style: Remove serialize_basicshape_position.

Per w3c/csswg-drafts#2274. There's a whole lot of new failures, but those need to be updated along with the spec changes in that issue.

We did resolve that position serialized the same everywhere though.

Differential Revision: https://phabricator.services.mozilla.com/D1933

components/style/values/specified/basic_shape.rs

@@ -8,20 +8,17 @@
 //! [basic-shape]: https://drafts.csswg.org/css-shapes/#typedef-basic-shape
 
 use crate::parser::{Parse, ParserContext};
-use crate::values::computed::Percentage;
 use crate::values::generics::basic_shape as generic;
 use crate::values::generics::basic_shape::{GeometryBox, Path, PolygonCoord};
 use crate::values::generics::basic_shape::{ShapeBox, ShapeSource};
 use crate::values::generics::rect::Rect;
 use crate::values::specified::border::BorderRadius;
 use crate::values::specified::image::Image;
-use crate::values::specified::position::{HorizontalPosition, Position, PositionComponent};
-use crate::values::specified::position::{Side, VerticalPosition};
+use crate::values::specified::position::{HorizontalPosition, VerticalPosition, Position};
 use crate::values::specified::url::SpecifiedUrl;
 use crate::values::specified::LengthOrPercentage;
 use crate::values::specified::SVGPathData;
 use cssparser::Parser;
-use std::borrow::Cow;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 
@@ -249,7 +246,7 @@ impl ToCss for Circle {
         }
 
         dest.write_str("at ")?;
-        serialize_basicshape_position(&self.position, dest)?;
+        self.position.to_css(dest)?;
         dest.write_str(")")
     }
 }
@@ -305,7 +302,7 @@ impl ToCss for Ellipse {
         }
 
         dest.write_str("at ")?;
-        serialize_basicshape_position(&self.position, dest)?;
+        self.position.to_css(dest)?;
         dest.write_str(")")
     }
 }
@@ -326,82 +323,6 @@ impl Parse for ShapeRadius {
     }
 }
 
-/// <https://drafts.csswg.org/css-shapes/#basic-shape-serialization>
-///
-/// Positions get serialized differently with basic shapes. Keywords
-/// are converted to percentages where possible. Only the two or four
-/// value forms are used. In case of two keyword-percentage pairs,
-/// the keywords are folded into the percentages
-fn serialize_basicshape_position<W>(position: &Position, dest: &mut CssWriter<W>) -> fmt::Result
-where
-    W: Write,
-{
-    fn to_keyword_and_lop<S>(component: &PositionComponent<S>) -> (S, Cow<LengthOrPercentage>)
-    where
-        S: Copy + Side,
-    {
-        match *component {
-            PositionComponent::Center => (
-                S::start(),
-                Cow::Owned(LengthOrPercentage::Percentage(Percentage(0.5))),
-            ),
-            PositionComponent::Side(keyword, None) => {
-                // left | top => 0%
-                // right | bottom => 100%
-                let p = if keyword.is_start() { 0. } else { 1. };
-                (
-                    S::start(),
-                    Cow::Owned(LengthOrPercentage::Percentage(Percentage(p))),
-                )
-            },
-            PositionComponent::Side(keyword, Some(ref lop)) if !keyword.is_start() => {
-                if let LengthOrPercentage::Percentage(p) = *to_non_zero_length(lop) {
-                    (
-                        S::start(),
-                        Cow::Owned(LengthOrPercentage::Percentage(Percentage(1. - p.0))),
-                    )
-                } else {
-                    (keyword, Cow::Borrowed(lop))
-                }
-            },
-            PositionComponent::Length(ref lop) | PositionComponent::Side(_, Some(ref lop)) => {
-                (S::start(), to_non_zero_length(lop))
-            },
-        }
-    }
-
-    fn to_non_zero_length(lop: &LengthOrPercentage) -> Cow<LengthOrPercentage> {
-        match *lop {
-            LengthOrPercentage::Length(ref l) if l.is_zero() => {
-                Cow::Owned(LengthOrPercentage::Percentage(Percentage(0.)))
-            },
-            _ => Cow::Borrowed(lop),
-        }
-    }
-
-    fn write_pair<A, B, W>(a: &A, b: &B, dest: &mut CssWriter<W>) -> fmt::Result
-    where
-        A: ToCss,
-        B: ToCss,
-        W: Write,
-    {
-        a.to_css(dest)?;
-        dest.write_str(" ")?;
-        b.to_css(dest)
-    }
-
-    let (x_pos, x_lop) = to_keyword_and_lop(&position.horizontal);
-    let (y_pos, y_lop) = to_keyword_and_lop(&position.vertical);
-
-    if x_pos.is_start() && y_pos.is_start() {
-        return write_pair(&*x_lop, &*y_lop, dest);
-    }
-
-    write_pair(&x_pos, &*x_lop, dest)?;
-    dest.write_str(" ")?;
-    write_pair(&y_pos, &*y_lop, dest)
-}
-
 impl Parse for Polygon {
     fn parse<'i, 't>(
         context: &ParserContext,