ui/events/platform/platform_event_source_unittest.cc

   1 // Copyright 2014 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 "ui/events/platform/platform_event_source.h"
   6
   7 #include "base/bind.h"
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/memory/scoped_vector.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/run_loop.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13 #include "ui/events/platform/platform_event_dispatcher.h"
  14 #include "ui/events/platform/platform_event_observer.h"
  15 #include "ui/events/platform/scoped_event_dispatcher.h"
  16
  17 namespace ui {
  18
  19 namespace {
  20
  21 scoped_ptr<PlatformEvent> CreatePlatformEvent() {
  22   scoped_ptr<PlatformEvent> event(new PlatformEvent());
  23   memset(event.get(), 0, sizeof(PlatformEvent));
  24   return event.Pass();
  25 }
  26
  27 template <typename T>
  28 void DestroyScopedPtr(scoped_ptr<T> object) {}
  29
  30 void RemoveDispatcher(PlatformEventDispatcher* dispatcher) {
  31   PlatformEventSource::GetInstance()->RemovePlatformEventDispatcher(dispatcher);
  32 }
  33
  34 void RemoveDispatchers(PlatformEventDispatcher* first,
  35                        PlatformEventDispatcher* second) {
  36   PlatformEventSource::GetInstance()->RemovePlatformEventDispatcher(first);
  37   PlatformEventSource::GetInstance()->RemovePlatformEventDispatcher(second);
  38 }
  39
  40 void AddDispatcher(PlatformEventDispatcher* dispatcher) {
  41   PlatformEventSource::GetInstance()->AddPlatformEventDispatcher(dispatcher);
  42 }
  43
  44 }  // namespace
  45
  46 class TestPlatformEventSource : public PlatformEventSource {
  47  public:
  48   TestPlatformEventSource() {}
  49   virtual ~TestPlatformEventSource() {}
  50
  51   uint32_t Dispatch(const PlatformEvent& event) { return DispatchEvent(event); }
  52
  53   // Dispatches the stream of events, and returns the number of events that are
  54   // dispatched before it is requested to stop.
  55   size_t DispatchEventStream(const ScopedVector<PlatformEvent>& events) {
  56     for (size_t count = 0; count < events.size(); ++count) {
  57       uint32_t action = DispatchEvent(*events[count]);
  58       if (action & POST_DISPATCH_QUIT_LOOP)
  59         return count + 1;
  60     }
  61     return events.size();
  62   }
  63
  64  private:
  65   DISALLOW_COPY_AND_ASSIGN(TestPlatformEventSource);
  66 };
  67
  68 class TestPlatformEventDispatcher : public PlatformEventDispatcher {
  69  public:
  70   TestPlatformEventDispatcher(int id, std::vector<int>* list)
  71       : id_(id), list_(list), post_dispatch_action_(POST_DISPATCH_NONE) {
  72     PlatformEventSource::GetInstance()->AddPlatformEventDispatcher(this);
  73   }
  74   virtual ~TestPlatformEventDispatcher() {
  75     PlatformEventSource::GetInstance()->RemovePlatformEventDispatcher(this);
  76   }
  77
  78   void set_post_dispatch_action(uint32_t action) {
  79     post_dispatch_action_ = action;
  80   }
  81
  82  protected:
  83   // PlatformEventDispatcher:
  84   virtual bool CanDispatchEvent(const PlatformEvent& event) OVERRIDE {
  85     return true;
  86   }
  87
  88   virtual uint32_t DispatchEvent(const PlatformEvent& event) OVERRIDE {
  89     list_->push_back(id_);
  90     return post_dispatch_action_;
  91   }
  92
  93  private:
  94   int id_;
  95   std::vector<int>* list_;
  96   uint32_t post_dispatch_action_;
  97
  98   DISALLOW_COPY_AND_ASSIGN(TestPlatformEventDispatcher);
  99 };
 100
 101 class TestPlatformEventObserver : public PlatformEventObserver {
 102  public:
