Donner CSS library, a standalone composable CSS parser. More...

Namespaces
namespace	parser
	Parsers for various CSS data types, such as the top-level StylesheetParser and SelectorParser, as well as internal details such as ColorParser.

Classes
struct	RGBA
	Represents as 32-bit RGBA color, with each component in the range [0, 255]. More...
struct	HSLA
	Represents an HSLA color. More...
struct	Color
	Represents a CSS color value, like a RGBA color from a #rrggbb or #rgb hex value, or the currentcolor keyword. More...
struct	Function
	A CSS function, such as rgb(255, 0, 0), parsed into a function name and a list of parameter values. More...
struct	SimpleBlock
	A CSS simple block, such as a rule block or a parenthesized expression. More...
struct	ComponentValue
	A CSS component value, which is either a token, or a parsed function or block. More...
class	CSS
	Public API for parsing CSS. More...
struct	Declaration
	A declaration is a CSS name/value pair, such as color: red;. More...
struct	DeclarationOrAtRule
	Return value of parsers that may return either a declaration or an AtRule, specifically donner::css::parser::DeclarationListParser::Parse. More...
struct	AnbValue
	An+B microsyntax value, which is parsed by parser::AnbMicrosyntaxParser. More...
struct	FontFaceSource
	A single entry listed in src:—either a local face, a URL, or inline data. More...
struct	FontFace
	In-memory representation of a single @font-face rule. More...
struct	AtRule
	Rules starting with an @ are called At-Rules, and are used to define CSS features such as @media, @font-face, @keyframes, etc. More...
struct	QualifiedRule
	A QualifiedRule has a list of component values and a block, this is the intermediate representation of a stylesheet rule. More...
struct	InvalidRule
	InvalidRule is used to represent a rule which could not be parsed, such as an invalid at-rule. More...
struct	Rule
	Holds a CSS rule which can either be a standard QualifiedRule, an AtRule, or an InvalidRule if there was a parse error. More...
struct	Selector
	A top-level Selector, which is a list of ComplexSelector. More...
struct	AttributeSelector
	Selectors which match against element attributes, such as a[href^="https://"] or h1[title]. More...
struct	ClassSelector
	Selector which match the element's class attribute, for example .foo matches an element with class foo. More...
struct	SelectorMatchResult
	Returned by Selector::matches to indicate whether the selector matched, and if so, the specificity of the match. More...
struct	ComplexSelector
	A complex selector is a sequence of one or more compound selectors, separated by combinators. More...
struct	CompoundSelector
	A compound selector is a sequence of simple selectors, which represents a set of conditions that are combined to match a single element. More...
struct	IdSelector
	Selector which match the element's id attribute, for example #foo matches an element with an id="foo" attribute. More...
struct	PseudoClassSelector
	Selectors which start with one colon, e.g. More...
struct	PseudoElementSelector
	Selectors which start with two colons are called pseudo-elements, e.g. More...
struct	SelectorMatchOptions
	Options for matching a selector against an element. More...
struct	TypeSelector
	Selector which matches the element type, e.g. More...
class	Specificity
	A CSS specificity value (id, class, type), as defined in https://www.w3.org/TR/selectors-4/#specificity-rules, which is used during cascading to determine which style takes precedence. More...
struct	SelectorRule
	A rule in a stylesheet, which consists of a selector and a list of declarations. More...
class	Stylesheet
	A CSS stylesheet, which is a list of rules. More...
struct	Token
	A CSS token, which are created as a first step when parsing a CSS string. More...
struct	WqName
	A CSS qualified name, which is a name optionally associated with a namespace. More...

Typedefs
using	TokenIndex = size_t
	Type of the token unique identifier, which is returned by Token::tokenIndex() and Token::indexOf<T>().

Enumerations
enum class	AttrMatcher { Includes , DashMatch , PrefixMatch , SuffixMatch , SubstringMatch , Eq }
	For attribute selectors, different match modes are available, which are specified by this enum. More...
enum class	Combinator { Descendant , Child , NextSibling , SubsequentSibling , Column }
	Between two compound selectors, there can be a combinator, which specifies how the two elements are associated in the tree. More...
enum class	NumberType { Integer , Number }
	Indicates if a number is an integer or a floating point number, used for number-containing tokens such as Token::Number and Token::Dimension. More...

Functions
constexpr Color	RgbHex (uint32_t value)
	Construct a donner::css::Color from a 24-bit RGB hex literal.
constexpr Color	RgbaHex (uint32_t value)
	Construct a donner::css::Color from a 32-bit RGBA hex literal.
std::string	mergeStyleDeclarations (std::span< const Declaration > existing, std::span< const Declaration > updates)
	Merge two sets of CSS declarations, where `updates` override declarations in `existing` that have the same property name (case-insensitive).
std::ostream &	operator<< (std::ostream &os, AttrMatcher matcher)
	Ostream output operator.
std::ostream &	operator<< (std::ostream &os, Combinator combinator)
	Ostream output operator.

Detailed Description

Donner CSS library, a standalone composable CSS parser.

This library is designed to be used in other projects, and provides building blocks to add CSS parsing to any application. This is used by Donner itself to parse SVG stylesheets, but it can be used for HTML-based CSS as well.

This library includes support for parsing rules and declarations, as well as matching selectors against a DOM tree.

To get started, parse a Stylesheet using CSS::ParseStylesheet, and then use the returned Stylesheet object to match against a DOM tree:

ParseWarningSink warnings;
auto stylesheet = CSS::ParseStylesheet("svg { fill: red; }", warnings);
for (const css::SelectorRule& rule : stylesheet.rules()) {
  if (css::SelectorMatchResult match = rule.selector.matches(domNode)) {
    applyDeclaration(rule.declarations, match.specificity);
  }
}

Class Documentation

◆ donner::css::FontFace

struct donner::css::FontFace

In-memory representation of a single @font-face rule.

