Make BorderRadius generic

components/style/values/generics/basic_shape.rs

@@ -0,0 +1,80 @@
+/* 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/. */
+
+//! CSS handling for the [`basic-shape`](https://drafts.csswg.org/css-shapes/#typedef-basic-shape)
+//! types that are generic over their `ToCss` implementations.
+
+use euclid::size::Size2D;
+use properties::shorthands::serialize_four_sides;
+use std::fmt;
+use style_traits::ToCss;
+use values::computed::{Context, ToComputedValue};
+use values::generics::BorderRadiusSize;
+
+/// A generic type used for `border-radius`, `outline-radius` and `inset()` values.
+///
+/// https://drafts.csswg.org/css-backgrounds-3/#border-radius
+#[derive(Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+pub struct BorderRadius<L> {
+    /// The top left radius.
+    pub top_left: BorderRadiusSize<L>,
+    /// The top right radius.
+    pub top_right: BorderRadiusSize<L>,
+    /// The bottom right radius.
+    pub bottom_right: BorderRadiusSize<L>,
+    /// The bottom left radius.
+    pub bottom_left: BorderRadiusSize<L>,
+}
+
+/// Serialization helper for types of longhands like `border-radius` and `outline-radius`
+pub fn serialize_radius_values<L, W>(dest: &mut W, top_left: &Size2D<L>,
+                                     top_right: &Size2D<L>, bottom_right: &Size2D<L>,
+                                     bottom_left: &Size2D<L>) -> fmt::Result
+    where L: ToCss + PartialEq, W: fmt::Write
+{
+    if top_left.width == top_left.height && top_right.width == top_right.height &&
+       bottom_right.width == bottom_right.height && bottom_left.width == bottom_left.height {
+        serialize_four_sides(dest, &top_left.width, &top_right.width,
+                             &bottom_right.width, &bottom_left.width)
+    } else {
+        serialize_four_sides(dest, &top_left.width, &top_right.width,
+                             &bottom_right.width, &bottom_left.width)?;
+        dest.write_str(" / ")?;
+        serialize_four_sides(dest, &top_left.height, &top_right.height,
+                             &bottom_right.height, &bottom_left.height)
+    }
+}
+
+impl<L: ToCss + PartialEq> ToCss for BorderRadius<L> {
+    #[inline]
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
+        serialize_radius_values(dest, &self.top_left.0, &self.top_right.0,
+                                &self.bottom_right.0, &self.bottom_left.0)
+    }
+}
+
+impl<L: ToComputedValue> ToComputedValue for BorderRadius<L> {
+    type ComputedValue = BorderRadius<L::ComputedValue>;
+
+    #[inline]
+    fn to_computed_value(&self, cx: &Context) -> Self::ComputedValue {
+        BorderRadius {
+            top_left: self.top_left.to_computed_value(cx),
+            top_right: self.top_right.to_computed_value(cx),
+            bottom_right: self.bottom_right.to_computed_value(cx),
+            bottom_left: self.bottom_left.to_computed_value(cx),
+        }
+    }
+
+    #[inline]
+    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
+        BorderRadius {
+            top_left: ToComputedValue::from_computed_value(&computed.top_left),
+            top_right: ToComputedValue::from_computed_value(&computed.top_right),
+            bottom_right: ToComputedValue::from_computed_value(&computed.bottom_right),
+            bottom_left: ToComputedValue::from_computed_value(&computed.bottom_left),
+        }
+    }
+}