 103   TestPlatformEventObserver(int id, std::vector<int>* list)
 104       : id_(id), list_(list) {
 105     PlatformEventSource::GetInstance()->AddPlatformEventObserver(this);
 106   }
 107   virtual ~TestPlatformEventObserver() {
 108     PlatformEventSource::GetInstance()->RemovePlatformEventObserver(this);
 109   }
 110
 111  protected:
 112   // PlatformEventObserver:
 113   virtual void WillProcessEvent(const PlatformEvent& event) OVERRIDE {
 114     list_->push_back(id_);
 115   }
 116
 117   virtual void DidProcessEvent(const PlatformEvent& event) OVERRIDE {}
 118
 119  private:
 120   int id_;
 121   std::vector<int>* list_;
 122
 123   DISALLOW_COPY_AND_ASSIGN(TestPlatformEventObserver);
 124 };
 125
 126 class PlatformEventTest : public testing::Test {
 127  public:
 128   PlatformEventTest() {}
 129   virtual ~PlatformEventTest() {}
 130
 131   TestPlatformEventSource* source() { return source_.get(); }
 132
 133  protected:
 134   // testing::Test:
 135   virtual void SetUp() OVERRIDE {
 136     source_.reset(new TestPlatformEventSource());
 137   }
 138
 139  private:
 140   scoped_ptr<TestPlatformEventSource> source_;
 141
 142   DISALLOW_COPY_AND_ASSIGN(PlatformEventTest);
 143 };
 144
 145 // Tests that a dispatcher receives an event.
 146 TEST_F(PlatformEventTest, DispatcherBasic) {
 147   std::vector<int> list_dispatcher;
 148   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 149   source()->Dispatch(*event);
 150   EXPECT_EQ(0u, list_dispatcher.size());
 151   {
 152     TestPlatformEventDispatcher dispatcher(1, &list_dispatcher);
 153
 154     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 155     source()->Dispatch(*event);
 156     ASSERT_EQ(1u, list_dispatcher.size());
 157     EXPECT_EQ(1, list_dispatcher[0]);
 158   }
 159
 160   list_dispatcher.clear();
 161   event = CreatePlatformEvent();
 162   source()->Dispatch(*event);
 163   EXPECT_EQ(0u, list_dispatcher.size());
 164 }
 165
 166 // Tests that dispatchers receive events in the correct order.
 167 TEST_F(PlatformEventTest, DispatcherOrder) {
 168   std::vector<int> list_dispatcher;
 169   int sequence[] = {21, 3, 6, 45};
 170   ScopedVector<TestPlatformEventDispatcher> dispatchers;
 171   for (size_t i = 0; i < arraysize(sequence); ++i) {
 172     dispatchers.push_back(
 173         new TestPlatformEventDispatcher(sequence[i], &list_dispatcher));
 174   }
 175   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 176   source()->Dispatch(*event);
 177   ASSERT_EQ(arraysize(sequence), list_dispatcher.size());
 178   EXPECT_EQ(std::vector<int>(sequence, sequence + arraysize(sequence)),
 179             list_dispatcher);
 180 }
 181
 182 // Tests that if a dispatcher consumes the event, the subsequent dispatchers do
 183 // not receive the event.
 184 TEST_F(PlatformEventTest, DispatcherConsumesEventToStopDispatch) {
 185   std::vector<int> list_dispatcher;
 186   TestPlatformEventDispatcher first(12, &list_dispatcher);
 187   TestPlatformEventDispatcher second(23, &list_dispatcher);
 188
 189   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 190   source()->Dispatch(*event);
 191   ASSERT_EQ(2u, list_dispatcher.size());
 192   EXPECT_EQ(12, list_dispatcher[0]);
 193   EXPECT_EQ(23, list_dispatcher[1]);
 194   list_dispatcher.clear();
 195
 196   first.set_post_dispatch_action(POST_DISPATCH_STOP_PROPAGATION);
 197   event = CreatePlatformEvent();
 198   source()->Dispatch(*event);
 199   ASSERT_EQ(1u, list_dispatcher.size());
 200   EXPECT_EQ(12, list_dispatcher[0]);
 201 }
 202
 203 // Tests that observers receive events.
