content/renderer/accessibility/renderer_accessibility_browsertest.cc

   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 "base/strings/utf_string_conversions.h"
   6 #include "base/time/time.h"
   7 #include "content/common/frame_messages.h"
   8 #include "content/common/view_message_enums.h"
   9 #include "content/public/test/render_view_test.h"
  10 #include "content/renderer/accessibility/renderer_accessibility.h"
  11 #include "content/renderer/render_frame_impl.h"
  12 #include "content/renderer/render_view_impl.h"
  13 #include "testing/gtest/include/gtest/gtest.h"
  14 #include "third_party/WebKit/public/platform/WebSize.h"
  15 #include "third_party/WebKit/public/web/WebAXObject.h"
  16 #include "third_party/WebKit/public/web/WebDocument.h"
  17 #include "third_party/WebKit/public/web/WebView.h"
  18 #include "ui/accessibility/ax_node_data.h"
  19
  20 using blink::WebAXObject;
  21 using blink::WebDocument;
  22
  23 namespace content {
  24
  25 class TestRendererAccessibility : public RendererAccessibility {
  26  public:
  27   explicit TestRendererAccessibility(RenderFrameImpl* render_frame)
  28     : RendererAccessibility(render_frame) {
  29   }
  30
  31   void SendPendingAccessibilityEvents() {
  32     RendererAccessibility::SendPendingAccessibilityEvents();
  33   }
  34 };
  35
  36 class RendererAccessibilityTest : public RenderViewTest {
  37  public:
  38   RendererAccessibilityTest() {}
  39
  40   RenderViewImpl* view() {
  41     return static_cast<RenderViewImpl*>(view_);
  42   }
  43
  44   RenderFrameImpl* frame() {
  45     return static_cast<RenderFrameImpl*>(view()->GetMainRenderFrame());
  46   }
  47
  48   void SetUp() override {
  49     RenderViewTest::SetUp();
  50     sink_ = &render_thread_->sink();
  51   }
  52
  53   void SetMode(AccessibilityMode mode) {
  54     frame()->OnSetAccessibilityMode(mode);
  55   }
  56
  57   void GetLastAccEvent(
  58       AccessibilityHostMsg_EventParams* params) {
  59     const IPC::Message* message =
  60         sink_->GetUniqueMessageMatching(AccessibilityHostMsg_Events::ID);
  61     ASSERT_TRUE(message);
  62     Tuple<std::vector<AccessibilityHostMsg_EventParams>, int> param;
  63     AccessibilityHostMsg_Events::Read(message, &param);
  64     ASSERT_GE(get<0>(param).size(), 1U);
  65     *params = get<0>(param)[0];
  66   }
  67
  68   int CountAccessibilityNodesSentToBrowser() {
  69     AccessibilityHostMsg_EventParams event;
  70     GetLastAccEvent(&event);
  71     return event.update.nodes.size();
  72   }
  73
  74  protected:
  75   IPC::TestSink* sink_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(RendererAccessibilityTest);
  78
  79 };
  80
  81 TEST_F(RendererAccessibilityTest, SendFullAccessibilityTreeOnReload) {
  82   // The job of RendererAccessibility is to serialize the
  83   // accessibility tree built by WebKit and send it to the browser.
  84   // When the accessibility tree changes, it tries to send only
  85   // the nodes that actually changed or were reparented. This test
  86   // ensures that the messages sent are correct in cases when a page
  87   // reloads, and that internal state is properly garbage-collected.
  88   std::string html =
  89       "<body>"
  90       "  <div role='group' id='A'>"
  91       "    <div role='group' id='A1'></div>"
  92       "    <div role='group' id='A2'></div>"
  93       "  </div>"
  94       "</body>";
  95   LoadHTML(html.c_str());
  96
  97   // Creating a RendererAccessibility should sent the tree to the browser.
  98   scoped_ptr<TestRendererAccessibility> accessibility(
  99       new TestRendererAccessibility(frame()));
 100   accessibility->SendPendingAccessibilityEvents();
 101   EXPECT_EQ(4, CountAccessibilityNodesSentToBrowser());
 102
 103   // If we post another event but the tree doesn't change,
 104   // we should only send 1 node to the browser.
 105   sink_->ClearMessages();
 106   WebDocument document = view()->GetWebView()->mainFrame()->document();
 107   WebAXObject root_obj = document.accessibilityObject();
 108   accessibility->HandleAXEvent(
 109       root_obj,
 110       ui::AX_EVENT_LAYOUT_COMPLETE);
 111   accessibility->SendPendingAccessibilityEvents();
 112   EXPECT_EQ(1, CountAccessibilityNodesSentToBrowser());
 113   {
 114     // Make sure it's the root object that was updated.
