| // Copyright 2012 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_linear_fade.h" |
| |
| #include "base/time/time.h" |
| #include "cc/layers/layer_impl.h" |
| #include "cc/layers/scrollbar_layer_impl_base.h" |
| |
| namespace cc { |
| |
| scoped_ptr<ScrollbarAnimationControllerLinearFade> |
| ScrollbarAnimationControllerLinearFade::Create(LayerImpl* scroll_layer, |
| base::TimeDelta fadeout_delay, |
| base::TimeDelta fadeout_length) { |
| return make_scoped_ptr(new ScrollbarAnimationControllerLinearFade( |
| scroll_layer, fadeout_delay, fadeout_length)); |
| } |
| |
| ScrollbarAnimationControllerLinearFade::ScrollbarAnimationControllerLinearFade( |
| LayerImpl* scroll_layer, |
| base::TimeDelta fadeout_delay, |
| base::TimeDelta fadeout_length) |
| : ScrollbarAnimationController(), |
| scroll_layer_(scroll_layer), |
| scroll_gesture_in_progress_(false), |
| scroll_gesture_has_scrolled_(false), |
| fadeout_delay_(fadeout_delay), |
| fadeout_length_(fadeout_length) {} |
| |
| ScrollbarAnimationControllerLinearFade:: |
| ~ScrollbarAnimationControllerLinearFade() {} |
| |
| bool ScrollbarAnimationControllerLinearFade::IsAnimating() const { |
| return !last_awaken_time_.is_null(); |
| } |
| |
| base::TimeDelta ScrollbarAnimationControllerLinearFade::DelayBeforeStart( |
| base::TimeTicks now) const { |
| if (now > last_awaken_time_ + fadeout_delay_) |
| return base::TimeDelta(); |
| return fadeout_delay_ - (now - last_awaken_time_); |
| } |
| |
| bool ScrollbarAnimationControllerLinearFade::Animate(base::TimeTicks now) { |
| float opacity = OpacityAtTime(now); |
| ApplyOpacityToScrollbars(opacity); |
| if (!opacity) |
| last_awaken_time_ = base::TimeTicks(); |
| return IsAnimating() && DelayBeforeStart(now) == base::TimeDelta(); |
| } |
| |
| void ScrollbarAnimationControllerLinearFade::DidScrollGestureBegin() { |
| scroll_gesture_in_progress_ = true; |
| scroll_gesture_has_scrolled_ = false; |
| } |
| |
| void ScrollbarAnimationControllerLinearFade::DidScrollGestureEnd( |
| base::TimeTicks now) { |
| // The animation should not be triggered if no scrolling has occurred. |
| if (scroll_gesture_has_scrolled_) |
| last_awaken_time_ = now; |
| scroll_gesture_has_scrolled_ = false; |
| scroll_gesture_in_progress_ = false; |
| } |
| |
| bool ScrollbarAnimationControllerLinearFade::DidScrollUpdate( |
| base::TimeTicks now) { |
| ApplyOpacityToScrollbars(1.0f); |
| // The animation should only be activated if the scroll updated occurred |
| // programatically, outside the scope of a scroll gesture. |
| if (scroll_gesture_in_progress_) { |
| last_awaken_time_ = base::TimeTicks(); |
| scroll_gesture_has_scrolled_ = true; |
| return true; |
| } |
| |
| last_awaken_time_ = now; |
| return false; |
| } |
| |
| float ScrollbarAnimationControllerLinearFade::OpacityAtTime( |
| base::TimeTicks now) { |
| if (scroll_gesture_has_scrolled_) |
| return 1.0f; |
| |
| if (last_awaken_time_.is_null()) |
| return 0.0f; |
| |
| base::TimeDelta delta = now - last_awaken_time_; |
| |
| if (delta <= fadeout_delay_) |
| return 1.0f; |
| if (delta < fadeout_delay_ + fadeout_length_) { |
| return (fadeout_delay_ + fadeout_length_ - delta).InSecondsF() / |
| fadeout_length_.InSecondsF(); |
| } |
| return 0.0f; |
| } |
| |
| void ScrollbarAnimationControllerLinearFade::ApplyOpacityToScrollbars( |
| float opacity) { |
| ScrollbarLayerImplBase* horizontal_scrollbar = |
| scroll_layer_->horizontal_scrollbar_layer(); |
| if (horizontal_scrollbar) |
| horizontal_scrollbar->SetOpacity(opacity); |
| |
| ScrollbarLayerImplBase* vertical_scrollbar = |
| scroll_layer_->vertical_scrollbar_layer(); |
| if (vertical_scrollbar) |
| vertical_scrollbar->SetOpacity(opacity); |
| } |
| |
| } // namespace cc |