 204 TEST_F(PlatformEventTest, ObserverBasic) {
 205   std::vector<int> list_observer;
 206   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 207   source()->Dispatch(*event);
 208   EXPECT_EQ(0u, list_observer.size());
 209   {
 210     TestPlatformEventObserver observer(31, &list_observer);
 211
 212     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 213     source()->Dispatch(*event);
 214     ASSERT_EQ(1u, list_observer.size());
 215     EXPECT_EQ(31, list_observer[0]);
 216   }
 217
 218   list_observer.clear();
 219   event = CreatePlatformEvent();
 220   source()->Dispatch(*event);
 221   EXPECT_EQ(0u, list_observer.size());
 222 }
 223
 224 // Tests that observers receive events in the correct order.
 225 TEST_F(PlatformEventTest, ObserverOrder) {
 226   std::vector<int> list_observer;
 227   const int sequence[] = {21, 3, 6, 45};
 228   ScopedVector<TestPlatformEventObserver> observers;
 229   for (size_t i = 0; i < arraysize(sequence); ++i) {
 230     observers.push_back(
 231         new TestPlatformEventObserver(sequence[i], &list_observer));
 232   }
 233   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 234   source()->Dispatch(*event);
 235   ASSERT_EQ(arraysize(sequence), list_observer.size());
 236   EXPECT_EQ(std::vector<int>(sequence, sequence + arraysize(sequence)),
 237             list_observer);
 238 }
 239
 240 // Tests that observers and dispatchers receive events in the correct order.
 241 TEST_F(PlatformEventTest, DispatcherAndObserverOrder) {
 242   std::vector<int> list;
 243   TestPlatformEventDispatcher first_d(12, &list);
 244   TestPlatformEventObserver first_o(10, &list);
 245   TestPlatformEventDispatcher second_d(23, &list);
 246   TestPlatformEventObserver second_o(20, &list);
 247   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 248   source()->Dispatch(*event);
 249   const int expected[] = {10, 20, 12, 23};
 250   EXPECT_EQ(std::vector<int>(expected, expected + arraysize(expected)), list);
 251 }
 252
 253 // Tests that an overridden dispatcher receives events before the default
 254 // dispatchers.
 255 TEST_F(PlatformEventTest, OverriddenDispatcherBasic) {
 256   std::vector<int> list;
 257   TestPlatformEventDispatcher dispatcher(10, &list);
 258   TestPlatformEventObserver observer(15, &list);
 259   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 260   source()->Dispatch(*event);
 261   ASSERT_EQ(2u, list.size());
 262   EXPECT_EQ(15, list[0]);
 263   EXPECT_EQ(10, list[1]);
 264   list.clear();
 265
 266   TestPlatformEventDispatcher overriding_dispatcher(20, &list);
 267   source()->RemovePlatformEventDispatcher(&overriding_dispatcher);
 268   scoped_ptr<ScopedEventDispatcher> handle =
 269       source()->OverrideDispatcher(&overriding_dispatcher);
 270   source()->Dispatch(*event);
 271   ASSERT_EQ(2u, list.size());
 272   EXPECT_EQ(15, list[0]);
 273   EXPECT_EQ(20, list[1]);
 274 }
 275
 276 // Tests that an overridden dispatcher can request that the default dispatchers
 277 // can dispatch the events.
 278 TEST_F(PlatformEventTest, OverriddenDispatcherInvokeDefaultDispatcher) {
 279   std::vector<int> list;
 280   TestPlatformEventDispatcher dispatcher(10, &list);
 281   TestPlatformEventObserver observer(15, &list);
 282   TestPlatformEventDispatcher overriding_dispatcher(20, &list);
 283   source()->RemovePlatformEventDispatcher(&overriding_dispatcher);
 284   scoped_ptr<ScopedEventDispatcher> handle =
 285       source()->OverrideDispatcher(&overriding_dispatcher);
 286   overriding_dispatcher.set_post_dispatch_action(POST_DISPATCH_PERFORM_DEFAULT);
 287
 288   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 289   source()->Dispatch(*event);
 290   // First the observer, then the overriding dispatcher, then the default
 291   // dispatcher.
 292   ASSERT_EQ(3u, list.size());
 293   EXPECT_EQ(15, list[0]);
 294   EXPECT_EQ(20, list[1]);
 295   EXPECT_EQ(10, list[2]);
 296   list.clear();
 297
 298   // Install a second overriding dispatcher.
