Prevent overlay scrollbars expand or hover together

cc/input/scrollbar_animation_controller_thinning.cc

Index: cc/input/scrollbar_animation_controller_thinning.cc
diff --git a/cc/input/scrollbar_animation_controller_thinning.cc b/cc/input/scrollbar_animation_controller_thinning.cc
index 2006d98fddb44a0779c850a7be0c32edb12c5d1c..8c2bb1a9007d0e930c8c4deb7172e447cd809bca 100644
--- a/cc/input/scrollbar_animation_controller_thinning.cc
+++ b/cc/input/scrollbar_animation_controller_thinning.cc
@@ -11,13 +11,14 @@
 #include "cc/trees/layer_tree_impl.h"
 
 namespace {
-const float kIdleThicknessScale = 0.4f;
 const float kDefaultMouseMoveDistanceToTriggerAnimation = 25.f;
 }
 
 namespace cc {
 
-std::unique_ptr<ScrollbarAnimationControllerThinning>
+using std::for_each;
+
+unique_ptr<ScrollbarAnimationControllerThinning>
 ScrollbarAnimationControllerThinning::Create(
     int scroll_layer_id,
     ScrollbarAnimationControllerClient* client,
@@ -40,213 +41,116 @@ ScrollbarAnimationControllerThinning::ScrollbarAnimationControllerThinning(
     : ScrollbarAnimationController(scroll_layer_id,
                                    client,
                                    delay_before_starting,
-                                   resize_delay_before_starting),
-      opacity_(0.0f),
-      captured_(false),
-      mouse_is_over_scrollbar_(false),
-      mouse_is_near_scrollbar_(false),
-      thickness_change_(NONE),
-      mouse_move_distance_to_trigger_animation_(
-          kDefaultMouseMoveDistanceToTriggerAnimation),
-      fade_duration_(fade_duration),
-      thinning_duration_(thinning_duration),
-      current_animating_property_(OPACITY) {
-  ApplyOpacity(0.f);
-  ApplyThumbThicknessScale(kIdleThicknessScale);
+                                   resize_delay_before_starting) {
+  scrollbar_controllers.push_back(
+      SingleScrollbarAnimationControllerThinning::Create(
+          scroll_layer_id, ScrollbarOrientation::VERTICAL, client,
+          delay_before_starting, resize_delay_before_starting, fade_duration,
+          thinning_duration));
+  scrollbar_controllers.push_back(
+      SingleScrollbarAnimationControllerThinning::Create(
+          scroll_layer_id, ScrollbarOrientation::HORIZONTAL, client,
+          delay_before_starting, resize_delay_before_starting, fade_duration,
+          thinning_duration));
 }
 
 ScrollbarAnimationControllerThinning::~ScrollbarAnimationControllerThinning() {}
 
-void ScrollbarAnimationControllerThinning::RunAnimationFrame(float progress) {
-  if (captured_)
-    return;
-
-  if (current_animating_property_ == OPACITY)
-    ApplyOpacity(1.f - progress);
-  else
-    ApplyThumbThicknessScale(ThumbThicknessScaleAt(progress));
-
-  client_->SetNeedsRedrawForScrollbarAnimation();
-  if (progress == 1.f) {
-    StopAnimation();
-    if (current_animating_property_ == THICKNESS) {
-      thickness_change_ = NONE;
-      SetCurrentAnimatingProperty(OPACITY);
-      PostDelayedAnimationTask(false);
+void ScrollbarAnimationControllerThinning::GetScrollbarAnimationController(
+    ScrollbarOrientation orientation,
+    SingleScrollbarAnimationControllerThinning* scrollbar_controller) const {
+  for (auto itr = scrollbar_controllers.begin();
+       itr != scrollbar_controllers.end(); itr++) {
+    if ((*itr)->orientation() == orientation) {
+      scrollbar_controller = itr->get();
     }
   }
+  DCHECK(scrollbar_controller);
 }
 
-const base::TimeDelta& ScrollbarAnimationControllerThinning::Duration() {
-  if (current_animating_property_ == OPACITY)
-    return fade_duration_;
-  else
-    return thinning_duration_;
+bool ScrollbarAnimationControllerThinning::mouse_is_over_scrollbar(
+    ScrollbarOrientation orientation) const {
+  SingleScrollbarAnimationControllerThinning* scrollbar_controller_ptr =
+      nullptr;
+  GetScrollbarAnimationController(orientation, scrollbar_controller_ptr);
+  return scrollbar_controller_ptr->mouse_is_over_scrollbar();
 }
 
