Struct FontRegistry 

pub struct FontRegistry { /* private fields */ }

Font registry that discovers and caches system fonts

Implementations

impl FontRegistry

pub fn new() -> FontRegistry

Create a new font registry with lazy loading

Only loads known essential system fonts by path. Full system font scan is deferred until needed.

pub fn load_font_data(&mut self, data: Vec<u8>) -> usize

Load a font from raw data (e.g., embedded or bundled fonts)

This is useful for loading fonts that aren’t in the standard system paths, such as app-bundled fonts or fonts loaded via CoreText on iOS.

Returns the number of font faces loaded from the data.

pub fn preload_fonts(&mut self, names: &[&str])

Preload specific fonts by name with all available variants (call at startup for fonts your app uses)

This discovers and loads all variants (bold, italic, etc.) of each font. Note: This may trigger a full system font scan if the font isn’t found in the known fonts.

pub fn load_font(&mut self, name: &str) -> Result<Arc<FontFace>, TextError>

Load a font by name (e.g., “Fira Code”, “Inter”, “Arial”)

pub fn load_font_with_style( &mut self, name: &str, weight: u16, italic: bool, ) -> Result<Arc<FontFace>, TextError>

Load a font by name with specific weight and italic style

Arguments

• name - Font family name (e.g., “Fira Code”, “Inter”)
• weight - Font weight (100-900, where 400 is normal, 700 is bold)
• italic - Whether to load italic variant

pub fn load_generic( &mut self, generic: GenericFont, ) -> Result<Arc<FontFace>, TextError>

Load a generic font category

pub fn load_generic_with_style( &mut self, generic: GenericFont, weight: u16, italic: bool, ) -> Result<Arc<FontFace>, TextError>

Load a generic font category with specific weight and italic style

Arguments

• generic - Generic font category (System, Monospace, Serif, SansSerif)
• weight - Font weight (100-900, where 400 is normal, 700 is bold)
• italic - Whether to load italic variant

pub fn load_with_fallback( &mut self, name: Option<&str>, generic: GenericFont, ) -> Result<Arc<FontFace>, TextError>

Load a font with fallback to generic category

pub fn load_with_fallback_styled( &mut self, name: Option<&str>, generic: GenericFont, weight: u16, italic: bool, ) -> Result<Arc<FontFace>, TextError>

Load a font with fallback to generic category, with specific weight and style

pub fn get_cached(&self, name: &str) -> Option<Arc<FontFace>>

Get cached font by name (doesn’t load - for use during render)

pub fn get_cached_with_style( &self, name: &str, weight: u16, italic: bool, ) -> Option<Arc<FontFace>>

Get cached font by name with specific weight and style

pub fn get_cached_generic(&self, generic: GenericFont) -> Option<Arc<FontFace>>

Get cached generic font (doesn’t load - for use during render)

pub fn get_cached_generic_with_style( &self, generic: GenericFont, weight: u16, italic: bool, ) -> Option<Arc<FontFace>>

Get cached generic font with specific weight and style

pub fn get_for_render( &self, name: Option<&str>, generic: GenericFont, ) -> Option<Arc<FontFace>>

Fast font lookup for rendering - only uses cache, never loads Returns the requested font if cached, or None if loading is needed

pub fn get_for_render_with_style( &self, name: Option<&str>, generic: GenericFont, weight: u16, italic: bool, ) -> Option<Arc<FontFace>>

Fast font lookup for rendering with specific weight and style

pub fn get_emoji_font(&self) -> Option<Arc<FontFace>>

Get the emoji font if available (cached)

Returns the cached emoji font if it was successfully loaded during initialization, or None if no emoji font is available.

pub fn needs_emoji_font(c: char) -> bool

Check if a character needs an emoji font

Returns true for emoji characters that typically need a color emoji font.

pub fn list_families(&mut self) -> Vec<String>

List available font families on the system

Note: This triggers a full system font scan if not already done.

pub fn has_font(&mut self, name: &str) -> bool

Check if a font is available

Note: This may trigger a full system font scan if the font isn’t found in the initially loaded fonts.

pub fn preload_font_family(&mut self, name: &str)

Preload all variants (weights and styles) of a font family

This discovers all available variants of the font using fontdb and loads each one into the cache.

Trait Implementations

impl Default for FontRegistry

fn default() -> FontRegistry

Returns the “default value” for a type.