using afBeanUtils
using afIoc
using fwt
** (Service) -
** An eventing strategy for Reflux Apps.
**
** To receive events, classes must first register themselves with 'EventHub'.
** Given 'MyEvents' is an event mixin:
**
** syntax: fantom
** class MyService : MyEvents {
** new make(EventHub eventHub) {
** eventHub.register(this)
** }
**
** override Void onEvent() { ... }
** }
**
** Note that instances of 'Panels', 'Views' and 'GlobalCommands' are already automatically added
** to 'EventHub' by default.
mixin EventHub {
** Registers an object to receive events.
** The object must implement one or more contributed event types else an 'ArgErr' is thrown.
abstract Void register(Obj eventSink, Bool checked := true)
** Fires an event. There should be very little need to call this directly.
** Just '@Inject' the service and call the event method instead!
abstract Void fireEvent(Method method, Obj?[]? args := null)
** Fires an event after the given delay.
abstract Void fireEventIn(Duration delay, Method method, Obj?[]? args := null)
}
internal class EventHubImpl : EventHub {
@Inject private EventTypes eventTypes
@Inject private Errors errors
private Obj[] eventSinks := [,]
private new make(|This| in) {
in(this)
}
// TODO: save into map of sinks, for optomidation
override Void register(Obj eventSink, Bool checked := true) {
if (!eventTypes.eventTypes.any { eventSink.typeof.fits(it) })
if (checked) throw ArgNotFoundErr("EventSink ${eventSink.typeof} does not implement a contributed EventType", eventTypes.eventTypes); else return
// it's important that Reflux is notified first, so it can set the activeView
if (eventSink is RefluxImpl)
eventSinks.insert(0, eventSink)
else
eventSinks.add(eventSink)
}
override Void fireEvent(Method method, Obj?[]? args := null) {
check
:= eventTypes.eventTypes.find { it.fits(method.parent) }
?: throw ArgNotFoundErr("Method '${method.qname}' does not belong to an event type ", eventTypes.eventTypes)
sinks := eventSinks.findAll { it.typeof.fits(method.parent) }
sinks.each {
try method.callOn(it, args)
catch (Err err)
errors.add(err)
}
}
override Void fireEventIn(Duration delay, Method method, Obj?[]? args := null) {
Desktop.callLater(delay) |->| { fireEvent(method, args) }
}
}