diff --git a/Tests/LibWeb/Text/expected/css/transition-basics.txt b/Tests/LibWeb/Text/expected/css/transition-basics.txt
new file mode 100644
index 00000000000..224848202fd
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/css/transition-basics.txt
@@ -0,0 +1,5 @@
+ left starts at: 0px
+shortly after starting, left is >= 0px? true and < 200px? true
+half-way through, left is > 0px? true and < 200px? true
+near the end, left is > 0px? true and < 200px? true
+after the transition, left is: 200px
diff --git a/Tests/LibWeb/Text/input/css/transition-basics.html b/Tests/LibWeb/Text/input/css/transition-basics.html
new file mode 100644
index 00000000000..3571f4d0be5
--- /dev/null
+++ b/Tests/LibWeb/Text/input/css/transition-basics.html
@@ -0,0 +1,48 @@
+
+
+
+
+
+
+
diff --git a/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp b/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
index 8a913915b0f..4de6f14e322 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
@@ -1,22 +1,30 @@
/*
- * Copyright (c) 2024, Matthew Olsson .
+ * Copyright (c) 2024, Matthew Olsson
+ * Copyright (c) 2024, Sam Atkins
*
* SPDX-License-Identifier: BSD-2-Clause
*/
+#include
#include
#include
#include
#include
+#include
+#include
#include
+#include
namespace Web::CSS {
JS_DEFINE_ALLOCATOR(CSSTransition);
-JS::NonnullGCPtr CSSTransition::create(JS::Realm& realm, PropertyID property_id, size_t transition_generation)
+JS::NonnullGCPtr CSSTransition::start_a_transition(DOM::Element& element, PropertyID property_id, size_t transition_generation,
+ double start_time, double end_time, NonnullRefPtr start_value, NonnullRefPtr end_value,
+ NonnullRefPtr reversing_adjusted_start_value, double reversing_shortening_factor)
{
- return realm.heap().allocate(realm, realm, property_id, transition_generation);
+ auto& realm = element.realm();
+ return realm.heap().allocate(realm, realm, element, property_id, transition_generation, start_time, end_time, start_value, end_value, reversing_adjusted_start_value, reversing_shortening_factor);
}
Animations::AnimationClass CSSTransition::animation_class() const
@@ -67,16 +75,53 @@ Optional CSSTransition::class_specific_composite_order(JS::NonnullGCPtr start_value, NonnullRefPtr end_value,
+ NonnullRefPtr reversing_adjusted_start_value, double reversing_shortening_factor)
: Animations::Animation(realm)
, m_transition_property(property_id)
, m_transition_generation(transition_generation)
+ , m_start_time(start_time)
+ , m_end_time(end_time)
+ , m_start_value(move(start_value))
+ , m_end_value(move(end_value))
+ , m_reversing_adjusted_start_value(move(reversing_adjusted_start_value))
+ , m_reversing_shortening_factor(reversing_shortening_factor)
+ , m_keyframe_effect(Animations::KeyframeEffect::create(realm))
{
// FIXME:
// Transitions generated using the markup defined in this specification are not added to the global animation list
// when they are created. Instead, these animations are appended to the global animation list at the first moment
// when they transition out of the idle play state after being disassociated from their owning element. Transitions
// that have been disassociated from their owning element but are still idle do not have a defined composite order.
