1 files changed, 88 insertions, 0 deletions
diff --git a/servo/components/style/values/animated/color.rs b/servo/components/style/values/animated/color.rs
new file mode 100644
index 0000000000..f608b72e53
--- /dev/null
+++ b/servo/components/style/values/animated/color.rs
@@ -0,0 +1,88 @@
+/* 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/. */
+
+//! Animated types for CSS colors.
+
+use crate::color::mix::ColorInterpolationMethod;
+use crate::color::AbsoluteColor;
+use crate::values::animated::{Animate, Procedure, ToAnimatedZero};
+use crate::values::computed::Percentage;
+use crate::values::distance::{ComputeSquaredDistance, SquaredDistance};
+use crate::values::generics::color::{ColorMixFlags, GenericColor, GenericColorMix};
+
+impl Animate for AbsoluteColor {
+    #[inline]
+    fn animate(&self, other: &Self, procedure: Procedure) -> Result<Self, ()> {
+        let (left_weight, right_weight) = procedure.weights();
+        Ok(crate::color::mix::mix(
+            ColorInterpolationMethod::best_interpolation_between(self, other),
+            self,
+            left_weight as f32,
+            other,
+            right_weight as f32,
+            ColorMixFlags::empty(),
+        ))
+    }
+}
+
+impl ComputeSquaredDistance for AbsoluteColor {
+    #[inline]
+    fn compute_squared_distance(&self, other: &Self) -> Result<SquaredDistance, ()> {
+        let start = [
+            self.alpha,
+            self.components.0 * self.alpha,
+            self.components.1 * self.alpha,
+            self.components.2 * self.alpha,
+        ];
+        let end = [
+            other.alpha,
+            other.components.0 * other.alpha,
+            other.components.1 * other.alpha,
+            other.components.2 * other.alpha,
+        ];
+        start
+            .iter()
+            .zip(&end)
+            .map(|(this, other)| this.compute_squared_distance(other))
+            .sum()
+    }
+}
+
+/// An animated value for `<color>`.
+pub type Color = GenericColor<Percentage>;
+
+/// An animated value for `<color-mix>`.
+pub type ColorMix = GenericColorMix<Color, Percentage>;
+
+impl Animate for Color {
+    #[inline]
+    fn animate(&self, other: &Self, procedure: Procedure) -> Result<Self, ()> {
+        let (left_weight, right_weight) = procedure.weights();
+        Ok(Self::from_color_mix(ColorMix {
+            interpolation: ColorInterpolationMethod::srgb(),
+            left: self.clone(),
+            left_percentage: Percentage(left_weight as f32),
+            right: other.clone(),
+            right_percentage: Percentage(right_weight as f32),
+            // See https://github.com/w3c/csswg-drafts/issues/7324
+            flags: ColorMixFlags::empty(),
+        }))
+    }
+}
+
+impl ComputeSquaredDistance for Color {
+    #[inline]
+    fn compute_squared_distance(&self, other: &Self) -> Result<SquaredDistance, ()> {
+        let current_color = AbsoluteColor::TRANSPARENT_BLACK;
+        self.resolve_to_absolute(&current_color)
+            .compute_squared_distance(&other.resolve_to_absolute(&current_color))
+    }
+}
+
+impl ToAnimatedZero for Color {
+    #[inline]
+    fn to_animated_zero(&self) -> Result<Self, ()> {
+        Ok(Color::Absolute(AbsoluteColor::TRANSPARENT_BLACK))
+    }
+}