 299   TestPlatformEventDispatcher second_overriding(50, &list);
 300   source()->RemovePlatformEventDispatcher(&second_overriding);
 301   scoped_ptr<ScopedEventDispatcher> second_override_handle =
 302       source()->OverrideDispatcher(&second_overriding);
 303   source()->Dispatch(*event);
 304   ASSERT_EQ(2u, list.size());
 305   EXPECT_EQ(15, list[0]);
 306   EXPECT_EQ(50, list[1]);
 307   list.clear();
 308
 309   second_overriding.set_post_dispatch_action(POST_DISPATCH_PERFORM_DEFAULT);
 310   source()->Dispatch(*event);
 311   // First the observer, then the second overriding dispatcher, then the default
 312   // dispatcher.
 313   ASSERT_EQ(3u, list.size());
 314   EXPECT_EQ(15, list[0]);
 315   EXPECT_EQ(50, list[1]);
 316   EXPECT_EQ(10, list[2]);
 317 }
 318
 319 // Runs a callback during an event dispatch.
 320 class RunCallbackDuringDispatch : public TestPlatformEventDispatcher {
 321  public:
 322   RunCallbackDuringDispatch(int id, std::vector<int>* list)
 323       : TestPlatformEventDispatcher(id, list) {}
 324   virtual ~RunCallbackDuringDispatch() {}
 325
 326   void set_callback(const base::Closure& callback) {
 327     callback_ = callback;
 328   }
 329
 330  protected:
 331   // PlatformEventDispatcher:
 332   virtual uint32_t DispatchEvent(const PlatformEvent& event) OVERRIDE {
 333     if (!callback_.is_null())
 334       callback_.Run();
 335     return TestPlatformEventDispatcher::DispatchEvent(event);
 336   }
 337
 338  private:
 339   base::Closure callback_;
 340
 341   DISALLOW_COPY_AND_ASSIGN(RunCallbackDuringDispatch);
 342 };
 343
 344 // Test that if a dispatcher removes another dispatcher that is later in the
 345 // dispatcher list during dispatching an event, then event dispatching still
 346 // continues correctly.
 347 TEST_F(PlatformEventTest, DispatcherRemovesNextDispatcherDuringDispatch) {
 348   std::vector<int> list;
 349   TestPlatformEventDispatcher first(10, &list);
 350   RunCallbackDuringDispatch second(15, &list);
 351   TestPlatformEventDispatcher third(20, &list);
 352   TestPlatformEventDispatcher fourth(30, &list);
 353
 354   second.set_callback(base::Bind(&RemoveDispatcher, base::Unretained(&third)));
 355
 356   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 357   source()->Dispatch(*event);
 358   // |second| removes |third| from the dispatcher list during dispatch. So the
 359   // event should only reach |first|, |second|, and |fourth|.
 360   ASSERT_EQ(3u, list.size());
 361   EXPECT_EQ(10, list[0]);
 362   EXPECT_EQ(15, list[1]);
 363   EXPECT_EQ(30, list[2]);
 364 }
 365
 366 // Tests that if a dispatcher removes itself from the dispatcher list during
 367 // dispatching an event, then event dispatching continues correctly.
 368 TEST_F(PlatformEventTest, DispatcherRemovesSelfDuringDispatch) {
 369   std::vector<int> list;
 370   TestPlatformEventDispatcher first(10, &list);
 371   RunCallbackDuringDispatch second(15, &list);
 372   TestPlatformEventDispatcher third(20, &list);
 373
 374   second.set_callback(base::Bind(&RemoveDispatcher, base::Unretained(&second)));
 375
 376   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 377   source()->Dispatch(*event);
 378   // |second| removes itself from the dispatcher list during dispatch. So the
 379   // event should reach all three dispatchers in the list.
 380   ASSERT_EQ(3u, list.size());
 381   EXPECT_EQ(10, list[0]);
 382   EXPECT_EQ(15, list[1]);
 383   EXPECT_EQ(20, list[2]);
 384 }
 385
 386 // Tests that if a dispatcher removes itself from the dispatcher list during
 387 // dispatching an event, and this dispatcher is last in the dispatcher-list,
 388 // then event dispatching ends correctly.