+
+ set_start_time(start_time - element.document().timeline()->current_time().value());
+
+ // Construct a KeyframesEffect for our animation
+ m_keyframe_effect->set_target(&element);
+ m_keyframe_effect->set_start_delay(start_time);
+ m_keyframe_effect->set_iteration_duration(m_end_time - start_time);
+ m_keyframe_effect->set_timing_function(element.property_transition_attributes(property_id)->timing_function);
+
+ auto key_frame_set = adopt_ref(*new Animations::KeyframeEffect::KeyFrameSet);
+ Animations::KeyframeEffect::KeyFrameSet::ResolvedKeyFrame initial_keyframe;
+ initial_keyframe.properties.set(property_id, m_start_value);
+
+ Animations::KeyframeEffect::KeyFrameSet::ResolvedKeyFrame final_keyframe;
+ final_keyframe.properties.set(property_id, m_end_value);
+
+ key_frame_set->keyframes_by_key.insert(0, initial_keyframe);
+ key_frame_set->keyframes_by_key.insert(100 * Animations::KeyframeEffect::AnimationKeyFrameKeyScaleFactor, final_keyframe);
+
+ m_keyframe_effect->set_key_frame_set(key_frame_set);
+ set_timeline(element.document().timeline());
+ set_owning_element(element);
+ set_effect(m_keyframe_effect);
+ element.associate_with_animation(*this);
+ element.set_transition(m_transition_property, *this);
+
+ HTML::TemporaryExecutionContext context(element.document().relevant_settings_object());
+ play().release_value_but_fixme_should_propagate_errors();
}
void CSSTransition::initialize(JS::Realm& realm)
@@ -89,6 +134,25 @@ void CSSTransition::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_cached_declaration);
+ visitor.visit(m_keyframe_effect);
+}
+
+double CSSTransition::timing_function_output_at_time(double t) const
+{
+ auto progress = (t - transition_start_time()) / (transition_end_time() - transition_start_time());
+ // FIXME: Is this before_flag value correct?
+ bool before_flag = t < transition_start_time();
+ return m_keyframe_effect->timing_function().evaluate_at(progress, before_flag);
+}
+
+NonnullRefPtr CSSTransition::value_at_time(double t) const
+{
+ // https://drafts.csswg.org/css-transitions/#application
+ auto progress = timing_function_output_at_time(t);
+ auto result = interpolate_property(*m_keyframe_effect->target(), m_transition_property, m_start_value, m_end_value, progress);
+ if (result)
+ return result.release_nonnull();
+ return m_start_value;
}
}
diff --git a/Userland/Libraries/LibWeb/CSS/CSSTransition.h b/Userland/Libraries/LibWeb/CSS/CSSTransition.h
index 8eac75a3c8a..ac017e208f9 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSTransition.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSTransition.h
@@ -1,5 +1,6 @@
/*
- * Copyright (c) 2024, Matthew Olsson .
+ * Copyright (c) 2024, Matthew Olsson
+ * Copyright (c) 2024, Sam Atkins
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@@ -9,6 +10,7 @@
#include
#include
#include
+#include
#include
namespace Web::CSS {
@@ -18,18 +20,29 @@ class CSSTransition : public Animations::Animation {
JS_DECLARE_ALLOCATOR(CSSTransition);
public:
- static JS::NonnullGCPtr create(JS::Realm&, PropertyID, size_t transition_generation);
+ static JS::NonnullGCPtr start_a_transition(DOM::Element&, PropertyID, size_t transition_generation,
+ double start_time, double end_time, NonnullRefPtr start_value, NonnullRefPtr end_value,
+ NonnullRefPtr reversing_adjusted_start_value, double reversing_shortening_factor);
StringView transition_property() const { return string_from_property_id(m_transition_property); }
- JS::GCPtr cached_declaration() const { return m_cached_declaration; }
- void set_cached_declaration(JS::GCPtr declaration) { m_cached_declaration = declaration; }
-
virtual Animations::AnimationClass animation_class() const override;
virtual Optional class_specific_composite_order(JS::NonnullGCPtr other) const override;
+ double transition_start_time() const { return m_start_time; }
+ double transition_end_time() const { return m_end_time; }
+ NonnullRefPtr transition_start_value() const { return m_start_value; }
+ NonnullRefPtr transition_end_value() const { return m_end_value; }
+ NonnullRefPtr reversing_adjusted_start_value() const { return m_reversing_adjusted_start_value; }
+ double reversing_shortening_factor() const { return m_reversing_shortening_factor; }
+
+ double timing_function_output_at_time(double t) const;
+ NonnullRefPtr value_at_time(double t) const;
+
private:
- CSSTransition(JS::Realm&, PropertyID, size_t transition_generation);
