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Diffstat (limited to '')
| -rw-r--r-- | servo/components/style/values/specified/position.rs | 911 |
1 files changed, 911 insertions, 0 deletions
diff --git a/servo/components/style/values/specified/position.rs b/servo/components/style/values/specified/position.rs new file mode 100644 index 0000000000..e447c52f0c --- /dev/null +++ b/servo/components/style/values/specified/position.rs @@ -0,0 +1,911 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ + +//! CSS handling for the specified value of +//! [`position`][position]s +//! +//! [position]: https://drafts.csswg.org/css-backgrounds-3/#position + +use crate::parser::{Parse, ParserContext}; +use crate::selector_map::PrecomputedHashMap; +use crate::str::HTML_SPACE_CHARACTERS; +use crate::values::computed::LengthPercentage as ComputedLengthPercentage; +use crate::values::computed::{Context, Percentage, ToComputedValue}; +use crate::values::generics::position::AspectRatio as GenericAspectRatio; +use crate::values::generics::position::Position as GenericPosition; +use crate::values::generics::position::PositionComponent as GenericPositionComponent; +use crate::values::generics::position::PositionOrAuto as GenericPositionOrAuto; +use crate::values::generics::position::ZIndex as GenericZIndex; +use crate::values::specified::{AllowQuirks, Integer, LengthPercentage, NonNegativeNumber}; +use crate::{Atom, Zero}; +use cssparser::Parser; +use selectors::parser::SelectorParseErrorKind; +use servo_arc::Arc; +use std::fmt::{self, Write}; +use style_traits::values::specified::AllowedNumericType; +use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss}; + +/// The specified value of a CSS `<position>` +pub type Position = GenericPosition<HorizontalPosition, VerticalPosition>; + +/// The specified value of an `auto | <position>`. +pub type PositionOrAuto = GenericPositionOrAuto<Position>; + +/// The specified value of a horizontal position. +pub type HorizontalPosition = PositionComponent<HorizontalPositionKeyword>; + +/// The specified value of a vertical position. +pub type VerticalPosition = PositionComponent<VerticalPositionKeyword>; + +/// The specified value of a component of a CSS `<position>`. +#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)] +pub enum PositionComponent<S> { + /// `center` + Center, + /// `<length-percentage>` + Length(LengthPercentage), + /// `<side> <length-percentage>?` + Side(S, Option<LengthPercentage>), +} + +/// A keyword for the X direction. +#[derive( + Clone, + Copy, + Debug, + Eq, + Hash, + MallocSizeOf, + Parse, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[allow(missing_docs)] +#[repr(u8)] +pub enum HorizontalPositionKeyword { + Left, + Right, +} + +/// A keyword for the Y direction. +#[derive( + Clone, + Copy, + Debug, + Eq, + Hash, + MallocSizeOf, + Parse, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[allow(missing_docs)] +#[repr(u8)] +pub enum VerticalPositionKeyword { + Top, + Bottom, +} + +impl Parse for Position { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + let position = Self::parse_three_value_quirky(context, input, AllowQuirks::No)?; + if position.is_three_value_syntax() { + return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)); + } + Ok(position) + } +} + +impl Position { + /// Parses a `<bg-position>`, with quirks. + pub fn parse_three_value_quirky<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + allow_quirks: AllowQuirks, + ) -> Result<Self, ParseError<'i>> { + match input.try_parse(|i| PositionComponent::parse_quirky(context, i, allow_quirks)) { + Ok(x_pos @ PositionComponent::Center) => { + if let Ok(y_pos) = + input.try_parse(|i| PositionComponent::parse_quirky(context, i, allow_quirks)) + { + return