-void ScrollbarAnimationControllerThinning::DidMouseDown() {
-  if (!mouse_is_over_scrollbar_ || opacity_ == 0.0f)
-    return;
+bool ScrollbarAnimationControllerThinning::mouse_is_near_scrollbar(
+    ScrollbarOrientation orientation) const {
+  SingleScrollbarAnimationControllerThinning* scrollbar_controller_ptr =
+      nullptr;
+  GetScrollbarAnimationController(orientation, scrollbar_controller_ptr);
+  return scrollbar_controller_ptr->mouse_is_near_scrollbar();
+}
 
-  StopAnimation();
-  captured_ = true;
-  ApplyOpacity(1.f);
-  ApplyThumbThicknessScale(1.f);
+bool ScrollbarAnimationControllerThinning::ScrollbarsHidden() const {
+  return scrollbar_controllers[0]->ScrollbarsHidden();
 }
 
-void ScrollbarAnimationControllerThinning::DidMouseUp() {
-  if (!captured_ || opacity_ == 0.0f)
-    return;
-
-  captured_ = false;
-  StopAnimation();
-
-  if (!mouse_is_near_scrollbar_) {
-    SetCurrentAnimatingProperty(THICKNESS);
-    thickness_change_ = DECREASE;
-    StartAnimation();
-  } else {
-    SetCurrentAnimatingProperty(OPACITY);
-    PostDelayedAnimationTask(false);
+void ScrollbarAnimationControllerThinning::set_mouse_move_distance_for_test(
+    float distance) {
+  for (auto itr = scrollbar_controllers.begin();
+       itr != scrollbar_controllers.end(); itr++) {
+    (*itr)->set_mouse_move_distance_for_test(distance);
   }
 }
 
-void ScrollbarAnimationControllerThinning::DidMouseLeave() {
-  if (!mouse_is_over_scrollbar_ && !mouse_is_near_scrollbar_)
-    return;
-
-  mouse_is_over_scrollbar_ = false;
-  mouse_is_near_scrollbar_ = false;
-
-  if (captured_ || opacity_ == 0.0f)
-    return;
+bool ScrollbarAnimationControllerThinning::Animate(base::TimeTicks now) {
+  bool result = false;
+  for (auto itr = scrollbar_controllers.begin();
+       itr != scrollbar_controllers.end(); itr++) {
+    result |= (*itr)->Animate(now);
+  }
 
-  thickness_change_ = DECREASE;
-  SetCurrentAnimatingProperty(THICKNESS);
-  StartAnimation();
+  return result;
 }
 
-void ScrollbarAnimationControllerThinning::DidScrollUpdate(bool on_resize) {
-  if (captured_)
-    return;
-
-  ScrollbarAnimationController::DidScrollUpdate(on_resize);
-  ApplyOpacity(1.f);
-  ApplyThumbThicknessScale(mouse_is_near_scrollbar_ ? 1.f
-                                                    : kIdleThicknessScale);
-  SetCurrentAnimatingProperty(OPACITY);
+void ScrollbarAnimationControllerThinning::RunAnimationFrame(float progress) {
+  // do nothing
 }
 
-void ScrollbarAnimationControllerThinning::DidMouseMoveNear(float distance) {
-  bool mouse_is_over_scrollbar = distance == 0.0f;
-  bool mouse_is_near_scrollbar =
-      distance < mouse_move_distance_to_trigger_animation_;
-
-  if (captured_ || opacity_ == 0.0f) {
-    mouse_is_near_scrollbar_ = mouse_is_near_scrollbar;
-    mouse_is_over_scrollbar_ = mouse_is_over_scrollbar;
-    return;
-  }
-
-  if (mouse_is_over_scrollbar == mouse_is_over_scrollbar_ &&
-      mouse_is_near_scrollbar == mouse_is_near_scrollbar_)
-    return;
-
-  if (mouse_is_over_scrollbar_ != mouse_is_over_scrollbar)
-    mouse_is_over_scrollbar_ = mouse_is_over_scrollbar;
-
-  if (mouse_is_near_scrollbar_ != mouse_is_near_scrollbar) {
-    mouse_is_near_scrollbar_ = mouse_is_near_scrollbar;
-    thickness_change_ = mouse_is_near_scrollbar_ ? INCREASE : DECREASE;
-  }
-
-  SetCurrentAnimatingProperty(THICKNESS);
-  StartAnimation();
+const base::TimeDelta& ScrollbarAnimationControllerThinning::Duration() {
+  // should not call
+  return scrollbar_controllers[0]->Duration();
 }
 
