ui/events/gesture_detection/velocity_tracker_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 "base/basictypes.h"
   6 #include "base/logging.h"
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/time/time.h"
   9 #include "testing/gtest/include/gtest/gtest.h"
  10 #include "ui/events/gesture_detection/velocity_tracker_state.h"
  11 #include "ui/events/test/motion_event_test_utils.h"
  12 #include "ui/gfx/geometry/point_f.h"
  13 #include "ui/gfx/geometry/vector2d_f.h"
  14
  15 using base::TimeDelta;
  16 using base::TimeTicks;
  17 using ui::test::MockMotionEvent;
  18
  19 namespace ui {
  20 namespace {
  21
  22 const TimeDelta kTenMillis = TimeDelta::FromMilliseconds(10);
  23 const TimeDelta kOneSecond = TimeDelta::FromSeconds(1);
  24 const float kEpsilson = .01f;
  25
  26 const char* GetStrategyName(VelocityTracker::Strategy strategy) {
  27   switch (strategy) {
  28     case VelocityTracker::LSQ1: return "LSQ1";
  29     case VelocityTracker::LSQ2: return "LSQ2";
  30     case VelocityTracker::LSQ2_RESTRICTED: return "LSQ2_RESTRICTED";
  31     case VelocityTracker::LSQ3: return "LSQ3";
  32     case VelocityTracker::WLSQ2_DELTA: return "WLSQ2_DELTA";
  33     case VelocityTracker::WLSQ2_CENTRAL: return "WLSQ2_CENTRAL";
  34     case VelocityTracker::WLSQ2_RECENT: return "WLSQ2_RECENT";
  35     case VelocityTracker::INT1: return "INT1";
  36     case VelocityTracker::INT2: return "INT2";
  37   };
  38   NOTREACHED() << "Invalid strategy";
  39   return "";
  40 }
  41
  42 }  // namespace
  43
  44 class VelocityTrackerTest : public testing::Test {
  45  public:
  46   VelocityTrackerTest() {}
  47   ~VelocityTrackerTest() override {}
  48
  49  protected:
  50   static MockMotionEvent Sample(MotionEvent::Action action,
  51                                 gfx::PointF p0,
  52                                 TimeTicks t0,
  53                                 gfx::Vector2dF v,
  54                                 TimeDelta dt) {
  55     const gfx::PointF p = p0 + ScaleVector2d(v, dt.InSecondsF());
  56     return MockMotionEvent(action, t0 + dt, p.x(), p.y());
  57   }
  58
  59   static void ApplyMovementSequence(VelocityTrackerState* state,
  60                                     gfx::PointF p0,
  61                                     gfx::Vector2dF v,
  62                                     TimeTicks t0,
  63                                     TimeDelta t,
  64                                     size_t samples) {
  65     EXPECT_TRUE(!!samples);
  66     if (!samples)
  67       return;
  68     const base::TimeDelta dt = t / samples;
  69     state->AddMovement(Sample(MotionEvent::ACTION_DOWN, p0, t0, v, dt * 0));
  70     ApplyMovement(state, p0, v, t0, t, samples);
  71     state->AddMovement(Sample(MotionEvent::ACTION_UP, p0, t0, v, t));
  72   }
  73
  74   static void ApplyMovement(VelocityTrackerState* state,
  75                             gfx::PointF p0,
  76                             gfx::Vector2dF v,
  77                             TimeTicks t0,
  78                             TimeDelta t,
  79                             size_t samples) {
  80     EXPECT_TRUE(!!samples);
  81     if (!samples)
  82       return;
  83     const base::TimeDelta dt = t / samples;
  84     for (size_t i = 0; i < samples; ++i)
  85       state->AddMovement(Sample(MotionEvent::ACTION_MOVE, p0, t0, v, dt * i));
  86   }
  87 };
  88
  89 TEST_F(VelocityTrackerTest, Basic) {
  90   const gfx::PointF p0(0, 0);
  91   const gfx::Vector2dF v(0, 500);
  92   const size_t samples = 60;
  93
  94   for (int i = 0; i <= VelocityTracker::STRATEGY_MAX; ++i) {
  95     VelocityTracker::Strategy strategy =
  96         static_cast<VelocityTracker::Strategy>(i);
  97
  98     SCOPED_TRACE(GetStrategyName(strategy));
  99     VelocityTrackerState state(strategy);
 100
 101     // Default state should report zero velocity.
