Auto merge of #20252 - NeverHappened:extract_text_emphasis_style, r=upsuper

Extract text emphasis style

<!-- Please describe your changes on the following line: -->
Extracted the text-emphasis-style property out of the inherited_text.mako.rs.
This is a part of #19015

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] `./mach cargo-geckolib check` does not report any errors
- [X] These changes fix #19940 (github issue number if applicable).

<!-- Either: -->
- [X] These changes do not require tests because it's a refactoring

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/20252)
<!-- Reviewable:end -->

components/style/values/computed/mod.rs

@@ -75,7 +75,7 @@ pub use self::svg::{SVGPaintOrder, SVGStrokeDashArray, SVGWidth};
 pub use self::svg::MozContextProperties;
 pub use self::table::XSpan;
 pub use self::text::{InitialLetter, LetterSpacing, LineHeight, MozTabSize};
-pub use self::text::{TextAlign, TextOverflow, WordSpacing};
+pub use self::text::{TextAlign, TextEmphasisStyle, TextOverflow, WordSpacing};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, TimingFunction, Transform, TransformOperation};
 pub use self::transform::{TransformOrigin, TransformStyle, Translate};

components/style/values/computed/text.rs

@@ -15,7 +15,7 @@ use values::generics::text::InitialLetter as GenericInitialLetter;
 use values::generics::text::LineHeight as GenericLineHeight;
 use values::generics::text::MozTabSize as GenericMozTabSize;
 use values::generics::text::Spacing;
-use values::specified::text::{TextOverflowSide, TextDecorationLine};
+use values::specified::text::{TextDecorationLine, TextEmphasisFillMode, TextEmphasisShapeKeyword, TextOverflowSide};
 
 pub use values::specified::TextAlignKeyword as TextAlign;
 
@@ -151,3 +151,23 @@ impl TextDecorationsInEffect {
 
 /// A specified value for the `-moz-tab-size` property.
 pub type MozTabSize = GenericMozTabSize<NonNegativeNumber, NonNegativeLength>;
+
+/// computed value for the text-emphasis-style property
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+pub enum TextEmphasisStyle {
+    /// Keyword value for the text-emphasis-style property (`filled` `open`)
+    Keyword(TextEmphasisKeywordValue),
+    /// `none`
+    None,
+    /// String (will be used only first grapheme cluster) for the text-emphasis-style property
+    String(String),
+}
+
+/// Keyword value for the text-emphasis-style property
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+pub struct TextEmphasisKeywordValue {
+    /// fill for the text-emphasis-style property
+    pub fill: TextEmphasisFillMode,
+    /// shape for the text-emphasis-style property
+    pub shape: TextEmphasisShapeKeyword,
+}

components/style/values/specified/mod.rs

@@ -71,7 +71,7 @@ pub use self::svg::{SVGLength, SVGOpacity, SVGPaint, SVGPaintKind};
 pub use self::svg::{SVGPaintOrder, SVGStrokeDashArray, SVGWidth};
 pub use self::svg::MozContextProperties;
 pub use self::table::XSpan;
-pub use self::text::{InitialLetter, LetterSpacing, LineHeight, MozTabSize, TextAlign};
+pub use self::text::{InitialLetter, LetterSpacing, LineHeight, MozTabSize, TextAlign, TextEmphasisStyle};
 pub use self::text::{TextAlignKeyword, TextDecorationLine, TextOverflow, WordSpacing};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, TimingFunction, Transform};

components/style/values/specified/text.rs

@@ -6,11 +6,15 @@
 
 use cssparser::{Parser, Token};
 use parser::{Parse, ParserContext};
+use properties::longhands::writing_mode::computed_value::T as SpecifiedWritingMode;
 use selectors::parser::SelectorParseErrorKind;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
+use unicode_segmentation::UnicodeSegmentation;
 use values::computed::{Context, ToComputedValue};
 use values::computed::text::LineHeight as ComputedLineHeight;
+use values::computed::text::TextEmphasisKeywordValue as ComputedTextEmphasisKeywordValue;
+use values::computed::text::TextEmphasisStyle as ComputedTextEmphasisStyle;
 use values::computed::text::TextOverflow as ComputedTextOverflow;
 use values::generics::text::InitialLetter as GenericInitialLetter;
 use values::generics::text::LineHeight as GenericLineHeight;
@@ -420,7 +424,6 @@ pub enum TextAlign {
     /// unlike other values.
     #[cfg(feature = "gecko")]
     MozCenterOrInherit,
-
 }
 
 impl Parse for TextAlign {
@@ -515,6 +518,154 @@ impl ToComputedValue for TextAlign {
     }
 }
 
