Struct Event

pub struct Event<A: Copy + Send, H: EventHandler<A>> { /* private fields */ }

An event manages multiple handlers which can be registered.

Type Parameters

• A: The type of event arguments which are distributed to the handlers.
• H: The type of event handlers which can be registered with this event. To allow for different types, use Box<dyn EventHandler<...>>.

Implementations

impl<A: Copy + Send, H: EventHandler<A>> Event<A, H>

pub fn new() -> Event<A, H>

Creates a new event without handlers.

pub fn emit(&mut self, arg: A) -> bool

Emits an event, invoking all currently registered handlers in parallel. If all event handlers terminated without panicking, true is returned. If any event handler panics, false is returned.

Parameters

• arg: The event argument to dispatch.

pub fn add_handler(&mut self, handler: H) -> HandlerId

Adds an event handler to notify for future events. A handler ID is returned, which can be used to identify the handler later.

Parameters

• handler: The event handler to register.

pub fn get_handler(&self, id: HandlerId) -> Option<&H>

Gets a reference to the event handler registered under the given ID wrapped in a Some option variant. If no such handler is registered, None is returned.

Parameters

• id: The handler ID for which to get the associated event handler.

impl<'a, A: Copy + Send> Event<A, Box<dyn EventHandler<A> + 'a>>

pub fn add_handler_boxed( &'a mut self, handler: impl EventHandler<A> + 'a, ) -> HandlerId

Adds an event handler wrapped into a box to this event. This is mainly syntactic sugar for event.add_handler(Box::new(handler)).

Parameters

• handler: The event handler to wrap in a box and register with this event.