrapper(AccessibilityObject * obj)40 void AXObjectCache::detachWrapper(AccessibilityObject* obj)
41 {
42 // On Windows, AccessibilityObjects are created when get_accChildCount is
43 // called, but they are not wrapped until get_accChild is called, so this
44 // object may not have a wrapper.
45 if (AccessibilityObjectWrapper* wrapper = obj->wrapper())
46 wrapper->detach();
47 }
48
attachWrapper(AccessibilityObject *)49 void AXObjectCache::attachWrapper(AccessibilityObject*)
50 {
51 // On Windows, AccessibilityObjects are wrapped when the accessibility
52 // software requests them via get_accChild.
53 }
54
handleScrolledToAnchor(const Node * anchorNode)55 void AXObjectCache::handleScrolledToAnchor(const Node* anchorNode)
56 {
57 // The anchor node may not be accessible. Post the notification for the
58 // first accessible object.
59 postPlatformNotification(AccessibilityObject::firstAccessibleObjectFromNode(anchorNode), AXScrolledToAnchor);
60 }
61
postPlatformNotification(AccessibilityObject * obj,AXNotification notification)62 void AXObjectCache::postPlatformNotification(AccessibilityObject* obj, AXNotification notification)
63 {
64 if (!obj)
65 return;
66
67 Document* document = obj->document();
68 if (!document)
69 return;
70
71 Page* page = document->page();
72 if (!page || !page->chrome()->platformPageClient())
73 return;
74
75 DWORD msaaEvent;
76 switch (notification) {
77 case AXFocusedUIElementChanged:
78 case AXActiveDescendantChanged:
79 msaaEvent = EVENT_OBJECT_FOCUS;
80 break;
81
82 case AXScrolledToAnchor:
83 msaaEvent = EVENT_SYSTEM_SCROLLINGSTART;
84 break;
85
86 case AXValueChanged:
87 case AXMenuListValueChanged:
88 msaaEvent = EVENT_OBJECT_VALUECHANGE;
89 break;
90
91 default:
92 return;
93 }
94
95 // Windows will end up calling get_accChild() on the root accessible
96 // object for the WebView, passing the child ID that we specify below. We
97 // negate the AXID so we know that the caller is passing the ID of an
98 // element, not the index of a child element.
99
100 ASSERT(obj->axObjectID() >= 1);
101 ASSERT(obj->axObjectID() <= numeric_limits<LONG>::max());
102
103 NotifyWinEvent(msaaEvent, page->chrome()->platformPageClient(), OBJID_CLIENT, -static_cast<LONG>(obj->axObjectID()));
104 }
105
nodeTextChangePlatformNotification(AccessibilityObject *,AXTextChange,unsigned,unsigned)106 void AXObjectCache::nodeTextChangePlatformNotification(AccessibilityObject*, AXTextChange, unsigned, unsigned)
107 {
108 }
109
platformGenerateAXID() const110 AXID AXObjectCache::platformGenerateAXID() const
111 {
112 static AXID lastUsedID = 0;
113
114 // Generate a new ID. Windows accessibility relies on a positive AXID,
115 // ranging from 1 to LONG_MAX.
116 AXID objID = lastUsedID;
117 do {
118 ++objID;
119 objID %= std::numeric_limits<LONG>::max();
120 } while (objID == 0 || HashTraits<AXID>::isDeletedValue(objID) || m_idsInUse.contains(objID));
121
122 ASSERT(objID >= 1 && objID <= std::numeric_limits<LONG>::max());
123
124 lastUsedID = objID;
125
126 return objID;
127 }
128
handleFocusedUIElementChanged(RenderObject *,RenderObject * newFocusedRenderer)129 void AXObjectCache::handleFocusedUIElementChanged(RenderObject*, RenderObject* newFocusedRenderer)
130 {
131 if (!newFocusedRenderer)
132 return;
133
134 Page* page = newFocusedRenderer->document()->page();
135 if (!page || !page->chrome()->platformPageClient())
136 return;
137
138 AccessibilityObject* focusedObject = focusedUIElementForPage(page);
139 if (!focusedObject)
140 return;
141
142 ASSERT(!focusedObject->accessibilityIsIgnored());
143
144 postPlatformNotification(focusedObject, AXFocusedUIElementChanged);
145 }
146
147 } // namespace WebCore
148