Type Alias LangSys

pub type LangSys<'a> = TableRef<'a, LangSysMarker>;

Language System Table

Aliased Type

struct LangSys<'a> { /* private fields */ }

Implementations

impl LangSys<'_>

pub fn feature_index_for_tag( &self, list: &FeatureList<'_>, tag: Tag, ) -> Option<u16>

If the language system references a feature with the given tag, returns the index of that feature in the specified feature list.

The feature list can be obtained from the feature_list method on the parent Gsub or Gpos tables.

impl<'a> LangSys<'a>

pub fn required_feature_index(&self) -> u16

Index of a feature required for this language system; if no required features = 0xFFFF

pub fn feature_index_count(&self) -> u16

Number of feature index values for this language system — excludes the required feature

pub fn feature_indices(&self) -> &'a [BigEndian<u16>]

Array of indices into the FeatureList, in arbitrary order

impl<'a, T> TableRef<'a, T>

pub fn resolve_offset<O: Offset, R: FontRead<'a>>( &self, offset: O, ) -> Result<R, ReadError>

Resolve the provided offset from the start of this table.

pub fn offset_data(&self) -> FontData<'a>

Return a reference to this table’s raw data.

We use this in the compile crate to resolve offsets.

pub fn shape(&self) -> &T

Return a reference to the table’s ‘Shape’ struct.

This is a low level implementation detail, but it can be useful in some cases where you want to know things about a table’s layout, such as the byte offsets of specific fields.

Trait Implementations

impl<'a> FontRead<'a> for LangSys<'a>

fn read(data: FontData<'a>) -> Result<Self, ReadError>

Read an instance of Self from the provided data, performing validation.

impl<'a, T: Clone> Clone for TableRef<'a, T>

fn clone(&self) -> TableRef<'a, T>

Returns a copy of the value.

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

Performs copy-assignment from source.