Replace LengthOrNone by a specific type for the perspective property

This was its only use, and it was bugged: AFAIK this didn't properly
clamp animated values below 0.

components/style/values/computed/box.rs

@@ -5,8 +5,9 @@
 //! Computed types for box properties.
 
 use values::computed::Number;
-use values::computed::length::LengthOrPercentage;
+use values::computed::length::{LengthOrPercentage, NonNegativeLength};
 use values::generics::box_::AnimationIterationCount as GenericAnimationIterationCount;
+use values::generics::box_::Perspective as GenericPerspective;
 use values::generics::box_::VerticalAlign as GenericVerticalAlign;
 
 pub use values::specified::box_::{AnimationName, Display, OverflowClipBox, Contain};
@@ -25,3 +26,6 @@ impl AnimationIterationCount {
         GenericAnimationIterationCount::Number(1.0)
     }
 }
+
+/// A computed value for the `perspective` property.
+pub type Perspective = GenericPerspective<NonNegativeLength>;

components/style/values/computed/length.rs

@@ -13,7 +13,7 @@ use std::ops::{Add, Neg};
 use style_traits::{CssWriter, ToCss};
 use style_traits::values::specified::AllowedNumericType;
 use super::{Number, ToComputedValue, Context, Percentage};
-use values::{Auto, CSSFloat, Either, None_, Normal, specified};
+use values::{Auto, CSSFloat, Either, Normal, specified};
 use values::animated::{Animate, Procedure, ToAnimatedValue, ToAnimatedZero};
 use values::computed::NonNegativeNumber;
 use values::distance::{ComputeSquaredDistance, SquaredDistance};
@@ -792,9 +792,6 @@ impl From<Au> for CSSPixelLength {
 /// An alias of computed `<length>` value.
 pub type Length = CSSPixelLength;
 
-/// Either a computed `<length>` or the `none` keyword.
-pub type LengthOrNone = Either<Length, None_>;
-
 /// Either a computed `<length>` or the `auto` keyword.
 pub type LengthOrAuto = Either<Length, Auto>;
 

components/style/values/computed/mod.rs

@@ -47,8 +47,9 @@ pub use self::font::{FontSize, FontSizeAdjust, FontSynthesis, FontWeight, FontVa
 pub use self::font::{FontFamily, FontLanguageOverride, FontVariationSettings, FontVariantEastAsian};
 pub use self::font::{FontVariantLigatures, FontVariantNumeric, FontFeatureSettings};
 pub use self::font::{MozScriptLevel, MozScriptMinSize, MozScriptSizeMultiplier, XTextZoom, XLang};
-pub use self::box_::{AnimationIterationCount, AnimationName, Display, OverscrollBehavior, Contain};
-pub use self::box_::{OverflowClipBox, ScrollSnapType, TouchAction, VerticalAlign, WillChange};
+pub use self::box_::{AnimationIterationCount, AnimationName, Contain, Display};
+pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective};
+pub use self::box_::{ScrollSnapType, TouchAction, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};
 pub use self::column::ColumnCount;
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterReset};
@@ -61,7 +62,7 @@ pub use self::gecko::ScrollSnapPoint;
 pub use self::rect::LengthOrNumberRect;
 pub use super::{Auto, Either, None_};
 pub use super::specified::{BorderStyle, TextDecorationLine};
-pub use self::length::{CalcLengthOrPercentage, Length, LengthOrNone, LengthOrNumber, LengthOrPercentage};
+pub use self::length::{CalcLengthOrPercentage, Length, LengthOrNumber, LengthOrPercentage};
 pub use self::length::{LengthOrPercentageOrAuto, LengthOrPercentageOrNone, MaxLength, MozLength};
 pub use self::length::{CSSPixelLength, ExtremumLength, NonNegativeLength, NonNegativeLengthOrPercentage};
 pub use self::list::{ListStyleImage, Quotes};

components/style/values/generics/box.rs

@@ -55,3 +55,21 @@ pub enum AnimationIterationCount<Number> {
     /// The `infinite` keyword.
     Infinite,
 }
+
+/// A generic value for the `perspective` property.
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf)]
+#[derive(PartialEq, ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+pub enum Perspective<NonNegativeLength> {
+    /// A non-negative length.
+    Length(NonNegativeLength),
+    /// The keyword `none`.
+    None,
+}
+
+impl<L> Perspective<L> {
+    /// Returns `none`.
+    #[inline]
+    pub fn none() -> Self {
+        Perspective::None
+    }
+}