 115     AccessibilityHostMsg_EventParams event;
 116     GetLastAccEvent(&event);
 117     EXPECT_EQ(root_obj.axID(), event.update.nodes[0].id);
 118   }
 119
 120   // If we reload the page and send a event, we should send
 121   // all 4 nodes to the browser. Also double-check that we didn't
 122   // leak any of the old BrowserTreeNodes.
 123   LoadHTML(html.c_str());
 124   document = view()->GetWebView()->mainFrame()->document();
 125   root_obj = document.accessibilityObject();
 126   sink_->ClearMessages();
 127   accessibility->HandleAXEvent(
 128       root_obj,
 129       ui::AX_EVENT_LAYOUT_COMPLETE);
 130   accessibility->SendPendingAccessibilityEvents();
 131   EXPECT_EQ(4, CountAccessibilityNodesSentToBrowser());
 132
 133   // Even if the first event is sent on an element other than
 134   // the root, the whole tree should be updated because we know
 135   // the browser doesn't have the root element.
 136   LoadHTML(html.c_str());
 137   document = view()->GetWebView()->mainFrame()->document();
 138   root_obj = document.accessibilityObject();
 139   sink_->ClearMessages();
 140   const WebAXObject& first_child = root_obj.childAt(0);
 141   accessibility->HandleAXEvent(
 142       first_child,
 143       ui::AX_EVENT_LIVE_REGION_CHANGED);
 144   accessibility->SendPendingAccessibilityEvents();
 145   EXPECT_EQ(4, CountAccessibilityNodesSentToBrowser());
 146 }
 147
 148 // http://crbug.com/253537
 149 #if defined(OS_ANDROID)
 150 #define MAYBE_AccessibilityMessagesQueueWhileSwappedOut \
 151         DISABLED_AccessibilityMessagesQueueWhileSwappedOut
 152 #else
 153 #define MAYBE_AccessibilityMessagesQueueWhileSwappedOut \
 154         AccessibilityMessagesQueueWhileSwappedOut
 155 #endif
 156
 157 TEST_F(RendererAccessibilityTest,
 158        MAYBE_AccessibilityMessagesQueueWhileSwappedOut) {
 159   std::string html =
 160       "<body>"
 161       "  <p>Hello, world.</p>"
 162       "</body>";
 163   LoadHTML(html.c_str());
 164   static const int kProxyRoutingId = 13;
 165
 166   // Creating a RendererAccessibility should send the tree to the browser.
 167   scoped_ptr<TestRendererAccessibility> accessibility(
 168       new TestRendererAccessibility(frame()));
 169   accessibility->SendPendingAccessibilityEvents();
 170   EXPECT_EQ(5, CountAccessibilityNodesSentToBrowser());
 171
 172   // Post a "value changed" event, but then swap out
 173   // before sending it. It shouldn't send the event while
 174   // swapped out.
 175   sink_->ClearMessages();
 176   WebDocument document = view()->GetWebView()->mainFrame()->document();
 177   WebAXObject root_obj = document.accessibilityObject();
 178   accessibility->HandleAXEvent(
 179       root_obj,
 180       ui::AX_EVENT_VALUE_CHANGED);
 181   view()->GetMainRenderFrame()->OnSwapOut(kProxyRoutingId, true,
 182                                           content::FrameReplicationState());
 183   accessibility->SendPendingAccessibilityEvents();
 184   EXPECT_FALSE(sink_->GetUniqueMessageMatching(
 185       AccessibilityHostMsg_Events::ID));
 186
 187   // Navigate, so we're not swapped out anymore. Now we should
 188   // send accessibility events again. Note that the
 189   // message that was queued up before will be quickly discarded
 190   // because the element it was referring to no longer exists,
 191   // so the event here is from loading this new page.
 192   FrameMsg_Navigate_Params nav_params;
 193   nav_params.common_params.url = GURL("data:text/html,<p>Hello, again.</p>");
 194   nav_params.common_params.navigation_type = FrameMsg_Navigate_Type::NORMAL;
 195   nav_params.common_params.transition = ui::PAGE_TRANSITION_TYPED;
 196   nav_params.current_history_list_length = 1;
 197   nav_params.current_history_list_offset = 0;
 198   nav_params.pending_history_list_offset = 1;
 199   nav_params.page_id = -1;
 200   nav_params.commit_params.browser_navigation_start =
 201       base::TimeTicks::FromInternalValue(1);
 202   frame()->OnNavigate(nav_params);
 203   accessibility->SendPendingAccessibilityEvents();
 204   EXPECT_TRUE(sink_->GetUniqueMessageMatching(
 205       AccessibilityHostMsg_Events::ID));
 206 }
 207
 208 TEST_F(RendererAccessibilityTest, HideAccessibilityObject) {
 209   // Test RendererAccessibility and make sure it sends the
 210   // proper event to the browser when an object in the tree
 211   // is hidden, but its children are not.
