Struct WeakEvent 

pub struct WeakEvent<S: WeakEventSender, A: WeakEventArgs + ?Sized> { /* private fields */ }

Manages subscriptions to events using weak listeners.

One instance describes one event (usually a thread-local static, see WeakEvents). For each sender it adds a single handler to the event, while there are subscribers, and forwards the events to the subscribers that are still alive. The sender holds the subscription; neither the sender nor the subscription holds the subscribers.

Implementations

impl<S: WeakEventSender, A: WeakEventArgs + ?Sized> WeakEvent<S, A>

pub fn register<Sub, Unsub>(subscribe: Sub, unsubscribe: Unsub) -> Rc<Self>

where Sub: Fn(&S, &Rc<WeakEventHandler<A>>) + 'static, Unsub: Fn(&S, &Rc<WeakEventHandler<A>>) + 'static,

Registers an event through the functions that add a handler to it and remove the handler from it.

The managed original removes the handler through the sender it captured; here the removal holds the sender weakly (a strong reference would keep it alive through its own subscription), so the handler is not removed from a sender that no longer exists. It also holds the handler weakly: the handler holds the subscription, which holds the removal, and the sender owns the handler.

pub fn register_returning_unsubscribe<Sub>(subscribe: Sub) -> Rc<Self>

where Sub: Fn(&S, Rc<WeakEventHandler<A>>) -> Box<dyn FnOnce()> + 'static,

Registers an event through a function that adds a handler to it and returns the action that removes the handler.

The action must not hold the sender strongly: the sender holds the subscription, and the subscription holds the action.

pub fn subscribe( &self, target: &S, subscriber: &Rc<dyn IWeakEventSubscriber<A>>, )

pub fn unsubscribe( &self, target: &S, subscriber: &Rc<dyn IWeakEventSubscriber<A>>, )

impl<S: WeakEventSender> WeakEvent<S, EventArgs>

pub fn register_plain<Sub, Unsub>( subscribe: Sub, unsubscribe: Unsub, ) -> Rc<Self>

where Sub: Fn(&S, &Rc<WeakEventHandler<EventArgs>>) + 'static, Unsub: Fn(&S, &Rc<WeakEventHandler<EventArgs>>) + 'static,

Registers an event whose handlers take the plain event arguments, through the functions that add a handler to it and remove the handler from it.