Implement #[compute(clone)] for #[derive(ToComputedValue)]

components/style/values/computed/image.rs

@@ -18,8 +18,7 @@ use values::generics::image::{CompatMode, ColorStop as GenericColorStop, EndingS
 use values::generics::image::{Gradient as GenericGradient, GradientItem as GenericGradientItem};
 use values::generics::image::{Image as GenericImage, GradientKind as GenericGradientKind};
 use values::generics::image::{LineDirection as GenericLineDirection, MozImageRect as GenericMozImageRect};
-use values::specified::image::{Gradient as SpecifiedGradient, LineDirection as SpecifiedLineDirection};
-use values::specified::image::{GradientKind as SpecifiedGradientKind};
+use values::specified::image::LineDirection as SpecifiedLineDirection;
 use values::specified::position::{X, Y};
 
 /// A computed image layer.
@@ -181,25 +180,3 @@ impl ToComputedValue for SpecifiedLineDirection {
         }
     }
 }
-
-impl ToComputedValue for SpecifiedGradient {
-    type ComputedValue = Gradient;
-
-    fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
-        Self::ComputedValue {
-            kind: self.kind.to_computed_value(context),
-            items: self.items.to_computed_value(context),
-            repeating: self.repeating,
-            compat_mode: self.compat_mode
-        }
-    }
-
-    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-        Self {
-            kind: SpecifiedGradientKind::from_computed_value(&computed.kind),
-            items: ToComputedValue::from_computed_value(&computed.items),
-            repeating: computed.repeating,
-            compat_mode: computed.compat_mode
-        }
-    }
-}

components/style/values/generics/grid.rs

@@ -349,8 +349,8 @@ no_viewport_percentage!(RepeatCount);
 ///
 /// It can also hold `repeat()` function parameters, which expands into the respective
 /// values in its computed form.
-#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[derive(Clone, Debug, PartialEq, ToComputedValue)]
 pub struct TrackRepeat<L> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
     pub count: RepeatCount,
@@ -359,6 +359,7 @@ pub struct TrackRepeat<L> {
     /// If there's no `<line-names>`, then it's represented by an empty vector.
     /// For N `<track-size>` values, there will be N+1 `<line-names>`, and so this vector's
     /// length is always one value more than that of the `<track-size>`.
+    #[compute(clone)]
     pub line_names: Box<[Box<[CustomIdent]>]>,
     /// `<track-size>` values.
     pub track_sizes: Vec<TrackSize<L>>,
@@ -446,31 +447,6 @@ impl<L: Clone> TrackRepeat<L> {
         }
     }
 }
-impl<L: ToComputedValue> ToComputedValue for TrackRepeat<L> {
-    type ComputedValue = TrackRepeat<L::ComputedValue>;
-
-    #[inline]
-    fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
-        TrackRepeat {
-            count: self.count,
-            track_sizes: self.track_sizes.iter()
-                                         .map(|val| val.to_computed_value(context))
-                                         .collect(),
-            line_names: self.line_names.clone(),
-        }
-    }
-
-    #[inline]
-    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-        TrackRepeat {
-            count: computed.count,
-            track_sizes: computed.track_sizes.iter()
-                                             .map(ToComputedValue::from_computed_value)
-                                             .collect(),
-            line_names: computed.line_names.clone(),
-        }
-    }
-}
 
 /// The type of a `<track-list>` as determined during parsing.
 ///
@@ -500,8 +476,8 @@ impl ComputedValueAsSpecified for TrackListType {}
 /// A grid `<track-list>` type.
 ///
 /// https://drafts.csswg.org/css-grid/#typedef-track-list
-#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[derive(Clone, Debug, PartialEq, ToComputedValue)]
 pub struct TrackList<T> {
     /// The type of this `<track-list>` (auto, explicit or general).
     ///
@@ -515,6 +491,7 @@ pub struct TrackList<T> {
     /// If there's no `<line-names>`, then it's represented by an empty vector.
     /// For N values, there will be N+1 `<line-names>`, and so this vector's
     /// length is always one value more than that of the `<track-size>`.
+    #[compute(clone)]
     pub line_names: Box<[Box<[CustomIdent]>]>,
     /// `<auto-repeat>` value. There can only be one `<auto-repeat>` in a TrackList.
     pub auto_repeat: Option<TrackRepeat<T>>,