components/style/values/specified/box.rs

@@ -13,9 +13,10 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 use values::CustomIdent;
 use values::KeyframesName;
 use values::generics::box_::AnimationIterationCount as GenericAnimationIterationCount;
+use values::generics::box_::Perspective as GenericPerspective;
 use values::generics::box_::VerticalAlign as GenericVerticalAlign;
 use values::specified::{AllowQuirks, Number};
-use values::specified::length::LengthOrPercentage;
+use values::specified::length::{LengthOrPercentage, NonNegativeLength};
 
 #[allow(missing_docs)]
 #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
@@ -588,3 +589,18 @@ impl Parse for Contain {
         }
     }
 }
+
+/// A specified value for the `perspective` property.
+pub type Perspective = GenericPerspective<NonNegativeLength>;
+
+impl Parse for Perspective {
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>
+    ) -> Result<Self, ParseError<'i>> {
+        if input.try(|i| i.expect_ident_matching("none")).is_ok() {
+            return Ok(GenericPerspective::None);
+        }
+        Ok(GenericPerspective::Length(NonNegativeLength::parse(context, input)?))
+    }
+}

components/style/values/specified/length.rs

@@ -17,7 +17,7 @@ use std::ops::{Add, Mul};
 use style_traits::{ParseError, StyleParseErrorKind};
 use style_traits::values::specified::AllowedNumericType;
 use super::{AllowQuirks, Number, ToComputedValue, Percentage};
-use values::{Auto, CSSFloat, Either, None_, Normal};
+use values::{Auto, CSSFloat, Either, Normal};
 use values::computed::{self, CSSPixelLength, Context, ExtremumLength};
 use values::generics::NonNegative;
 use values::specified::NonNegativeNumber;
@@ -1062,9 +1062,6 @@ impl NonNegativeLengthOrPercentage {
     }
 }
 
-/// Either a `<length>` or the `none` keyword.
-pub type LengthOrNone = Either<Length, None_>;
-
 /// Either a `<length>` or the `normal` keyword.
 pub type LengthOrNormal = Either<Length, Normal>;
 

components/style/values/specified/mod.rs

@@ -39,8 +39,9 @@ pub use self::font::{FontSize, FontSizeAdjust, FontSynthesis, FontWeight, FontVa
 pub use self::font::{FontFamily, FontLanguageOverride, FontVariationSettings, FontVariantEastAsian};
 pub use self::font::{FontVariantLigatures, FontVariantNumeric, FontFeatureSettings};
 pub use self::font::{MozScriptLevel, MozScriptMinSize, MozScriptSizeMultiplier, XTextZoom, XLang};
-pub use self::box_::{AnimationIterationCount, AnimationName, Display, OverscrollBehavior, Contain};
-pub use self::box_::{OverflowClipBox, ScrollSnapType, TouchAction, VerticalAlign, WillChange};
+pub use self::box_::{AnimationIterationCount, AnimationName, Contain, Display};
+pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective};
+pub use self::box_::{ScrollSnapType, TouchAction, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterReset};
 pub use self::effects::{BoxShadow, Filter, SimpleShadow};
@@ -51,7 +52,7 @@ pub use self::image::{ColorStop, EndingShape as GradientEndingShape, Gradient};
 pub use self::image::{GradientItem, GradientKind, Image, ImageLayer, MozImageRect};
 pub use self::inherited_box::ImageOrientation;
 pub use self::length::{AbsoluteLength, CalcLengthOrPercentage, CharacterWidth};
-pub use self::length::{FontRelativeLength, Length, LengthOrNone, LengthOrNumber};
+pub use self::length::{FontRelativeLength, Length, LengthOrNumber};
 pub use self::length::{LengthOrPercentage, LengthOrPercentageOrAuto};
 pub use self::length::{LengthOrPercentageOrNone, MaxLength, MozLength};
 pub use self::length::{NoCalcLength, ViewportPercentageLength};