 389 TEST_F(PlatformEventTest, DispatcherRemovesSelfDuringDispatchLast) {
 390   std::vector<int> list;
 391   TestPlatformEventDispatcher first(10, &list);
 392   RunCallbackDuringDispatch second(15, &list);
 393
 394   second.set_callback(base::Bind(&RemoveDispatcher, base::Unretained(&second)));
 395
 396   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 397   source()->Dispatch(*event);
 398   // |second| removes itself during dispatch. So both dispatchers will have
 399   // received the event.
 400   ASSERT_EQ(2u, list.size());
 401   EXPECT_EQ(10, list[0]);
 402   EXPECT_EQ(15, list[1]);
 403 }
 404
 405 // Tests that if a dispatcher removes a single dispatcher that comes before it
 406 // in the dispatcher list, then dispatch continues correctly.
 407 TEST_F(PlatformEventTest, DispatcherRemovesPrevDispatcherDuringDispatch) {
 408   std::vector<int> list;
 409   TestPlatformEventDispatcher first(10, &list);
 410   RunCallbackDuringDispatch second(15, &list);
 411   TestPlatformEventDispatcher third(20, &list);
 412
 413   second.set_callback(base::Bind(&RemoveDispatcher, base::Unretained(&first)));
 414
 415   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 416   source()->Dispatch(*event);
 417   // |second| removes |first| from the dispatcher list during dispatch. The
 418   // event should reach all three dispatchers.
 419   ASSERT_EQ(3u, list.size());
 420   EXPECT_EQ(10, list[0]);
 421   EXPECT_EQ(15, list[1]);
 422   EXPECT_EQ(20, list[2]);
 423 }
 424
 425 // Tests that if a dispatcher removes multiple dispatchers that comes before it
 426 // in the dispatcher list, then dispatch continues correctly.
 427 TEST_F(PlatformEventTest, DispatcherRemovesPrevDispatchersDuringDispatch) {
 428   std::vector<int> list;
 429   TestPlatformEventDispatcher first(10, &list);
 430   TestPlatformEventDispatcher second(12, &list);
 431   RunCallbackDuringDispatch third(15, &list);
 432   TestPlatformEventDispatcher fourth(20, &list);
 433
 434   third.set_callback(base::Bind(&RemoveDispatchers,
 435                                 base::Unretained(&first),
 436                                 base::Unretained(&second)));
 437
 438   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 439   source()->Dispatch(*event);
 440   // |third| removes |first| and |second| from the dispatcher list during
 441   // dispatch. The event should reach all three dispatchers.
 442   ASSERT_EQ(4u, list.size());
 443   EXPECT_EQ(10, list[0]);
 444   EXPECT_EQ(12, list[1]);
 445   EXPECT_EQ(15, list[2]);
 446   EXPECT_EQ(20, list[3]);
 447 }
 448
 449 // Tests that adding a dispatcher during dispatching an event receives that
 450 // event.
 451 TEST_F(PlatformEventTest, DispatcherAddedDuringDispatchReceivesEvent) {
 452   std::vector<int> list;
 453   TestPlatformEventDispatcher first(10, &list);
 454   RunCallbackDuringDispatch second(15, &list);
 455   TestPlatformEventDispatcher third(20, &list);
 456   TestPlatformEventDispatcher fourth(30, &list);
 457   RemoveDispatchers(&third, &fourth);
 458
 459   scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 460   source()->Dispatch(*event);
 461   ASSERT_EQ(2u, list.size());
 462   EXPECT_EQ(10, list[0]);
 463   EXPECT_EQ(15, list[1]);
 464
 465   second.set_callback(base::Bind(&AddDispatcher, base::Unretained(&third)));
 466   list.clear();
 467   source()->Dispatch(*event);
 468   ASSERT_EQ(3u, list.size());
 469   EXPECT_EQ(10, list[0]);
 470   EXPECT_EQ(15, list[1]);
 471   EXPECT_EQ(20, list[2]);
 472
 473   second.set_callback(base::Bind(&AddDispatcher, base::Unretained(&fourth)));
 474   list.clear();
 475   source()->Dispatch(*event);
 476   ASSERT_EQ(4u, list.size());
 477   EXPECT_EQ(10, list[0]);
 478   EXPECT_EQ(15, list[1]);
 479   EXPECT_EQ(20, list[2]);
 480   EXPECT_EQ(30, list[3]);
 481 }
 482
 483 // Provides mechanism for running tests from inside an active message-loop.