+/// Specified value of text-emphasis-style property.
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+pub enum TextEmphasisStyle {
+    /// <fill> <shape>
+    Keyword(TextEmphasisKeywordValue),
+    /// `none`
+    None,
+    /// String (will be used only first grapheme cluster) for the text-emphasis-style property
+    String(String),
+}
+
+/// Keyword value for the text-emphasis-style property
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+pub enum TextEmphasisKeywordValue {
+    /// <fill>
+    Fill(TextEmphasisFillMode),
+    /// <shape>
+    Shape(TextEmphasisShapeKeyword),
+    /// <fill> <shape>
+    FillAndShape(TextEmphasisFillMode, TextEmphasisShapeKeyword),
+}
+
+impl TextEmphasisKeywordValue {
+    fn fill(&self) -> Option<TextEmphasisFillMode> {
+        match *self {
+            TextEmphasisKeywordValue::Fill(fill) |
+            TextEmphasisKeywordValue::FillAndShape(fill, _) => Some(fill),
+            _ => None,
+        }
+    }
+
+    fn shape(&self) -> Option<TextEmphasisShapeKeyword> {
+        match *self {
+            TextEmphasisKeywordValue::Shape(shape) |
+            TextEmphasisKeywordValue::FillAndShape(_, shape) => Some(shape),
+            _ => None,
+        }
+    }
+}
+
+/// Fill mode for the text-emphasis-style property
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, ToCss)]
+pub enum TextEmphasisFillMode {
+    /// `filled`
+    Filled,
+    /// `open`
+    Open,
+}
+
+/// Shape keyword for the text-emphasis-style property
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToCss)]
+pub enum TextEmphasisShapeKeyword {
+    /// `dot`
+    Dot,
+    /// `circle`
+    Circle,
+    /// `double-circle`
+    DoubleCircle,
+    /// `triangle`
+    Triangle,
+    /// `sesame`
+    Sesame,
+}
+
+impl TextEmphasisShapeKeyword {
+    /// converts fill mode to a unicode char
+    pub fn char(&self, fill: TextEmphasisFillMode) -> &str {
+        let fill = fill == TextEmphasisFillMode::Filled;
+        match *self {
+            TextEmphasisShapeKeyword::Dot => if fill { "\u{2022}" } else { "\u{25e6}" },
+            TextEmphasisShapeKeyword::Circle => if fill { "\u{25cf}" } else { "\u{25cb}" },
+            TextEmphasisShapeKeyword::DoubleCircle => if fill { "\u{25c9}" } else { "\u{25ce}" },
+            TextEmphasisShapeKeyword::Triangle => if fill { "\u{25b2}" } else { "\u{25b3}" },
+            TextEmphasisShapeKeyword::Sesame => if fill { "\u{fe45}" } else { "\u{fe46}" },
+        }
+    }
+}
+
+impl ToComputedValue for TextEmphasisStyle {
+    type ComputedValue = ComputedTextEmphasisStyle;
+
+    #[inline]
+    fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
+        match *self {
+            TextEmphasisStyle::Keyword(ref keyword) => {
+                let default_shape = if context.style().get_inheritedbox()
+                                                .clone_writing_mode() == SpecifiedWritingMode::HorizontalTb {
+                    TextEmphasisShapeKeyword::Circle
+                } else {
+                    TextEmphasisShapeKeyword::Sesame
+                };
+                ComputedTextEmphasisStyle::Keyword(ComputedTextEmphasisKeywordValue {
+                    fill: keyword.fill().unwrap_or(TextEmphasisFillMode::Filled),
+                    shape: keyword.shape().unwrap_or(default_shape),
+                })
+            },
+            TextEmphasisStyle::None => ComputedTextEmphasisStyle::None,
+            TextEmphasisStyle::String(ref s) => {
+                // Passing `true` to iterate over extended grapheme clusters, following
+                // recommendation at http://www.unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries
+                let string = s.graphemes(true).next().unwrap_or("").to_string();
+                ComputedTextEmphasisStyle::String(string)
+            }
+        }
+    }
+    #[inline]
+    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
+        match *computed {
+            ComputedTextEmphasisStyle::Keyword(ref keyword) =>
+                TextEmphasisStyle::Keyword(TextEmphasisKeywordValue::FillAndShape(keyword.fill, keyword.shape)),
+            ComputedTextEmphasisStyle::None => TextEmphasisStyle::None,
+            ComputedTextEmphasisStyle::String(ref string) => TextEmphasisStyle::String(string.clone())
+        }
+    }
+}
+
+impl Parse for TextEmphasisStyle {
+    fn parse<'i, 't>(
+        _context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+            return Ok(TextEmphasisStyle::None);
+        }
+
+        if let Ok(s) = input.try(|i| i.expect_string().map(|s| s.as_ref().to_owned())) {
+            // Handle <string>
+            return Ok(TextEmphasisStyle::String(s));
+        }
+
+        // Handle a pair of keywords
+        let mut shape = input.try(TextEmphasisShapeKeyword::parse).ok();
+        let fill = input.try(TextEmphasisFillMode::parse).ok();
+        if shape.is_none() {
+            shape = input.try(TextEmphasisShapeKeyword::parse).ok();
+        }
+
+        // At least one of shape or fill must be handled
+        let keyword_value = match (fill, shape) {
+            (Some(fill), Some(shape)) => TextEmphasisKeywordValue::FillAndShape(fill, shape),
+            (Some(fill), None) => TextEmphasisKeywordValue::Fill(fill),
+            (None, Some(shape)) => TextEmphasisKeywordValue::Shape(shape),
+            _ => return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)),
+        };
+        Ok(TextEmphasisStyle::Keyword(keyword_value))
+    }
+}
+
 /// A specified value for the `-moz-tab-size` property.
 pub type MozTabSize = GenericMozTabSize<NonNegativeNumber, NonNegativeLength>;