Enum LineHeight 

pub enum LineHeight {
    Normal,
    Px(f32),
}

CSS line-height value.

Normal defers resolution to the point where font metrics are available, computing (ascent + |descent| + lineGap) / upem * fontSize. Px is an already-resolved pixel value from an explicit CSS declaration (e.g. line-height: 1.5 → Px(fontSize * 1.5)).

Variants

Normal

line-height: normal — resolve from font metrics at layout time

Px(f32)

Pre-resolved pixel value (from CSS line-height: <number|length|percentage>)

Implementations

impl LineHeight

pub fn resolve( &self, font_size_px: f32, ascent: f32, descent: f32, line_gap: f32, units_per_em: u16, ) -> f32

Resolve to a pixel value, using font metrics when Normal.

ascent, descent (negative in OpenType convention), line_gap are in font units. font_size_px and units_per_em are used to scale.

pub fn resolve_with_metrics( &self, font_size_px: f32, metrics: &LayoutFontMetrics, ) -> f32

Resolve using a LayoutFontMetrics struct for convenience.

Trait Implementations

impl Clone for LineHeight

fn clone(&self) -> LineHeight

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LineHeight

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LineHeight

fn default() -> Self

Returns the “default value” for a type.

impl Hash for LineHeight

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LineHeight

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for LineHeight

impl Eq for LineHeight