Struct FontContext 

pub struct FontContext {

    system_font_service_proxy: Arc<SystemFontServiceProxy>,
    resource_threads: Mutex<CoreResourceThread>,
    paint_api: Mutex<CrossProcessPaintApi>,
    fonts: RwLock<HashMap<FontCacheKey, Option<FontRef>>>,
    resolved_font_groups: RwLock<HashMap<FontGroupCacheKey, Arc<FontGroup>>>,
    web_fonts: CrossThreadFontStore,
    webrender_font_keys: RwLock<HashMap<FontIdentifier, FontKey>>,
    webrender_font_instance_keys: RwLock<HashMap<FontParameters, FontInstanceKey>>,
    font_data: RwLock<HashMap<FontIdentifier, FontData>>,
    have_removed_web_fonts: AtomicBool,
    currently_downloading_fonts: Mutex<HashMap<ServoUrl, Vec<WebFontDownloadState>>>,
    known_font_face_rules: Mutex<KnownFontFaceRules>,
    font_feature_value_map: AtomicRefCell<Option<FontFeatureValueMap>>,
    number_of_loading_web_fonts: AtomicUsize,
}

The FontContext represents the per-thread/thread state necessary for working with fonts. It is the public API used by the layout and paint code. It talks directly to the system font service where required.

Fields

system_font_service_proxy: Arc<SystemFontServiceProxy>

resource_threads: Mutex<CoreResourceThread>

paint_api: Mutex<CrossProcessPaintApi>

A sender that can send messages and receive replies from Paint.

fonts: RwLock<HashMap<FontCacheKey, Option<FontRef>>>

The actual instances of fonts ie a FontTemplate combined with a size and other font properties, along with the font data and a platform font instance.

resolved_font_groups: RwLock<HashMap<FontGroupCacheKey, Arc<FontGroup>>>

A caching map between the specification of a font in CSS style and resolved FontGroup which contains information about all fonts that can be selected with that style.

web_fonts: CrossThreadFontStore

webrender_font_keys: RwLock<HashMap<FontIdentifier, FontKey>>

A collection of WebRender FontKeys generated for the web fonts that this FontContext controls.

webrender_font_instance_keys: RwLock<HashMap<FontParameters, FontInstanceKey>>

A collection of WebRender FontInstanceKeys generated for the web fonts that this FontContext controls.

font_data: RwLock<HashMap<FontIdentifier, FontData>>

The data for each web font FontIdentifier. This data might be used by more than one FontTemplate as each identifier refers to a URL.

have_removed_web_fonts: AtomicBool

currently_downloading_fonts: Mutex<HashMap<ServoUrl, Vec<WebFontDownloadState>>>

Maps from a URL to all the @font-face rules that are currently waiting for the load to finish.

known_font_face_rules: Mutex<KnownFontFaceRules>

The set of @font-face rules that are currently present in the CSS cascade. This is not necessarily equivalent to the rules that actually apply to the page, because rules that are invalid or not yet downloaded are also included.

font_feature_value_map: AtomicRefCell<Option<FontFeatureValueMap>>

A lazily-computed map of feature names from @font-feature-value rules.

number_of_loading_web_fonts: AtomicUsize

The number of fonts that are currently loading.

Implementations

impl FontContext

pub fn new( system_font_service_proxy: Arc<SystemFontServiceProxy>, paint_api: CrossProcessPaintApi, resource_threads: ResourceThreads, ) -> Self

pub fn web_fonts_still_loading(&self) -> usize

fn get_font_data(&self, identifier: &FontIdentifier) -> Option<FontData>

pub fn font_group(&self, style: ServoArc<FontStyleStruct>) -> Arc<FontGroup>

Returns a FontGroup representing fonts which can be used for layout, given the style. Font groups are cached, so subsequent calls with the same style will return a reference to an existing FontGroup.

pub fn font_group_with_size( &self, style: ServoArc<FontStyleStruct>, size: Au, ) -> Arc<FontGroup>

Like Self::font_group, but overriding the size found in the FontStyleStruct with the given size in pixels.

pub fn font( &self, font_template: FontTemplateRef, font_descriptor: &FontDescriptor, ) -> Option<FontRef>

Returns a font matching the parameters. Fonts are cached, so repeated calls will return a reference to the same underlying Font.