+ CSSTransition(JS::Realm&, DOM::Element&, PropertyID, size_t transition_generation,
+ double start_time, double end_time, NonnullRefPtr start_value, NonnullRefPtr end_value,
+ NonnullRefPtr reversing_adjusted_start_value, double reversing_shortening_factor);
virtual void initialize(JS::Realm&) override;
virtual void visit_edges(Cell::Visitor&) override;
@@ -41,6 +54,26 @@ private:
// https://drafts.csswg.org/css-transitions-2/#transition-generation
size_t m_transition_generation;
+ // https://drafts.csswg.org/css-transitions/#transition-start-time
+ double m_start_time;
+
+ // https://drafts.csswg.org/css-transitions/#transition-end-time
+ double m_end_time;
+
+ // https://drafts.csswg.org/css-transitions/#transition-start-value
+ NonnullRefPtr m_start_value;
+
+ // https://drafts.csswg.org/css-transitions/#transition-end-value
+ NonnullRefPtr m_end_value;
+
+ // https://drafts.csswg.org/css-transitions/#transition-reversing-adjusted-start-value
+ NonnullRefPtr m_reversing_adjusted_start_value;
+
+ // https://drafts.csswg.org/css-transitions/#transition-reversing-shortening-factor
+ double m_reversing_shortening_factor;
+
+ JS::NonnullGCPtr m_keyframe_effect;
+
JS::GCPtr m_cached_declaration;
};
diff --git a/Userland/Libraries/LibWeb/CSS/Interpolation.cpp b/Userland/Libraries/LibWeb/CSS/Interpolation.cpp
index 44832b37629..db90aa056ec 100644
--- a/Userland/Libraries/LibWeb/CSS/Interpolation.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Interpolation.cpp
@@ -72,6 +72,22 @@ ValueComparingRefPtr interpolate_property(DOM::Element& ele
}
}
+// https://drafts.csswg.org/css-transitions/#transitionable
+bool property_values_are_transitionable(PropertyID property_id, CSSStyleValue const& old_value, CSSStyleValue const& new_value)
+{
+ // When comparing the before-change style and after-change style for a given property,
+ // the property values are transitionable if they have an animation type that is neither not animatable nor discrete.
+
+ auto animation_type = animation_type_from_longhand_property(property_id);
+ if (animation_type == AnimationType::None || animation_type == AnimationType::Discrete)
+ return false;
+
+ // FIXME: Even when a property is transitionable, the two values may not be. The spec uses the example of inset/non-inset shadows.
+ (void)old_value;
+ (void)new_value;
+ return true;
+}
+
// A null return value means the interpolated matrix was not invertible or otherwise invalid
RefPtr interpolate_transform(DOM::Element& element, CSSStyleValue const& from, CSSStyleValue const& to, float delta)
{
diff --git a/Userland/Libraries/LibWeb/CSS/Interpolation.h b/Userland/Libraries/LibWeb/CSS/Interpolation.h
index cf17a33c897..59f9e859e12 100644
--- a/Userland/Libraries/LibWeb/CSS/Interpolation.h
+++ b/Userland/Libraries/LibWeb/CSS/Interpolation.h
@@ -13,6 +13,9 @@ namespace Web::CSS {
ValueComparingRefPtr interpolate_property(DOM::Element&, PropertyID, CSSStyleValue const& from, CSSStyleValue const& to, float delta);
+// https://drafts.csswg.org/css-transitions/#transitionable
+bool property_values_are_transitionable(PropertyID, CSSStyleValue const& old_value, CSSStyleValue const& new_value);
+
NonnullRefPtr interpolate_value(DOM::Element&, CSSStyleValue const& from, CSSStyleValue const& to, float delta);
NonnullRefPtr interpolate_box_shadow(DOM::Element&, CSSStyleValue const& from, CSSStyleValue const& to, float delta);
RefPtr interpolate_transform(DOM::Element&, CSSStyleValue const& from, CSSStyleValue const& to, float delta);
diff --git a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
index 97db8482237..0277d8e2034 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -32,6 +32,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -1294,6 +1295,198 @@ static void compute_transitioned_properties(StyleProperties const& style, DOM::E
}
}
+// https://drafts.csswg.org/css-transitions/#starting
+void StyleComputer::start_needed_transitions(StyleProperties const& previous_style, StyleProperties& new_style, DOM::Element& element, Optional pseudo_element) const
+{
+ // FIXME: Implement transitions for pseudo-elements
+ (void)pseudo_element;
+
+ // https://drafts.csswg.org/css-transitions/#transition-combined-duration
+ auto combined_duration = [](Animations::Animatable::TransitionAttributes const& transition_attributes) {
+ // Define the combined duration of the transition as the sum of max(matching transition duration, 0s) and the matching transition delay.