 484 class PlatformEventTestWithMessageLoop : public PlatformEventTest {
 485  public:
 486   PlatformEventTestWithMessageLoop() {}
 487   virtual ~PlatformEventTestWithMessageLoop() {}
 488
 489   void Run() {
 490     message_loop_.PostTask(
 491         FROM_HERE,
 492         base::Bind(&PlatformEventTestWithMessageLoop::RunTest,
 493                    base::Unretained(this)));
 494     message_loop_.Run();
 495   }
 496
 497  protected:
 498   void RunTest() {
 499     RunTestImpl();
 500     message_loop_.Quit();
 501   }
 502
 503   virtual void RunTestImpl() = 0;
 504
 505  private:
 506   base::MessageLoopForUI message_loop_;
 507
 508   DISALLOW_COPY_AND_ASSIGN(PlatformEventTestWithMessageLoop);
 509 };
 510
 511 #define RUN_TEST_IN_MESSAGE_LOOP(name) \
 512   TEST_F(name, Run) { Run(); }
 513
 514 // Tests that a ScopedEventDispatcher restores the previous dispatcher when
 515 // destroyed.
 516 class ScopedDispatcherRestoresAfterDestroy
 517     : public PlatformEventTestWithMessageLoop {
 518  public:
 519   // PlatformEventTestWithMessageLoop:
 520   virtual void RunTestImpl() OVERRIDE {
 521     std::vector<int> list;
 522     TestPlatformEventDispatcher dispatcher(10, &list);
 523     TestPlatformEventObserver observer(15, &list);
 524
 525     TestPlatformEventDispatcher first_overriding(20, &list);
 526     source()->RemovePlatformEventDispatcher(&first_overriding);
 527     scoped_ptr<ScopedEventDispatcher> first_override_handle =
 528         source()->OverrideDispatcher(&first_overriding);
 529
 530     // Install a second overriding dispatcher.
 531     TestPlatformEventDispatcher second_overriding(50, &list);
 532     source()->RemovePlatformEventDispatcher(&second_overriding);
 533     scoped_ptr<ScopedEventDispatcher> second_override_handle =
 534         source()->OverrideDispatcher(&second_overriding);
 535
 536     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 537     source()->Dispatch(*event);
 538     ASSERT_EQ(2u, list.size());
 539     EXPECT_EQ(15, list[0]);
 540     EXPECT_EQ(50, list[1]);
 541     list.clear();
 542
 543     second_override_handle.reset();
 544     source()->Dispatch(*event);
 545     ASSERT_EQ(2u, list.size());
 546     EXPECT_EQ(15, list[0]);
 547     EXPECT_EQ(20, list[1]);
 548   }
 549 };
 550
 551 RUN_TEST_IN_MESSAGE_LOOP(ScopedDispatcherRestoresAfterDestroy)
 552
 553 // This dispatcher destroys the handle to the ScopedEventDispatcher when
 554 // dispatching an event.
 555 class DestroyScopedHandleDispatcher : public TestPlatformEventDispatcher {
 556  public:
 557   DestroyScopedHandleDispatcher(int id, std::vector<int>* list)
 558       : TestPlatformEventDispatcher(id, list) {}
 559   virtual ~DestroyScopedHandleDispatcher() {}
 560
 561   void SetScopedHandle(scoped_ptr<ScopedEventDispatcher> handler) {
 562     handler_ = handler.Pass();
 563   }
 564
 565  private:
 566   // PlatformEventDispatcher:
 567   virtual bool CanDispatchEvent(const PlatformEvent& event) OVERRIDE {
 568     return true;
 569   }
 570
 571   virtual uint32_t DispatchEvent(const PlatformEvent& event) OVERRIDE {
 572     handler_.reset();
 573     return TestPlatformEventDispatcher::DispatchEvent(event);
 574   }
 575
 576   scoped_ptr<ScopedEventDispatcher> handler_;
 577
 578   DISALLOW_COPY_AND_ASSIGN(DestroyScopedHandleDispatcher);
 579 };
 580
 581 // Tests that resetting an overridden dispatcher causes the nested message-loop
 582 // iteration to stop and the rest of the events are dispatched in the next
 583 // iteration.
