1 files changed, 140 insertions, 0 deletions
diff --git a/servo/components/style/values/generics/animation.rs b/servo/components/style/values/generics/animation.rs
new file mode 100644
index 0000000000..edee9e9f25
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+++ b/servo/components/style/values/generics/animation.rs
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Generic values for properties related to animations and transitions.
+
+use crate::values::generics::length::GenericLengthPercentageOrAuto;
+use crate::values::specified::animation::{ScrollAxis, ScrollFunction};
+use crate::values::TimelineName;
+use std::fmt::{self, Write};
+use style_traits::{CssWriter, ToCss};
+
+/// The view() notation.
+/// https://drafts.csswg.org/scroll-animations-1/#view-notation
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[css(function = "view")]
+#[repr(C)]
+pub struct GenericViewFunction<LengthPercent> {
+    /// The axis of scrolling that drives the progress of the timeline.
+    #[css(skip_if = "ScrollAxis::is_default")]
+    pub axis: ScrollAxis,
+    /// An adjustment of the view progress visibility range.
+    #[css(skip_if = "GenericViewTimelineInset::is_auto")]
+    #[css(field_bound)]
+    pub inset: GenericViewTimelineInset<LengthPercent>,
+}
+
+pub use self::GenericViewFunction as ViewFunction;
+
+/// A value for the <single-animation-timeline>.
+///
+/// https://drafts.csswg.org/css-animations-2/#typedef-single-animation-timeline
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C, u8)]
+pub enum GenericAnimationTimeline<LengthPercent> {
+    /// Use default timeline. The animation’s timeline is a DocumentTimeline.
+    Auto,
+    /// The scroll-timeline name or view-timeline-name.
+    /// https://drafts.csswg.org/scroll-animations-1/#scroll-timelines-named
+    /// https://drafts.csswg.org/scroll-animations-1/#view-timeline-name
+    Timeline(TimelineName),
+    /// The scroll() notation.
+    /// https://drafts.csswg.org/scroll-animations-1/#scroll-notation
+    Scroll(ScrollFunction),
+    /// The view() notation.
+    /// https://drafts.csswg.org/scroll-animations-1/#view-notation
+    View(#[css(field_bound)] GenericViewFunction<LengthPercent>),
+}
+
+pub use self::GenericAnimationTimeline as AnimationTimeline;
+
+impl<LengthPercent> AnimationTimeline<LengthPercent> {
+    /// Returns the `auto` value.
+    pub fn auto() -> Self {
+        Self::Auto
+    }
+
+    /// Returns true if it is auto (i.e. the default value).
+    pub fn is_auto(&self) -> bool {
+        matches!(self, Self::Auto)
+    }
+}
+
+/// A generic value for the `[ [ auto | <length-percentage> ]{1,2} ]`.
+///
+/// https://drafts.csswg.org/scroll-animations-1/#view-timeline-inset
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C)]
+pub struct GenericViewTimelineInset<LengthPercent> {
+    /// The start inset in the relevant axis.
+    pub start: GenericLengthPercentageOrAuto<LengthPercent>,
+    /// The end inset.
+    pub end: GenericLengthPercentageOrAuto<LengthPercent>,
+}
+
+pub use self::GenericViewTimelineInset as ViewTimelineInset;
+
+impl<LengthPercent> ViewTimelineInset<LengthPercent> {
+    /// Returns true if it is auto.
+    #[inline]
+    fn is_auto(&self) -> bool {
+        self.start.is_auto() && self.end.is_auto()
+    }
+}
+
+impl<LengthPercent> ToCss for ViewTimelineInset<LengthPercent>
+where
+    LengthPercent: PartialEq + ToCss,
+{
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: Write,
+    {
+        self.start.to_css(dest)?;
+        if self.end != self.start {
+            dest.write_char(' ')?;
+            self.end.to_css(dest)?;
+        }
+        Ok(())
+    }
+}
+
+impl<LengthPercent> Default for ViewTimelineInset<LengthPercent> {
+    fn default() -> Self {
+        Self {
+            start: GenericLengthPercentageOrAuto::auto(),
+            end: GenericLengthPercentageOrAuto::auto(),
+        }
+    }
+}