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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "cc/animation/scroll_timeline.h"
#include <memory>
#include <vector>
#include "cc/animation/animation_id_provider.h"
#include "cc/animation/worklet_animation.h"
#include "cc/trees/property_tree.h"
#include "cc/trees/scroll_node.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/size.h"
namespace cc {
namespace {
bool IsVertical(ScrollTimeline::ScrollDirection direction) {
return direction == ScrollTimeline::ScrollUp ||
direction == ScrollTimeline::ScrollDown;
}
bool IsReverse(ScrollTimeline::ScrollDirection direction) {
return direction == ScrollTimeline::ScrollUp ||
direction == ScrollTimeline::ScrollLeft;
}
} // namespace
ScrollTimeline::ScrollTimeline(std::optional<ElementId> scroller_id,
ScrollDirection direction,
std::optional<ScrollOffsets> scroll_offsets,
int animation_timeline_id)
: AnimationTimeline(animation_timeline_id, /* is_impl_only */ false),
pending_id_(scroller_id),
direction_(direction),
pending_offsets_(scroll_offsets) {}
ScrollTimeline::~ScrollTimeline() = default;
scoped_refptr<ScrollTimeline> ScrollTimeline::Create(
std::optional<ElementId> scroller_id,
ScrollTimeline::ScrollDirection direction,
std::optional<ScrollOffsets> scroll_offsets) {
return base::WrapRefCounted(
new ScrollTimeline(scroller_id, direction, scroll_offsets,
AnimationIdProvider::NextTimelineId()));
}
scoped_refptr<AnimationTimeline> ScrollTimeline::CreateImplInstance() const {
return base::WrapRefCounted(
new ScrollTimeline(pending_id(), direction(), pending_offsets(), id()));
}
bool ScrollTimeline::IsActive(const ScrollTree& scroll_tree,
bool is_active_tree) const {
// Blink passes empty scroll offsets when the timeline is inactive.
if ((is_active_tree && !active_offsets()) ||
(!is_active_tree && !pending_offsets())) {
return false;
}
// If pending tree with our scroller hasn't been activated, or the scroller
// has been removed (e.g. if it is no longer composited).
if ((is_active_tree && !active_id()) || (!is_active_tree && !pending_id())) {
return false;
}
ElementId scroller_id =
is_active_tree ? active_id().value() : pending_id().value();
// The scroller is not in the ScrollTree if it is not currently scrollable
// (e.g. has overflow: visible). In this case the timeline is not active.
return scroll_tree.FindNodeFromElementId(scroller_id);
}
// https://drafts.csswg.org/scroll-animations-1/#current-time-algorithm
std::optional<base::TimeTicks> ScrollTimeline::CurrentTime(
const ScrollTree& scroll_tree,
bool is_active_tree) const {
// If the timeline is not active return unresolved value by the spec.
// https://github.com/WICG/scroll-animations/issues/31
// https://wicg.github.io/scroll-animations/#current-time-algorithm
if (!IsActive(scroll_tree, is_active_tree)) {
return std::nullopt;
}
ElementId scroller_id =
is_active_tree ? active_id().value() : pending_id().value();
const ScrollNode* scroll_node =
scroll_tree.FindNodeFromElementId(scroller_id);
gfx::PointF offset =
scroll_tree.GetScrollOffsetForScrollTimeline(*scroll_node);
DCHECK_GE(offset.x(), 0);
DCHECK_GE(offset.y(), 0);
gfx::PointF scroll_dimensions = scroll_tree.MaxScrollOffset(scroll_node->id);
double max_offset =
IsVertical(direction()) ? scroll_dimensions.y() : scroll_dimensions.x();
double current_physical_offset =
IsVertical(direction()) ? offset.y() : offset.x();
double current_offset = IsReverse(direction())
? max_offset - current_physical_offset
: current_physical_offset;
DCHECK_GE(max_offset, 0);
DCHECK_GE(current_offset, 0);
double start_offset = 0;
if (is_active_tree) {
DCHECK(active_offsets());
start_offset = active_offsets()->start;
} else {
DCHECK(pending_offsets());
start_offset = pending_offsets()->start;
}
int64_t progress_us = base::ClampRound((current_offset - start_offset) *
kScrollTimelineMicrosecondsPerPixel);
return base::TimeTicks() + base::Microseconds(progress_us);
}
std::optional<base::TimeTicks> ScrollTimeline::Duration(
const ScrollTree& scroll_tree,
bool is_active_tree) const {
double start_offset = 0;
double end_offset = 0;
if (is_active_tree) {
DCHECK(active_offsets());
start_offset = active_offsets()->start;
end_offset = active_offsets()->end;
} else {
DCHECK(pending_offsets());
start_offset = pending_offsets()->start;
end_offset = pending_offsets()->end;
}
int64_t duration_us = base::ClampRound((end_offset - start_offset) *
kScrollTimelineMicrosecondsPerPixel);
return base::TimeTicks() + base::Microseconds(duration_us);
}
void ScrollTimeline::PushPropertiesTo(AnimationTimeline* impl_timeline) {
AnimationTimeline::PushPropertiesTo(impl_timeline);
DCHECK(impl_timeline);
ScrollTimeline* scroll_timeline = ToScrollTimeline(impl_timeline);
scroll_timeline->pending_id_.Write(*this) = pending_id_.Read(*this);
scroll_timeline->pending_offsets_.Write(*this) = pending_offsets_.Read(*this);
}
void ScrollTimeline::ActivateTimeline() {
active_id_.Write(*this) = pending_id_.Read(*this);
active_offsets_.Write(*this) = pending_offsets_.Read(*this);
for (auto& kv : id_to_animation_map_.Write(*this)) {
auto& animation = kv.second;
if (animation->IsWorkletAnimation())
ToWorkletAnimation(animation.get())->ReleasePendingTreeLock();
}
}
bool ScrollTimeline::TickScrollLinkedAnimations(
const std::vector<scoped_refptr<Animation>>& ticking_animations,
const ScrollTree& scroll_tree,
bool is_active_tree) {
std::optional<base::TimeTicks> tick_time =
CurrentTime(scroll_tree, is_active_tree);
if (!tick_time)
return false;
bool animated = false;
// This potentially iterates over all ticking animations multiple
// times (# of ScrollTimeline * # of ticking_animations_).
// The alternative we have considered here was to maintain a
// ticking_animations_ list for each timeline but at the moment we
// have opted to avoid this complexity in favor of simpler but less
// efficient solution.
for (auto& animation : ticking_animations) {
if (animation->animation_timeline() != this)
continue;
// Worklet animations are ticked at a later stage.
if (animation->IsWorkletAnimation())
continue;
if (!animation->IsScrollLinkedAnimation())
continue;
animation->Tick(tick_time.value());
animated = true;
}
return animated;
}
void ScrollTimeline::UpdateScrollerIdAndScrollOffsets(
std::optional<ElementId> pending_id,
std::optional<ScrollOffsets> pending_offsets) {
if (pending_id_.Read(*this) == pending_id &&
pending_offsets_.Read(*this) == pending_offsets) {
return;
}
// When the scroller id changes it will first be modified in the pending tree.
// Then later (when the pending tree is promoted to active)
// |ActivateTimeline| will be called and will set the |active_id_|.
pending_id_.Write(*this) = pending_id;
pending_offsets_.Write(*this) = pending_offsets;
SetNeedsPushProperties();
}
bool ScrollTimeline::IsScrollTimeline() const {
return true;
}
bool ScrollTimeline::IsLinkedToScroller(ElementId scroller) const {
auto& id = active_id();
return id && id.value() == scroller;
}
} // namespace cc
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