Overlay scrollbars expand only when mouse is near thumb

cc/input/single_scrollbar_animation_controller_thinning_unittest.cc

Index: cc/input/single_scrollbar_animation_controller_thinning_unittest.cc
diff --git a/cc/input/single_scrollbar_animation_controller_thinning_unittest.cc b/cc/input/single_scrollbar_animation_controller_thinning_unittest.cc
index e5e652b3d1a70525126196df65a439c30d042676..0faa8d3265bd0134ab5cfeef7bf29dde7eb42398 100644
--- a/cc/input/single_scrollbar_animation_controller_thinning_unittest.cc
+++ b/cc/input/single_scrollbar_animation_controller_thinning_unittest.cc
@@ -23,9 +23,11 @@ namespace {
 
 const float kIdleThicknessScale =
     SingleScrollbarAnimationControllerThinning::kIdleThicknessScale;
-const float kDefaultMouseMoveDistanceToTriggerAnimation =
+const float kMouseMoveDistanceToTriggerExpand =
     SingleScrollbarAnimationControllerThinning::
-        kDefaultMouseMoveDistanceToTriggerAnimation;
+        kMouseMoveDistanceToTriggerExpand;
+const float kMouseMoveDistanceToTriggerFadeIn =
+    ScrollbarAnimationController::kMouseMoveDistanceToTriggerFadeIn;
 
 class MockSingleScrollbarAnimationControllerClient
     : public ScrollbarAnimationControllerClient {
@@ -74,6 +76,7 @@ class SingleScrollbarAnimationControllerThinningTest : public testing::Test {
     const int kId = 2;
     const int kThumbThickness = 10;
     const int kTrackStart = 0;
+    const int kTrackLength = 100;
     const bool kIsLeftSideVerticalScrollbar = false;
     const bool kIsOverlayScrollbar = true;
 
@@ -87,6 +90,8 @@ class SingleScrollbarAnimationControllerThinningTest : public testing::Test {
     clip_layer_->test_properties()->AddChild(std::move(scroll_layer));
     host_impl_.active_tree()->SetRootLayerForTesting(std::move(clip));
 
+    scrollbar_layer_->SetBounds(gfx::Size(kThumbThickness, kTrackLength));
+    scrollbar_layer_->SetPosition(gfx::PointF(90, 0));
     scrollbar_layer_->SetScrollElementId(scroll_layer_ptr->element_id());
     scrollbar_layer_->test_properties()->opacity_can_animate = true;
     clip_layer_->SetBounds(gfx::Size(100, 100));
@@ -108,6 +113,13 @@ class SingleScrollbarAnimationControllerThinningTest : public testing::Test {
   NiceMock<MockSingleScrollbarAnimationControllerClient> client_;
 };
 
+// Return a point with given offset from the top-left of scrollbar.
+gfx::PointF NearScrollbar(float offset_x, float offset_y) {
+  gfx::PointF p(90, 0);
+  p.Offset(offset_x, offset_y);
+  return p;
+}
+
 // Check initialization of scrollbar. Should start thin.
 TEST_F(SingleScrollbarAnimationControllerThinningTest, Idle) {
   EXPECT_FLOAT_EQ(kIdleThicknessScale,
@@ -120,7 +132,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseNear) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  scrollbar_controller_->DidMouseMoveNear(1);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(-1, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(kIdleThicknessScale,
                   scrollbar_layer_->thumb_thickness_scale_factor());
@@ -131,15 +143,24 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseNear) {
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Subsequent moves within the nearness threshold should not change anything.
-  scrollbar_controller_->DidMouseMoveNear(2);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(-2, 0));
   scrollbar_controller_->Animate(time);
   time += base::TimeDelta::FromSeconds(10);
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
-  // Now move away from bar.
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation);
+  // Now move away from thumb.
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand, 0));
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Move away from track.
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerFadeIn, 0));
   scrollbar_controller_->Animate(time);
   time += kThinningDuration;
   scrollbar_controller_->Animate(time);
@@ -153,7 +174,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseOver) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(0, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(kIdleThicknessScale,
                   scrollbar_layer_->thumb_thickness_scale_factor());
@@ -164,7 +185,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseOver) {
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Subsequent moves should not change anything.
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(0, 0));
   scrollbar_controller_->Animate(time);
   time += base::TimeDelta::FromSeconds(10);
   scrollbar_controller_->Animate(time);
@@ -172,16 +193,16 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseOver) {
 