 102     EXPECT_EQ(0, state.GetXVelocity(0));
 103     EXPECT_EQ(0, state.GetYVelocity(0));
 104
 105     // Sample a constant velocity sequence.
 106     ApplyMovementSequence(&state, p0, v, TimeTicks::Now(), kOneSecond, samples);
 107
 108     // The computed velocity should match that of the input.
 109     state.ComputeCurrentVelocity(1000, 20000);
 110     EXPECT_NEAR(v.x(), state.GetXVelocity(0), kEpsilson * v.x());
 111     EXPECT_NEAR(v.y(), state.GetYVelocity(0), kEpsilson * v.y());
 112
 113     // A pointer ID of -1 should report the velocity of the active pointer.
 114     EXPECT_NEAR(v.x(), state.GetXVelocity(-1), kEpsilson * v.x());
 115     EXPECT_NEAR(v.y(), state.GetYVelocity(-1), kEpsilson * v.y());
 116
 117     // Invalid pointer ID's should report zero velocity.
 118     EXPECT_EQ(0, state.GetXVelocity(1));
 119     EXPECT_EQ(0, state.GetYVelocity(1));
 120     EXPECT_EQ(0, state.GetXVelocity(7));
 121     EXPECT_EQ(0, state.GetYVelocity(7));
 122   }
 123 }
 124
 125 TEST_F(VelocityTrackerTest, MaxVelocity) {
 126   const gfx::PointF p0(0, 0);
 127   const gfx::Vector2dF v(-50000, 50000);
 128   const size_t samples = 3;
 129   const base::TimeDelta dt = kTenMillis * 2;
 130
 131   VelocityTrackerState state(VelocityTracker::Strategy::LSQ2);
 132   ApplyMovementSequence(&state, p0, v, TimeTicks::Now(), dt, samples);
 133
 134   // The computed velocity should be restricted to the provided maximum.
 135   state.ComputeCurrentVelocity(1000, 100);
 136   EXPECT_NEAR(-100, state.GetXVelocity(0), kEpsilson);
 137   EXPECT_NEAR(100, state.GetYVelocity(0), kEpsilson);
 138
 139   state.ComputeCurrentVelocity(1000, 1000);
 140   EXPECT_NEAR(-1000, state.GetXVelocity(0), kEpsilson);
 141   EXPECT_NEAR(1000, state.GetYVelocity(0), kEpsilson);
 142 }
 143
 144 TEST_F(VelocityTrackerTest, VaryingVelocity) {
 145   const gfx::PointF p0(0, 0);
 146   const gfx::Vector2dF vFast(0, 500);
 147   const gfx::Vector2dF vSlow = ScaleVector2d(vFast, 0.5f);
 148   const size_t samples = 12;
 149
 150   for (int i = 0; i <= VelocityTracker::STRATEGY_MAX; ++i) {
 151     VelocityTracker::Strategy strategy =
 152         static_cast<VelocityTracker::Strategy>(i);
 153
 154     SCOPED_TRACE(GetStrategyName(strategy));
 155     VelocityTrackerState state(strategy);
 156
 157     base::TimeTicks t0 = base::TimeTicks::Now();
 158     base::TimeDelta dt = kTenMillis * 10;
 159     state.AddMovement(
 160         Sample(MotionEvent::ACTION_DOWN, p0, t0, vFast, base::TimeDelta()));
 161
 162     // Apply some fast movement and compute the velocity.
 163     gfx::PointF pCurr = p0;
 164     base::TimeTicks tCurr = t0;
 165     ApplyMovement(&state, pCurr, vFast, tCurr, dt, samples);
 166     state.ComputeCurrentVelocity(1000, 20000);
 167     float vOldY = state.GetYVelocity(0);
 168
 169     // Apply some slow movement.
 170     pCurr += ScaleVector2d(vFast, dt.InSecondsF());
 171     tCurr += dt;
 172     ApplyMovement(&state, pCurr, vSlow, tCurr, dt, samples);
 173
 174     // The computed velocity should have decreased.
 175     state.ComputeCurrentVelocity(1000, 20000);
 176     float vCurrentY = state.GetYVelocity(0);
 177     EXPECT_GT(vFast.y(), vCurrentY);
 178     EXPECT_GT(vOldY, vCurrentY);
 179     vOldY = vCurrentY;
 180
 181     // Apply some additional fast movement.
