Auto merge of #17446 - servo:derive-all-the-things, r=emilio

Simplify machinery to serialise optional parts of CSS values

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components/style/properties/longhand/border.mako.rs

@@ -214,7 +214,6 @@ ${helpers.predefined_type("border-image-outset", "LengthOrNumberRect",
 
 <%helpers:longhand name="border-image-repeat" animation_value_type="discrete"
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-repeat">
-    use std::fmt;
     use style_traits::ToCss;
 
     no_viewport_percentage!(SpecifiedValue);
@@ -227,8 +226,8 @@ ${helpers.predefined_type("border-image-outset", "LengthOrNumberRect",
         pub struct T(pub RepeatKeyword, pub RepeatKeyword);
     }
 
-    #[derive(Debug, Clone, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+    #[derive(Debug, Clone, PartialEq, ToCss)]
     pub struct SpecifiedValue(pub RepeatKeyword,
                               pub Option<RepeatKeyword>);
 
@@ -238,17 +237,6 @@ ${helpers.predefined_type("border-image-outset", "LengthOrNumberRect",
                              "round" => Round,
                              "space" => Space);
 
-    impl ToCss for SpecifiedValue {
-        fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-            self.0.to_css(dest)?;
-            if let Some(second) = self.1 {
-                dest.write_str(" ")?;
-                second.to_css(dest)?;
-            }
-            Ok(())
-        }
-    }
-
     #[inline]
     pub fn get_initial_value() -> computed_value::T {
         computed_value::T(RepeatKeyword::Stretch, RepeatKeyword::Stretch)

components/style/properties/longhand/inherited_table.mako.rs

@@ -23,8 +23,6 @@ ${helpers.single_keyword("caption-side", "top bottom",
 <%helpers:longhand name="border-spacing" animation_value_type="ComputedValue" boxed="True"
                    spec="https://drafts.csswg.org/css-tables/#propdef-border-spacing">
     use app_units::Au;
-    use std::fmt;
-    use style_traits::ToCss;
     use values::specified::{AllowQuirks, Length};
 
     pub mod computed_value {
@@ -64,8 +62,8 @@ ${helpers.single_keyword("caption-side", "top bottom",
         }
     }
 
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+    #[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
     pub struct SpecifiedValue {
         pub horizontal: Length,
         pub vertical: Option<Length>,
@@ -79,19 +77,6 @@ ${helpers.single_keyword("caption-side", "top bottom",
         }
     }
 
-    impl ToCss for SpecifiedValue {
-        fn to_css<W>(&self, dest: &mut W) -> fmt::Result
-            where W: fmt::Write,
-        {
-            self.horizontal.to_css(dest)?;
-            if let Some(vertical) = self.vertical.as_ref() {
-                dest.write_str(" ")?;
-                vertical.to_css(dest)?;
-            }
-            Ok(())
-        }
-    }
-
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 

components/style/values/generics/basic_shape.rs

@@ -43,7 +43,7 @@ add_impls_for_keyword_enum!(ShapeBox);
 /// A shape source, for some reference box.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum ShapeSource<BasicShape, ReferenceBox> {
     Url(SpecifiedUrl),
     Shape(BasicShape, Option<ReferenceBox>),
@@ -126,22 +126,6 @@ impl<B, T> HasViewportPercentage for ShapeSource<B, T> {
     fn has_viewport_percentage(&self) -> bool { false }
 }
 
