| // Copyright 2014 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/animation/scrollbar_animation_controller.h" |
| |
| #include <algorithm> |
| |
| #include "base/time/time.h" |
| #include "cc/trees/layer_tree_impl.h" |
| |
| namespace cc { |
| |
| ScrollbarAnimationController::ScrollbarAnimationController( |
| LayerImpl* scroll_layer, |
| ScrollbarAnimationControllerClient* client, |
| base::TimeDelta delay_before_starting, |
| base::TimeDelta resize_delay_before_starting, |
| base::TimeDelta duration) |
| : scroll_layer_(scroll_layer), |
| client_(client), |
| delay_before_starting_(delay_before_starting), |
| resize_delay_before_starting_(resize_delay_before_starting), |
| duration_(duration), |
| is_animating_(false), |
| currently_scrolling_(false), |
| scroll_gesture_has_scrolled_(false), |
| weak_factory_(this) { |
| } |
| |
| ScrollbarAnimationController::~ScrollbarAnimationController() { |
| if (is_animating_) |
| client_->StopAnimatingScrollbarAnimationController(this); |
| } |
| |
| void ScrollbarAnimationController::Animate(base::TimeTicks now) { |
| if (!is_animating_) |
| return; |
| |
| if (last_awaken_time_.is_null()) |
| last_awaken_time_ = now; |
| |
| float progress = AnimationProgressAtTime(now); |
| RunAnimationFrame(progress); |
| } |
| |
| float ScrollbarAnimationController::AnimationProgressAtTime( |
| base::TimeTicks now) { |
| base::TimeDelta delta = now - last_awaken_time_; |
| float progress = delta.InSecondsF() / duration_.InSecondsF(); |
| return std::max(std::min(progress, 1.f), 0.f); |
| } |
| |
| void ScrollbarAnimationController::DidScrollBegin() { |
| currently_scrolling_ = true; |
| } |
| |
| void ScrollbarAnimationController::DidScrollUpdate(bool on_resize) { |
| StopAnimation(); |
| delayed_scrollbar_fade_.Cancel(); |
| |
| // As an optimization, we avoid spamming fade delay tasks during active fast |
| // scrolls. But if we're not within one, we need to post every scroll update. |
| if (!currently_scrolling_) |
| PostDelayedAnimationTask(on_resize); |
| else |
| scroll_gesture_has_scrolled_ = true; |
| } |
| |
| void ScrollbarAnimationController::DidScrollEnd() { |
| if (scroll_gesture_has_scrolled_) { |
| PostDelayedAnimationTask(false); |
| scroll_gesture_has_scrolled_ = false; |
| } |
| |
| currently_scrolling_ = false; |
| } |
| |
| void ScrollbarAnimationController::PostDelayedAnimationTask(bool on_resize) { |
| base::TimeDelta delay = |
| on_resize ? resize_delay_before_starting_ : delay_before_starting_; |
| delayed_scrollbar_fade_.Reset( |
| base::Bind(&ScrollbarAnimationController::StartAnimation, |
| weak_factory_.GetWeakPtr())); |
| client_->PostDelayedScrollbarAnimationTask(delayed_scrollbar_fade_.callback(), |
| delay); |
| } |
| |
| void ScrollbarAnimationController::StartAnimation() { |
| delayed_scrollbar_fade_.Cancel(); |
| is_animating_ = true; |
| last_awaken_time_ = base::TimeTicks(); |
| client_->StartAnimatingScrollbarAnimationController(this); |
| } |
| |
| void ScrollbarAnimationController::StopAnimation() { |
| is_animating_ = false; |
| client_->StopAnimatingScrollbarAnimationController(this); |
| } |
| |
| } // namespace cc |