style_traits/
lib.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! This module contains shared types and messages for use by devtools/script.
6//! The traits are here instead of in script so that the devtools crate can be
7//! modified independently of the rest of Servo.
8
9#![crate_name = "style_traits"]
10#![crate_type = "rlib"]
11#![deny(unsafe_code, missing_docs)]
12
13#[macro_use]
14extern crate malloc_size_of_derive;
15#[macro_use]
16extern crate serde;
17#[macro_use]
18extern crate to_shmem_derive;
19#[cfg(feature = "servo")]
20extern crate url;
21
22use bitflags::bitflags;
23use cssparser::{CowRcStr, Token};
24use selectors::parser::SelectorParseErrorKind;
25#[cfg(feature = "servo")]
26use stylo_atoms::Atom;
27
28/// One hardware pixel.
29///
30/// This unit corresponds to the smallest addressable element of the display hardware.
31#[derive(Clone, Copy, Debug)]
32pub enum DevicePixel {}
33
34/// Represents a mobile style pinch zoom factor.
35#[derive(Clone, Copy, Debug, PartialEq)]
36#[cfg_attr(feature = "servo", derive(Deserialize, Serialize, MallocSizeOf))]
37pub struct PinchZoomFactor(f32);
38
39impl PinchZoomFactor {
40    /// Construct a new pinch zoom factor.
41    pub fn new(scale: f32) -> PinchZoomFactor {
42        PinchZoomFactor(scale)
43    }
44
45    /// Get the pinch zoom factor as an untyped float.
46    pub fn get(&self) -> f32 {
47        self.0
48    }
49}
50
51/// One CSS "px" in the coordinate system of the "initial viewport":
52/// <http://www.w3.org/TR/css-device-adapt/#initial-viewport>
53///
54/// `CSSPixel` is equal to `DeviceIndependentPixel` times a "page zoom" factor controlled by the user.  This is
55/// the desktop-style "full page" zoom that enlarges content but then reflows the layout viewport
56/// so it still exactly fits the visible area.
57///
58/// At the default zoom level of 100%, one `CSSPixel` is equal to one `DeviceIndependentPixel`.  However, if the
59/// document is zoomed in or out then this scale may be larger or smaller.
60#[derive(Clone, Copy, Debug)]
61pub enum CSSPixel {}
62
63// In summary, the hierarchy of pixel units and the factors to convert from one to the next:
64//
65// DevicePixel
66//   / hidpi_ratio => DeviceIndependentPixel
67//     / desktop_zoom => CSSPixel
68
69pub mod arc_slice;
70pub mod dom;
71pub mod specified_value_info;
72#[macro_use]
73pub mod values;
74pub mod owned_slice;
75pub mod owned_str;
76
77pub use crate::specified_value_info::{CssType, KeywordsCollectFn, SpecifiedValueInfo};
78pub use crate::values::{
79    Comma, CommaWithSpace, CssString, CssStringWriter, CssWriter, OneOrMoreSeparated, Separator,
80    Space, ToCss, ToTyped, TypedValue,
81};
82
83/// The error type for all CSS parsing routines.
84pub type ParseError<'i> = cssparser::ParseError<'i, StyleParseErrorKind<'i>>;
85
86/// Error in property value parsing
87pub type ValueParseError<'i> = cssparser::ParseError<'i, ValueParseErrorKind<'i>>;
88
89#[derive(Clone, Debug, PartialEq)]
90/// Errors that can be encountered while parsing CSS values.
91pub enum StyleParseErrorKind<'i> {
92    /// A bad URL token in a DVB.
93    BadUrlInDeclarationValueBlock(CowRcStr<'i>),
94    /// A bad string token in a DVB.
95    BadStringInDeclarationValueBlock(CowRcStr<'i>),
96    /// Unexpected closing parenthesis in a DVB.
97    UnbalancedCloseParenthesisInDeclarationValueBlock,
98    /// Unexpected closing bracket in a DVB.
99    UnbalancedCloseSquareBracketInDeclarationValueBlock,
100    /// Unexpected closing curly bracket in a DVB.
101    UnbalancedCloseCurlyBracketInDeclarationValueBlock,
102    /// A property declaration value had input remaining after successfully parsing.
103    PropertyDeclarationValueNotExhausted,
104    /// An unexpected dimension token was encountered.