 212   std::string html =
 213       "<body>"
 214       "  <div role='group' id='A'>"
 215       "    <div role='group' id='B'>"
 216       "      <div role='group' id='C' style='visibility:visible'>"
 217       "      </div>"
 218       "    </div>"
 219       "  </div>"
 220       "</body>";
 221   LoadHTML(html.c_str());
 222
 223   scoped_ptr<TestRendererAccessibility> accessibility(
 224       new TestRendererAccessibility(frame()));
 225   accessibility->SendPendingAccessibilityEvents();
 226   EXPECT_EQ(4, CountAccessibilityNodesSentToBrowser());
 227
 228   WebDocument document = view()->GetWebView()->mainFrame()->document();
 229   WebAXObject root_obj = document.accessibilityObject();
 230   WebAXObject node_a = root_obj.childAt(0);
 231   WebAXObject node_b = node_a.childAt(0);
 232   WebAXObject node_c = node_b.childAt(0);
 233
 234   // Hide node 'B' ('C' stays visible).
 235   ExecuteJavaScript(
 236       "document.getElementById('B').style.visibility = 'hidden';");
 237   // Force layout now.
 238   ExecuteJavaScript("document.getElementById('B').offsetLeft;");
 239
 240   // Send a childrenChanged on 'A'.
 241   sink_->ClearMessages();
 242   accessibility->HandleAXEvent(
 243       node_a,
 244       ui::AX_EVENT_CHILDREN_CHANGED);
 245
 246   accessibility->SendPendingAccessibilityEvents();
 247   AccessibilityHostMsg_EventParams event;
 248   GetLastAccEvent(&event);
 249   ASSERT_EQ(2U, event.update.nodes.size());
 250
 251   // RendererAccessibility notices that 'C' is being reparented,
 252   // so it clears the subtree rooted at 'A', then updates 'A' and then 'C'.
 253   EXPECT_EQ(node_a.axID(), event.update.node_id_to_clear);
 254   EXPECT_EQ(node_a.axID(), event.update.nodes[0].id);
 255   EXPECT_EQ(node_c.axID(), event.update.nodes[1].id);
 256   EXPECT_EQ(2, CountAccessibilityNodesSentToBrowser());
 257 }
 258
 259 TEST_F(RendererAccessibilityTest, ShowAccessibilityObject) {
 260   // Test RendererAccessibility and make sure it sends the
 261   // proper event to the browser when an object in the tree
 262   // is shown, causing its own already-visible children to be
 263   // reparented to it.
 264   std::string html =
 265       "<body>"
 266       "  <div role='group' id='A'>"
 267       "    <div role='group' id='B' style='visibility:hidden'>"
 268       "      <div role='group' id='C' style='visibility:visible'>"
 269       "      </div>"
 270       "    </div>"
 271       "  </div>"
 272       "</body>";
 273   LoadHTML(html.c_str());
 274
 275   scoped_ptr<TestRendererAccessibility> accessibility(
 276       new TestRendererAccessibility(frame()));
 277   accessibility->SendPendingAccessibilityEvents();
 278   EXPECT_EQ(3, CountAccessibilityNodesSentToBrowser());
 279
 280   // Show node 'B', then send a childrenChanged on 'A'.
 281   ExecuteJavaScript(
 282       "document.getElementById('B').style.visibility = 'visible';");
 283   ExecuteJavaScript("document.getElementById('B').offsetLeft;");
 284
 285   sink_->ClearMessages();
 286   WebDocument document = view()->GetWebView()->mainFrame()->document();
 287   WebAXObject root_obj = document.accessibilityObject();
 288   WebAXObject node_a = root_obj.childAt(0);
 289   WebAXObject node_b = node_a.childAt(0);
 290   WebAXObject node_c = node_b.childAt(0);
 291
 292   accessibility->HandleAXEvent(
 293       node_a,
 294       ui::AX_EVENT_CHILDREN_CHANGED);
 295
 296   accessibility->SendPendingAccessibilityEvents();
 297   AccessibilityHostMsg_EventParams event;
 298   GetLastAccEvent(&event);
 299
 300   ASSERT_EQ(3U, event.update.nodes.size());
 301   EXPECT_EQ(node_a.axID(), event.update.node_id_to_clear);
 302   EXPECT_EQ(node_a.axID(), event.update.nodes[0].id);
 303   EXPECT_EQ(node_b.axID(), event.update.nodes[1].id);
 304   EXPECT_EQ(node_c.axID(), event.update.nodes[2].id);
 305   EXPECT_EQ(3, CountAccessibilityNodesSentToBrowser());
 306 }
 307
 308 TEST_F(RendererAccessibilityTest, DetachAccessibilityObject) {
 309   // Test RendererAccessibility and make sure it sends the
 310   // proper event to the browser when an object in the tree
 311   // is detached, but its children are not. This can happen when
 312   // a layout occurs and an anonymous render block is no longer needed.
