src/ui/events/event_rewriter_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/event_rewriter.h"
   6
   7 #include <list>
   8 #include <map>
   9 #include <set>
  10 #include <utility>
  11
  12 #include "testing/gtest/include/gtest/gtest.h"
  13 #include "ui/events/test/test_event_processor.h"
  14
  15 namespace ui {
  16
  17 namespace {
  18
  19 // To test the handling of |EventRewriter|s through |EventSource|,
  20 // we rewrite and test event types.
  21 class TestEvent : public Event {
  22  public:
  23   explicit TestEvent(EventType type)
  24       : Event(type, base::TimeDelta(), 0), unique_id_(next_unique_id_++) {}
  25   virtual ~TestEvent() {}
  26   int unique_id() const { return unique_id_; }
  27
  28  private:
  29   static int next_unique_id_;
  30   int unique_id_;
  31 };
  32
  33 int TestEvent::next_unique_id_ = 0;
  34
  35 // TestEventRewriteProcessor is set up with a sequence of event types,
  36 // and fails if the events received via OnEventFromSource() do not match
  37 // this sequence. These expected event types are consumed on receipt.
  38 class TestEventRewriteProcessor : public test::TestEventProcessor {
  39  public:
  40   TestEventRewriteProcessor() {}
  41   virtual ~TestEventRewriteProcessor() { CheckAllReceived(); }
  42
  43   void AddExpectedEvent(EventType type) { expected_events_.push_back(type); }
  44   // Test that all expected events have been received.
  45   void CheckAllReceived() { EXPECT_TRUE(expected_events_.empty()); }
  46
  47   // EventProcessor:
  48   virtual EventDispatchDetails OnEventFromSource(Event* event) OVERRIDE {
  49     EXPECT_FALSE(expected_events_.empty());
  50     EXPECT_EQ(expected_events_.front(), event->type());
  51     expected_events_.pop_front();
  52     return EventDispatchDetails();
  53   }
  54
  55  private:
  56   std::list<EventType> expected_events_;
  57   DISALLOW_COPY_AND_ASSIGN(TestEventRewriteProcessor);
  58 };
  59
  60 // Trivial EventSource that does nothing but send events.
  61 class TestEventRewriteSource : public EventSource {
  62  public:
  63   explicit TestEventRewriteSource(EventProcessor* processor)
  64       : processor_(processor) {}
  65   virtual EventProcessor* GetEventProcessor() OVERRIDE { return processor_; }
  66   void Send(EventType type) {
  67     scoped_ptr<Event> event(new TestEvent(type));
  68     (void)SendEventToProcessor(event.get());
  69   }
  70
  71  private:
  72   EventProcessor* processor_;
  73 };
  74
  75 // This EventRewriter always returns the same status, and if rewriting, the
  76 // same event type; it is used to test simple rewriting, and rewriter addition,
  77 // removal, and sequencing. Consequently EVENT_REWRITE_DISPATCH_ANOTHER is not
  78 // supported here (calls to NextDispatchEvent() would continue indefinitely).
  79 class TestConstantEventRewriter : public EventRewriter {
  80  public:
  81   TestConstantEventRewriter(EventRewriteStatus status, EventType type)
  82       : status_(status), type_(type) {
  83     CHECK_NE(EVENT_REWRITE_DISPATCH_ANOTHER, status);
  84   }
  85
  86   virtual EventRewriteStatus RewriteEvent(const Event& event,
  87                                           scoped_ptr<Event>* rewritten_event)
  88       OVERRIDE {
  89     if (status_ == EVENT_REWRITE_REWRITTEN)
  90       rewritten_event->reset(new TestEvent(type_));
  91     return status_;
  92   }
  93   virtual EventRewriteStatus NextDispatchEvent(const Event& last_event,
  94                                                scoped_ptr<Event>* new_event)
  95       OVERRIDE {
  96     NOTREACHED();
  97     return status_;
  98   }
  99
 100  private:
 101   EventRewriteStatus status_;
 102   EventType type_;
 103 };
 104
 105 // This EventRewriter runs a simple state machine; it is used to test
 106 // EVENT_REWRITE_DISPATCH_ANOTHER.
