1 // Copyright (c) 2012 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 "content/renderer/accessibility/renderer_accessibility_focus_only.h"
6
7 #include "content/common/accessibility_node_data.h"
8 #include "content/renderer/render_view_impl.h"
9 #include "third_party/WebKit/public/web/WebDocument.h"
10 #include "third_party/WebKit/public/web/WebElement.h"
11 #include "third_party/WebKit/public/web/WebFrame.h"
12 #include "third_party/WebKit/public/web/WebNode.h"
13 #include "third_party/WebKit/public/web/WebView.h"
14
15 using blink::WebDocument;
16 using blink::WebElement;
17 using blink::WebFrame;
18 using blink::WebNode;
19 using blink::WebView;
20
21 namespace {
22 // The root node will always have id 1. Let each child node have a new
23 // id starting with 2.
24 const int kInitialId = 2;
25 }
26
27 namespace content {
28
RendererAccessibilityFocusOnly(RenderViewImpl * render_view)29 RendererAccessibilityFocusOnly::RendererAccessibilityFocusOnly(
30 RenderViewImpl* render_view)
31 : RendererAccessibility(render_view),
32 next_id_(kInitialId) {
33 }
34
~RendererAccessibilityFocusOnly()35 RendererAccessibilityFocusOnly::~RendererAccessibilityFocusOnly() {
36 }
37
HandleWebAccessibilityEvent(const blink::WebAXObject & obj,blink::WebAXEvent event)38 void RendererAccessibilityFocusOnly::HandleWebAccessibilityEvent(
39 const blink::WebAXObject& obj, blink::WebAXEvent event) {
40 // Do nothing.
41 }
42
FocusedNodeChanged(const WebNode & node)43 void RendererAccessibilityFocusOnly::FocusedNodeChanged(const WebNode& node) {
44 // Send the new accessible tree and post a native focus event.
45 HandleFocusedNodeChanged(node, true);
46 }
47
DidFinishLoad(blink::WebFrame * frame)48 void RendererAccessibilityFocusOnly::DidFinishLoad(blink::WebFrame* frame) {
49 WebView* view = render_view()->GetWebView();
50 if (view->focusedFrame() != frame)
51 return;
52
53 WebDocument document = frame->document();
54 // Send an accessible tree to the browser, but do not post a native
55 // focus event. This is important so that if focus is initially in an
56 // editable text field, Windows will know to pop up the keyboard if the
57 // user touches it and focus doesn't change.
58 HandleFocusedNodeChanged(document.focusedNode(), false);
59 }
60
HandleFocusedNodeChanged(const WebNode & node,bool send_focus_event)61 void RendererAccessibilityFocusOnly::HandleFocusedNodeChanged(
62 const WebNode& node,
63 bool send_focus_event) {
64 const WebDocument& document = GetMainDocument();
65 if (document.isNull())
66 return;
67
68 bool node_has_focus;
69 bool node_is_editable_text;
70 // Check HasIMETextFocus first, because it will correctly handle
71 // focus in a text box inside a ppapi plug-in. Otherwise fall back on
72 // checking the focused node in WebKit.
73 if (render_view_->HasIMETextFocus()) {
74 node_has_focus = true;
75 node_is_editable_text = true;
76 } else {
77 node_has_focus = !node.isNull();
78 node_is_editable_text =
79 node_has_focus && render_view_->IsEditableNode(node);
80 }
81
82 std::vector<AccessibilityHostMsg_EventParams> events;
83 events.push_back(AccessibilityHostMsg_EventParams());
84 AccessibilityHostMsg_EventParams& event = events[0];
85
86 // If we want to update the browser's accessibility tree but not send a
87 // native focus changed event, we can send a LayoutComplete
88 // event, which doesn't post a native event on Windows.
89 event.event_type =
90 send_focus_event ?
91 blink::WebAXEventFocus :
92 blink::WebAXEventLayoutComplete;
93
94 // Set the id that the event applies to: the root node if nothing
95 // has focus, otherwise the focused node.
96 event.id = node_has_focus ? next_id_ : 1;
97
98 event.nodes.resize(2);
99 AccessibilityNodeData& root = event.nodes[0];
100 AccessibilityNodeData& child = event.nodes[1];
101
102 // Always include the root of the tree, the document. It always has id 1.
103 root.id = 1;
104 root.role = blink::WebAXRoleRootWebArea;
105 root.state =
106 (1 << blink::WebAXStateReadonly) |
107 (1 << blink::WebAXStateFocusable);
108 if (!node_has_focus)
109 root.state |= (1 << blink::WebAXStateFocused);
110 root.location = gfx::Rect(render_view_->size());
111 root.child_ids.push_back(next_id_);
112
113 child.id = next_id_;
114 child.role = blink::WebAXRoleGroup;
115
116 if (!node.isNull() && node.isElementNode()) {
117 child.location = gfx::Rect(
118 const_cast<WebNode&>(node).to<WebElement>().boundsInViewportSpace());
119 } else if (render_view_->HasIMETextFocus()) {
120 child.location = root.location;
121 } else {
122 child.location = gfx::Rect();
123 }
124
125 if (node_has_focus) {
126 child.state =
127 (1 << blink::WebAXStateFocusable) |
128 (1 << blink::WebAXStateFocused);
129 if (!node_is_editable_text)
130 child.state |= (1 << blink::WebAXStateReadonly);
131 }
132
133 #ifndef NDEBUG
134 if (logging_) {
135 VLOG(0) << "Accessibility update: \n"
136 << "routing id=" << routing_id()
137 << " event="
138 << AccessibilityEventToString(event.event_type)
139 << "\n" << event.nodes[0].DebugString(true);
140 }
141 #endif
142
143 Send(new AccessibilityHostMsg_Events(routing_id(), events));
144
145 // Increment the id, wrap back when we get past a million.
146 next_id_++;
147 if (next_id_ > 1000000)
148 next_id_ = kInitialId;
149 }
150
151 } // namespace content
152