-bool ScrollbarAnimationControllerThinning::ScrollbarsHidden() const {
-  return opacity_ == 0.0f;
-}
-
-float ScrollbarAnimationControllerThinning::ThumbThicknessScaleAt(
-    float progress) {
-  if (thickness_change_ == NONE)
-    return mouse_is_near_scrollbar_ ? 1.f : kIdleThicknessScale;
-  float factor = thickness_change_ == INCREASE ? progress : (1.f - progress);
-  return ((1.f - kIdleThicknessScale) * factor) + kIdleThicknessScale;
-}
-
-float ScrollbarAnimationControllerThinning::AdjustScale(
-    float new_value,
-    float current_value,
-    AnimationChange animation_change,
-    float min_value,
-    float max_value) {
-  float result;
-  if (animation_change == INCREASE && current_value > new_value)
-    result = current_value;
-  else if (animation_change == DECREASE && current_value < new_value)
-    result = current_value;
-  else
-    result = new_value;
-  if (result > max_value)
-    return max_value;
-  if (result < min_value)
-    return min_value;
-  return result;
+void ScrollbarAnimationControllerThinning::DidMouseDown() {
+  for_each(
+      scrollbar_controllers.begin(), scrollbar_controllers.end(),
+      [](unique_ptr<SingleScrollbarAnimationControllerThinning>&
+             scrollbar_controller) { scrollbar_controller->DidMouseDown(); });
 }
 
-void ScrollbarAnimationControllerThinning::ApplyOpacity(float opacity) {
-  for (ScrollbarLayerImplBase* scrollbar : Scrollbars()) {
-    if (!scrollbar->is_overlay_scrollbar())
-      continue;
-    float effective_opacity = scrollbar->CanScrollOrientation() ? opacity : 0;
-    PropertyTrees* property_trees =
-        scrollbar->layer_tree_impl()->property_trees();
-    // If this method is called during LayerImpl::PushPropertiesTo, we may not
-    // yet have valid effect_id_to_index_map entries as property trees are
-    // pushed after layers during activation. We can skip updating opacity in
-    // that case as we are only registering a scrollbar and because opacity will
-    // be overwritten anyway when property trees are pushed.
-    if (property_trees->IsInIdToIndexMap(PropertyTrees::TreeType::EFFECT,
-                                         scrollbar->id())) {
-      property_trees->effect_tree.OnOpacityAnimated(
-          effective_opacity,
-          property_trees->effect_id_to_index_map[scrollbar->id()],
-          scrollbar->layer_tree_impl());
-    }
-  }
-
-  bool previouslyVisible = opacity_ > 0.0f;
-  bool currentlyVisible = opacity > 0.0f;
-
-  opacity_ = opacity;
-
-  if (previouslyVisible != currentlyVisible)
-    client_->DidChangeScrollbarVisibility();
+void ScrollbarAnimationControllerThinning::DidMouseUp() {
+  for_each(
+      scrollbar_controllers.begin(), scrollbar_controllers.end(),
+      [](unique_ptr<SingleScrollbarAnimationControllerThinning>&
+             scrollbar_controller) { scrollbar_controller->DidMouseUp(); });
 }
 
-void ScrollbarAnimationControllerThinning::ApplyThumbThicknessScale(
-    float thumb_thickness_scale) {
-  for (ScrollbarLayerImplBase* scrollbar : Scrollbars()) {
-    if (!scrollbar->is_overlay_scrollbar())
-      continue;
-
-    scrollbar->SetThumbThicknessScaleFactor(AdjustScale(
-        thumb_thickness_scale, scrollbar->thumb_thickness_scale_factor(),
-        thickness_change_, kIdleThicknessScale, 1));
-  }
+void ScrollbarAnimationControllerThinning::DidMouseLeave() {
+  for_each(
+      scrollbar_controllers.begin(), scrollbar_controllers.end(),
+      [](unique_ptr<SingleScrollbarAnimationControllerThinning>&
+             scrollbar_controller) { scrollbar_controller->DidMouseLeave(); });
 }
 
-void ScrollbarAnimationControllerThinning::SetCurrentAnimatingProperty(
-    AnimatingProperty property) {
-  if (current_animating_property_ == property)
-    return;
-
-  StopAnimation();
-  current_animating_property_ = property;
-  if (current_animating_property_ == THICKNESS)
-    ApplyOpacity(1.f);
+void ScrollbarAnimationControllerThinning::DidScrollUpdate(bool on_resize) {
+  for_each(scrollbar_controllers.begin(), scrollbar_controllers.end(),
+           [&on_resize](unique_ptr<SingleScrollbarAnimationControllerThinning>&
+                            scrollbar_controller) {
+             scrollbar_controller->DidScrollUpdate(on_resize);
+           });
+}
+
+void ScrollbarAnimationControllerThinning::DidMouseMoveNear(
+    vector<DistanceToScrollbar> distances) {
+  for_each(scrollbar_controllers.begin(), scrollbar_controllers.end(),
+           [&distances](unique_ptr<SingleScrollbarAnimationControllerThinning>&
+                            scrollbar_controller) {
+             scrollbar_controller->DidMouseMoveNear(distances);
+           });
 }
 
 }  // namespace cc