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_frame_impl.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/WebLocalFrame.h"
12 #include "third_party/WebKit/public/web/WebNode.h"
13 #include "third_party/WebKit/public/web/WebView.h"
14 #include "ui/accessibility/ax_node_data.h"
15
16 using blink::WebDocument;
17 using blink::WebElement;
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(RenderFrameImpl * render_frame)29 RendererAccessibilityFocusOnly::RendererAccessibilityFocusOnly(
30 RenderFrameImpl* render_frame)
31 : RendererAccessibility(render_frame),
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
GetType()43 RendererAccessibilityType RendererAccessibilityFocusOnly::GetType() {
44 return RendererAccessibilityTypeFocusOnly;
45 }
46
FocusedNodeChanged(const WebNode & node)47 void RendererAccessibilityFocusOnly::FocusedNodeChanged(const WebNode& node) {
48 // Send the new accessible tree and post a native focus event.
49 HandleFocusedNodeChanged(node, true);
50 }
51
DidFinishLoad()52 void RendererAccessibilityFocusOnly::DidFinishLoad() {
53 // Send an accessible tree to the browser, but do not post a native
54 // focus event. This is important so that if focus is initially in an
55 // editable text field, Windows will know to pop up the keyboard if the
56 // user touches it and focus doesn't change.
57 const WebDocument& document = GetMainDocument();
58 HandleFocusedNodeChanged(document.focusedElement(), 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 Blink.
73 if (render_frame_->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_frame_->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 ? ui::AX_EVENT_FOCUS : ui::AX_EVENT_LAYOUT_COMPLETE;
91
92 // Set the id that the event applies to: the root node if nothing
93 // has focus, otherwise the focused node.
94 event.id = node_has_focus ? next_id_ : 1;
95
96 event.update.nodes.resize(2);
97 ui::AXNodeData& root = event.update.nodes[0];
98 ui::AXNodeData& child = event.update.nodes[1];
99
100 // Always include the root of the tree, the document. It always has id 1.
101 root.id = 1;
102 root.role = ui::AX_ROLE_ROOT_WEB_AREA;
103 root.state =
104 (1 << ui::AX_STATE_READ_ONLY) |
105 (1 << ui::AX_STATE_FOCUSABLE);
106 if (!node_has_focus)
107 root.state |= (1 << ui::AX_STATE_FOCUSED);
108 root.location = gfx::Rect(render_frame_->render_view()->size());
109 root.child_ids.push_back(next_id_);
110
111 child.id = next_id_;
112 child.role = ui::AX_ROLE_GROUP;
113
114 if (!node.isNull() && node.isElementNode()) {
115 child.location = gfx::Rect(
116 const_cast<WebNode&>(node).to<WebElement>().boundsInViewportSpace());
117 } else if (render_frame_->render_view()->HasIMETextFocus()) {
118 child.location = root.location;
119 } else {
120 child.location = gfx::Rect();
121 }
122
123 if (node_has_focus) {
124 child.state =
125 (1 << ui::AX_STATE_FOCUSABLE) |
126 (1 << ui::AX_STATE_FOCUSED);
127 if (!node_is_editable_text)
128 child.state |= (1 << ui::AX_STATE_READ_ONLY);
129 }
130
131 #ifndef NDEBUG
132 /**
133 if (logging_) {
134 VLOG(0) << "Accessibility update: \n"
135 << "routing id=" << routing_id()
136 << " event="
137 << AccessibilityEventToString(event.event_type)
138 << "\n" << event.nodes[0].DebugString(true);
139 }
140 **/
141 #endif
142
143 Send(new AccessibilityHostMsg_Events(routing_id(), events, false));
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