class_WSEventEmitter.ahk

class Event
{
    __new(ByRef emitter, ByRef data)
    {
        this.target := emitter
        this.data := data
        this.propagate := True
    }
    stopPropagation()
    {
        this.propagate := False
    }
}

class EventEmitter
{
    events := {}

    _addListener(eventName, ByRef listener, atStart := 0, once := 0)
    {
        if(!this.events[eventName])
        {
            this.events[eventName] := []
        }

        if(atStart)
        {
            this.events[eventName].InsertAt(1, {listener: listener, once: once})
        }
        else
        {
            this.events[eventName].Push({listener: listener, once: once})
        }
        return this
    }

    removeListener(event, ByRef listener)
    {
        if(this.events[event])
        {
            if(listener)
            {
                For i, eventListener in this.events[event]
                {
                    if(eventListener.listener == listener)
                    {
                        this.events[event].RemoveAt(i)
                    }
                }
            }
        }
        else
        {
            iListeners := this.events[eventName].Length()
            this.events[eventName].RemoveAt(1, iListeners-1)
        }
    }

    emit(eventName,ByRef data)
    {
        if(this.events[eventName])
        {
            iListeners := this.events[eventName].Length()
            if(iListeners)
            {
                e := new Event(this, data)
                For i, eventListener in this.events[eventName]
                {

                    eventListener.listener.Call(e)
                    if(eventListener.once)
                    {
                        this.events[eventName].RemoveAt(i)
                    }
                    if(!e.propagate)
                    {
                        break
                    }
                }
            }
            return iListeners
        }
        return 0
    }


    prependOnceListener(event, ByRef listener)
    {
        return this._addListener(event, listener, 1, 1)
    }

    prependListener(event, ByRef listener)
    {
        return this._addListener(event, listener, 1, 0)
    }

    addListener(event, ByRef listener)
    {
        return this._addListener(event, listener, 0, 0)
    }

    once(event, ByRef listener)
    {
        return this._addListener(event, listener, 0, 1)
    }

    on(event, ByRef listener)
    {
        return this.addListener(event, listener)
    }

    off(event, ByRef listener)
    {
        this.removeListener(event, listener)
    }
}