   // Moving off the scrollbar but still withing the "near" threshold should do
   // nothing.
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation - 1.f);
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand + 1, 0));
   scrollbar_controller_->Animate(time);
   time += base::TimeDelta::FromSeconds(10);
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
-  // Now move away from bar.
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation);
+  // Now move away from thumb.
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand, 0));
   scrollbar_controller_->Animate(time);
   time += kThinningDuration;
   scrollbar_controller_->Animate(time);
@@ -191,13 +212,13 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseOver) {
 
 // First move the pointer over the scrollbar off of it. Make sure the thinning
 // animation kicked off in DidMouseMoveOffScrollbar gets overridden by the
-// thickening animation in the DidMouseMoveNear call.
+// thickening animation in the DidMouseMove call.
 TEST_F(SingleScrollbarAnimationControllerThinningTest,
        MouseNearThenAwayWhileAnimating) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(0, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(kIdleThicknessScale,
                   scrollbar_layer_->thumb_thickness_scale_factor());
@@ -208,7 +229,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // This is tricky. The DidMouseLeave() is sent before the
-  // subsequent DidMouseMoveNear(), if the mouse moves in that direction.
+  // subsequent DidMouseMove(), if the mouse moves in that direction.
   // This results in the thumb thinning. We want to make sure that when the
   // thumb starts expanding it doesn't first narrow to the idle thinness.
   time += base::TimeDelta::FromSeconds(1);
@@ -225,7 +246,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
   // Now we get a notification for the mouse moving over the scroller. The
   // animation is reset to the thickening direction but we won't start
   // thickening until the new animation catches up to the current thickness.
-  scrollbar_controller_->DidMouseMoveNear(1);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(-1, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
                   scrollbar_layer_->thumb_thickness_scale_factor());
@@ -263,7 +284,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
   time += base::TimeDelta::FromSeconds(1);
 
   // Move over the scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(0, 0));
   scrollbar_controller_->Animate(time);
   time += kThinningDuration;
   scrollbar_controller_->Animate(time);
@@ -281,8 +302,8 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
 
   // Move outside the "near" threshold. Because the scrollbar is captured it
   // should remain thick.
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation);
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand, 0));
   time += kThinningDuration;
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
@@ -308,7 +329,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
   time += base::TimeDelta::FromSeconds(1);
 
   // Move over scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(0, 0));
   scrollbar_controller_->Animate(time);
   time += kThinningDuration;
   scrollbar_controller_->Animate(time);
@@ -323,8 +344,8 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Move away from scrollbar. Nothing should change.
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation);
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(kMouseMoveDistanceToTriggerExpand, 0));
   time += base::TimeDelta::FromSeconds(1);
   scrollbar_controller_->Animate(time);
   time += base::TimeDelta::FromSeconds(10);
@@ -333,7 +354,8 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest,
 
   // Move over scrollbar and release. Since we're near the scrollbar, it should
   // remain thick.
-  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand + 1, 0));
   scrollbar_controller_->DidMouseUp();
   time += base::TimeDelta::FromSeconds(1);
   scrollbar_controller_->Animate(time);
@@ -349,7 +371,7 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, ThicknessAnimated) {
 
   // Move mouse near scrollbar. Test that at half the duration time, the
   // thickness is half way through its animation.
-  scrollbar_controller_->DidMouseMoveNear(1);
+  scrollbar_controller_->DidMouseMove(NearScrollbar(-1, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(kIdleThicknessScale,
                   scrollbar_layer_->thumb_thickness_scale_factor());
@@ -365,8 +387,8 @@ TEST_F(SingleScrollbarAnimationControllerThinningTest, ThicknessAnimated) {
 
   // Move mouse away from scrollbar. Same check.
   time += base::TimeDelta::FromSeconds(1);
-  scrollbar_controller_->DidMouseMoveNear(
-      kDefaultMouseMoveDistanceToTriggerAnimation);
+  scrollbar_controller_->DidMouseMove(
+      NearScrollbar(-kMouseMoveDistanceToTriggerExpand, 0));
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());