Prevent overlay scrollbars expand or hover together

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
new file mode 100644
index 0000000000000000000000000000000000000000..050919e0912df3d26cffc2509e3fc8f96d554988
--- /dev/null
+++ b/cc/input/single_scrollbar_animation_controller_thinning_unittest.cc
@@ -0,0 +1,386 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/input/single_scrollbar_animation_controller_thinning.h"
+
+#include "cc/layers/solid_color_scrollbar_layer_impl.h"
+#include "cc/test/fake_impl_task_runner_provider.h"
+#include "cc/test/fake_layer_tree_host_impl.h"
+#include "cc/test/geometry_test_utils.h"
+#include "cc/test/test_task_graph_runner.h"
+#include "cc/trees/layer_tree_impl.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::AtLeast;
+using testing::Mock;
+using testing::NiceMock;
+using testing::_;
+
+namespace cc {
+namespace {
+
+// These constants are hard-coded and should match the values in
+// single_scrollbar_animation_controller_thinning.cc.
+const float kIdleThicknessScale = 0.4f;
+const float kDefaultMouseMoveDistanceToTriggerAnimation = 25.f;
+
+class MockSingleScrollbarAnimationControllerClient
+    : public ScrollbarAnimationControllerClient {
+ public:
+  explicit MockSingleScrollbarAnimationControllerClient(
+      LayerTreeHostImpl* host_impl)
+      : host_impl_(host_impl) {}
+  virtual ~MockSingleScrollbarAnimationControllerClient() {}
+
+  void PostDelayedScrollbarAnimationTask(const base::Closure& start_fade,

[bokan, 2017/01/06 20:17:56]

This should never be called, you can mock this. In fact, you should be able to
mock most of the methods here.

+                                         base::TimeDelta delay) override {
+    start_fade_ = start_fade;
+    delay_ = delay;
+  }
+  void SetNeedsRedrawForScrollbarAnimation() override {}
+  void SetNeedsAnimateForScrollbarAnimation() override {}
+  ScrollbarSet ScrollbarsFor(int scroll_layer_id) const override {
+    return host_impl_->ScrollbarsFor(scroll_layer_id);
+  }
+  MOCK_METHOD0(DidChangeScrollbarVisibility, void());
+
+  base::Closure& start_fade() { return start_fade_; }
+  base::TimeDelta& delay() { return delay_; }
+
+ private:
+  base::Closure start_fade_;
+  base::TimeDelta delay_;
+  LayerTreeHostImpl* host_impl_;
+};
+
+class SingleScrollbarAnimationControllerThinningTest : public testing::Test {
+ public:
+  SingleScrollbarAnimationControllerThinningTest()
+      : host_impl_(&task_runner_provider_, &task_graph_runner_),
+        client_(&host_impl_) {}
+
+ protected:
+  const base::TimeDelta kThinningDuration = base::TimeDelta::FromSeconds(2);
+
+  void SetUp() override {
+    std::unique_ptr<LayerImpl> scroll_layer =
+        LayerImpl::Create(host_impl_.active_tree(), 1);
+    std::unique_ptr<LayerImpl> clip =
+        LayerImpl::Create(host_impl_.active_tree(), 3);
+    clip_layer_ = clip.get();
+    scroll_layer->SetScrollClipLayer(clip_layer_->id());
+    LayerImpl* scroll_layer_ptr = scroll_layer.get();
+
+    const int kId = 2;
+    const int kThumbThickness = 10;
+    const int kTrackStart = 0;
+    const bool kIsLeftSideVerticalScrollbar = false;
+    const bool kIsOverlayScrollbar = true;
+
+    std::unique_ptr<SolidColorScrollbarLayerImpl> scrollbar =
+        SolidColorScrollbarLayerImpl::Create(
+            host_impl_.active_tree(), kId, HORIZONTAL, kThumbThickness,
+            kTrackStart, kIsLeftSideVerticalScrollbar, kIsOverlayScrollbar);
+    scrollbar_layer_ = scrollbar.get();
+
+    scroll_layer->test_properties()->AddChild(std::move(scrollbar));
+    clip_layer_->test_properties()->AddChild(std::move(scroll_layer));
+    host_impl_.active_tree()->SetRootLayerForTesting(std::move(clip));
+
+    scrollbar_layer_->SetScrollLayerId(scroll_layer_ptr->id());
+    scrollbar_layer_->test_properties()->opacity_can_animate = true;
+    clip_layer_->SetBounds(gfx::Size(100, 100));
+    scroll_layer_ptr->SetBounds(gfx::Size(200, 200));
+    host_impl_.active_tree()->BuildLayerListAndPropertyTreesForTesting();
+
+    scrollbar_controller_ = SingleScrollbarAnimationControllerThinning::Create(
+        scroll_layer_ptr->id(), HORIZONTAL, &client_, kThinningDuration);
+  }
+
+  FakeImplTaskRunnerProvider task_runner_provider_;
+  TestTaskGraphRunner task_graph_runner_;
+  FakeLayerTreeHostImpl host_impl_;
+  std::unique_ptr<SingleScrollbarAnimationControllerThinning>
+      scrollbar_controller_;
+  LayerImpl* clip_layer_;
+  SolidColorScrollbarLayerImpl* scrollbar_layer_;
+  NiceMock<MockSingleScrollbarAnimationControllerClient> client_;
+};
+
+// Check initialization of scrollbar. Should start thin.
+TEST_F(SingleScrollbarAnimationControllerThinningTest, Idle) {
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// Move the pointer near the scrollbar. Confirm it gets thick and narrow when
+// moved away.
+TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseNear) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  scrollbar_controller_->DidMouseMoveNear(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Should animate to thickened.
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  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_->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);
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// Move the pointer over the scrollbar. Make sure it gets thick that it gets
+// thin when moved away.
+TEST_F(SingleScrollbarAnimationControllerThinningTest, MouseOver) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Should animate to thickened.
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Subsequent moves should not change anything.
+  scrollbar_controller_->DidMouseMoveNear(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());
+
+  // Moving off the scrollbar but still withing the "near" threshold should do
+  // nothing.
+  scrollbar_controller_->DidMouseMoveNear(
+      kDefaultMouseMoveDistanceToTriggerAnimation - 1.f);
+  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);
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// 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.
+TEST_F(SingleScrollbarAnimationControllerThinningTest,
+       MouseNearThenAwayWhileAnimating) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Should animate to thickened.
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  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.
+  // 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);
+  scrollbar_controller_->DidMouseLeave();
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Let the animation run half of the way through the thinning animation.
+  time += kThinningDuration / 2;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // 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.

