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Diffstat (limited to 'servo/components/style/values/specified/motion.rs')
| -rw-r--r-- | servo/components/style/values/specified/motion.rs | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/servo/components/style/values/specified/motion.rs b/servo/components/style/values/specified/motion.rs new file mode 100644 index 0000000000..cf223800f4 --- /dev/null +++ b/servo/components/style/values/specified/motion.rs @@ -0,0 +1,222 @@ +/* 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/. */ + +//! Specified types for CSS values that are related to motion path. + +use crate::parser::{Parse, ParserContext}; +use crate::values::computed::motion::OffsetRotate as ComputedOffsetRotate; +use crate::values::computed::{Context, ToComputedValue}; +use crate::values::generics::motion::{ + GenericOffsetPath, GenericOffsetPosition, RayFunction, RaySize, +}; +use crate::values::specified::position::{HorizontalPosition, VerticalPosition}; +use crate::values::specified::{Angle, SVGPathData}; +use crate::Zero; +use cssparser::Parser; +use style_traits::{ParseError, StyleParseErrorKind}; + +/// The specified value of `offset-path`. +pub type OffsetPath = GenericOffsetPath<Angle>; + +/// The specified value of `offset-position`. +pub type OffsetPosition = GenericOffsetPosition<HorizontalPosition, VerticalPosition>; + +impl Parse for RayFunction<Angle> { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + if !static_prefs::pref!("layout.css.motion-path-ray.enabled") { + return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)); + } + + let mut angle = None; + let mut size = None; + let mut contain = false; + loop { + if angle.is_none() { + angle = input.try_parse(|i| Angle::parse(context, i)).ok(); + } + + if size.is_none() { + size = input.try_parse(RaySize::parse).ok(); + if size.is_some() { + continue; + } + } + + if !contain { + contain = input + .try_parse(|i| i.expect_ident_matching("contain")) + .is_ok(); + if contain { + continue; + } + } + break; + } + + if angle.is_none() { + return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)); + } + + Ok(RayFunction { + angle: angle.unwrap(), + // If no <ray-size> is specified it defaults to closest-side. + size: size.unwrap_or(RaySize::ClosestSide), + contain, + }) + } +} + +impl Parse for OffsetPath { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + use crate::values::specified::svg_path::AllowEmpty; + + // Parse none. + if input.try_parse(|i| i.expect_ident_matching("none")).is_ok() { + return Ok(OffsetPath::none()); + } + + // Parse possible functions. + let location = input.current_source_location(); + let function = input.expect_function()?.clone(); + input.parse_nested_block(move |i| { + match_ignore_ascii_case! { &function, + // Bug 1186329: Implement the parser for <basic-shape>, <geometry-box>, + // and <url>. + "path" => SVGPathData::parse(i, AllowEmpty::No).map(OffsetPath::Path), + "ray" => RayFunction::parse(context, i).map(OffsetPath::Ray), + _ => { + Err(location.new_custom_error( + StyleParseErrorKind::UnexpectedFunction(function.clone()) + )) + }, + } + }) + } +} + +/// The direction of offset-rotate. +#[derive( + Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem, +)] +#[repr(u8)] +pub enum OffsetRotateDirection { + /// Unspecified direction keyword. + #[css(skip)] + None, + /// 0deg offset (face forward). + Auto, + /// 180deg offset (face backward). + Reverse, +} + +impl OffsetRotateDirection { + /// Returns true if it is none (i.e. the keyword is not specified). + #[inline] + fn is_none(&self) -> bool { + *self == OffsetRotateDirection::None + } +} + +#[inline] +fn direction_specified_and_angle_is_zero(direction: &OffsetRotateDirection, angle: &Angle) -> bool { + !direction.is_none() && angle.is_zero() +} + +/// The specified offset-rotate. +/// The syntax is: "[ auto | reverse ] || <angle>" +/// +/// https://drafts.fxtf.org/motion-1/#offset-rotate-property +#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)] +pub struct OffsetRotate { + /// [auto | reverse]. + #[css(skip_if = "OffsetRotateDirection::is_none")] + direction: OffsetRotateDirection, + /// <angle>. + /// If direction is None, this is a fixed angle which indicates a + /// constant clockwise rotation transformation applied to it by this + /// specified rotation angle. Otherwise, the angle will be added to + /// the angle of the direction in layout. + #[css(contextual_skip_if = "direction_specified_and_angle_is_zero")] + angle: Angle, +} + +impl OffsetRotate { + /// Returns the initial value, auto. + #[inline] + pub fn auto() -> Self { + OffsetRotate { + direction: OffsetRotateDirection::Auto, + angle: Angle::zero(), + } + } + + /// Returns true if self is auto 0deg. + #[inline] + pub fn is_auto(&self) -> bool { + self.direction == OffsetRotateDirection::Auto && self.angle.is_zero() + } +} + +impl Parse for OffsetRotate { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + let location = input.current_source_location(); + let mut direction = input.try_parse(OffsetRotateDirection::parse); + let angle = input.try_parse(|i| Angle::parse(context, i)); + if direction.is_err() { + // The direction and angle could be any order, so give it a change to parse + // direction again. + direction = input.try_parse(OffsetRotateDirection::parse); + } + + if direction.is_err() && angle.is_err() { + return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError)); + } + + Ok(OffsetRotate { + direction: direction.unwrap_or(OffsetRotateDirection::None), + angle: angle.unwrap_or(Zero::zero()), + }) + } +} + +impl ToComputedValue for OffsetRotate { + type ComputedValue = ComputedOffsetRotate; + + #[inline] + fn to_computed_value(&self, context: &Context) -> Self::ComputedValue { + use crate::values::computed::Angle as ComputedAngle; + + ComputedOffsetRotate { + auto: !self.direction.is_none(), + angle: if self.direction == OffsetRotateDirection::Reverse { + // The computed value should always convert "reverse" into "auto". + // e.g. "reverse calc(20deg + 10deg)" => "auto 210deg" + self.angle.to_computed_value(context) + ComputedAngle::from_degrees(180.0) + } else { + self.angle.to_computed_value(context) + }, + } + } + + #[inline] + fn from_computed_value(computed: &Self::ComputedValue) -> Self { + OffsetRotate { + direction: if computed.auto { + OffsetRotateDirection::Auto + } else { + OffsetRotateDirection::None + }, + angle: ToComputedValue::from_computed_value(&computed.angle), + } + } +} |