 584 class DestroyedNestedOverriddenDispatcherQuitsNestedLoopIteration
 585     : public PlatformEventTestWithMessageLoop {
 586  public:
 587   void NestedTask(std::vector<int>* list,
 588                   TestPlatformEventDispatcher* dispatcher) {
 589     ScopedVector<PlatformEvent> events;
 590     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 591     events.push_back(event.release());
 592     event = CreatePlatformEvent();
 593     events.push_back(event.release());
 594
 595     // Attempt to dispatch a couple of events. Dispatching the first event will
 596     // have terminated the ScopedEventDispatcher object, which will terminate
 597     // the current iteration of the message-loop.
 598     size_t count = source()->DispatchEventStream(events);
 599     EXPECT_EQ(1u, count);
 600     ASSERT_EQ(2u, list->size());
 601     EXPECT_EQ(15, (*list)[0]);
 602     EXPECT_EQ(20, (*list)[1]);
 603     list->clear();
 604
 605     ASSERT_LT(count, events.size());
 606     events.erase(events.begin(), events.begin() + count);
 607
 608     count = source()->DispatchEventStream(events);
 609     EXPECT_EQ(1u, count);
 610     ASSERT_EQ(2u, list->size());
 611     EXPECT_EQ(15, (*list)[0]);
 612     EXPECT_EQ(10, (*list)[1]);
 613     list->clear();
 614
 615     // Terminate the message-loop.
 616     base::MessageLoopForUI::current()->QuitNow();
 617   }
 618
 619   // PlatformEventTestWithMessageLoop:
 620   virtual void RunTestImpl() OVERRIDE {
 621     std::vector<int> list;
 622     TestPlatformEventDispatcher dispatcher(10, &list);
 623     TestPlatformEventObserver observer(15, &list);
 624
 625     DestroyScopedHandleDispatcher overriding(20, &list);
 626     source()->RemovePlatformEventDispatcher(&overriding);
 627     scoped_ptr<ScopedEventDispatcher> override_handle =
 628         source()->OverrideDispatcher(&overriding);
 629
 630     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 631     source()->Dispatch(*event);
 632     ASSERT_EQ(2u, list.size());
 633     EXPECT_EQ(15, list[0]);
 634     EXPECT_EQ(20, list[1]);
 635     list.clear();
 636
 637     overriding.SetScopedHandle(override_handle.Pass());
 638     base::RunLoop run_loop;
 639     base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 640     base::MessageLoopForUI::ScopedNestableTaskAllower allow_nested(loop);
 641     loop->PostTask(
 642         FROM_HERE,
 643         base::Bind(
 644             &DestroyedNestedOverriddenDispatcherQuitsNestedLoopIteration::
 645                 NestedTask,
 646             base::Unretained(this),
 647             base::Unretained(&list),
 648             base::Unretained(&overriding)));
 649     run_loop.Run();
 650
 651     // Dispatching the event should now reach the default dispatcher.
 652     source()->Dispatch(*event);
 653     ASSERT_EQ(2u, list.size());
 654     EXPECT_EQ(15, list[0]);
 655     EXPECT_EQ(10, list[1]);
 656   }
 657 };
 658
 659 RUN_TEST_IN_MESSAGE_LOOP(
 660     DestroyedNestedOverriddenDispatcherQuitsNestedLoopIteration)
 661
 662 // Tests that resetting an overridden dispatcher, and installing another
 663 // overridden dispatcher before the nested message-loop completely unwinds
 664 // function correctly.