Ok(Self::new(x_pos, y_pos)); + } + let x_pos = input + .try_parse(|i| PositionComponent::parse_quirky(context, i, allow_quirks)) + .unwrap_or(x_pos); + let y_pos = PositionComponent::Center; + return Ok(Self::new(x_pos, y_pos)); + }, + Ok(PositionComponent::Side(x_keyword, lp)) => { + if input + .try_parse(|i| i.expect_ident_matching("center")) + .is_ok() + { + let x_pos = PositionComponent::Side(x_keyword, lp); + let y_pos = PositionComponent::Center; + return Ok(Self::new(x_pos, y_pos)); + } + if let Ok(y_keyword) = input.try_parse(VerticalPositionKeyword::parse) { + let y_lp = input + .try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + .ok(); + let x_pos = PositionComponent::Side(x_keyword, lp); + let y_pos = PositionComponent::Side(y_keyword, y_lp); + return Ok(Self::new(x_pos, y_pos)); + } + let x_pos = PositionComponent::Side(x_keyword, None); + let y_pos = lp.map_or(PositionComponent::Center, PositionComponent::Length); + return Ok(Self::new(x_pos, y_pos)); + }, + Ok(x_pos @ PositionComponent::Length(_)) => { + if let Ok(y_keyword) = input.try_parse(VerticalPositionKeyword::parse) { + let y_pos = PositionComponent::Side(y_keyword, None); + return Ok(Self::new(x_pos, y_pos)); + } + if let Ok(y_lp) = + input.try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + { + let y_pos = PositionComponent::Length(y_lp); + return Ok(Self::new(x_pos, y_pos)); + } + let y_pos = PositionComponent::Center; + let _ = input.try_parse(|i| i.expect_ident_matching("center")); + return Ok(Self::new(x_pos, y_pos)); + }, + Err(_) => {}, + } + let y_keyword = VerticalPositionKeyword::parse(input)?; + let lp_and_x_pos: Result<_, ParseError> = input.try_parse(|i| { + let y_lp = i + .try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + .ok(); + if let Ok(x_keyword) = i.try_parse(HorizontalPositionKeyword::parse) { + let x_lp = i + .try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + .ok(); + let x_pos = PositionComponent::Side(x_keyword, x_lp); + return Ok((y_lp, x_pos)); + }; + i.expect_ident_matching("center")?; + let x_pos = PositionComponent::Center; + Ok((y_lp, x_pos)) + }); + if let Ok((y_lp, x_pos)) = lp_and_x_pos { + let y_pos = PositionComponent::Side(y_keyword, y_lp); + return Ok(Self::new(x_pos, y_pos)); + } + let x_pos = PositionComponent::Center; + let y_pos = PositionComponent::Side(y_keyword, None); + Ok(Self::new(x_pos, y_pos)) + } + + /// `center center` + #[inline] + pub fn center() -> Self { + Self::new(PositionComponent::Center, PositionComponent::Center) + } + + /// Returns true if this uses a 3 value syntax. + #[inline] + fn is_three_value_syntax(&self) -> bool { + self.horizontal.component_count() != self.vertical.component_count() + } +} + +impl ToCss for Position { + fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result + where + W: Write, + { + match (&self.horizontal, &self.vertical) { + ( + x_pos @ &PositionComponent::Side(_, Some(_)), + &PositionComponent::Length(ref y_lp), + ) => { + x_pos.to_css(dest)?; + dest.write_str(" top ")?; + y_lp.to_css(dest) + }, + ( + &PositionComponent::Length(ref x_lp), + y_pos @ &PositionComponent::Side(_, Some(_)), + ) => { + dest.write_str("left ")?; + x_lp.to_css(dest)?; + dest.write_str(" ")?; + y_pos.to_css(dest) + }, + (x_pos, y_pos) => { + x_pos.to_css(dest)?; + dest.write_str(" ")?; + y_pos.to_css(dest) + }, + } + } +} + +impl<S: Parse> Parse for PositionComponent<S> { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + Self::parse_quirky(context, input, AllowQuirks::No) + } +} + +impl<S: Parse> PositionComponent<S> { + /// Parses a component of a CSS position, with quirks. + pub fn parse_quirky<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + allow_quirks: AllowQuirks, + ) -> Result<Self, ParseError<'i>> { + if input + .try_parse(|i| i.expect_ident_matching("center")) + .is_ok() + { + return Ok(PositionComponent::Center); + } + if let Ok(lp) = + input.try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + { + return Ok(PositionComponent::Length(lp)); + } + let keyword = S::parse(context, input)?; + let lp = input + .try_parse(|i| LengthPercentage::parse_quirky(context, i, allow_quirks)) + .ok(); + Ok(PositionComponent::Side(keyword, lp)) + } +} + +impl<S> GenericPositionComponent for PositionComponent<S> { + fn is_center(&self) -> bool { + match *self { + PositionComponent::Center => true, + PositionComponent::Length(LengthPercentage::Percentage(ref per)) => per.0 == 0.5, + // 50% from any side is still the center. + PositionComponent::Side(_, Some(LengthPercentage::Percentage(ref per))) => per.0 == 0.5, + _ => false, + } + } +} + +impl<S> PositionComponent<S> { + /// `0%` + pub fn zero() -> Self { + PositionComponent::Length(LengthPercentage::Percentage(Percentage::zero())) + } + + /// Returns the count of this component. + fn component_count(&self) -> usize { + match *self { + PositionComponent::Length(..) | PositionComponent::Center => 1, + PositionComponent::Side(_, ref lp) => { + if lp.is_some() { + 2 + } else { + 1 + } + }, + } + } +} + +impl<S: Side> ToComputedValue for PositionComponent<S> { + type ComputedValue = ComputedLengthPercentage; + + fn to_computed_value(&self, context: &Context) -> Self::ComputedValue { + match *self { + PositionComponent::Center => ComputedLengthPercentage::new_percent(Percentage(0.5)), + PositionComponent::Side(ref keyword, None) => { + let p = Percentage(if keyword.is_start() { 0. } else { 1. }); + ComputedLengthPercentage::new_percent(p) + }, + PositionComponent::Side(ref keyword, Some(ref length)) if !keyword.is_start() => { + let length = length.to_computed_value(context); + // We represent `<end-side> <length>` as `calc(100% - <length>)`. + ComputedLengthPercentage::hundred_percent_minus(length, AllowedNumericType::All) + }, + PositionComponent::Side(_, Some(ref length)) | + PositionComponent::Length(ref length) => length.to_computed_value(context), + } + } + + fn from_computed_value(computed: &Self::ComputedValue) -> Self { + PositionComponent::Length(ToComputedValue::from_computed_value(computed)) + } +} + +impl<S: Side> PositionComponent<S> { + /// The initial specified value of a position component, i.e. the start side. + pub fn initial_specified_value() -> Self { + PositionComponent::Side(S::start(), None) + } +} + +/// Represents a side, either horizontal or vertical, of a CSS position. +pub trait Side { + /// Returns the start side. + fn start() -> Self; + + /// Returns whether this side is the start side. + fn is_start(&self) -> bool; +} + +impl Side for HorizontalPositionKeyword { + #[inline] + fn start() -> Self { + HorizontalPositionKeyword::Left + } + + #[inline] + fn is_start(&self) -> bool { + *self == Self::start() + } +} + +impl Side for VerticalPositionKeyword { + #[inline] + fn start() -> Self { + VerticalPositionKeyword::Top + } + + #[inline] + fn is_start(&self) -> bool { + *self == Self::start() + } +} + +bitflags! { + /// Controls how the auto-placement algorithm works + /// specifying exactly how auto-placed items get flowed into the grid + #[derive( + MallocSizeOf, + SpecifiedValueInfo, + ToComputedValue, + ToResolvedValue, + ToShmem + )] + #[value_info(other_values = "row,column,dense")] + #[repr(C)] + pub struct GridAutoFlow: u8 { + /// 'row' - mutually exclusive with 'column' + const ROW = 1 << 0; + /// 'column' - mutually exclusive with 'row' + const COLUMN = 1 << 1; + /// 'dense' + const DENSE = 1 << 2; + } +} + +#[repr(u8)] +#[derive( + Clone, + Copy, + Debug, + Eq, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +/// Masonry auto-placement algorithm packing. +pub