-impl<B: ToCss, T: ToCss> ToCss for ShapeSource<B, T> {
-    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-        match *self {
-            ShapeSource::Url(ref url) => url.to_css(dest),
-            ShapeSource::Shape(ref shape, Some(ref ref_box)) => {
-                shape.to_css(dest)?;
-                dest.write_str(" ")?;
-                ref_box.to_css(dest)
-            },
-            ShapeSource::Shape(ref shape, None) => shape.to_css(dest),
-            ShapeSource::Box(ref val) => val.to_css(dest),
-            ShapeSource::None => dest.write_str("none"),
-        }
-    }
-}
-
 impl<L> ToCss for InsetRect<L>
     where L: ToCss + PartialEq
 {

components/style/values/generics/image.rs

@@ -123,7 +123,7 @@ pub enum GradientItem<Color, LengthOrPercentage> {
 
 /// A color stop.
 /// https://drafts.csswg.org/css-images/#typedef-color-stop-list
-#[derive(Clone, Copy, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct ColorStop<Color, LengthOrPercentage> {
     /// The color of this stop.
@@ -321,19 +321,6 @@ impl<C, L> fmt::Debug for ColorStop<C, L>
     }
 }
 
-impl<C, L> ToCss for ColorStop<C, L>
-    where C: ToCss, L: ToCss,
-{
-    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-        self.color.to_css(dest)?;
-        if let Some(ref position) = self.position {
-            dest.write_str(" ")?;
-            position.to_css(dest)?;
-        }
-        Ok(())
-    }
-}
-
 impl<C> ToCss for ImageRect<C>
     where C: ToCss,
 {

components/style/values/specified/effects.rs

@@ -6,13 +6,9 @@
 
 use cssparser::{BasicParseError, Parser, Token};
 use parser::{Parse, ParserContext};
-#[cfg(feature = "gecko")]
-use std::fmt;
 use style_traits::ParseError;
 #[cfg(not(feature = "gecko"))]
 use style_traits::StyleParseError;
-#[cfg(feature = "gecko")]
-use style_traits::ToCss;
 use values::computed::{Context, Number as ComputedNumber, ToComputedValue};
 use values::computed::effects::DropShadow as ComputedDropShadow;
 use values::generics::effects::Filter as GenericFilter;
@@ -55,7 +51,7 @@ pub enum DropShadow {}
 /// Contrary to the canonical order from the spec, the color is serialised
 /// first, like in Gecko's computed values and in all Webkit's values.
 #[cfg(feature = "gecko")]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
 pub struct DropShadow {
     /// Color.
     pub color: Option<Color>,
@@ -220,25 +216,3 @@ impl ToComputedValue for DropShadow {
         }
     }
 }
-
-#[cfg(feature = "gecko")]
-impl ToCss for DropShadow {
-    #[inline]
-    fn to_css<W>(&self, dest: &mut W) -> fmt::Result
-    where
-        W: fmt::Write,
-    {
-        if let Some(ref color) = self.color {
-            color.to_css(dest)?;
-            dest.write_str(" ")?;
-        }
-        self.horizontal.to_css(dest)?;
-        dest.write_str(" ")?;
-        self.vertical.to_css(dest)?;
-        if let Some(ref blur) = self.blur {
-            dest.write_str(" ")?;
-            blur.to_css(dest)?;
-        }
-        Ok(())
-    }
-}

components/style/values/specified/position.rs

@@ -27,7 +27,7 @@ pub type VerticalPosition = PositionComponent<Y>;
 
 /// The specified value of a component of a CSS `<position>`.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum PositionComponent<S> {
     /// `center`
     Center,
@@ -197,27 +197,6 @@ impl<S> PositionComponent<S> {
     }
 }
 
-impl<S: ToCss> ToCss for PositionComponent<S> {
-    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-        match *self {
-            PositionComponent::Center => {
-                dest.write_str("center")
-            },
-            PositionComponent::Length(ref lop) => {
-                lop.to_css(dest)
-            },
-            PositionComponent::Side(ref keyword, ref lop) => {
-                keyword.to_css(dest)?;
-                if let Some(ref lop) = *lop {
-                    dest.write_str(" ")?;
-                    lop.to_css(dest)?;
-                }
-                Ok(())
-            },
-        }
-    }
-}
-
 impl<S: Side> ToComputedValue for PositionComponent<S> {
     type ComputedValue = ComputedLengthOrPercentage;