+ return max(transition_attributes.duration, 0) + transition_attributes.delay;
+ };
+
+ // For each element and property, the implementation must act as follows:
+ auto style_change_event_time = m_document->timeline()->current_time().value();
+
+ for (auto i = to_underlying(CSS::first_longhand_property_id); i <= to_underlying(CSS::last_longhand_property_id); ++i) {
+ auto property_id = static_cast(i);
+ auto matching_transition_properties = element.property_transition_attributes(property_id);
+ auto before_change_value = previous_style.property(property_id, StyleProperties::WithAnimationsApplied::No);
+ auto after_change_value = new_style.property(property_id, StyleProperties::WithAnimationsApplied::No);
+
+ auto existing_transition = element.property_transition(property_id);
+ bool has_running_transition = existing_transition && !existing_transition->is_finished();
+ bool has_completed_transition = existing_transition && existing_transition->is_finished();
+
+ auto start_a_transition = [&](auto start_time, auto end_time, auto start_value, auto end_value, auto reversing_adjusted_start_value, auto reversing_shortening_factor) {
+ dbgln("Starting a transition of {} from {} to {}", string_from_property_id(property_id), start_value->to_string(), end_value->to_string());
+
+ auto transition = CSSTransition::start_a_transition(element, property_id, document().transition_generation(),
+ start_time, end_time, start_value, end_value, reversing_adjusted_start_value, reversing_shortening_factor);
+ // Immediately set the property's value to the transition's current value, to prevent single-frame jumps.
+ new_style.set_animated_property(property_id, transition->value_at_time(style_change_event_time));
+ };
+
+ // 1. If all of the following are true:
+ if (
+ // - the element does not have a running transition for the property,
+ (!has_running_transition) &&
+ // - the before-change style is different from the after-change style for that property, and the values for the property are transitionable,
+ (!before_change_value->equals(after_change_value) && property_values_are_transitionable(property_id, before_change_value, after_change_value)) &&
+ // - the element does not have a completed transition for the property
+ // or the end value of the completed transition is different from the after-change style for the property,
+ (!has_completed_transition || !existing_transition->transition_end_value()->equals(after_change_value)) &&
+ // - there is a matching transition-property value, and
+ (matching_transition_properties.has_value()) &&
+ // - the combined duration is greater than 0s,
+ (combined_duration(matching_transition_properties.value()) > 0)) {
+
+ dbgln("Transition step 1.");
+
+ // then implementations must remove the completed transition (if present) from the set of completed transitions
+ if (has_completed_transition)
+ element.remove_transition(property_id);
+ // and start a transition whose:
+
+ // - start time is the time of the style change event plus the matching transition delay,
+ auto start_time = style_change_event_time + matching_transition_properties->delay;
+
+ // - end time is the start time plus the matching transition duration,
+ auto end_time = start_time + matching_transition_properties->duration;
+
+ // - start value is the value of the transitioning property in the before-change style,
+ auto start_value = before_change_value;
+
+ // - end value is the value of the transitioning property in the after-change style,
+ auto end_value = after_change_value;
+
+ // - reversing-adjusted start value is the same as the start value, and
+ auto reversing_adjusted_start_value = start_value;
+
+ // - reversing shortening factor is 1.