 665 class ConsecutiveOverriddenDispatcherInTheSameMessageLoopIteration
 666     : public PlatformEventTestWithMessageLoop {
 667  public:
 668   void NestedTask(scoped_ptr<ScopedEventDispatcher> dispatch_handle,
 669                   std::vector<int>* list) {
 670     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 671     source()->Dispatch(*event);
 672     ASSERT_EQ(2u, list->size());
 673     EXPECT_EQ(15, (*list)[0]);
 674     EXPECT_EQ(20, (*list)[1]);
 675     list->clear();
 676
 677     // Reset the override dispatcher. This should restore the default
 678     // dispatcher.
 679     dispatch_handle.reset();
 680     source()->Dispatch(*event);
 681     ASSERT_EQ(2u, list->size());
 682     EXPECT_EQ(15, (*list)[0]);
 683     EXPECT_EQ(10, (*list)[1]);
 684     list->clear();
 685
 686     // Install another override-dispatcher.
 687     DestroyScopedHandleDispatcher second_overriding(70, list);
 688     source()->RemovePlatformEventDispatcher(&second_overriding);
 689     scoped_ptr<ScopedEventDispatcher> second_override_handle =
 690         source()->OverrideDispatcher(&second_overriding);
 691
 692     source()->Dispatch(*event);
 693     ASSERT_EQ(2u, list->size());
 694     EXPECT_EQ(15, (*list)[0]);
 695     EXPECT_EQ(70, (*list)[1]);
 696     list->clear();
 697
 698     second_overriding.SetScopedHandle(second_override_handle.Pass());
 699     second_overriding.set_post_dispatch_action(POST_DISPATCH_QUIT_LOOP);
 700     base::RunLoop run_loop;
 701     base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 702     base::MessageLoopForUI::ScopedNestableTaskAllower allow_nested(loop);
 703     loop->PostTask(
 704         FROM_HERE,
 705         base::Bind(base::IgnoreResult(&TestPlatformEventSource::Dispatch),
 706                    base::Unretained(source()),
 707                    *event));
 708     run_loop.Run();
 709     ASSERT_EQ(2u, list->size());
 710     EXPECT_EQ(15, (*list)[0]);
 711     EXPECT_EQ(70, (*list)[1]);
 712     list->clear();
 713
 714     // Terminate the message-loop.
 715     base::MessageLoopForUI::current()->QuitNow();
 716   }
 717
 718   // PlatformEventTestWithMessageLoop:
 719   virtual void RunTestImpl() OVERRIDE {
 720     std::vector<int> list;
 721     TestPlatformEventDispatcher dispatcher(10, &list);
 722     TestPlatformEventObserver observer(15, &list);
 723
 724     TestPlatformEventDispatcher overriding(20, &list);
 725     source()->RemovePlatformEventDispatcher(&overriding);
 726     scoped_ptr<ScopedEventDispatcher> override_handle =
 727         source()->OverrideDispatcher(&overriding);
 728
 729     scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
 730     source()->Dispatch(*event);
 731     ASSERT_EQ(2u, list.size());
 732     EXPECT_EQ(15, list[0]);
 733     EXPECT_EQ(20, list[1]);
 734     list.clear();
 735
 736     // Start a nested message-loop, and destroy |override_handle| in the nested
 737     // loop. That should terminate the nested loop, restore the previous
 738     // dispatchers, and return control to this function.
 739     base::RunLoop run_loop;
 740     base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 741     base::MessageLoopForUI::ScopedNestableTaskAllower allow_nested(loop);
 742     loop->PostTask(
 743         FROM_HERE,
 744         base::Bind(
 745             &ConsecutiveOverriddenDispatcherInTheSameMessageLoopIteration::
 746                 NestedTask,
 747             base::Unretained(this),
 748             base::Passed(&override_handle),
 749             base::Unretained(&list)));
 750     run_loop.Run();
 751
 752     // Dispatching the event should now reach the default dispatcher.
 753     source()->Dispatch(*event);
 754     ASSERT_EQ(2u, list.size());
 755     EXPECT_EQ(15, list[0]);
 756     EXPECT_EQ(10, list[1]);
 757   }
 758 };
 759
 760 RUN_TEST_IN_MESSAGE_LOOP(
 761     ConsecutiveOverriddenDispatcherInTheSameMessageLoopIteration)
 762
 763 }  // namespace ui