Class CssPropertyRegistry

Namespace

Egami.Css

Assembly

Egami.Css.dll

The properties the cascade knows. CreateDefault() gives the common text properties of CSS; consumers add their own, such as Egami.Svg's fill and stroke. Unregistered properties cascade too, as non-inherited properties without an initial value. Do not change a registry while a cascade built from it is in use.

public sealed class CssPropertyRegistry

Inheritance

object

CssPropertyRegistry

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// The registry says which properties inherit and their initial values; consumers add their own.
CssPropertyRegistry registry = CssPropertyRegistry.CreateDefault();
registry.Register(new CssPropertyDefinition("fill", Inherited: true, InitialValue: "black")
{
    Validate = value => CssColor.TryParse(value, out _),
});
registry.RegisterShorthand(new CssShorthandDefinition("marker", ["marker-start", "marker-end"],
    value => [new CssDeclaration("marker-start", value), new CssDeclaration("marker-end", value)]));

CssStyleSheet userAgent = CssStyleSheet.Parse("rect { fill: gray }");
CssStyleSheet author = CssStyleSheet.Parse("""
    svg { --accent: teal; font: 12px sans-serif }
    .layer { fill: var(--accent) }
    #r { fill: inherit; opacity: 0.5 }
    """);
var cascade = new CssCascade(
    [(userAgent, CssOrigin.UserAgent), (author, CssOrigin.Author)],
    new CssCascadeOptions { Registry = registry, Media = new CssMediaContext { Width = 800 } });

// Cascade each element (presentation attributes as hints, the style attribute as inline style), then compute it
// from its parent's computed style.
CssComputedStyle rootStyle = cascade.Compute(cascade.Cascade(root), null);
CssComputedStyle groupStyle = cascade.Compute(cascade.Cascade(group), rootStyle);
CssCascadedStyle cascaded = cascade.Cascade(rect,
    presentationHints: [CssDeclaration.Create("fill", "red")],
    inlineStyle: CssDeclaration.ParseList("stroke: blue"));
CssComputedStyle style = cascade.Compute(cascaded, groupStyle);

cascaded.TryGetDeclaration("fill", out CssDeclaration? winner, out CssOrigin origin); // fill: inherit, Author
string? fill = style.GetValueText("fill");           // "teal": inherited, var() substituted
string? fontSize = style.GetValueText("font-size");  // "12px": from the font shorthand, inherited
if (style.TryGetValue("opacity", out IReadOnlyList<CssComponentValue>? opacity))
{
    // The consumer parses each property by its type.
}

Properties

Properties

Gets the registered longhand properties.

public IEnumerable<CssPropertyDefinition> Properties { get; }

Property Value

IEnumerable<CssPropertyDefinition>

Shorthands

Gets the registered shorthands.

public IEnumerable<CssShorthandDefinition> Shorthands { get; }

Property Value

IEnumerable<CssShorthandDefinition>

Methods

CreateDefault()

Creates a registry with the CSS properties SVG and HTML documents share, each with its value grammar, so an invalid declaration is dropped. Text: color, the font- longhands and the font and font-variant shorthands, line-height, letter-spacing, word-spacing, text-decoration and its longhands, text-align, text-indent, text-transform, white-space, direction, unicode-bidi, writing-mode, text-orientation, visibility, display and opacity. Boxes: the margin-, padding- and border- longhands with the margin, padding, border, border-width, border-style, border-color, border-top (and the other sides) and border-radius shorthands; width, height, their min- and max- forms and box-sizing. Backgrounds: the background- longhands, one comma-separated item per layer, and the background shorthand. Lists: list-style-type, list-style-position, list-style-image and list-style. Tables: border-collapse, border-spacing, caption-side, empty-cells, table-layout and vertical-align. Flow: float, clear, overflow-x, overflow-y and overflow. Fragmentation: break-before, break-after, break-inside, orphans, widows, box-decoration-break, page and the legacy page-break- shorthands. Pages (for CascadePage(CssPage)): size, page-orientation, marks and bleed. Generated content: content, counter-reset, counter-increment and counter-set. The all shorthand is always understood.

public static CssPropertyRegistry CreateDefault()

Returns

CssPropertyRegistry

A new registry the caller may extend.

Register(CssPropertyDefinition)

Registers a longhand property, replacing one of the same name.

public void Register(CssPropertyDefinition definition)

Parameters

definition CssPropertyDefinition

The property.

RegisterShorthand(CssShorthandDefinition)

Registers a shorthand, replacing one of the same name.

public void RegisterShorthand(CssShorthandDefinition definition)

Parameters

definition CssShorthandDefinition

The shorthand.

TryGetProperty(string, out CssPropertyDefinition?)

Looks up a longhand property.

public bool TryGetProperty(string name, out CssPropertyDefinition? definition)

Parameters

name string

The name in lowercase.

definition CssPropertyDefinition

The property when registered.

Returns

bool

True when registered.

TryGetShorthand(string, out CssShorthandDefinition?)

Looks up a shorthand.

public bool TryGetShorthand(string name, out CssShorthandDefinition? definition)

Parameters

name string

The name in lowercase.

definition CssShorthandDefinition

The shorthand when registered.

Returns

bool

True when registered.