This crate provides a low-level primitive for building Node.js-like event listeners.
The 3 primitives are Bag that is a container for Fn() event handlers, BagOnce the same for FnOnce() event handlers and HandlerId that will remove event handler from the bag on drop.
Trivial example: ```rust use eventlistenerprimitives::{Bag, HandlerId}; use std::sync::Arc;
fn main() { let bag = Bag::default();
let handler_id = bag.add(Arc::new(|| {
println!("Hello");
}));
bag.call_simple();
} ```
Close to real-world usage example:
```rust use eventlistenerprimitives::{Bag, BagOnce, HandlerId}; use std::sync::Arc;
struct Handlers {
action: Bag
pub struct Container { handlers: Handlers, }
impl Drop for Container { fn drop(&mut self) { self.handlers.closed.call_simple(); } }
impl Container { pub fn new() -> Self { let handlers = Handlers::default();
Self { handlers }
}
pub fn do_action(&self) {
// Do things...
self.handlers.action.call_simple();
}
pub fn do_other_action(&self) {
// Do things...
self.handlers.action.call(|callback| {
callback();
});
}
pub fn on_action<F: Fn() + Send + Sync + 'static>(&self, callback: F) -> HandlerId {
self.handlers.action.add(Arc::new(callback))
}
pub fn on_closed<F: FnOnce() + Send + 'static>(&self, callback: F) -> HandlerId {
self.handlers.closed.add(Box::new(callback))
}
}
fn main() { let container = Container::new(); let onactionhandlerid = container.onaction(|| { println!("On action"); }); container .onclosed(|| { println!("On container closed"); }) .detach(); // This will trigger "action" callback just fine since its handler ID is not dropped yet container.doaction(); drop(onactionhandlerid); // This will not trigger "action" callback since its handler ID was already dropped container.doother_action(); // This will trigger "closed" callback though since we've detached handler ID drop(container);
println!("Done");
} ```
The output will be:
text
On action
On closed
Done
Feel free to create issues and send pull requests, they are highly appreciated!
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