hybridgroup.gobot/event.go

50 lines
947 B
Go

package gobot
type callback struct {
f func(interface{})
once bool
}
// Event executes the list of Callbacks when Chan is written to.
type Event struct {
Chan chan interface{}
Callbacks []callback
}
// NewEvent returns a new Event which is now listening for data.
func NewEvent() *Event {
e := &Event{
Chan: make(chan interface{}, 1),
Callbacks: []callback{},
}
go func() {
for {
e.Read()
}
}()
return e
}
// Write writes data to the Event, it will not block and will not buffer if there
// are no active subscribers to the Event.
func (e *Event) Write(data interface{}) {
select {
case e.Chan <- data:
default:
}
}
// Read executes all Callbacks when new data is available.
func (e *Event) Read() {
for s := range e.Chan {
tmp := []callback{}
for i := range e.Callbacks {
go e.Callbacks[i].f(s)
if !e.Callbacks[i].once {
tmp = append(tmp, e.Callbacks[i])
}
}
e.Callbacks = tmp
}
}