enum MasonryPlacement { + /// Place the item in the track(s) with the smallest extent so far. + Pack, + /// Place the item after the last item, from start to end. + Next, +} + +#[repr(u8)] +#[derive( + Clone, + Copy, + Debug, + Eq, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +/// Masonry auto-placement algorithm item sorting option. +pub enum MasonryItemOrder { + /// Place all items with a definite placement before auto-placed items. + DefiniteFirst, + /// Place items in `order-modified document order`. + Ordered, +} + +#[derive( + Clone, + Copy, + Debug, + Eq, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[repr(C)] +/// Controls how the Masonry layout algorithm works +/// specifying exactly how auto-placed items get flowed in the masonry axis. +pub struct MasonryAutoFlow { + /// Specify how to pick a auto-placement track. + #[css(contextual_skip_if = "is_pack_with_non_default_order")] + pub placement: MasonryPlacement, + /// Specify how to pick an item to place. + #[css(skip_if = "is_item_order_definite_first")] + pub order: MasonryItemOrder, +} + +#[inline] +fn is_pack_with_non_default_order(placement: &MasonryPlacement, order: &MasonryItemOrder) -> bool { + *placement == MasonryPlacement::Pack && *order != MasonryItemOrder::DefiniteFirst +} + +#[inline] +fn is_item_order_definite_first(order: &MasonryItemOrder) -> bool { + *order == MasonryItemOrder::DefiniteFirst +} + +impl MasonryAutoFlow { + #[inline] + /// Get initial `masonry-auto-flow` value. + pub fn initial() -> MasonryAutoFlow { + MasonryAutoFlow { + placement: MasonryPlacement::Pack, + order: MasonryItemOrder::DefiniteFirst, + } + } +} + +impl Parse for MasonryAutoFlow { + /// [ definite-first | ordered ] || [ pack | next ] + fn parse<'i, 't>( + _context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<MasonryAutoFlow, ParseError<'i>> { + let mut value = MasonryAutoFlow::initial(); + let mut got_placement = false; + let mut got_order = false; + while !input.is_exhausted() { + let location = input.current_source_location(); + let ident = input.expect_ident()?; + let success = match_ignore_ascii_case! { &ident, + "pack" if !got_placement => { + got_placement = true; + true + }, + "next" if !got_placement => { + value.placement = MasonryPlacement::Next; + got_placement = true; + true + }, + "definite-first" if !got_order => { + got_order = true; + true + }, + "ordered" if !got_order => { + value.order = MasonryItemOrder::Ordered; + got_order = true; + true + }, + _ => false + }; + if !success { + return Err(location + .new_custom_error(SelectorParseErrorKind::UnexpectedIdent(ident.clone()))); + } + } + + if got_placement || got_order { + Ok(value) + } else { + Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)) + } + } +} + +// TODO: Can be derived with some care. +impl Parse for GridAutoFlow { + /// [ row | column ] || dense + fn parse<'i, 't>( + _context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<GridAutoFlow, ParseError<'i>> { + let mut track = None; + let mut dense = GridAutoFlow::empty(); + + while !input.is_exhausted() { + let location = input.current_source_location(); + let ident = input.expect_ident()?; + let success = match_ignore_ascii_case! { &ident, + "row" if track.is_none() => { + track = Some(GridAutoFlow::ROW); + true + }, + "column" if track.is_none() => { + track = Some(GridAutoFlow::COLUMN); + true + }, + "dense" if dense.is_empty() => { + dense = GridAutoFlow::DENSE; + true + }, + _ => false, + }; + if !success { + return Err(location + .new_custom_error(SelectorParseErrorKind::UnexpectedIdent(ident.clone()))); + } + } + + if track.is_some() || !dense.is_empty() { + Ok(track.unwrap_or(GridAutoFlow::ROW) | dense) + } else { + Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)) + } + } +} + +impl ToCss for GridAutoFlow { + fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result + where + W: Write, + { + if *self == GridAutoFlow::ROW { + return dest.write_str("row"); + } + + if *self == GridAutoFlow::COLUMN { + return dest.write_str("column"); + } + + if *self == GridAutoFlow::ROW | GridAutoFlow::DENSE { + return dest.write_str("dense"); + } + + if *self == GridAutoFlow::COLUMN | GridAutoFlow::DENSE { + return dest.write_str("column dense"); + } + + debug_assert!