style: Generalise BorderCornerRadius as Size.

components/style/values/generics/size.rs

@@ -0,0 +1,103 @@
+/* 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/. */
+
+//! Generic type for CSS properties that are composed by two dimensions.
+
+use cssparser::Parser;
+use euclid::Size2D;
+use parser::ParserContext;
+use std::fmt;
+use style_traits::{ToCss, ParseError};
+use values::animated::ToAnimatedValue;
+
+/// A generic size, for `border-*-radius` longhand properties, or
+/// `border-spacing`.
+#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
+#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
+#[derive(PartialEq, ToComputedValue)]
+pub struct Size<L>(pub Size2D<L>);
+
+impl<L> Size<L> {
+    #[inline]
+    /// Create a new `Size` for an area of given width and height.
+    pub fn new(width: L, height: L) -> Size<L> {
+        Size(Size2D::new(width, height))
+    }
+
+    /// Returns the width component.
+    pub fn width(&self) -> &L {
+        &self.0.width
+    }
+
+    /// Returns the height component.
+    pub fn height(&self) -> &L {
+        &self.0.height
+    }
+
+    /// Parse a `Size` with a given parsing function.
+    pub fn parse_with<'i, 't, F>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+        parse_one: F,
+    ) -> Result<Self, ParseError<'i>>
+    where
+        L: Clone,
+        F: Fn(&ParserContext, &mut Parser<'i, 't>) -> Result<L, ParseError<'i>>
+    {
+        let first = parse_one(context, input)?;
+        let second = input
+            .try(|i| parse_one(context, i))
+            .unwrap_or_else(|_| first.clone());
+        Ok(Self::new(first, second))
+    }
+}
+
+impl<L: Clone> From<L> for Size<L> {
+    fn from(size: L) -> Self {
+        Self::new(size.clone(), size)
+    }
+}
+
+impl<L> ToCss for Size<L>
+where L:
+    ToCss + PartialEq,
+{
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result
+    where W:
+        fmt::Write
+    {
+        self.0.width.to_css(dest)?;
+
+        if self.0.height != self.0.width {
+            dest.write_str(" ")?;
+            self.0.height.to_css(dest)?;
+        }
+
+        Ok(())
+    }
+}
+
+impl<L> ToAnimatedValue for Size<L>
+where L:
+    ToAnimatedValue,
+{
+    type AnimatedValue = Size<L::AnimatedValue>;
+
+    #[inline]
+    fn to_animated_value(self) -> Self::AnimatedValue {
+        Size(Size2D::new(
+            self.0.width.to_animated_value(),
+            self.0.height.to_animated_value(),
+        ))
+    }
+
+    #[inline]
+    fn from_animated_value(animated: Self::AnimatedValue) -> Self {
+        Size(Size2D::new(
+            L::from_animated_value(animated.0.width),
+            L::from_animated_value(animated.0.height),
+        ))
+    }
+}