+ double reversing_shortening_factor = 1;
+
+ start_a_transition(start_time, end_time, start_value, end_value, reversing_adjusted_start_value, reversing_shortening_factor);
+ }
+
+ // 2. Otherwise, if the element has a completed transition for the property
+ // and the end value of the completed transition is different from the after-change style for the property,
+ // then implementations must remove the completed transition from the set of completed transitions.
+ else if (has_completed_transition && !existing_transition->transition_end_value()->equals(after_change_value)) {
+ dbgln("Transition step 2.");
+ element.remove_transition(property_id);
+ }
+
+ // 3. If the element has a running transition or completed transition for the property,
+ // and there is not a matching transition-property value,
+ if (existing_transition && !matching_transition_properties.has_value()) {
+ // then implementations must cancel the running transition or remove the completed transition from the set of completed transitions.
+ dbgln("Transition step 3.");
+ if (has_running_transition)
+ existing_transition->cancel();
+ else
+ element.remove_transition(property_id);
+ }
+
+ // 4. If the element has a running transition for the property,
+ // there is a matching transition-property value,
+ // and the end value of the running transition is not equal to the value of the property in the after-change style, then:
+ if (has_running_transition && matching_transition_properties.has_value() && !existing_transition->transition_end_value()->equals(after_change_value)) {
+ dbgln("Transition step 4. existing end value = {}, after change value = {}", existing_transition->transition_end_value()->to_string(), after_change_value->to_string());
+ // 1. If the current value of the property in the running transition is equal to the value of the property in the after-change style,
+ // or if these two values are not transitionable,
+ // then implementations must cancel the running transition.
+ auto current_value = existing_transition->value_at_time(style_change_event_time);
+ if (current_value->equals(after_change_value) || !property_values_are_transitionable(property_id, current_value, after_change_value)) {
+ dbgln("Transition step 4.1");
+ existing_transition->cancel();
+ }
+
+ // 2. Otherwise, if the combined duration is less than or equal to 0s,
+ // or if the current value of the property in the running transition is not transitionable with the value of the property in the after-change style,
+ // then implementations must cancel the running transition.
+ else if ((combined_duration(matching_transition_properties.value()) <= 0)
+ || !property_values_are_transitionable(property_id, current_value, after_change_value)) {
+ dbgln("Transition step 4.2");
+ existing_transition->cancel();
+ }
+
+ // 3. Otherwise, if the reversing-adjusted start value of the running transition is the same as the value of the property in the after-change style
+ // (see the section on reversing of transitions for why these case exists),
+ else if (existing_transition->reversing_adjusted_start_value()->equals(after_change_value)) {
+ dbgln("Transition step 4.3");
+ // implementations must cancel the running transition and start a new transition whose:
+ existing_transition->cancel();
+ // AD-HOC: Remove the cancelled transition, otherwise it breaks the invariant that there is only one
+ // running or completed transition for a property at once.
+ element.remove_transition(property_id);
+
+ // - reversing-adjusted start value is the end value of the running transition,
+ auto reversing_adjusted_start_value = existing_transition->transition_end_value();
+
+ // - reversing shortening factor is the absolute value, clamped to the range [0, 1], of the sum of:
+ // 1. the output of the timing function of the old transition at the time of the style change event,
+ // times the reversing shortening factor of the old transition
+ auto term_1 = existing_transition->timing_function_output_at_time(style_change_event_time) * existing_transition->reversing_shortening_factor();
+ // 2. 1 minus the reversing shortening factor of the old transition.
