Source code
Revision control
Copy as Markdown
Other Tools
/* 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
//! Generic types for the handling of
use crate::parser::{Parse, ParserContext};
use crate::values::specified;
use crate::values::{CSSFloat, CustomIdent};
use crate::{One, Zero};
use cssparser::Parser;
use std::fmt::{self, Write};
use std::{cmp, usize};
use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
/// These are the limits that we choose to clamp grid line numbers to.
/// line_num is clamped to this range at parse time.
pub const MIN_GRID_LINE: i32 = -10000;
/// See above.
pub const MAX_GRID_LINE: i32 = 10000;
/// A `<grid-line>` type.
///
#[derive(
Clone,
Debug,
Default,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct GenericGridLine<Integer> {
/// A custom identifier for named lines, or the empty atom otherwise.
///
pub ident: CustomIdent,
/// Denotes the nth grid line from grid item's placement.
///
/// This is clamped by MIN_GRID_LINE and MAX_GRID_LINE.
///
/// NOTE(emilio): If we ever allow animating these we need to either do
/// something more complicated for the clamping, or do this clamping at
/// used-value time.
pub line_num: Integer,
/// Flag to check whether it's a `span` keyword.
pub is_span: bool,
}
pub use self::GenericGridLine as GridLine;
impl<Integer> GridLine<Integer>
where
Integer: PartialEq + Zero,
{
/// The `auto` value.
pub fn auto() -> Self {
Self {
is_span: false,
line_num: Zero::zero(),
ident: CustomIdent(atom!("")),
}
}
/// Check whether this `<grid-line>` represents an `auto` value.
pub fn is_auto(&self) -> bool {
self.ident.0 == atom!("") && self.line_num.is_zero() && !self.is_span
}
/// Check whether this `<grid-line>` represents a `<custom-ident>` value.
pub fn is_ident_only(&self) -> bool {
self.ident.0 != atom!("") && self.line_num.is_zero() && !self.is_span
}
/// Check if `self` makes `other` omittable according to the rules at:
pub fn can_omit(&self, other: &Self) -> bool {
if self.is_ident_only() {
self == other
} else {
other.is_auto()
}
}
}
impl<Integer> ToCss for GridLine<Integer>
where
Integer: ToCss + PartialEq + Zero + One,
{
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
// 1. `auto`
if self.is_auto() {
return dest.write_str("auto");
}
// 2. `<custom-ident>`
if self.is_ident_only() {
return self.ident.to_css(dest);
}
// 3. `[ span && [ <integer [1,∞]> || <custom-ident> ] ]`
let has_ident = self.ident.0 != atom!("");
if self.is_span {
dest.write_str("span")?;
debug_assert!(!self.line_num.is_zero() || has_ident);
// We omit `line_num` if
// 1. we don't specify it, or
// 2. it is the default value, i.e. 1.0, and the ident is specified.
if !self.line_num.is_zero() && !(self.line_num.is_one() && has_ident) {
dest.write_char(' ')?;
self.line_num.to_css(dest)?;
}
if has_ident {
dest.write_char(' ')?;
self.ident.to_css(dest)?;
}
return Ok(());
}
// 4. `[ <integer [-∞,-1]> | <integer [1,∞]> ] && <custom-ident>? ]`
debug_assert!(!self.line_num.is_zero());
self.line_num.to_css(dest)?;
if has_ident {
dest.write_char(' ')?;
self.ident.to_css(dest)?;
}
Ok(())
}
}
impl Parse for GridLine<specified::Integer> {
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
) -> Result<Self, ParseError<'i>> {
let mut grid_line = Self::auto();
if input.try_parse(|i| i.expect_ident_matching("auto")).is_ok() {
return Ok(grid_line);
}
// <custom-ident> | [ <integer> && <custom-ident>? ] | [ span && [ <integer> || <custom-ident> ] ]
// This <grid-line> horror is simply,
// [ span? && [ <custom-ident> || <integer> ] ]
// And, for some magical reason, "span" should be the first or last value and not in-between.