(false, "Unknown or invalid grid-autoflow value"); + Ok(()) + } +} + +#[derive( + Clone, + Debug, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[repr(C)] +/// https://drafts.csswg.org/css-grid/#named-grid-area +pub struct TemplateAreas { + /// `named area` containing for each template area + #[css(skip)] + pub areas: crate::OwnedSlice<NamedArea>, + /// The original CSS string value of each template area + #[css(iterable)] + pub strings: crate::OwnedSlice<crate::OwnedStr>, + /// The number of columns of the grid. + #[css(skip)] + pub width: u32, +} + +impl TemplateAreas { + /// Transform `vector` of str into `template area` + pub fn from_vec(strings: Vec<crate::OwnedStr>) -> Result<Self, ()> { + if strings.is_empty() { + return Err(()); + } + let mut areas: Vec<NamedArea> = vec![]; + let mut width = 0; + { + let mut row = 0u32; + let mut area_indices = PrecomputedHashMap::<Atom, usize>::default(); + for string in &strings { + let mut current_area_index: Option<usize> = None; + row += 1; + let mut column = 0u32; + for token in TemplateAreasTokenizer(string) { + column += 1; + let name = if let Some(token) = token? { + Atom::from(token) + } else { + if let Some(index) = current_area_index.take() { + if areas[index].columns.end != column { + return Err(()); + } + } + continue; + }; + if let Some(index) = current_area_index { + if areas[index].name == name { + if areas[index].rows.start == row { + areas[index].columns.end += 1; + } + continue; + } + if areas[index].columns.end != column { + return Err(()); + } + } + if let Some(index) = area_indices.get(&name).cloned() { + if areas[index].columns.start != column || areas[index].rows.end != row { + return Err(()); + } + areas[index].rows.end += 1; + current_area_index = Some(index); + continue; + } + let index = areas.len(); + assert!(area_indices.insert(name.clone(), index).is_none()); + areas.push(NamedArea { + name, + columns: UnsignedRange { + start: column, + end: column + 1, + }, + rows: UnsignedRange { + start: row, + end: row + 1, + }, + }); + current_area_index = Some(index); + } + if column == 0 { + // Each string must produce a valid token. + // https://github.com/w3c/csswg-drafts/issues/5110 + return Err(()); + } + if let Some(index) = current_area_index { + if areas[index].columns.end != column + 1 { + assert_ne!(areas[index].rows.start, row); + return Err(()); + } + } + if row == 1 { + width = column; + } else if width != column { + return Err(()); + } + } + } + Ok(TemplateAreas { + areas: areas.into(), + strings: strings.into(), + width, + }) + } +} + +impl Parse for TemplateAreas { + fn parse<'i, 't>( + _context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + let mut strings = vec![]; + while let Ok(string) = + input.try_parse(|i| i.expect_string().map(|s| s.as_ref().to_owned().into())) + { + strings.push(string); + } + + TemplateAreas::from_vec(strings) + .map_err(|()| input.new_custom_error(StyleParseErrorKind::UnspecifiedError)) + } +} + +/// Arc type for `Arc<TemplateAreas>` +#[derive( + Clone, + Debug, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[repr(transparent)] +pub struct TemplateAreasArc(#[ignore_malloc_size_of = "Arc"] pub Arc<TemplateAreas>); + +impl Parse for TemplateAreasArc { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + let parsed = TemplateAreas::parse(context, input)?; + Ok(TemplateAreasArc(Arc::new(parsed))) + } +} + +/// A range of rows or columns. Using this instead of std::ops::Range for FFI +/// purposes. +#[repr(C)] +#[derive( + Clone, + Debug, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToResolvedValue, + ToShmem, +)] +pub struct UnsignedRange { + /// The start of the range. + pub start: u32, + /// The end of the range. + pub end: u32, +} + +#[derive( + Clone, + Debug, + MallocSizeOf, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToResolvedValue, + ToShmem, +)] +#[repr(C)] +/// Not associated with any particular grid item, but can be referenced from the +/// grid-placement properties. +pub struct NamedArea { + /// Name of the `named area` + pub name: Atom, + /// Rows of the `named area` + pub rows: UnsignedRange, + /// Columns of the `named area` + pub columns: UnsignedRange, +} + +/// Tokenize the string into a list of the tokens, +/// using longest-match semantics +struct TemplateAreasTokenizer<'a>(&'a str); + +impl<'a> Iterator for TemplateAreasTokenizer<'a> { + type Item = Result<Option<&'a str>, ()>; + + fn next(&mut self) -> Option<Self::Item> { + let rest = self.0.trim_start_matches(HTML_SPACE_CHARACTERS); + if rest.is_empty() { + return None; + } + if rest.starts_with('.') { + self.0 = &rest[rest.find(|c| c != '.').unwrap_or(rest.len())..]; + return Some(Ok(None)); + } + if !rest.starts_with(is_name_code_point) { + return Some(Err(())); + } + let token_len = rest.find(|c| !is_name_code_point(c)).unwrap_or(rest.len()); + let token = &rest[..token_len]; + self.0 = &rest[token_len..]; + Some(Ok(Some(token))) + } +} + +fn is_name_code_point(c: char) -> bool { + c >= 'A' && c <= 'Z' || + c >= 'a' && c <= 'z' || + c >= '\u{80}' || + c == '_' || + c >= '0' && c <= '9' || + c == '-' +} + +/// This property specifies named grid areas. +/// +/// The syntax of this property also provides a visualization of the structure +/// of the grid, making the overall layout of the grid container easier to +/// understand. +#[repr(C, u8)] +#[derive( + Clone, + Debug, + MallocSizeOf, + Parse, + PartialEq, + SpecifiedValueInfo, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +pub enum GridTemplateAreas { + /// The `none` value. + None, + /// The actual value. + Areas(TemplateAreasArc), +} + +impl GridTemplateAreas { + #[inline] + /// Get default value as `none` + pub fn none() -> GridTemplateAreas { + GridTemplateAreas::None + } +} + +/// A specified value for the `z-index` property. +pub type ZIndex = GenericZIndex<Integer>; + +/// A specified value for the `aspect-ratio` property. +pub type AspectRatio = GenericAspectRatio<NonNegativeNumber>; + +impl Parse for AspectRatio { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + use crate::values::generics::position::PreferredRatio; + use crate::values::specified::Ratio; + + let location = input.current_source_location(); + let mut auto = input.try_parse(|i| i.expect_ident_matching("auto")); + let ratio = input.try_parse(|i| Ratio::parse(context, i)); + if auto.is_err() { + auto = input.try_parse(|i| i.expect_ident_matching("auto")); + } + + if auto.is_err() && ratio.is_err() { + return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError)); + } + + Ok(AspectRatio { + auto: auto.is_ok(), + ratio: match ratio { + Ok(ratio) => PreferredRatio::Ratio(ratio), + Err(..) => PreferredRatio::None, + }, + }) + } +} + +impl AspectRatio { + /// Returns Self by a valid ratio. + pub fn from_mapped_ratio(w: f32, h: f32) -> Self { + use crate::values::generics::position::PreferredRatio; + use crate::values::generics::ratio::Ratio; + AspectRatio { + auto: true, + ratio: PreferredRatio::Ratio(Ratio( + NonNegativeNumber::new(w), + NonNegativeNumber::new(h), + )), + } + } +} |