Use generics for the border-image-width property

components/style/values/specified/border.rs

@@ -0,0 +1,41 @@
+/* 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/. */
+
+//! Specified types for CSS values related to borders.
+
+use cssparser::Parser;
+use parser::{Parse, ParserContext};
+use values::generics::border::BorderImageWidthSide as GenericBorderImageWidthSide;
+use values::generics::rect::Rect;
+use values::specified::Number;
+use values::specified::length::LengthOrPercentage;
+
+/// A specified value for the `border-image-width` property.
+pub type BorderImageWidth = Rect<BorderImageWidthSide>;
+
+/// A specified value for a single side of a `border-image-width` property.
+pub type BorderImageWidthSide = GenericBorderImageWidthSide<LengthOrPercentage, Number>;
+
+impl BorderImageWidthSide {
+    /// Returns `1`.
+    #[inline]
+    pub fn one() -> Self {
+        GenericBorderImageWidthSide::Number(Number::new(1.))
+    }
+}
+
+impl Parse for BorderImageWidthSide {
+    fn parse(context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
+        if input.try(|i| i.expect_ident_matching("auto")).is_ok() {
+            return Ok(GenericBorderImageWidthSide::Auto);
+        }
+
+        if let Ok(len) = input.try(|i| LengthOrPercentage::parse_non_negative(context, i)) {
+            return Ok(GenericBorderImageWidthSide::Length(len));
+        }
+
+        let num = Number::parse_non_negative(context, input)?;
+        Ok(GenericBorderImageWidthSide::Number(num))
+    }
+}