components/style/values/generics/image.rs

@@ -35,16 +35,18 @@ pub enum Image<Gradient, MozImageRect, ImageUrl> {
 
 /// A CSS gradient.
 /// https://drafts.csswg.org/css-images/#gradients
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
 pub struct Gradient<LineDirection, Length, LengthOrPercentage, Position, Color, Angle> {
     /// Gradients can be linear or radial.
     pub kind: GradientKind<LineDirection, Length, LengthOrPercentage, Position, Angle>,
     /// The color stops and interpolation hints.
     pub items: Vec<GradientItem<Color, LengthOrPercentage>>,
     /// True if this is a repeating gradient.
+    #[compute(clone)]
     pub repeating: bool,
     /// Compatibility mode.
+    #[compute(clone)]
     pub compat_mode: CompatMode,
 }
 

components/style/values/specified/grid.rs

@@ -11,7 +11,6 @@ use std::ascii::AsciiExt;
 use std::mem;
 use style_traits::{HasViewportPercentage, ParseError, StyleParseError};
 use values::{CSSFloat, CustomIdent};
-use values::computed::{self, Context, ToComputedValue};
 use values::generics::grid::{GridTemplateComponent, RepeatCount, TrackBreadth, TrackKeyword, TrackRepeat};
 use values::generics::grid::{LineNameList, TrackSize, TrackList, TrackListType};
 use values::specified::LengthOrPercentage;
@@ -286,42 +285,6 @@ impl HasViewportPercentage for TrackList<LengthOrPercentage> {
     }
 }
 
-
-impl ToComputedValue for TrackList<LengthOrPercentage> {
-    type ComputedValue = TrackList<computed::LengthOrPercentage>;
-
-    #[inline]
-    fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
-        let mut values = Vec::with_capacity(self.values.len() + 1);
-        for value in self.values.iter().map(|val| val.to_computed_value(context)) {
-            values.push(value);
-        }
-
-        TrackList {
-            list_type: self.list_type.to_computed_value(context),
-            values: values,
-            line_names: self.line_names.clone(),
-            auto_repeat: self.auto_repeat.clone().map(|repeat| repeat.to_computed_value(context)),
-        }
-    }
-
-    #[inline]
-    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-        let mut values = Vec::with_capacity(computed.values.len() + 1);
-        for value in computed.values.iter().map(ToComputedValue::from_computed_value) {
-            values.push(value);
-        }
-
-        TrackList {
-            list_type: computed.list_type,
-            values: values,
-            line_names: computed.line_names.clone(),
-            auto_repeat: computed.auto_repeat.clone().map(|ref repeat| TrackRepeat::from_computed_value(repeat)),
-        }
-    }
-}
-
-
 impl Parse for GridTemplateComponent<LengthOrPercentage> {
     // FIXME: Derive Parse (probably with None_)
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {

components/style_derive/lib.rs

@@ -49,7 +49,7 @@ pub fn derive_to_animated_zero(stream: TokenStream) -> TokenStream {
     to_animated_zero::derive(input).to_string().parse().unwrap()
 }
 
-#[proc_macro_derive(ToComputedValue)]
+#[proc_macro_derive(ToComputedValue, attributes(compute))]
 pub fn derive_to_computed_value(stream: TokenStream) -> TokenStream {
     let input = syn::parse_derive_input(&stream.to_string()).unwrap();
     to_computed_value::derive(input).to_string().parse().unwrap()

components/style_derive/to_computed_value.rs

@@ -14,15 +14,32 @@ pub fn derive(input: DeriveInput) -> Tokens {
         cg::fmap_trait_parts(&input, trait_path, "ComputedValue");
 
     let to_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
+        let attrs = cg::parse_field_attrs::<ComputedValueAttrs>(&binding.field);
+        if attrs.clone {
+            if cg::is_parameterized(&binding.field.ty, where_clause.params, None) {
+                where_clause.inner.predicates.push(cg::where_predicate(
+                    binding.field.ty.clone(),
+                    &["std", "clone", "Clone"],
+                    None,
+                ));
+            }
+            quote! { ::std::clone::Clone::clone(#binding) }
+        } else {
             where_clause.add_trait_bound(&binding.field.ty);
             quote! {
                 ::values::computed::ToComputedValue::to_computed_value(#binding, context)
             }
+        }
     });
     let from_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
+        let attrs = cg::parse_field_attrs::<ComputedValueAttrs>(&binding.field);
+        if attrs.clone {
+            quote! { ::std::clone::Clone::clone(#binding) }
+        } else {
             quote! {
                 ::values::computed::ToComputedValue::from_computed_value(#binding)
             }
+        }
     });
 
     quote! {
@@ -46,3 +63,9 @@ pub fn derive(input: DeriveInput) -> Tokens {
         }
     }
 }
+
+#[darling(attributes(compute), default)]
+#[derive(Default, FromField)]
+struct ComputedValueAttrs {
+    clone: bool,
+}