Module pixel 

CSS length and pixel value types, parsing, and unit resolution.

Defines PixelValue (a numeric value + CSS unit like px, em, rem, %), ResolutionContext (contextual information for resolving relative units), and PropertyContext (which property is being resolved, affecting % and em semantics).

Resolution paths:

• resolve_with_context() — the correct method for new code; properly distinguishes em vs rem, and resolves % based on property type per the CSS spec.
• to_pixels_internal() — legacy fallback used by prop_cache.rs; does not distinguish rem from em. Marked #[doc(hidden)].

Structs

CssLogicalSize

Logical size in CSS logical coordinate system

NormalizedPercentage

A normalized percentage value (0.0 = 0%, 1.0 = 100%)

PhysicalSize

Physical size (always width x height, regardless of writing mode)

PixelNoValueGivenError

Wrapper for NoValueGiven error in pixel value parsing.

PixelValue

A CSS length value consisting of a numeric value and a unit (px, em, rem, %, etc.).

PixelValueNoPercent

Same as PixelValue, but doesn’t allow a “%” sign

ResolutionContext

Context information needed to properly resolve CSS units (em, rem, %) to pixels.

Enums

CssPixelValueParseError

CssPixelValueParseErrorOwned

Owned version of CssPixelValueParseError.

OptionPixelValue

OptionPixelValueNoPercent

PixelValueOrSystem

A pixel value reference that can be either a concrete value or a system metric. System metrics are lazily evaluated at runtime based on the user’s system theme.

PixelValueWithAuto

PropertyContext

Specifies which property context we’re resolving for, to determine correct reference values

SystemMetricRef

Reference to a specific system metric value. These are resolved at runtime based on the user’s system preferences.

Constants

DEFAULT_FONT_SIZE

Default font size in pixels (16px), matching the CSS “medium” keyword and all major browser defaults (CSS 2.1 §15.7).

MEDIUM_BORDER_THICKNESS

border-width: medium = 3px (per CSS spec, default)

PT_TO_PX

Conversion factor from points to pixels (1pt = 1/72 inch, 1in = 96px, therefore 1pt = 96/72 px)

THICK_BORDER_THICKNESS

border-width: thick = 5px (per CSS spec)

THIN_BORDER_THICKNESS

border-width: thin = 1px (per CSS spec)

Functions

parse_pixel_value

parse_pixel_value_no_percent

parse_pixel_value_or_system

Parse a pixel value that may include system metric references.

parse_pixel_value_with_auto

Parses a pixel value, but also tries values like “auto”, “initial”, “inherit” and “none”