Auto merge of #19051 - CYBAI:moz-script-min-size-no-mako, r=emilio,canaltinova

style: Move font -moz-script-min-size outside of mako

This is a sub-PR for #19015
r? emilio

---
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #19034 (github issue number if applicable).
- [X] These changes do not require tests because _____

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components/style/values/computed/font.rs

@@ -8,9 +8,11 @@ use app_units::Au;
 use std::fmt;
 use style_traits::ToCss;
 use values::animated::ToAnimatedValue;
-use values::computed::NonNegativeLength;
+use values::computed::{Context, NonNegativeLength, ToComputedValue};
 use values::specified::font as specified;
+use values::specified::length::{FontBaseSize, NoCalcLength};
 
+pub use values::computed::Length as MozScriptMinSize;
 pub use values::specified::font::XTextZoom;
 
 #[derive(Animate, ComputeSquaredDistance, MallocSizeOf, ToAnimatedZero)]
@@ -94,3 +96,28 @@ impl ToAnimatedValue for FontSize {
         }
     }
 }
+
+impl ToComputedValue for specified::MozScriptMinSize {
+    type ComputedValue = MozScriptMinSize;
+
+    fn to_computed_value(&self, cx: &Context) -> MozScriptMinSize {
+        // this value is used in the computation of font-size, so
+        // we use the parent size
+        let base_size = FontBaseSize::InheritedStyle;
+        match self.0 {
+            NoCalcLength::FontRelative(value) => {
+                value.to_computed_value(cx, base_size)
+            }
+            NoCalcLength::ServoCharacterWidth(value) => {
+                value.to_computed_value(base_size.resolve(cx))
+            }
+            ref l => {
+                l.to_computed_value(cx)
+            }
+        }
+    }
+
+    fn from_computed_value(other: &MozScriptMinSize) -> Self {
+        specified::MozScriptMinSize(ToComputedValue::from_computed_value(other))
+    }
+}

components/style/values/computed/mod.rs

@@ -36,7 +36,7 @@ pub use self::angle::Angle;
 pub use self::background::{BackgroundSize, BackgroundRepeat};
 pub use self::border::{BorderImageSlice, BorderImageWidth, BorderImageSideWidth};
 pub use self::border::{BorderRadius, BorderCornerRadius, BorderSpacing};
-pub use self::font::XTextZoom;
+pub use self::font::{XTextZoom, MozScriptMinSize};
 pub use self::box_::{AnimationIterationCount, AnimationName, ScrollSnapType, VerticalAlign};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};
 pub use self::effects::{BoxShadow, Filter, SimpleShadow};

components/style/values/specified/font.rs

@@ -12,9 +12,11 @@ use parser::{Parse, ParserContext};
 use properties::longhands::system_font::SystemFont;
 use std::fmt;
 use style_traits::{ToCss, StyleParseErrorKind, ParseError};
-use values::computed::{font as computed, Context, NonNegativeLength, ToComputedValue};
+use values::computed::{font as computed, Context, Length, NonNegativeLength, ToComputedValue};
 use values::specified::{LengthOrPercentage, NoCalcLength};
-use values::specified::length::FontBaseSize;
+use values::specified::length::{AU_PER_PT, AU_PER_PX, FontBaseSize};
+
+const DEFAULT_SCRIPT_MIN_SIZE_PT: u32 = 8;
 
 #[derive(Clone, Debug, MallocSizeOf, PartialEq)]
 /// A specified font-size value
@@ -391,3 +393,24 @@ impl ToCss for XTextZoom {
         Ok(())
     }
 }
+
+#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
+#[derive(Clone, Debug, PartialEq, ToCss)]
+/// Specifies the minimum font size allowed due to changes in scriptlevel.
+/// Ref: https://wiki.mozilla.org/MathML:mstyle
+pub struct MozScriptMinSize(pub NoCalcLength);
+
+impl MozScriptMinSize {
+    #[inline]
+    /// Calculate initial value of -moz-script-min-size.
+    pub fn get_initial_value() -> Length {
+        Length::new(DEFAULT_SCRIPT_MIN_SIZE_PT as f32 * (AU_PER_PT / AU_PER_PX))
+    }
+}
+
+impl Parse for MozScriptMinSize {
+    fn parse<'i, 't>(_: &ParserContext, input: &mut Parser<'i, 't>) -> Result<MozScriptMinSize, ParseError<'i>> {
+        debug_assert!(false, "Should be set directly by presentation attributes only.");
+        Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError))
+    }
+}

components/style/values/specified/mod.rs

@@ -30,7 +30,7 @@ pub use self::align::{AlignItems, AlignJustifyContent, AlignJustifySelf, Justify
 pub use self::background::{BackgroundRepeat, BackgroundSize};
 pub use self::border::{BorderCornerRadius, BorderImageSlice, BorderImageWidth};
 pub use self::border::{BorderImageSideWidth, BorderRadius, BorderSideWidth, BorderSpacing};
-pub use self::font::XTextZoom;
+pub use self::font::{XTextZoom, MozScriptMinSize};
 pub use self::box_::{AnimationIterationCount, AnimationName, ScrollSnapType, VerticalAlign};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};
 pub use self::effects::{BoxShadow, Filter, SimpleShadow};