let mut val_before_span = false;
for _ in 0..3 {
// Maximum possible entities for <grid-line>
let location = input.current_source_location();
if input.try_parse(|i| i.expect_ident_matching("span")).is_ok() {
if grid_line.is_span {
return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
if !grid_line.line_num.is_zero() || grid_line.ident.0 != atom!("") {
val_before_span = true;
}
grid_line.is_span = true;
} else if let Ok(i) = input.try_parse(|i| specified::Integer::parse(context, i)) {
// FIXME(emilio): Probably shouldn't reject if it's calc()...
let value = i.value();
if value == 0 || val_before_span || !grid_line.line_num.is_zero() {
return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
grid_line.line_num = specified::Integer::new(cmp::max(
MIN_GRID_LINE,
cmp::min(value, MAX_GRID_LINE),
));
} else if let Ok(name) = input.try_parse(|i| CustomIdent::parse(i, &["auto"])) {
if val_before_span || grid_line.ident.0 != atom!("") {
return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
// NOTE(emilio): `span` is consumed above, so we only need to
// reject `auto`.
grid_line.ident = name;
} else {
break;
}
}
if grid_line.is_auto() {
return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
if grid_line.is_span {
if !grid_line.line_num.is_zero() {
if grid_line.line_num.value() <= 0 {
// disallow negative integers for grid spans
return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
} else if grid_line.ident.0 == atom!("") {
// integer could be omitted
return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
}
}
Ok(grid_line)
}
}
/// A track breadth for explicit grid track sizing. It's generic solely to
/// avoid re-implementing it for the computed type.
///
#[derive(
Animate,
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum GenericTrackBreadth<L> {
/// The generic type is almost always a non-negative `<length-percentage>`
Breadth(L),
/// A flex fraction specified in `fr` units.
#[css(dimension)]
Fr(CSSFloat),
/// `auto`
Auto,
/// `min-content`
MinContent,
/// `max-content`
MaxContent,
}
pub use self::GenericTrackBreadth as TrackBreadth;
impl<L> TrackBreadth<L> {
/// Check whether this is a `<fixed-breadth>` (i.e., it only has `<length-percentage>`)
///
#[inline]
pub fn is_fixed(&self) -> bool {
matches!(*self, TrackBreadth::Breadth(..))
}
}
/// A `<track-size>` type for explicit grid track sizing. Like `<track-breadth>`, this is
/// generic only to avoid code bloat. It only takes `<length-percentage>`
///
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum GenericTrackSize<L> {
/// A flexible `<track-breadth>`
Breadth(GenericTrackBreadth<L>),
/// A `minmax` function for a range over an inflexible `<track-breadth>`
/// and a flexible `<track-breadth>`
///
#[css(function)]
Minmax(GenericTrackBreadth<L>, GenericTrackBreadth<L>),
/// A `fit-content` function.
///
/// This stores a TrackBreadth<L> for convenience, but it can only be a
/// LengthPercentage.
///
#[css(function)]
FitContent(GenericTrackBreadth<L>),
}
pub use self::GenericTrackSize as TrackSize;
impl<L> TrackSize<L> {
/// The initial value.
const INITIAL_VALUE: Self = TrackSize::Breadth(TrackBreadth::Auto);
/// Returns the initial value.
pub const fn initial_value() -> Self {
Self::INITIAL_VALUE
}
/// Returns true if `self` is the initial value.
pub fn is_initial(&self) -> bool {
matches!(*self, TrackSize::Breadth(TrackBreadth::Auto)) // FIXME: can't use Self::INITIAL_VALUE here yet: https://github.com/rust-lang/rust/issues/66585
}
/// Check whether this is a `<fixed-size>`
///
pub fn is_fixed(&self) -> bool {
match *self {
TrackSize::Breadth(ref breadth) => breadth.is_fixed(),
// For minmax function, it could be either
// minmax(<fixed-breadth>, <track-breadth>) or minmax(<inflexible-breadth>, <fixed-breadth>),
// and since both variants are a subset of minmax(<inflexible-breadth>, <track-breadth>), we only
// need to make sure that they're fixed. So, we don't have to modify the parsing function.