Collaboration diagram for donner::css::FontFace:

[legend]

Class Members
RcString	familyName	font-family descriptor
int	fontStretch = 5	font-stretch descriptor (1-9, 5=normal, matching FontStretch enum)
int	fontStyle = 0	font-style descriptor (0=normal, 1=italic, 2=oblique)
int	fontWeight = 400	font-weight descriptor (100-900, 400=normal, 700=bold)
vector< FontFaceSource >	sources	ordered src list

◆ donner::css::SelectorMatchOptions

struct donner::css::SelectorMatchOptions

template<ElementLike T>
struct donner::css::SelectorMatchOptions< T >

Options for matching a selector against an element.

This is used to pass additional information to the matching algorithm, such as the element to match against for relative queries.

Template Parameters

T	A type that fulfills the ElementLike concept, matching the Selector::matches method.

Collaboration diagram for donner::css::SelectorMatchOptions< T >:

[legend]

Class Members
const T *	relativeToElement	Enables relative querying and uses this element as the reference point. For example, > div will match div that is a child of relativeToElement.
const T *	scopeElement = nullptr	Element to match against :scope queries. Cannot be matched directly, but can be used for relative matching.

Enumeration Type Documentation

◆ AttrMatcher

enum class donner::css::AttrMatcher

strong

For attribute selectors, different match modes are available, which are specified by this enum.

See https://www.w3.org/TR/selectors-4/#attribute-selectors for the full definition.

These are used within square brackets on the selector list, such as a[href^="https://"] or h1[title], and AttrMatcher represents the separator between the attribute name and string, such as ^= or =.

Enumerator
Includes	"~=", matches if the attribute value is a whitespace-separated list of values, and one of them exactly matches the matcher value.
DashMatch	"\|=", matches if the attribute value either exactly matches, or begins with the value immediately followed by a dash ("-").
PrefixMatch	"^=", matches if the attribute value begins with the matcher value.
SuffixMatch	"$=", matches if the attribute value ends with the matcher value.
SubstringMatch	"*=", matches if the attribute value contains the matcher value.
Eq	"=", matches if the attribute value exactly matches the matcher value.

◆ Combinator

enum class donner::css::Combinator

strong

Between two compound selectors, there can be a combinator, which specifies how the two elements are associated in the tree.

By default, a space between compound selectors is a descendant combinator, e.g. div span is a Descendant combinator, while div > span is a Child combinator.

Enumerator
Descendant	Space-separated, finds descendants in the tree.
Child	'>', finds direct children in the tree.
NextSibling	'+', finds the next sibling in the tree.
SubsequentSibling	'~', finds all subsequent siblings in the tree.
Column	'\|\|', finds the next column in the tree. Note that this is a new feature in CSS Selectors Level 4, but isn't applicable to SVG.

◆ NumberType

enum class donner::css::NumberType

strong

Indicates if a number is an integer or a floating point number, used for number-containing tokens such as Token::Number and Token::Dimension.

Enumerator
Integer	Integer number (no decimal point).
Number	Floating point number.

Function Documentation

◆ mergeStyleDeclarations()

std::string donner::css::mergeStyleDeclarations	(	std::span< const Declaration >	existing,
		std::span< const Declaration >	updates )

Merge two sets of CSS declarations, where updates override declarations in existing that have the same property name (case-insensitive).

Unrelated existing declarations are preserved. Duplicate property names within updates are deduplicated, keeping the last occurrence.

Parameters

existing	Existing declarations.
updates	Updated declarations to apply.

Returns: Merged style string with declarations separated by "; ".

◆ operator<<()

std::ostream & donner::css::operator<<	(	std::ostream &	os,
		Combinator	combinator )

inline

Ostream output operator.

Outputs the combinator character, e.g. ' ', '>', '+', '~' or '||'.

Parameters

os	The output stream.
combinator	The combinator.

◆ RgbaHex()

Color donner::css::RgbaHex ( uint32_t value )

constexpr

Construct a donner::css::Color from a 32-bit RGBA hex literal.

For example, for 50% opacity red:

const Color red = RgbaHex(0xFF000080);

donner::css::RgbaHex

constexpr Color RgbaHex(uint32_t value)

Construct a donner::css::Color from a 32-bit RGBA hex literal.

Definition Color.h:256

donner::css::Color

Represents a CSS color value, like a RGBA color from a #rrggbb or #rgb hex value, or the currentcolor...

Definition Color.h:113

Parameters

value Integer representation of the color value (0xRRGGBBAA).

◆ RgbHex()

Color donner::css::RgbHex ( uint32_t value )

constexpr

Construct a donner::css::Color from a 24-bit RGB hex literal.

For example:

const Color red = RgbHex(0xFF0000);

donner::css::RgbHex

constexpr Color RgbHex(uint32_t value)

Construct a donner::css::Color from a 24-bit RGB hex literal.

Definition Color.h:242

Parameters

value Integer representation of the color value (0xRRGGBB).

Namespaces

Classes

Typedefs

Enumerations

Functions

Detailed Description

Class Documentation

◆ donner::css::FontFace

◆ donner::css::SelectorMatchOptions

Enumeration Type Documentation

◆ AttrMatcher

◆ Combinator

◆ NumberType

Function Documentation

◆ mergeStyleDeclarations()

◆ operator<<()

◆ RgbaHex()

◆ RgbHex()