module eventbus pub type EventHandlerFn fn(voidptr, voidptr, voidptr) pub struct Publisher { mut: registry &Registry } pub struct Subscriber { mut: registry &Registry } struct Registry { mut: events []EventHandler } struct EventHandler { name string handler EventHandlerFn receiver voidptr once bool } pub struct EventBus { pub mut: registry &Registry publisher &Publisher pub: subscriber &Subscriber } pub fn new() &EventBus { registry := &Registry{ events: [] } return &EventBus{ registry,&Publisher{ registry},&Subscriber{ registry} } } // EventBus Methods pub fn (eb &EventBus) publish(name string, sender voidptr, args voidptr) { mut publisher := eb.publisher publisher.publish(name, sender, args) } pub fn (eb &EventBus) clear_all() { mut publisher := eb.publisher publisher.clear_all() } pub fn (eb &EventBus) has_subscriber(name string) bool { return eb.registry.check_subscriber(name) } // Publisher Methods fn (pb mut Publisher) publish(name string, sender voidptr, args voidptr) { for i, event in pb.registry.events { if event.name == name { if event.once { pb.registry.events.delete(i) } if event.receiver != 0 { event.handler(event.receiver, args, sender) } else { event.handler(sender, args, voidptr(0)) } } } } fn (p mut Publisher) clear_all() { if p.registry.events.len == 0 { return } for i := p.registry.events.len - 1; i >= 0; i-- { p.registry.events.delete(i) } } // Subscriber Methods pub fn (s mut Subscriber) subscribe(name string, handler EventHandlerFn) { s.registry.events << EventHandler { name: name handler: handler receiver: voidptr(0) } } pub fn (s mut Subscriber) subscribe_method(name string, handler EventHandlerFn, receiver voidptr) { s.registry.events << EventHandler { name: name handler: handler receiver: receiver } } pub fn (s mut Subscriber) subscribe_once(name string, handler EventHandlerFn) { s.registry.events << EventHandler { name: name handler: handler receiver: voidptr(0) once: true } } pub fn (s &Subscriber) is_subscribed(name string) bool { return s.registry.check_subscriber(name) } pub fn (s mut Subscriber) unsubscribe(name string, handler EventHandlerFn) { // v := voidptr(handler) for i, event in s.registry.events { if event.name == name { if event.handler == handler { s.registry.events.delete(i) } } } } // Registry Methods fn (r &Registry) check_subscriber(name string) bool { for event in r.events { if event.name == name { return true } } return false }