105    UnexpectedDimension(CowRcStr<'i>),
106    /// Missing or invalid media feature name.
107    MediaQueryExpectedFeatureName(CowRcStr<'i>),
108    /// Missing or invalid media feature value.
109    MediaQueryExpectedFeatureValue,
110    /// A media feature range operator was not expected.
111    MediaQueryUnexpectedOperator,
112    /// min- or max- properties must have a value.
113    RangedExpressionWithNoValue,
114    /// A function was encountered that was not expected.
115    UnexpectedFunction(CowRcStr<'i>),
116    /// Error encountered parsing a @property's `syntax` descriptor
117    PropertySyntaxField(PropertySyntaxParseError),
118    /// Error encountered parsing a @property's `inherits` descriptor.
119    ///
120    /// TODO(zrhoffman, bug 1920365): Include the custom property name in error messages.
121    PropertyInheritsField(PropertyInheritsParseError),
122    /// @namespace must be before any rule but @charset and @import
123    UnexpectedNamespaceRule,
124    /// @import must be before any rule but @charset
125    UnexpectedImportRule,
126    /// @import rules are disallowed in the parser.
127    DisallowedImportRule,
128    /// Unexpected @charset rule encountered.
129    UnexpectedCharsetRule,
130    /// The @property `<custom-property-name>` must start with `--`
131    UnexpectedIdent(CowRcStr<'i>),
132    /// A placeholder for many sources of errors that require more specific variants.
133    UnspecifiedError,
134    /// An unexpected token was found within a namespace rule.
135    UnexpectedTokenWithinNamespace(Token<'i>),
136    /// An error was encountered while parsing a property value.
137    ValueError(ValueParseErrorKind<'i>),
138    /// An error was encountered while parsing a selector
139    SelectorError(SelectorParseErrorKind<'i>),
140    /// The property declaration was for an unknown property.
141    UnknownProperty(CowRcStr<'i>),
142    /// The property declaration was for a disabled experimental property.
143    ExperimentalProperty,
144    /// The property declaration contained an invalid color value.
145    InvalidColor(CowRcStr<'i>, Token<'i>),
146    /// The property declaration contained an invalid filter value.
147    InvalidFilter(CowRcStr<'i>, Token<'i>),
148    /// The property declaration contained an invalid value.
149    OtherInvalidValue(CowRcStr<'i>),
150    /// `!important` declarations are disallowed in `@position-try` or keyframes.
151    UnexpectedImportantDeclaration,
152}
153
154impl<'i> From<ValueParseErrorKind<'i>> for StyleParseErrorKind<'i> {
155    fn from(this: ValueParseErrorKind<'i>) -> Self {
156        StyleParseErrorKind::ValueError(this)
157    }
158}
159
160impl<'i> From<SelectorParseErrorKind<'i>> for StyleParseErrorKind<'i> {
161    fn from(this: SelectorParseErrorKind<'i>) -> Self {
162        StyleParseErrorKind::SelectorError(this)
163    }
164}
165
166/// Specific errors that can be encountered while parsing property values.
167#[derive(Clone, Debug, PartialEq)]
168pub enum ValueParseErrorKind<'i> {
169    /// An invalid token was encountered while parsing a color value.
170    InvalidColor(Token<'i>),
171    /// An invalid filter value was encountered.
172    InvalidFilter(Token<'i>),
173}
174
175impl<'i> StyleParseErrorKind<'i> {
176    /// Create an InvalidValue parse error
177    pub fn new_invalid<S>(name: S, value_error: ParseError<'i>) -> ParseError<'i>
178    where
179        S: Into<CowRcStr<'i>>,
180    {
181        let name = name.into();
182        let variant = match value_error.kind {
183            cssparser::ParseErrorKind::Custom(StyleParseErrorKind::ValueError(e)) => match e {
184                ValueParseErrorKind::InvalidColor(token) => {
185                    StyleParseErrorKind::InvalidColor(name, token)
186                },
187                ValueParseErrorKind::InvalidFilter(token) => {
188                    StyleParseErrorKind::InvalidFilter(name, token)
189                },
190            },
191            _ => StyleParseErrorKind::OtherInvalidValue(name),
192        };
193        cssparser::ParseError {
194            kind: cssparser::ParseErrorKind::Custom(variant),
195            location: value_error.location,
196        }
197    }
198}
199
200/// Errors that can be encountered while parsing the @property rule's syntax descriptor.
