ladybird/Libraries/LibWeb/Animations/DocumentTimeline.cpp
Callum Law 69f05bd45d LibWeb: Store animation time values in abstract type
In level 2 of the web animations spec, times are no longer always
measures in milliseconds, they can also be percents when dealing with
progress-based (i.e. scroll-based) timelines.

We don't actually support percent times yet but this change will make it
easier to implement when we do.
2025-12-12 10:49:18 +00:00

94 lines
4.2 KiB
C++
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* Copyright (c) 2023, Matthew Olsson <mattco@serenityos.org>.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGC/Heap.h>
#include <LibJS/Runtime/Realm.h>
#include <LibWeb/Animations/DocumentTimeline.h>
#include <LibWeb/Bindings/DocumentTimelinePrototype.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/HTML/Window.h>
#include <LibWeb/HighResolutionTime/Performance.h>
#include <LibWeb/HighResolutionTime/TimeOrigin.h>
#include <LibWeb/WebIDL/ExceptionOr.h>
namespace Web::Animations {
GC_DEFINE_ALLOCATOR(DocumentTimeline);
GC::Ref<DocumentTimeline> DocumentTimeline::create(JS::Realm& realm, DOM::Document& document, HighResolutionTime::DOMHighResTimeStamp origin_time)
{
auto timeline = realm.create<DocumentTimeline>(realm, document, origin_time);
auto current_time = document.last_animation_frame_timestamp();
if (!current_time.has_value()) {
// The document hasn't processed an animation frame yet, we use the navigation start time, which is either the time
// that the previous document started to be unloaded or the creation time of the current document.
current_time = HighResolutionTime::relative_high_resolution_time(document.load_timing_info().navigation_start_time, realm.global_object());
}
timeline->update_current_time(current_time.value());
return timeline;
}
// https://www.w3.org/TR/web-animations-1/#dom-documenttimeline-documenttimeline
WebIDL::ExceptionOr<GC::Ref<DocumentTimeline>> DocumentTimeline::construct_impl(JS::Realm& realm, DocumentTimelineOptions options)
{
// Creates a new DocumentTimeline. The Document with which the timeline is associated is the Document associated
// with the Window that is the current global object.
auto& window = as<HTML::Window>(realm.global_object());
return create(realm, window.associated_document(), options.origin_time);
}
// https://www.w3.org/TR/web-animations-1/#ref-for-timeline-time-to-origin-relative-time
Optional<double> DocumentTimeline::convert_a_timeline_time_to_an_origin_relative_time(Optional<TimeValue> timeline_time)
{
// To convert a timeline time, timeline time, to an origin-relative time for a document timeline, timeline, return
// the sum of the timeline time and timelines origin time. If timeline is inactive, return an unresolved time
// value.
if (is_inactive() || !timeline_time.has_value())
return {};
// NB: We know the timeline time of a DocumentTimeline is always in milliseconds because it's only ever set from
// update_current_time()
VERIFY(timeline_time->type == TimeValue::Type::Milliseconds);
return timeline_time->value + m_origin_time;
}
// https://drafts.csswg.org/web-animations-1/#document-timeline
void DocumentTimeline::update_current_time(double timestamp)
{
// A document timeline is a type of timeline that is associated with a document and whose current time is calculated
// as a fixed offset from the now timestamp provided each time the update animations and send events procedure is
// run. This fixed offset is equal to the current time of the default document timeline when this timelines current
// time was zero, and is thus referred to as the document timelines origin time.
set_current_time(TimeValue { TimeValue::Type::Milliseconds, timestamp - m_origin_time });
// https://drafts.csswg.org/web-animations-1/#ref-for-active-timeline
// After a document timeline becomes active, it is monotonically increasing.
if (!m_is_monotonically_increasing && !is_inactive())
m_is_monotonically_increasing = true;
}
// https://www.w3.org/TR/web-animations-1/#document-timelines
bool DocumentTimeline::is_inactive() const
{
// A document timeline that is associated with a Document which is not an active document is also considered to be
// inactive.
return Base::is_inactive() || !associated_document()->is_active();
}
DocumentTimeline::DocumentTimeline(JS::Realm& realm, DOM::Document& document, HighResolutionTime::DOMHighResTimeStamp origin_time)
: AnimationTimeline(realm)
, m_origin_time(origin_time)
{
set_associated_document(document);
}
void DocumentTimeline::initialize(JS::Realm& realm)
{
WEB_SET_PROTOTYPE_FOR_INTERFACE(DocumentTimeline);
Base::initialize(realm);
}
}