fn get_font_maybe_synthesizing_small_caps( &self, font_template: FontTemplateRef, font_descriptor: &FontDescriptor, synthesize_small_caps: bool, ) -> Option<FontRef>

fn matching_web_font_templates( &self, descriptor_to_match: &FontDescriptor, family_descriptor: &FontFamilyDescriptor, ) -> Option<Vec<FontTemplateRef>>

pub fn matching_templates( &self, descriptor_to_match: &FontDescriptor, family_descriptor: &FontFamilyDescriptor, ) -> Vec<FontTemplateRef>

Try to find matching templates in this FontContext, first looking in the list of web fonts and falling back to asking the super::SystemFontService for a matching system font.

fn create_font( &self, font_template: FontTemplateRef, font_descriptor: FontDescriptor, synthesized_small_caps: Option<FontRef>, ) -> Result<FontRef, &'static str>

Create a Font for use in layout calculations, from a FontTemplateData returned by the cache thread and a FontDescriptor which contains the styling parameters.

pub(crate) fn create_font_instance_key( &self, font: &Font, painter_id: PainterId, ) -> FontInstanceKey

fn create_web_font_instance( &self, font_template: FontTemplateRef, pt_size: Au, flags: FontInstanceFlags, variations: Vec<FontVariation>, painter_id: PainterId, ) -> FontInstanceKey

fn invalidate_font_groups_after_web_font_load(&self)

pub fn is_supported_web_font_source(source: &&Source) -> bool

fn is_local_or_unknown_url_font( &self, family_name: &LowercaseFontFamilyName, source: &Source, ) -> bool

pub(crate) fn handle_web_font_request_started( &self, url: ServoUrl, state: WebFontDownloadState, ) -> bool

Adds the provided new web font request to the list of pending downloads.

Returns a boolean indicating whether a new download should be started. If there is already a pending request for the same URL then there is no need to start a new one.

pub(crate) fn handle_web_font_request_succeeded( &self, font_data: FontData, url: ServoUrl, ) -> bool

Handle a web font load finishing, adding the new font to the FontStore. If the web font load was canceled (for instance, if the stylesheet was removed), then do nothing and return false.

All download states waiting for this entry to load will have their promise fulfilled.

pub fn decrement_count_of_loading_fonts_by_one(&self)

Decrement the count of font loads blocking the document.fonts.ready promise by one.

pub(crate) fn is_font_face_rule_active( &self, target_rule: &ServoArc<LockedFontFaceRule>, ) -> bool

Returns true iff a @font-face rule is part of the active set.

A font face rule might be removed from this set if its stylesheet is removed for example.

impl FontContext

pub fn collect_unused_webrender_resources( &self, all: bool, ) -> (Vec<FontKey>, Vec<FontInstanceKey>)

fn remove_single_font_face_rule( &self, font_face_rule: &FontFaceRuleDescriptors, font_store: &mut FontStore, ) -> bool

Returns true if any font templates were removed.

pub fn add_template_to_font_context( &self, family_name: LowercaseFontFamilyName, new_template: FontTemplate, )

pub fn construct_web_font_from_data( &self, data: &[u8], descriptors: CSSFontFaceDescriptors, ) -> Option<(LowercaseFontFamilyName, FontTemplate)>

fn start_loading_one_web_font( self: &Arc<FontContext>, webview_id: Option<WebViewId>, source_list: &SourceList, css_font_face_descriptors: CSSFontFaceDescriptors, completion_handler: WebFontLoadInitiator, document_context: &WebFontDocumentContext, )

pub(crate) fn process_next_web_font_source( self: &Arc<FontContext>, state: WebFontDownloadState, )

pub fn resolve_font_variant_alternate_identifiers_for( &self, font: &FontRef, alternates: &FontVariantAlternates, stylist: &Stylist, ) -> ResolvedFontVariantAlternates

Resolves the value of font-variant-alternates to a set of OpenType features to apply.

fn look_up_font_feature_alternate_name( &self, family_name: Atom, kind: AlternateKindRequiringResolution, name: Atom, stylist: &Stylist, ) -> Option<FontFeatureValue>

Resolves a single component of font-variant-alternates, like stylistic(foobar) to a font-specific set of OpenType features to apply.

If the map of @font-feature-values rules has not yet been computed then this method will compute it.

pub fn invalidate_font_feature_values_map(&self)

Trait Implementations

impl MallocSizeOf for FontContext

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.