style: Clamp to non-negative value after doing interpolation for circle(), ellipse(), and inset().

Replace LengthOrPercentage with NonNegativeLengthOrPercentage on
ShapeRadius, Circle, Ellipse. And derive ToAnimatedValue for ShapeSource and
its related types, so we clamp its interpolated results into non-negative
values. (i.e. The radius of circle()/ellipse() and the border-radius of
inset().)

Note: We may get negative values when using a negative easing function, so the
clamp is necessary to avoid the incorrect result or any undefined behavior.

Differential Revision: https://phabricator.services.mozilla.com/D14654

components/style/values/generics/basic_shape.rs

@@ -20,7 +20,16 @@ pub type ClippingShape<BasicShape, Url> = ShapeSource<BasicShape, GeometryBox, U
 /// <https://drafts.fxtf.org/css-masking-1/#typedef-geometry-box>
 #[allow(missing_docs)]
 #[derive(
-    Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
 )]
 pub enum GeometryBox {
     FillBox,
@@ -45,6 +54,7 @@ pub type FloatAreaShape<BasicShape, Image> = ShapeSource<BasicShape, ShapeBox, I
     Parse,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
     ToCss,
 )]
@@ -59,7 +69,15 @@ pub enum ShapeBox {
 #[allow(missing_docs)]
 #[animation(no_bound(ImageOrUrl))]
 #[derive(
-    Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
 )]
 pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     #[animation(error)]
@@ -82,13 +100,14 @@ pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     MallocSizeOf,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
     ToCss,
 )]
 pub enum BasicShape<H, V, LengthOrPercentage, NonNegativeLengthOrPercentage> {
     Inset(#[css(field_bound)] InsetRect<LengthOrPercentage, NonNegativeLengthOrPercentage>),
-    Circle(#[css(field_bound)] Circle<H, V, LengthOrPercentage>),
-    Ellipse(#[css(field_bound)] Ellipse<H, V, LengthOrPercentage>),
+    Circle(#[css(field_bound)] Circle<H, V, NonNegativeLengthOrPercentage>),
+    Ellipse(#[css(field_bound)] Ellipse<H, V, NonNegativeLengthOrPercentage>),
     Polygon(Polygon<LengthOrPercentage>),
 }
 
@@ -103,6 +122,7 @@ pub enum BasicShape<H, V, LengthOrPercentage, NonNegativeLengthOrPercentage> {
     MallocSizeOf,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
 )]
 pub struct InsetRect<LengthOrPercentage, NonNegativeLengthOrPercentage> {
@@ -122,11 +142,12 @@ pub struct InsetRect<LengthOrPercentage, NonNegativeLengthOrPercentage> {
     MallocSizeOf,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
 )]
-pub struct Circle<H, V, LengthOrPercentage> {
+pub struct Circle<H, V, NonNegativeLengthOrPercentage> {
     pub position: Position<H, V>,
-    pub radius: ShapeRadius<LengthOrPercentage>,
+    pub radius: ShapeRadius<NonNegativeLengthOrPercentage>,
 }
 
 /// <https://drafts.csswg.org/css-shapes/#funcdef-ellipse>
@@ -141,12 +162,13 @@ pub struct Circle<H, V, LengthOrPercentage> {
     MallocSizeOf,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
 )]
-pub struct Ellipse<H, V, LengthOrPercentage> {
+pub struct Ellipse<H, V, NonNegativeLengthOrPercentage> {
     pub position: Position<H, V>,
-    pub semiaxis_x: ShapeRadius<LengthOrPercentage>,
-    pub semiaxis_y: ShapeRadius<LengthOrPercentage>,
+    pub semiaxis_x: ShapeRadius<NonNegativeLengthOrPercentage>,
+    pub semiaxis_y: ShapeRadius<NonNegativeLengthOrPercentage>,
 }
 
 /// <https://drafts.csswg.org/css-shapes/#typedef-shape-radius>
@@ -160,11 +182,12 @@ pub struct Ellipse<H, V, LengthOrPercentage> {
     MallocSizeOf,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
     ToCss,
 )]
-pub enum ShapeRadius<LengthOrPercentage> {
-    Length(LengthOrPercentage),
+pub enum ShapeRadius<NonNegativeLengthOrPercentage> {
+    Length(NonNegativeLengthOrPercentage),
     #[animation(error)]
     ClosestSide,
     #[animation(error)]
@@ -175,7 +198,16 @@ pub enum ShapeRadius<LengthOrPercentage> {
 ///
 /// <https://drafts.csswg.org/css-shapes/#funcdef-polygon>
 #[css(comma, function)]
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
+)]
 pub struct Polygon<LengthOrPercentage> {
     /// The filling rule for a polygon.
     #[css(skip_if = "fill_is_default")]
@@ -186,7 +218,16 @@ pub struct Polygon<LengthOrPercentage> {
 }
 
 /// Coordinates for Polygon.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
+)]
 pub struct PolygonCoord<LengthOrPercentage>(pub LengthOrPercentage, pub LengthOrPercentage);
 
 // https://drafts.csswg.org/css-shapes/#typedef-fill-rule
@@ -204,6 +245,7 @@ pub struct PolygonCoord<LengthOrPercentage>(pub LengthOrPercentage, pub LengthOr
     Parse,
     PartialEq,
     SpecifiedValueInfo,
+    ToAnimatedValue,
     ToComputedValue,
     ToCss,
 )]
@@ -218,7 +260,15 @@ pub enum FillRule {
 /// https://drafts.csswg.org/css-shapes-2/#funcdef-path
 #[css(comma)]
 #[derive(
-    Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
 )]
 pub struct Path {
     /// The filling rule for the svg path.