Struct ImageStore 

pub struct ImageStore { /* private fields */ }

A cheap-to-clone handle to a shared image cache whose loads run off the UI thread — on the toolkit’s Background for ImageStore::new, or in the host for ImageStore::host_driven.

Implementations

impl ImageStore

pub fn with_host_factory_with_max_dimension<R>( factory: Rc<dyn Fn(u32) -> ImageStore>, construct: impl FnOnce() -> R, ) -> R

Construct app caches under a host’s asynchronous service while retaining the requested decoded-image bound and component wake custody.

pub fn new( fetch: &Arc<dyn Fn(&str) -> Option<Vec<u8>> + Send + Sync>, ) -> ImageStore

Build a store with the default worker count.

pub fn with_workers( fetch: &Arc<dyn Fn(&str) -> Option<Vec<u8>> + Send + Sync>, workers: usize, ) -> ImageStore

Build a store that runs at most workers fetch/decode jobs at once, clamped to 1..=4 so one store cannot monopolise the background pool.

pub fn with_max_dimension( fetch: &Arc<dyn Fn(&str) -> Option<Vec<u8>> + Send + Sync>, max_dimension: u32, ) -> ImageStore

Build a store for document images instead of small thumbnails.

Decoded dimensions are bounded to 1..=4096; the worker, queue and total cache memory limits remain the same as for the thumbnail store.

pub fn host_driven() -> (ImageStore, HostImageLoader)

A thumbnail store whose loading the host drives through the returned HostImageLoader; no background work is spawned.

pub fn host_driven_with_max_dimension( max_dimension: u32, ) -> (ImageStore, HostImageLoader)

A host-driven store with a bounded document-image decode dimension (clamped to 1..=4096).

pub fn get(&self, url: &str) -> Option<ImageData>

Decoded image for url, kicking off an async load the first time a URL is seen. Returns None while loading or after a failure — the caller paints a placeholder until a later frame returns Some.

pub fn is_known(&self, url: &str) -> bool

Whether url has been requested yet (Ready/Loading/Failed all count).

pub fn pending(&self) -> usize

Number of in-flight loads (queued or decoding).

pub fn is_idle(&self) -> bool

Whether every requested load has settled.

pub fn block_until_idle(&self, timeout: Duration)

Block until all in-flight loads settle or timeout elapses on the store’s executor clock. For the synchronous --shots pre-warm and tests only — never call this on a live app’s UI thread. A host-driven store settles only when its host completes requests.

Trait Implementations

impl Clone for ImageStore

fn clone(&self) -> ImageStore

Returns a duplicate of the value.

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

Performs copy-assignment from source.