TrackSize::Minmax(ref breadth_1, ref breadth_2) => {
if breadth_1.is_fixed() {
return true; // the second value is always a <track-breadth>
}
match *breadth_1 {
TrackBreadth::Fr(_) => false, // should be <inflexible-breadth> at this point
_ => breadth_2.is_fixed(),
}
},
TrackSize::FitContent(_) => false,
}
}
}
impl<L> Default for TrackSize<L> {
fn default() -> Self {
Self::initial_value()
}
}
impl<L: ToCss> ToCss for TrackSize<L> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
match *self {
TrackSize::Breadth(ref breadth) => breadth.to_css(dest),
TrackSize::Minmax(ref min, ref max) => {
// According to gecko minmax(auto, <flex>) is equivalent to <flex>,
// and both are serialized as <flex>.
if let TrackBreadth::Auto = *min {
if let TrackBreadth::Fr(_) = *max {
return max.to_css(dest);
}
}
dest.write_str("minmax(")?;
min.to_css(dest)?;
dest.write_str(", ")?;
max.to_css(dest)?;
dest.write_char(')')
},
TrackSize::FitContent(ref lp) => {
dest.write_str("fit-content(")?;
lp.to_css(dest)?;
dest.write_char(')')
},
}
}
}
/// A `<track-size>+`.
/// We use the empty slice as `auto`, and always parse `auto` as an empty slice.
/// This means it's impossible to have a slice containing only one auto item.
#[derive(
Clone,
Debug,
Default,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
)]
#[repr(transparent)]
pub struct GenericImplicitGridTracks<T>(
#[css(if_empty = "auto", iterable)] pub crate::OwnedSlice<T>,
);
pub use self::GenericImplicitGridTracks as ImplicitGridTracks;
impl<T: fmt::Debug + Default + PartialEq> ImplicitGridTracks<T> {
/// Returns true if current value is same as its initial value (i.e. auto).
pub fn is_initial(&self) -> bool {
debug_assert_ne!(
*self,
ImplicitGridTracks(crate::OwnedSlice::from(vec![Default::default()]))
);
self.0.is_empty()
}
}
/// Helper function for serializing identifiers with a prefix and suffix, used
/// for serializing <line-names> (in grid).
pub fn concat_serialize_idents<W>(
prefix: &str,
suffix: &str,
slice: &[CustomIdent],
sep: &str,
dest: &mut CssWriter<W>,
) -> fmt::Result
where
W: Write,
{
if let Some((ref first, rest)) = slice.split_first() {
dest.write_str(prefix)?;
first.to_css(dest)?;
for thing in rest {
dest.write_str(sep)?;
thing.to_css(dest)?;
}
dest.write_str(suffix)?;
}
Ok(())
}
/// The initial argument of the `repeat` function.
///
#[derive(
Clone,
Copy,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum RepeatCount<Integer> {
/// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
Number(Integer),
/// An `<auto-fill>` keyword allowed only for `<auto-repeat>`
AutoFill,
/// An `<auto-fit>` keyword allowed only for `<auto-repeat>`
AutoFit,
}
impl Parse for RepeatCount<specified::Integer> {
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
) -> Result<Self, ParseError<'i>> {
if let Ok(mut i) = input.try_parse(|i| specified::Integer::parse_positive(context, i)) {
if i.value() > MAX_GRID_LINE {
i = specified::Integer::new(MAX_GRID_LINE);
}
return Ok(RepeatCount::Number(i));
}
try_match_ident_ignore_ascii_case! { input,
"auto-fill" => Ok(RepeatCount::AutoFill),
"auto-fit" => Ok(RepeatCount::AutoFit),
}
}
}
/// The structure containing `<line-names>` and `<track-size>` values.
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[css(function = "repeat")]
#[repr(C)]
pub struct GenericTrackRepeat<L, I> {
/// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
pub count: RepeatCount<I>,
/// `<line-names>` accompanying `<track_size>` values.
///
/// If there's no `<line-names>`, then it's represented by an empty vector.
