Suppress accessibility events when user is navigating away.

chrome/browser/ui/views/accessibility/navigation_accessibility_win_uitest.cc

+// Copyright (c) 2015 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 <oleacc.h>
+
+#include "base/strings/string_util.h"
+#include "base/win/scoped_bstr.h"
+#include "base/win/scoped_com_initializer.h"
+#include "base/win/scoped_comptr.h"
+#include "base/win/scoped_variant.h"
+#include "chrome/app/chrome_command_ids.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/omnibox/omnibox_view.h"
+#include "chrome/browser/ui/views/frame/browser_view.h"
+#include "chrome/browser/ui/views/omnibox/omnibox_view_views.h"
+#include "chrome/browser/ui/views/toolbar/toolbar_view.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/interactive_test_utils.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/browser_accessibility_state.h"
+#include "net/dns/mock_host_resolver.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/base/test/ui_controls.h"
+#include "url/gurl.h"
+
+// We could move this into a utility file in the future if it ends up
+// being useful to other tests.
+class WinAccessibilityEventMonitor {
+ public:
+  WinAccessibilityEventMonitor(UINT event_min, UINT event_max);
+  ~WinAccessibilityEventMonitor();
+
+  // Blocks until the next event is received. When it's received, it
+  // queries accessibility information about the object that fired the
+  // event and populates the event, hwnd, role, state, and name in the
+  // passed arguments.
+  void WaitForNextEvent(DWORD* out_event,
+                        HWND* out_hwnd,
+                        UINT* out_role,
+                        UINT* out_state,
+                        std::string* out_name);
+
+ private:
+  void OnWinEventHook(HWINEVENTHOOK handle,
+                      DWORD event,
+                      HWND hwnd,
+                      LONG obj_id,
+                      LONG child_id,
+                      DWORD event_thread,
+                      DWORD event_time);
+
+  static void CALLBACK WinEventHookThunk(
+      HWINEVENTHOOK handle,
+      DWORD event,
+      HWND hwnd,
+      LONG obj_id,
+      LONG child_id,
+      DWORD event_thread,
+      DWORD event_time);
+
+  struct EventInfo {
+    DWORD event;
+    HWND hwnd;
+    LONG obj_id;
+    LONG child_id;
+  };
+
+  std::deque<EventInfo> event_queue_;
+  scoped_refptr<content::MessageLoopRunner> loop_runner_;
+  HWINEVENTHOOK win_event_hook_handle_;
+  static WinAccessibilityEventMonitor* instance_;
+
+  DISALLOW_COPY_AND_ASSIGN(WinAccessibilityEventMonitor);
+};
+
+// static
+WinAccessibilityEventMonitor* WinAccessibilityEventMonitor::instance_ = NULL;
+
+WinAccessibilityEventMonitor::WinAccessibilityEventMonitor(
+    UINT event_min, UINT event_max) {
+  CHECK(!instance_) << "There can be only one instance of"
+                    << " WinAccessibilityEventMonitor at a time.";
+  instance_ = this;
+  win_event_hook_handle_ = SetWinEventHook(
+      event_min,
+      event_max,
+      NULL,
+      &WinAccessibilityEventMonitor::WinEventHookThunk,
+      GetCurrentProcessId(),
+      0,  // Hook all threads
+      WINEVENT_OUTOFCONTEXT);
+}
+
+WinAccessibilityEventMonitor::~WinAccessibilityEventMonitor() {
+  UnhookWinEvent(win_event_hook_handle_);
+  instance_ = NULL;
+}
+
+void WinAccessibilityEventMonitor::WaitForNextEvent(
+    DWORD* out_event,
+    HWND* out_hwnd,
+    UINT* out_role,
+    UINT* out_state,
+    std::string* out_name) {
+  if (event_queue_.empty()) {
+    loop_runner_ = new content::MessageLoopRunner();
+    loop_runner_->Run();
+    loop_runner_ = NULL;
+  }
+  EventInfo event_info = event_queue_.front();
+  event_queue_.pop_front();
+
+  *out_event = event_info.event;
+  *out_hwnd = event_info.hwnd;
+
+  base::win::ScopedComPtr<IAccessible> acc_obj;
+  base::win::ScopedVariant child_variant;
+  CHECK(S_OK == AccessibleObjectFromEvent(
+      event_info.hwnd, event_info.obj_id, event_info.child_id,
+      acc_obj.Receive(), child_variant.Receive()));
+
+  base::win::ScopedVariant role_variant;
+  if (S_OK == acc_obj->get_accRole(child_variant, role_variant.Receive()))
+    *out_role = V_I4(&role_variant);
+  else
+    *out_role = 0;
+
