1 files changed, 143 insertions, 0 deletions
diff --git a/servo/components/style/values/specified/background.rs b/servo/components/style/values/specified/background.rs
new file mode 100644
index 0000000000..39a5a85193
--- /dev/null
+++ b/servo/components/style/values/specified/background.rs
@@ -0,0 +1,143 @@
+/* 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/. */
+
+//! Specified types for CSS values related to backgrounds.
+
+use crate::parser::{Parse, ParserContext};
+use crate::values::generics::background::BackgroundSize as GenericBackgroundSize;
+use crate::values::specified::length::{
+    NonNegativeLengthPercentage, NonNegativeLengthPercentageOrAuto,
+};
+use cssparser::Parser;
+use selectors::parser::SelectorParseErrorKind;
+use std::fmt::{self, Write};
+use style_traits::{CssWriter, ParseError, ToCss};
+
+/// A specified value for the `background-size` property.
+pub type BackgroundSize = GenericBackgroundSize<NonNegativeLengthPercentage>;
+
+impl Parse for BackgroundSize {
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        if let Ok(width) = input.try_parse(|i| NonNegativeLengthPercentageOrAuto::parse(context, i))
+        {
+            let height = input
+                .try_parse(|i| NonNegativeLengthPercentageOrAuto::parse(context, i))
+                .unwrap_or(NonNegativeLengthPercentageOrAuto::auto());
+            return Ok(GenericBackgroundSize::ExplicitSize { width, height });
+        }
+        Ok(try_match_ident_ignore_ascii_case! { input,
+            "cover" => GenericBackgroundSize::Cover,
+            "contain" => GenericBackgroundSize::Contain,
+        })
+    }
+}
+
+/// One of the keywords for `background-repeat`.
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[allow(missing_docs)]
+#[value_info(other_values = "repeat-x,repeat-y")]
+pub enum BackgroundRepeatKeyword {
+    Repeat,
+    Space,
+    Round,
+    NoRepeat,
+}
+
+/// The value of the `background-repeat` property, with `repeat-x` / `repeat-y`
+/// represented as the combination of `no-repeat` and `repeat` in the opposite
+/// axes.
+///
+/// https://drafts.csswg.org/css-backgrounds/#the-background-repeat
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+pub struct BackgroundRepeat(pub BackgroundRepeatKeyword, pub BackgroundRepeatKeyword);
+
+impl BackgroundRepeat {
+    /// Returns the `repeat repeat` value.
+    pub fn repeat() -> Self {
+        BackgroundRepeat(
+            BackgroundRepeatKeyword::Repeat,
+            BackgroundRepeatKeyword::Repeat,
+        )
+    }
+}
+
+impl ToCss for BackgroundRepeat {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: Write,
+    {
+        match (self.0, self.1) {
+            (BackgroundRepeatKeyword::Repeat, BackgroundRepeatKeyword::NoRepeat) => {
+                dest.write_str("repeat-x")
+            },
+            (BackgroundRepeatKeyword::NoRepeat, BackgroundRepeatKeyword::Repeat) => {
+                dest.write_str("repeat-y")
+            },
+            (horizontal, vertical) => {
+                horizontal.to_css(dest)?;
+                if horizontal != vertical {
+                    dest.write_char(' ')?;
+                    vertical.to_css(dest)?;
+                }
+                Ok(())
+            },
+        }
+    }
+}
+
+impl Parse for BackgroundRepeat {
+    fn parse<'i, 't>(
+        _context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        let ident = input.expect_ident_cloned()?;
+
+        match_ignore_ascii_case! { &ident,
+            "repeat-x" => {
+                return Ok(BackgroundRepeat(BackgroundRepeatKeyword::Repeat, BackgroundRepeatKeyword::NoRepeat));
+            },
+            "repeat-y" => {
+                return Ok(BackgroundRepeat(BackgroundRepeatKeyword::NoRepeat, BackgroundRepeatKeyword::Repeat));
+            },
+            _ => {},
+        }
+
+        let horizontal = match BackgroundRepeatKeyword::from_ident(&ident) {
+            Ok(h) => h,
+            Err(()) => {
+                return Err(
+                    input.new_custom_error(SelectorParseErrorKind::UnexpectedIdent(ident.clone()))
+                );
+            },
+        };
+
+        let vertical = input.try_parse(BackgroundRepeatKeyword::parse).ok();
+        Ok(BackgroundRepeat(horizontal, vertical.unwrap_or(horizontal)))
+    }
+}