 107 class TestStateMachineEventRewriter : public EventRewriter {
 108  public:
 109   TestStateMachineEventRewriter() : last_rewritten_event_(0), state_(0) {}
 110   void AddRule(int from_state, EventType from_type,
 111                int to_state, EventType to_type, EventRewriteStatus to_status) {
 112     RewriteResult r = {to_state, to_type, to_status};
 113     rules_.insert(std::pair<RewriteCase, RewriteResult>(
 114         RewriteCase(from_state, from_type), r));
 115   }
 116   virtual EventRewriteStatus RewriteEvent(const Event& event,
 117                                           scoped_ptr<Event>* rewritten_event)
 118       OVERRIDE {
 119     RewriteRules::iterator find =
 120         rules_.find(RewriteCase(state_, event.type()));
 121     if (find == rules_.end())
 122       return EVENT_REWRITE_CONTINUE;
 123     if ((find->second.status == EVENT_REWRITE_REWRITTEN) ||
 124         (find->second.status == EVENT_REWRITE_DISPATCH_ANOTHER)) {
 125       last_rewritten_event_ = new TestEvent(find->second.type);
 126       rewritten_event->reset(last_rewritten_event_);
 127     } else {
 128       last_rewritten_event_ = 0;
 129     }
 130     state_ = find->second.state;
 131     return find->second.status;
 132   }
 133   virtual EventRewriteStatus NextDispatchEvent(const Event& last_event,
 134                                                scoped_ptr<Event>* new_event)
 135       OVERRIDE {
 136     EXPECT_TRUE(last_rewritten_event_);
 137     const TestEvent* arg_last = static_cast<const TestEvent*>(&last_event);
 138     EXPECT_EQ(last_rewritten_event_->unique_id(), arg_last->unique_id());
 139     const TestEvent* arg_new = static_cast<const TestEvent*>(new_event->get());
 140     EXPECT_FALSE(arg_new && arg_last->unique_id() == arg_new->unique_id());
 141     return RewriteEvent(last_event, new_event);
 142   }
 143
 144  private:
 145   typedef std::pair<int, EventType> RewriteCase;
 146   struct RewriteResult {
 147     int state;
 148     EventType type;
 149     EventRewriteStatus status;
 150   };
 151   typedef std::map<RewriteCase, RewriteResult> RewriteRules;
 152   RewriteRules rules_;
 153   TestEvent* last_rewritten_event_;
 154   int state_;
 155 };
 156
 157 }  // namespace
 158
 159 TEST(EventRewriterTest, EventRewriting) {
 160   // TestEventRewriter r0 always rewrites events to ET_CANCEL_MODE;
 161   // it is placed at the beginning of the chain and later removed,
 162   // to verify that rewriter removal works.
 163   TestConstantEventRewriter r0(EVENT_REWRITE_REWRITTEN, ET_CANCEL_MODE);
 164
 165   // TestEventRewriter r1 always returns EVENT_REWRITE_CONTINUE;
 166   // it is placed at the beginning of the chain to verify that a
 167   // later rewriter sees the events.
 168   TestConstantEventRewriter r1(EVENT_REWRITE_CONTINUE, ET_UNKNOWN);
 169
 170   // TestEventRewriter r2 has a state machine, primarily to test
 171   // |EVENT_REWRITE_DISPATCH_ANOTHER|.
 172   TestStateMachineEventRewriter r2;
 173
 174   // TestEventRewriter r3 always rewrites events to ET_CANCEL_MODE;
 175   // it is placed at the end of the chain to verify that previously
 176   // rewritten events are not passed further down the chain.
 177   TestConstantEventRewriter r3(EVENT_REWRITE_REWRITTEN, ET_CANCEL_MODE);
 178
 179   TestEventRewriteProcessor p;
 180   TestEventRewriteSource s(&p);
 181   s.AddEventRewriter(&r0);
 182   s.AddEventRewriter(&r1);
 183   s.AddEventRewriter(&r2);
 184
 185   // These events should be rewritten by r0 to ET_CANCEL_MODE.
 186   p.AddExpectedEvent(ET_CANCEL_MODE);
 187   s.Send(ET_MOUSE_DRAGGED);
 188   p.AddExpectedEvent(ET_CANCEL_MODE);
 189   s.Send(ET_MOUSE_PRESSED);
 190   p.CheckAllReceived();
 191
 192   // Remove r0, and verify that it's gone and that events make it through.
 193   s.AddEventRewriter(&r3);
 194   s.RemoveEventRewriter(&r0);
 195   r2.AddRule(0, ET_SCROLL_FLING_START,
 196              0, ET_SCROLL_FLING_CANCEL, EVENT_REWRITE_REWRITTEN);
 197   p.AddExpectedEvent(ET_SCROLL_FLING_CANCEL);
 198   s.Send(ET_SCROLL_FLING_START);
 199   p.CheckAllReceived();
 200   s.RemoveEventRewriter(&r3);
 201
 202   // Verify EVENT_REWRITE_DISPATCH_ANOTHER using a state machine
 203   // (that happens to be analogous to sticky keys).
 204   r2.AddRule(0, ET_KEY_PRESSED,
 205              1, ET_KEY_PRESSED, EVENT_REWRITE_CONTINUE);
 206   r2.AddRule(1, ET_MOUSE_PRESSED,
 207              0, ET_MOUSE_PRESSED, EVENT_REWRITE_CONTINUE);
 208   r2.AddRule(1, ET_KEY_RELEASED,
 209              2, ET_KEY_RELEASED, EVENT_REWRITE_DISCARD);
 210   r2.AddRule(2, ET_MOUSE_RELEASED,
 211              3, ET_MOUSE_RELEASED, EVENT_REWRITE_DISPATCH_ANOTHER);
 212   r2.AddRule(3, ET_MOUSE_RELEASED,
 213              0, ET_KEY_RELEASED, EVENT_REWRITE_REWRITTEN);
 214   p.AddExpectedEvent(ET_KEY_PRESSED);
 215   s.Send(ET_KEY_PRESSED);
 216   s.Send(ET_KEY_RELEASED);
 217   p.AddExpectedEvent(ET_MOUSE_PRESSED);
 218   s.Send(ET_MOUSE_PRESSED);
 219
 220   // Removing rewriters r1 and r3 shouldn't affect r2.
 221   s.RemoveEventRewriter(&r1);
 222   s.RemoveEventRewriter(&r3);
 223
 224   // Continue with the state-based rewriting.
 225   p.AddExpectedEvent(ET_MOUSE_RELEASED);
 226   p.AddExpectedEvent(ET_KEY_RELEASED);
 227   s.Send(ET_MOUSE_RELEASED);
 228   p.CheckAllReceived();
 229 }
 230
 231 }  // namespace ui