 313   std::string html =
 314       "<body aria-label='Body'>"
 315       "<span>1</span><span style='display:block'>2</span>"
 316       "</body>";
 317   LoadHTML(html.c_str());
 318
 319   scoped_ptr<TestRendererAccessibility> accessibility(
 320       new TestRendererAccessibility(frame()));
 321   accessibility->SendPendingAccessibilityEvents();
 322   EXPECT_EQ(7, CountAccessibilityNodesSentToBrowser());
 323
 324   // Initially, the accessibility tree looks like this:
 325   //
 326   //   Document
 327   //   +--Body
 328   //      +--Anonymous Block
 329   //         +--Static Text "1"
 330   //            +--Inline Text Box "1"
 331   //      +--Static Text "2"
 332   //         +--Inline Text Box "2"
 333   WebDocument document = view()->GetWebView()->mainFrame()->document();
 334   WebAXObject root_obj = document.accessibilityObject();
 335   WebAXObject body = root_obj.childAt(0);
 336   WebAXObject anonymous_block = body.childAt(0);
 337   WebAXObject text_1 = anonymous_block.childAt(0);
 338   WebAXObject text_2 = body.childAt(1);
 339
 340   // Change the display of the second 'span' back to inline, which causes the
 341   // anonymous block to be destroyed.
 342   ExecuteJavaScript(
 343       "document.querySelectorAll('span')[1].style.display = 'inline';");
 344   // Force layout now.
 345   ExecuteJavaScript("document.body.offsetLeft;");
 346
 347   // Send a childrenChanged on the body.
 348   sink_->ClearMessages();
 349   accessibility->HandleAXEvent(
 350       body,
 351       ui::AX_EVENT_CHILDREN_CHANGED);
 352
 353   accessibility->SendPendingAccessibilityEvents();
 354
 355   // Afterwards, the accessibility tree looks like this:
 356   //
 357   //   Document
 358   //   +--Body
 359   //      +--Static Text "1"
 360   //         +--Inline Text Box "1"
 361   //      +--Static Text "2"
 362   //         +--Inline Text Box "2"
 363   //
 364   // We just assert that there are now four nodes in the
 365   // accessibility tree and that only three nodes needed
 366   // to be updated (the body, the static text 1, and
 367   // the static text 2).
 368
 369   AccessibilityHostMsg_EventParams event;
 370   GetLastAccEvent(&event);
 371   ASSERT_EQ(5U, event.update.nodes.size());
 372
 373   EXPECT_EQ(body.axID(), event.update.nodes[0].id);
 374   EXPECT_EQ(text_1.axID(), event.update.nodes[1].id);
 375   // The third event is to update text_2, but its id changes
 376   // so we don't have a test expectation for it.
 377 }
 378
 379 TEST_F(RendererAccessibilityTest, EventOnObjectNotInTree) {
 380   // Test RendererAccessibility and make sure it doesn't send anything
 381   // if we get a notification from Blink for an object that isn't in the
 382   // tree, like the scroll area that's the parent of the main document,
 383   // which we don't expose.
 384   std::string html = "<body><input></body>";
 385   LoadHTML(html.c_str());
 386
 387   scoped_ptr<TestRendererAccessibility> accessibility(
 388       new TestRendererAccessibility(frame()));
 389   accessibility->SendPendingAccessibilityEvents();
 390   EXPECT_EQ(3, CountAccessibilityNodesSentToBrowser());
 391
 392   WebDocument document = view()->GetWebView()->mainFrame()->document();
 393   WebAXObject root_obj = document.accessibilityObject();
 394   WebAXObject scroll_area = root_obj.parentObject();
 395   EXPECT_EQ(blink::WebAXRoleScrollArea, scroll_area.role());
 396
 397   // Try to fire a message on the scroll area, and assert that we just
 398   // ignore it.
 399   sink_->ClearMessages();
 400   accessibility->HandleAXEvent(scroll_area,
 401                                ui::AX_EVENT_VALUE_CHANGED);
 402
 403   accessibility->SendPendingAccessibilityEvents();
 404
 405   const IPC::Message* message =
 406       sink_->GetUniqueMessageMatching(AccessibilityHostMsg_Events::ID);
 407   ASSERT_TRUE(message);
 408   Tuple<std::vector<AccessibilityHostMsg_EventParams>, int> param;
 409   AccessibilityHostMsg_Events::Read(message, &param);
 410   ASSERT_EQ(0U, get<0>(param).size());
 411 }
 412
 413 }  // namespace content