 182     pCurr += ScaleVector2d(vSlow, dt.InSecondsF());
 183     tCurr += dt;
 184     ApplyMovement(&state, pCurr, vFast, tCurr, dt, samples);
 185
 186     // The computed velocity should have increased.
 187     state.ComputeCurrentVelocity(1000, 20000);
 188     vCurrentY = state.GetYVelocity(0);
 189     EXPECT_LT(vSlow.y(), vCurrentY);
 190     EXPECT_LT(vOldY, vCurrentY);
 191   }
 192 }
 193
 194 TEST_F(VelocityTrackerTest, DelayedActionUp) {
 195   const gfx::PointF p0(0, 0);
 196   const gfx::Vector2dF v(-50000, 50000);
 197   const size_t samples = 10;
 198   const base::TimeTicks t0 = base::TimeTicks::Now();
 199   const base::TimeDelta dt = kTenMillis * 2;
 200
 201   VelocityTrackerState state(VelocityTracker::Strategy::LSQ2);
 202   state.AddMovement(
 203       Sample(MotionEvent::ACTION_DOWN, p0, t0, v, base::TimeDelta()));
 204
 205   // Apply the movement and verify a (non-zero) velocity.
 206   ApplyMovement(&state, p0, v, t0, dt, samples);
 207   state.ComputeCurrentVelocity(1000, 1000);
 208   EXPECT_NEAR(-1000, state.GetXVelocity(0), kEpsilson);
 209   EXPECT_NEAR(1000, state.GetYVelocity(0), kEpsilson);
 210
 211   // Apply the delayed ACTION_UP.
 212   const gfx::PointF p1 = p0 + ScaleVector2d(v, dt.InSecondsF());
 213   const base::TimeTicks t1 = t0 + dt + kTenMillis * 10;
 214   state.AddMovement(Sample(
 215       MotionEvent::ACTION_UP, p1, t1, v, base::TimeDelta()));
 216
 217   // The tracked velocity should have been reset.
 218   state.ComputeCurrentVelocity(1000, 1000);
 219   EXPECT_EQ(0.f, state.GetXVelocity(0));
 220   EXPECT_EQ(0.f, state.GetYVelocity(0));
 221 }
 222
 223 // Tests that a rapid deceleration won't result in a velocity going in the
 224 // opposite direction to the pointers primary movement, with the LSQ_RESTRICTED
 225 // strategy. See crbug.com/417855.
 226 TEST_F(VelocityTrackerTest, NoDirectionReversal) {
 227   VelocityTrackerState state_unrestricted(VelocityTracker::LSQ2);
 228   VelocityTrackerState state_restricted(VelocityTracker::LSQ2_RESTRICTED);
 229   const base::TimeTicks t0 = base::TimeTicks::Now();
 230   const base::TimeDelta dt = base::TimeDelta::FromMilliseconds(1);
 231   const size_t samples = 60;
 232
 233   gfx::PointF p(0, 0);
 234
 235   MockMotionEvent m1(MotionEvent::ACTION_DOWN, t0, p.x(), p.y());
 236   state_unrestricted.AddMovement(m1);
 237   state_restricted.AddMovement(m1);
 238
 239   for (size_t i = 0; i < samples; ++i) {
 240     if (i < 50)
 241       p.set_y(p.y() + 10);
 242     MockMotionEvent mi(MotionEvent::ACTION_MOVE, t0 + dt * i, p.x(), p.y());
 243     state_unrestricted.AddMovement(mi);
 244     state_restricted.AddMovement(mi);
 245   }
 246
 247   // The computed velocity be zero, as we stopped at the end of the gesture. In
 248   // particular, it should not be negative, as all movement was in the positive
 249   // direction.
 250   state_restricted.ComputeCurrentVelocity(1000, 20000);
 251   EXPECT_EQ(0, state_restricted.GetXVelocity(0));
 252   EXPECT_EQ(0, state_restricted.GetYVelocity(0));
 253
 254   // This does not hold for the unrestricted LSQ2 strategy.
 255   state_unrestricted.ComputeCurrentVelocity(1000, 20000);
 256   EXPECT_EQ(0, state_unrestricted.GetXVelocity(0));
 257   // Y velocity is negative, despite the fact that the finger only moved in the
 258   // positive y direction.
 259   EXPECT_GT(0, state_unrestricted.GetYVelocity(0));
 260 }
 261
 262 }  // namespace ui