[bokan, 2017/01/06 20:17:56]

Hmm, I don't like this. Could we make it that the scrollbar starts thickening
immediately?

Is this the way it works today? If so we can change it in a followup.

[chaopeng, 2017/01/10 20:49:50]

Yes, today we just change the animation direction and set need animation(in
startAnimation) when we receive a mouse move.
https://cs.chromium.org/chromium/src/cc/input/scrollbar_animation_controller_...

+  scrollbar_controller_->DidMouseMoveNear(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Until we reach the half way point, the animation will have no effect.
+  time += kThinningDuration / 4;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += kThinningDuration / 4;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // We're now at three quarters of the way through so it should now started
+  // thickening again.
+  time += kThinningDuration / 4;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale + 3 * (1.0f - kIdleThicknessScale) / 4.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // And all the way to the end.
+  time += kThinningDuration / 4;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// First move the pointer on the scrollbar, then press it, then away.
+// Confirm that the bar gets thick. Then mouse up. Confirm that
+// the bar gets thin.
+TEST_F(SingleScrollbarAnimationControllerThinningTest,
+       MouseCaptureAndReleaseOutOfBar) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  // Move over the scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Capture
+  scrollbar_controller_->DidMouseDown();
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Should stay thick for a while.
+  time += base::TimeDelta::FromSeconds(10);
+  scrollbar_controller_->Animate(time);
+
+  // Move outside the "near" threshold. Because the scrollbar is captured it
+  // should remain thick.
+  scrollbar_controller_->DidMouseMoveNear(
+      kDefaultMouseMoveDistanceToTriggerAnimation);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Release.
+  scrollbar_controller_->DidMouseUp();
+
+  // Should become thin.
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// First move the pointer on the scrollbar, then press it, then away.  Confirm
+// that the bar gets thick. Then move point on the scrollbar and mouse up.
+// Confirm that the bar stays thick.
+TEST_F(SingleScrollbarAnimationControllerThinningTest,
+       MouseCaptureAndReleaseOnBar) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  // Move over scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->Animate(time);
+  time += kThinningDuration;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Capture. Nothing should change.
+  scrollbar_controller_->DidMouseDown();
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  time += base::TimeDelta::FromSeconds(10);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Move away from scrollbar. Nothing should change.
+  scrollbar_controller_->DidMouseMoveNear(
+      kDefaultMouseMoveDistanceToTriggerAnimation);
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  time += base::TimeDelta::FromSeconds(10);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Move over scrollbar and release. Since we're near the scrollbar, it should
+  // remain thick.
+  scrollbar_controller_->DidMouseMoveNear(0);
+  scrollbar_controller_->DidMouseUp();
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  time += base::TimeDelta::FromSeconds(10);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// Tests that the thickening/thinning effects are animated.
+TEST_F(SingleScrollbarAnimationControllerThinningTest, ThicknessAnimated) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  // 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_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += kThinningDuration / 2;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale + (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += kThinningDuration / 2;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Move mouse away from scrollbar. Same check.
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->DidMouseMoveNear(
+      kDefaultMouseMoveDistanceToTriggerAnimation);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += kThinningDuration / 2;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f - (1.0f - kIdleThicknessScale) / 2.0f,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += kThinningDuration / 2;
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(kIdleThicknessScale,
+                  scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+}  // namespace
+}  // namespace cc