Struct Registry 

pub struct Registry<H> { /* private fields */ }

A retained-handle registry keyed by SlotId, generic over the concrete platform handle type H so its core contract is host-testable with no FFI dependency (see the module doc, and this module’s tests).

Implementations

impl<H> Registry<H>

pub fn new() -> Self

An empty registry.

pub fn insert(&mut self, slot_id: SlotId, handle: H) -> Option<H>

Record a freshly created handle for slot_id, replacing (never panicking on) any handle already live under the same id — the surface-recreate-replay / rapid-recreate race this registry must handle. Returns the replaced handle, if any, so a caller can log the unexpected-replace path; dropping it releases its resources exactly like an explicit Self::remove would (the registry “treats attach-for-live-slot-id as replace- and-release-old”).

pub fn remove(&mut self, slot_id: SlotId) -> Option<H>

Release the handle for slot_id directly, by the slot id itself — for a caller that already knows exactly which slot it means (a future widget-teardown path), as opposed to Self::remove_matching’s identity-based lookup for the real platform dispose export, which never receives a slot id at all. A dispose for a slot id that was already replaced or already removed is a silent no-op (late/duplicate dispose, both expected once dispose can arrive idle-deferred — see the module doc), never an error.

pub fn remove_matching( &mut self, is_match: impl FnMut(&H) -> bool, ) -> Option<(SlotId, H)>

Find and remove the entry whose handle satisfies is_match, by identity — the real disposal contract every platform backend uses (Android: Env::is_same_object against the JObject the nativeDisposeControl(view) export receives, which carries no slot id at all). Never assumes “whichever slot was created most recently” is the one being disposed: a match against a handle that was already replaced (the module doc’s idle-deferred-dispose case) or already removed finds nothing and is a silent no-op, leaving whatever handle currently occupies that slot (if any) untouched.

pub fn contains(&self, slot_id: SlotId) -> bool

Whether slot_id currently has a live handle.

pub fn get(&self, slot_id: SlotId) -> Option<&H>

The handle currently live under slot_id, if any — what a caller holding a slot id (an UpdateParams command, a listener callback carrying its own slot id) resolves against, as opposed to Self::remove_matching’s identity lookup for a dispose that carries none.

pub fn get_mut(&mut self, slot_id: SlotId) -> Option<&mut H>

Self::get’s mutable counterpart, for a caller that mutates the handle in place (the runtime’s per-instance props/state).

pub fn live_count(&self) -> usize

The number of live handles — the leak bar every create/dispose cycle must return to 0.

Trait Implementations

impl<H> Default for Registry<H>

fn default() -> Self

Returns the “default value” for a type.