/// For N `<track-size>` values, there will be N+1 `<line-names>`, and so this vector's
/// length is always one value more than that of the `<track-size>`.
pub line_names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
/// `<track-size>` values.
pub track_sizes: crate::OwnedSlice<GenericTrackSize<L>>,
}
pub use self::GenericTrackRepeat as TrackRepeat;
impl<L: ToCss, I: ToCss> ToCss for TrackRepeat<L, I> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
dest.write_str("repeat(")?;
self.count.to_css(dest)?;
dest.write_str(", ")?;
let mut line_names_iter = self.line_names.iter();
for (i, (ref size, ref names)) in self
.track_sizes
.iter()
.zip(&mut line_names_iter)
.enumerate()
{
if i > 0 {
dest.write_char(' ')?;
}
concat_serialize_idents("[", "] ", names, " ", dest)?;
size.to_css(dest)?;
}
if let Some(line_names_last) = line_names_iter.next() {
concat_serialize_idents(" [", "]", line_names_last, " ", dest)?;
}
dest.write_char(')')?;
Ok(())
}
}
/// Track list values. Can be <track-size> or <track-repeat>
#[derive(
Animate,
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum GenericTrackListValue<LengthPercentage, Integer> {
/// A <track-size> value.
TrackSize(#[animation(field_bound)] GenericTrackSize<LengthPercentage>),
/// A <track-repeat> value.
TrackRepeat(#[animation(field_bound)] GenericTrackRepeat<LengthPercentage, Integer>),
}
pub use self::GenericTrackListValue as TrackListValue;
impl<L, I> TrackListValue<L, I> {
// FIXME: can't use TrackSize::initial_value() here b/c rustc error "is not yet stable as a const fn"
const INITIAL_VALUE: Self = TrackListValue::TrackSize(TrackSize::Breadth(TrackBreadth::Auto));
fn is_repeat(&self) -> bool {
matches!(*self, TrackListValue::TrackRepeat(..))
}
/// Returns true if `self` is the initial value.
pub fn is_initial(&self) -> bool {
matches!(
*self,
TrackListValue::TrackSize(TrackSize::Breadth(TrackBreadth::Auto))
}
}
impl<L, I> Default for TrackListValue<L, I> {
#[inline]
fn default() -> Self {
Self::INITIAL_VALUE
}
}
/// A grid `<track-list>` type.
///
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct GenericTrackList<LengthPercentage, Integer> {
/// The index in `values` where our `<auto-repeat>` value is, if in bounds.
#[css(skip)]
pub auto_repeat_index: usize,
/// A vector of `<track-size> | <track-repeat>` values.
pub values: crate::OwnedSlice<GenericTrackListValue<LengthPercentage, Integer>>,
/// `<line-names>` accompanying `<track-size> | <track-repeat>` values.
///
/// If there's no `<line-names>`, then it's represented by an empty vector.
/// For N values, there will be N+1 `<line-names>`, and so this vector's
/// length is always one value more than that of the `<track-size>`.
pub line_names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
}
pub use self::GenericTrackList as TrackList;
impl<L, I> TrackList<L, I> {
/// Whether this track list is an explicit track list (that is, doesn't have
/// any repeat values).
pub fn is_explicit(&self) -> bool {
!self.values.iter().any(|v| v.is_repeat())
}
/// Whether this track list has an `<auto-repeat>` value.
pub fn has_auto_repeat(&self) -> bool {
self.auto_repeat_index < self.values.len()
}
}
impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
let mut values_iter = self.values.iter().peekable();
let mut line_names_iter = self.line_names.iter().peekable();
for idx in 0.. {
let names = line_names_iter.next().unwrap(); // This should exist!
concat_serialize_idents("[", "]", names, " ", dest)?;
match values_iter.next() {
Some(value) => {
if !names.is_empty() {
dest.write_char(' ')?;
}
value.to_css(dest)?;
},
None => break,
}
if values_iter.peek().is_some() ||
line_names_iter.peek().map_or(false, |v| !v.is_empty()) ||
(idx + 1 == self.auto_repeat_index)
{
dest.write_char(' ')?;
}
}
Ok(())
}
}
/// The `<name-repeat>` for subgrids.
///
/// <name-repeat> = repeat( [ <integer [1,∞]> | auto-fill ], <line-names>+)
///
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct GenericNameRepeat<I> {
/// The number of times for the value to be repeated (could also be `auto-fill`).
