Use generics for the line-height property

components/style/values/computed/text.rs

@@ -0,0 +1,51 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+//! Computed types for text properties.
+
+use app_units::Au;
+use properties::animated_properties::Animatable;
+use values::CSSFloat;
+use values::generics::text::LineHeight as GenericLineHeight;
+
+/// A computed value for the `line-height` property.
+pub type LineHeight = GenericLineHeight<CSSFloat, Au>;
+
+impl Animatable for LineHeight {
+    #[inline]
+    fn add_weighted(&self, other: &Self, self_portion: f64, other_portion: f64) -> Result<Self, ()> {
+        match (*self, *other) {
+            (GenericLineHeight::Length(ref this), GenericLineHeight::Length(ref other)) => {
+                this.add_weighted(other, self_portion, other_portion).map(GenericLineHeight::Length)
+            },
+            (GenericLineHeight::Number(ref this), GenericLineHeight::Number(ref other)) => {
+                this.add_weighted(other, self_portion, other_portion).map(GenericLineHeight::Number)
+            },
+            (GenericLineHeight::Normal, GenericLineHeight::Normal) => {
+                Ok(GenericLineHeight::Normal)
+            },
+            #[cfg(feature = "gecko")]
+            (GenericLineHeight::MozBlockHeight, GenericLineHeight::MozBlockHeight) => {
+                Ok(GenericLineHeight::MozBlockHeight)
+            },
+            _ => Err(()),
+        }
+    }
+
+    #[inline]
+    fn compute_distance(&self, other: &Self) -> Result<f64, ()> {
+        match (*self, *other) {
+            (GenericLineHeight::Length(ref this), GenericLineHeight::Length(ref other)) => {
+                this.compute_distance(other)
+            },
+            (GenericLineHeight::Number(ref this), GenericLineHeight::Number(ref other)) => {
+                this.compute_distance(other)
+            },
+            (GenericLineHeight::Normal, GenericLineHeight::Normal) => Ok(0.),
+            #[cfg(feature = "gecko")]
+            (GenericLineHeight::MozBlockHeight, GenericLineHeight::MozBlockHeight) => Ok(0.),
+            _ => Err(()),
+        }
+    }
+}