201#[derive(Clone, Debug, PartialEq)]
202pub enum PropertySyntaxParseError {
203    /// The syntax descriptor is required for the @property rule to be valid; if it’s missing, the
204    /// @property rule is invalid.
205    ///
206    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#ref-for-descdef-property-syntax②>
207    NoSyntax,
208    /// The string's length was 0.
209    EmptyInput,
210    /// A non-whitespace, non-pipe character was fount after parsing a component.
211    ExpectedPipeBetweenComponents,
212    /// The start of an identifier was expected but not found.
213    ///
214    /// <https://drafts.csswg.org/css-syntax-3/#name-start-code-point>
215    InvalidNameStart,
216    /// The name is not a valid `<ident>`.
217    InvalidName,
218    /// The data type name was not closed.
219    ///
220    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#consume-data-type-name>
221    UnclosedDataTypeName,
222    /// The next byte was expected while parsing, but EOF was found instead.
223    UnexpectedEOF,
224    /// The data type is not a supported syntax component name.
225    ///
226    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#supported-names>
227    UnknownDataTypeName,
228}
229
230/// Errors that can be encountered while parsing the @property rule's inherits descriptor.
231#[derive(Clone, Debug, PartialEq)]
232pub enum PropertyInheritsParseError {
233    /// The inherits descriptor is required for the @property rule to be valid; if it’s missing,
234    /// the @property rule is invalid.
235    ///
236    /// <https://drafts.css-houdini.org/css-properties-values-api-1/#ref-for-descdef-property-inherits②>
237    NoInherits,
238
239    /// The inherits descriptor must successfully parse as `true` or `false`.
240    InvalidInherits,
241}
242
243bitflags! {
244    /// The mode to use when parsing values.
245    #[derive(Clone, Copy, Eq, PartialEq)]
246    #[repr(C)]
247    pub struct ParsingMode: u8 {
248        /// In CSS; lengths must have units, except for zero values, where the unit can be omitted.
249        /// <https://www.w3.org/TR/css3-values/#lengths>
250        const DEFAULT = 0;
251        /// In SVG; a coordinate or length value without a unit identifier (e.g., "25") is assumed
252        /// to be in user units (px).
253        /// <https://www.w3.org/TR/SVG/coords.html#Units>
254        const ALLOW_UNITLESS_LENGTH = 1;
255        /// In SVG; out-of-range values are not treated as an error in parsing.
256        /// <https://www.w3.org/TR/SVG/implnote.html#RangeClamping>
257        const ALLOW_ALL_NUMERIC_VALUES = 1 << 1;
258        /// In CSS Properties and Values, the initial value must be computationally
259        /// independent.
260        /// <https://drafts.css-houdini.org/css-properties-values-api-1/#ref-for-computationally-independent%E2%91%A0>
261        const DISALLOW_COMPUTATIONALLY_DEPENDENT = 1 << 2;
262    }
263}
264
265impl ParsingMode {
266    /// Whether the parsing mode allows unitless lengths for non-zero values to be intpreted as px.
267    #[inline]
268    pub fn allows_unitless_lengths(&self) -> bool {
269        self.intersects(ParsingMode::ALLOW_UNITLESS_LENGTH)
270    }
271
272    /// Whether the parsing mode allows all numeric values.
273    #[inline]
274    pub fn allows_all_numeric_values(&self) -> bool {
275        self.intersects(ParsingMode::ALLOW_ALL_NUMERIC_VALUES)
276    }
277
278    /// Whether the parsing mode allows units or functions that are not computationally independent.
279    #[inline]
280    pub fn allows_computational_dependence(&self) -> bool {
281        !self.intersects(ParsingMode::DISALLOW_COMPUTATIONALLY_DEPENDENT)
282    }
283}
284
285#[cfg(feature = "servo")]
286/// Speculatively execute paint code in the worklet thread pool.
287pub trait SpeculativePainter: Send + Sync {
288    /// <https://drafts.css-houdini.org/css-paint-api/#draw-a-paint-image>
289    fn speculatively_draw_a_paint_image(
290        &self,
291        properties: Vec<(Atom, String)>,
292        arguments: Vec<String>,
293    );
294}
style_traits/lib.rs

style_traits/
lib.rs