/// Note: `RepeatCount` accepts `auto-fit`, so we should reject it after parsing it.
pub count: RepeatCount<I>,
/// This represents `<line-names>+`. The length of the outer vector is at least one.
pub line_names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
}
pub use self::GenericNameRepeat as NameRepeat;
impl<I: ToCss> ToCss for NameRepeat<I> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
dest.write_str("repeat(")?;
self.count.to_css(dest)?;
dest.write_char(',')?;
for ref names in self.line_names.iter() {
if names.is_empty() {
// Note: concat_serialize_idents() skip the empty list so we have to handle it
// manually for NameRepeat.
dest.write_str(" []")?;
} else {
concat_serialize_idents(" [", "]", names, " ", dest)?;
}
}
dest.write_char(')')
}
}
impl<I> NameRepeat<I> {
/// Returns true if it is auto-fill.
#[inline]
pub fn is_auto_fill(&self) -> bool {
matches!(self.count, RepeatCount::AutoFill)
}
}
/// A single value for `<line-names>` or `<name-repeat>`.
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum GenericLineNameListValue<I> {
/// `<line-names>`.
LineNames(crate::OwnedSlice<CustomIdent>),
/// `<name-repeat>`.
Repeat(GenericNameRepeat<I>),
}
pub use self::GenericLineNameListValue as LineNameListValue;
impl<I: ToCss> ToCss for LineNameListValue<I> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
match *self {
Self::Repeat(ref r) => r.to_css(dest),
Self::LineNames(ref names) => {
dest.write_char('[')?;
if let Some((ref first, rest)) = names.split_first() {
first.to_css(dest)?;
for name in rest {
dest.write_char(' ')?;
name.to_css(dest)?;
}
}
dest.write_char(']')
},
}
}
}
/// The `<line-name-list>` for subgrids.
///
/// <line-name-list> = [ <line-names> | <name-repeat> ]+
/// <name-repeat> = repeat( [ <integer [1,∞]> | auto-fill ], <line-names>+)
///
#[derive(
Clone,
Debug,
Default,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct GenericLineNameList<I> {
/// The pre-computed length of line_names, without the length of repeat(auto-fill, ...).
// We precomputed this at parsing time, so we can avoid an extra loop when expanding
// repeat(auto-fill).
pub expanded_line_names_length: usize,
/// The line name list.
pub line_names: crate::OwnedSlice<GenericLineNameListValue<I>>,
}
pub use self::GenericLineNameList as LineNameList;
impl<I: ToCss> ToCss for LineNameList<I> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
dest.write_str("subgrid")?;
for value in self.line_names.iter() {
dest.write_char(' ')?;
value.to_css(dest)?;
}
Ok(())
}
}
/// Variants for `<grid-template-rows> | <grid-template-columns>`
#[derive(
Animate,
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
)]
#[value_info(other_values = "subgrid")]
#[repr(C, u8)]
pub enum GenericGridTemplateComponent<L, I> {
/// `none` value.
None,
/// The grid `<track-list>`
TrackList(
#[animation(field_bound)]
#[compute(field_bound)]
#[resolve(field_bound)]
#[shmem(field_bound)]
Box<GenericTrackList<L, I>>,
),
/// A `subgrid <line-name-list>?`
/// TODO: Support animations for this after subgrid is addressed in [grid-2] spec.
#[animation(error)]
Subgrid(Box<GenericLineNameList<I>>),
/// `masonry` value.
Masonry,
}
pub use self::GenericGridTemplateComponent as GridTemplateComponent;
impl<L, I> GridTemplateComponent<L, I> {
/// The initial value.
const INITIAL_VALUE: Self = Self::None;
/// Returns length of the <track-list>s <track-size>
pub fn track_list_len(&self) -> usize {
match *self {
GridTemplateComponent::TrackList(ref tracklist) => tracklist.values.len(),
_ => 0,
}
}
/// Returns true if `self` is the initial value.
pub fn is_initial(&self) -> bool {
matches!(*self, Self::None) // FIXME: can't use Self::INITIAL_VALUE here yet: https://github.com/rust-lang/rust/issues/66585
}
}
impl<L, I> Default for GridTemplateComponent<L, I> {
#[inline]
fn default() -> Self {
Self::INITIAL_VALUE
}
}