+ auto term_2 = 1 - existing_transition->reversing_shortening_factor();
+ double reversing_shortening_factor = clamp(abs(term_1 + term_2), 0.0, 1.0);
+
+ // - start time is the time of the style change event plus:
+ // 1. if the matching transition delay is nonnegative, the matching transition delay, or
+ // 2. if the matching transition delay is negative, the product of the new transition’s reversing shortening factor and the matching transition delay,
+ auto start_time = style_change_event_time
+ + (matching_transition_properties->delay >= 0
+ ? (matching_transition_properties->delay)
+ : (reversing_shortening_factor * matching_transition_properties->delay));
+
+ // - end time is the start time plus the product of the matching transition duration and the new transition’s reversing shortening factor,
+ auto end_time = start_time + (matching_transition_properties->duration * reversing_shortening_factor);
+
+ // - start value is the current value of the property in the running transition,
+ auto start_value = current_value;
+
+ // - end value is the value of the property in the after-change style,
+ auto end_value = after_change_value;
+
+ start_a_transition(start_time, end_time, start_value, end_value, reversing_adjusted_start_value, reversing_shortening_factor);
+ }
+
+ // 4. Otherwise,
+ else {
+ dbgln("Transition step 4.4");
+ // implementations must cancel the running transition and start a new transition whose:
+ existing_transition->cancel();
+ // AD-HOC: Remove the cancelled transition, otherwise it breaks the invariant that there is only one
+ // running or completed transition for a property at once.
+ element.remove_transition(property_id);
+
+ // - start time is the time of the style change event plus the matching transition delay,
+ auto start_time = style_change_event_time + matching_transition_properties->delay;
+
+ // - end time is the start time plus the matching transition duration,
+ auto end_time = start_time + matching_transition_properties->duration;
+
+ // - start value is the current value of the property in the running transition,
+ auto start_value = current_value;
+
+ // - end value is the value of the property in the after-change style,
+ auto end_value = after_change_value;
+
+ // - reversing-adjusted start value is the same as the start value, and
+ auto reversing_adjusted_start_value = start_value;
+
+ // - reversing shortening factor is 1.
+ double reversing_shortening_factor = 1;
+
+ start_a_transition(start_time, end_time, start_value, end_value, reversing_adjusted_start_value, reversing_shortening_factor);
+ }
+ }
+ }
+}
+
// https://www.w3.org/TR/css-cascade/#cascading
// https://drafts.csswg.org/css-cascade-5/#layering
void StyleComputer::compute_cascaded_values(StyleProperties& style, DOM::Element& element, Optional pseudo_element, bool& did_match_any_pseudo_element_rules, ComputeStyleMode mode) const
@@ -1440,7 +1633,9 @@ void StyleComputer::compute_cascaded_values(StyleProperties& style, DOM::Element
// Important user agent declarations
cascade_declarations(style, element, pseudo_element, matching_rule_set.user_agent_rules, CascadeOrigin::UserAgent, Important::Yes);
- // FIXME: Transition declarations [css-transitions-1]
+ // Transition declarations [css-transitions-1]
+ // Note that we have to do these after finishing computing the style,
+ // so they're not done here, but as the final step in compute_style_impl()
}
DOM::Element const* element_to_inherit_style_from(DOM::Element const* element, Optional pseudo_element)
@@ -2197,6 +2392,10 @@ RefPtr StyleComputer::compute_style_impl(DOM::Element& element,
// 9. Transition declarations [css-transitions-1]
// Theoretically this should be part of the cascade, but it works with computed values, which we don't have until now.
compute_transitioned_properties(style, element, pseudo_element);
+ if (auto const* previous_style = element.computed_css_values()) {
+ start_needed_transitions(*previous_style, style, element, pseudo_element);
+ }
+
return style;
}
diff --git a/Userland/Libraries/LibWeb/CSS/StyleComputer.h b/Userland/Libraries/LibWeb/CSS/StyleComputer.h
index 0ae43b8139d..9d854107343 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleComputer.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleComputer.h
@@ -174,6 +174,7 @@ private:
void compute_font(StyleProperties&, DOM::Element const*, Optional) const;
void compute_math_depth(StyleProperties&, DOM::Element const*, Optional) const;
void compute_defaulted_values(StyleProperties&, DOM::Element const*, Optional) const;
+ void start_needed_transitions(StyleProperties const& old_style, StyleProperties& new_style, DOM::Element&, Optional) const;
void absolutize_values(StyleProperties&) const;
void resolve_effective_overflow_values(StyleProperties&) const;
void transform_box_type_if_needed(StyleProperties&, DOM::Element const&, Optional) const;