Reimplement accessibility of web content by caching the entire

accessibility tree in the browser process.

Adds new RPCs for a browser tab to request accessibility info from
a renderer; the renderer responds with a complete tree of
accessibility metadata for the entire DOM, which is then cached
in the RenderWidgetHostView. This part is cross-platform and will
help with accessibility on both Windows and Mac OS X.

For Windows, MSAA support for web content has been rewritten to
use this new cache. Tested in JAWS and NVDA screen readers.
Using Chrome with a screen reader is now fast and stable,
unlike the previous implementation. However, note that most
advanced functionality is still not supported, and much work remains
to make Chrome work well with a screen reader. This is a necessary
step to improve stability first.

BUG=25564
BUG=13291
TEST=See http://codereview.chromium.org/1806001

Review URL: http://codereview.chromium.org/1637018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@46916 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 96 insertions, 0 deletions

diff --git a/chrome/common/render_messages_unittest.cc b/chrome/common/render_messages_unittest.cc
new file mode 100644
index 0000000..0dc3be8
--- /dev/null
+++ b/chrome/common/render_messages_unittest.cc
@@ -0,0 +1,96 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/scoped_ptr.h"
+#include "base/string16.h"
+#include "base/values.h"
+#include "chrome/common/render_messages.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(RenderMessagesUnittest, WebAccessibility) {
+  // Test a simple case.
+  webkit_glue::WebAccessibility input;
+  input.id = 123;
+  input.name = ASCIIToUTF16("name");
+  input.value = ASCIIToUTF16("value");
+  input.action = ASCIIToUTF16("action");
+  input.description = ASCIIToUTF16("description");
+  input.help = ASCIIToUTF16("help");
+  input.shortcut = ASCIIToUTF16("shortcut");
+  input.role = webkit_glue::WebAccessibility::ROLE_CHECKBUTTON;
+  input.state =
+      (1 << webkit_glue::WebAccessibility::STATE_CHECKED) |
+      (1 << webkit_glue::WebAccessibility::STATE_FOCUSED);
+  input.location = WebKit::WebRect(11, 22, 333, 444);
+
+  IPC::Message msg(1, 2, IPC::Message::PRIORITY_NORMAL);
+  IPC::WriteParam(&msg, input);
+
+  webkit_glue::WebAccessibility output;
+  void* iter = NULL;
+  EXPECT_TRUE(IPC::ReadParam(&msg, &iter, &output));
+  EXPECT_EQ(input.id, output.id);
+  EXPECT_EQ(input.name, output.name);
+  EXPECT_EQ(input.value, output.value);
+  EXPECT_EQ(input.action, output.action);
+  EXPECT_EQ(input.description, output.description);
+  EXPECT_EQ(input.help, output.help);
+  EXPECT_EQ(input.shortcut, output.shortcut);
+  EXPECT_EQ(input.role, output.role);
+  EXPECT_EQ(input.state, output.state);
+  EXPECT_EQ(input.location, output.location);
+  EXPECT_EQ(input.children.size(), output.children.size());
+
+  // Test a corrupt case.
+  IPC::Message bad_msg(1, 2, IPC::Message::PRIORITY_NORMAL);
+  bad_msg.WriteInt(99);
+  iter = NULL;
+  EXPECT_FALSE(IPC::ReadParam(&bad_msg, &iter, &output));
+
+  // Test a recursive case.
+  webkit_glue::WebAccessibility outer;
+  outer.id = 1000;
+  outer.name = ASCIIToUTF16("outer_name");
+  outer.role = webkit_glue::WebAccessibility::ROLE_GROUPING;
+  outer.state = 0;
+  outer.location = WebKit::WebRect(0, 0, 1000, 1000);
+  webkit_glue::WebAccessibility inner1;
+  inner1.id = 1001;
+  inner1.name = ASCIIToUTF16("inner1_name");
+  inner1.role = webkit_glue::WebAccessibility::ROLE_RADIOBUTTON;
+  inner1.state =
+      (1 << webkit_glue::WebAccessibility::STATE_CHECKED) |
+      (1 << webkit_glue::WebAccessibility::STATE_FOCUSED);
+  inner1.location = WebKit::WebRect(10, 10, 900, 400);
+  outer.children.push_back(inner1);
+  webkit_glue::WebAccessibility inner2;
+  inner2.id = 1002;
+  inner2.name = ASCIIToUTF16("inner2_name");
+  inner2.role = webkit_glue::WebAccessibility::ROLE_RADIOBUTTON;
+  inner2.state = (1 << webkit_glue::WebAccessibility::STATE_CHECKED);
+  inner2.location = WebKit::WebRect(10, 500, 900, 400);
+  outer.children.push_back(inner2);
+
+  IPC::Message msg2(1, 2, IPC::Message::PRIORITY_NORMAL);
+  IPC::WriteParam(&msg2, outer);
+
+  void* iter2 = NULL;
+  EXPECT_TRUE(IPC::ReadParam(&msg2, &iter2, &output));
+  EXPECT_EQ(outer.id, output.id);
+  EXPECT_EQ(outer.name, output.name);
+  EXPECT_EQ(outer.role, output.role);
+  EXPECT_EQ(outer.state, output.state);
+  EXPECT_EQ(outer.location, output.location);
+  EXPECT_EQ(outer.children.size(), output.children.size());
+  EXPECT_EQ(inner1.id, output.children[0].id);
+  EXPECT_EQ(inner1.name, output.children[0].name);
+  EXPECT_EQ(inner1.role, output.children[0].role);
+  EXPECT_EQ(inner1.state, output.children[0].state);
+  EXPECT_EQ(inner1.location, output.children[0].location);
+  EXPECT_EQ(inner2.id, output.children[1].id);
+  EXPECT_EQ(inner2.name, output.children[1].name);
+  EXPECT_EQ(inner2.role, output.children[1].role);
+  EXPECT_EQ(inner2.state, output.children[1].state);
+  EXPECT_EQ(inner2.location, output.children[1].location);
+}