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/renderer/render_view_impl.h"
8 #include "third_party/WebKit/public/web/WebDocument.h"
9 #include "third_party/WebKit/public/web/WebElement.h"
10 #include "third_party/WebKit/public/web/WebLocalFrame.h"
11 #include "third_party/WebKit/public/web/WebNode.h"
12 #include "third_party/WebKit/public/web/WebView.h"
13 #include "ui/accessibility/ax_node_data.h"
14
15 using blink::WebDocument;
16 using blink::WebElement;
17 using blink::WebNode;
18 using blink::WebView;
19
20 namespace {
21 // The root node will always have id 1. Let each child node have a new
22 // id starting with 2.
23 const int kInitialId = 2;
24 }
25
26 namespace content {
27
RendererAccessibilityFocusOnly(RenderViewImpl * render_view)28 RendererAccessibilityFocusOnly::RendererAccessibilityFocusOnly(
29 RenderViewImpl* render_view)
30 : RendererAccessibility(render_view),
31 next_id_(kInitialId) {
32 }
33
~RendererAccessibilityFocusOnly()34 RendererAccessibilityFocusOnly::~RendererAccessibilityFocusOnly() {
35 }
36
HandleWebAccessibilityEvent(const blink::WebAXObject & obj,blink::WebAXEvent event)37 void RendererAccessibilityFocusOnly::HandleWebAccessibilityEvent(
38 const blink::WebAXObject& obj, blink::WebAXEvent event) {
39 // Do nothing.
40 }
41
GetType()42 RendererAccessibilityType RendererAccessibilityFocusOnly::GetType() {
43 return RendererAccessibilityTypeFocusOnly;
44 }
45
FocusedNodeChanged(const WebNode & node)46 void RendererAccessibilityFocusOnly::FocusedNodeChanged(const WebNode& node) {
47 // Send the new accessible tree and post a native focus event.
48 HandleFocusedNodeChanged(node, true);
49 }
50
DidFinishLoad(blink::WebLocalFrame * frame)51 void RendererAccessibilityFocusOnly::DidFinishLoad(
52 blink::WebLocalFrame* frame) {
53 WebView* view = render_view()->GetWebView();
54 if (view->focusedFrame() != frame)
55 return;
56
57 WebDocument document = frame->document();
58 // Send an accessible tree to the browser, but do not post a native
59 // focus event. This is important so that if focus is initially in an
60 // editable text field, Windows will know to pop up the keyboard if the
61 // user touches it and focus doesn't change.
62 HandleFocusedNodeChanged(document.focusedElement(), false);
63 }
64
HandleFocusedNodeChanged(const WebNode & node,bool send_focus_event)65 void RendererAccessibilityFocusOnly::HandleFocusedNodeChanged(
66 const WebNode& node,
67 bool send_focus_event) {
68 const WebDocument& document = GetMainDocument();
69 if (document.isNull())
70 return;
71
72 bool node_has_focus;
73 bool node_is_editable_text;
74 // Check HasIMETextFocus first, because it will correctly handle
75 // focus in a text box inside a ppapi plug-in. Otherwise fall back on
76 // checking the focused node in Blink.
77 if (render_view_->HasIMETextFocus()) {
78 node_has_focus = true;
79 node_is_editable_text = true;
80 } else {
81 node_has_focus = !node.isNull();
82 node_is_editable_text =
83 node_has_focus && render_view_->IsEditableNode(node);
84 }
85
86 std::vector<AccessibilityHostMsg_EventParams> events;
87 events.push_back(AccessibilityHostMsg_EventParams());
88 AccessibilityHostMsg_EventParams& event = events[0];
89
90 // If we want to update the browser's accessibility tree but not send a
91 // native focus changed event, we can send a LayoutComplete
92 // event, which doesn't post a native event on Windows.
93 event.event_type =
94 send_focus_event ? ui::AX_EVENT_FOCUS : ui::AX_EVENT_LAYOUT_COMPLETE;
95
96 // Set the id that the event applies to: the root node if nothing
97 // has focus, otherwise the focused node.
98 event.id = node_has_focus ? next_id_ : 1;
99
100 event.update.nodes.resize(2);
101 ui::AXNodeData& root = event.update.nodes[0];
102 ui::AXNodeData& child = event.update.nodes[1];
103
104 // Always include the root of the tree, the document. It always has id 1.
105 root.id = 1;
106 root.role = ui::AX_ROLE_ROOT_WEB_AREA;
107 root.state =
108 (1 << ui::AX_STATE_READ_ONLY) |
109 (1 << ui::AX_STATE_FOCUSABLE);
110 if (!node_has_focus)
111 root.state |= (1 << ui::AX_STATE_FOCUSED);
112 root.location = gfx::Rect(render_view_->size());
113 root.child_ids.push_back(next_id_);
114
115 child.id = next_id_;
116 child.role = ui::AX_ROLE_GROUP;
117
118 if (!node.isNull() && node.isElementNode()) {
119 child.location = gfx::Rect(
120 const_cast<WebNode&>(node).to<WebElement>().boundsInViewportSpace());
121 } else if (render_view_->HasIMETextFocus()) {
122 child.location = root.location;
123 } else {
124 child.location = gfx::Rect();
125 }
126
127 if (node_has_focus) {
128 child.state =
129 (1 << ui::AX_STATE_FOCUSABLE) |
130 (1 << ui::AX_STATE_FOCUSED);
131 if (!node_is_editable_text)
132 child.state |= (1 << ui::AX_STATE_READ_ONLY);
133 }
134
135 #ifndef NDEBUG
136 /**
137 if (logging_) {
138 VLOG(0) << "Accessibility update: \n"
139 << "routing id=" << routing_id()
140 << " event="
141 << AccessibilityEventToString(event.event_type)
142 << "\n" << event.nodes[0].DebugString(true);
143 }
144 **/
145 #endif
146
147 Send(new AccessibilityHostMsg_Events(routing_id(), events));
148
149 // Increment the id, wrap back when we get past a million.
150 next_id_++;
151 if (next_id_ > 1000000)
152 next_id_ = kInitialId;
153 }
154
155 } // namespace content
156