+  base::win::ScopedVariant state_variant;
+  if (S_OK == acc_obj->get_accState(child_variant, state_variant.Receive()))
+    *out_state = V_I4(&state_variant);
+  else
+    *out_state = 0;
+
+  base::win::ScopedBstr name_bstr;
+  HRESULT hr = acc_obj->get_accName(child_variant, name_bstr.Receive());
+  if (S_OK == hr)
+    *out_name = base::UTF16ToUTF8(base::string16(name_bstr));
+  else
+    *out_name = "";
+}
+
+void WinAccessibilityEventMonitor::OnWinEventHook(
+    HWINEVENTHOOK handle,
+    DWORD event,
+    HWND hwnd,
+    LONG obj_id,
+    LONG child_id,
+    DWORD event_thread,
+    DWORD event_time) {
+  EventInfo event_info;
+  event_info.event = event;
+  event_info.hwnd = hwnd;
+  event_info.obj_id = obj_id;
+  event_info.child_id = child_id;
+  event_queue_.push_back(event_info);
+  if (loop_runner_.get())
+    loop_runner_->Quit();
+}
+
+// static
+void CALLBACK WinAccessibilityEventMonitor::WinEventHookThunk(
+    HWINEVENTHOOK handle,
+    DWORD event,
+    HWND hwnd,
+    LONG obj_id,
+    LONG child_id,
+    DWORD event_thread,
+    DWORD event_time) {
+  if (instance_) {
+    instance_->OnWinEventHook(handle, event, hwnd, obj_id, child_id,
+                              event_thread, event_time);
+  }
+}
+
+class NavigationAccessibilityTest : public InProcessBrowserTest {
+ protected:
+  NavigationAccessibilityTest() {}
+  virtual ~NavigationAccessibilityTest() {}
+
+  void SendKeyPress(ui::KeyboardCode key) {
+    gfx::NativeWindow native_window = browser()->window()->GetNativeWindow();
+    ASSERT_NO_FATAL_FAILURE(
+        ASSERT_TRUE(
+            ui_test_utils::SendKeyPressToWindowSync(
+                native_window, key, false, false, false, false)));
+  }
+
+ private:
+  base::win::ScopedCOMInitializer com_initializer_;
+
+  DISALLOW_COPY_AND_ASSIGN(NavigationAccessibilityTest);
+};
+
+// Tests that when focus is in the omnibox and the user types a url and
+// presses enter, no focus events are sent on the old document.
+IN_PROC_BROWSER_TEST_F(NavigationAccessibilityTest, TestNavigateToNewUrl) {
+  content::BrowserAccessibilityState::GetInstance()->EnableAccessibility();
+
+  ui_test_utils::NavigateToURL(browser(),
+                               GURL("data:text/html;charset=utf-8,"
+                                    "<head><title>First Page</title></head>"));
+
+  chrome::ExecuteCommand(browser(), IDC_FOCUS_LOCATION);
+
+  host_resolver()->AddRule("*", "127.0.0.1");
+  ASSERT_TRUE(test_server()->Start());
+  GURL main_url(test_server()->GetURL("files/english_page.html"));
+
+  OmniboxViewViews* omnibox_view =
+      BrowserView::GetBrowserViewForBrowser(browser())->
+      toolbar()->location_bar()->omnibox_view();
+  omnibox_view->SetUserText(base::UTF8ToUTF16(main_url.spec()),
+                            base::UTF8ToUTF16(main_url.spec()),
+                            false);
+
+  WinAccessibilityEventMonitor monitor(EVENT_OBJECT_FOCUS, EVENT_OBJECT_FOCUS);
+  SendKeyPress(ui::VKEY_RETURN);
+
+  for (;;) {
+    DWORD event;
+    HWND hwnd;
+    UINT role;
+    UINT state;
+    std::string name;
+    monitor.WaitForNextEvent(&event, &hwnd, &role, &state, &name);
+
+    LOG(INFO) << "Got event: "
+              << " event=" << event
+              << " hwnd=" << hwnd
+              << " role=" << role
+              << " state=" << state
+              << " name=" << name;
+
+    // We should get only focus events.
+    EXPECT_EQ(EVENT_OBJECT_FOCUS, event);
+
+    // We should get only focus events on document objects. (On a page with
+    // JavaScript or autofocus, additional focus events would be expected.)
+    EXPECT_EQ(ROLE_SYSTEM_DOCUMENT, role);
+
+    // We shouldn't get any events on the first page because from the time
+    // we start monitoring, the user has already initiated a load to the
+    // second page.
+    EXPECT_NE("First Page", name);

[dmazzoni, 2015/01/21 18:59:03]

The test will fail on this line if we don't get an accessibility notification
that the user has started navigating away in time.

+
+    // Finish when we get an event on the second page.
+    if (name == "This page is in English") {
+      LOG(INFO) << "Got event on second page, finishing test.";
+      break;
+    }
+  }
+}