interface.go

package eventemitter

// EventType is a type of event, each type of event should have a different type
type EventType string

// HandleFunc is a handler function for a given event type
type HandleFunc func(arguments ...interface{})

// Listener is a container struct used to remove the listener
type Listener struct {
	handler HandleFunc
}

// CaptureFunc is a capturer function that can capture all emitted events
type CaptureFunc func(event EventType, arguments ...interface{})

// Capturer is a container struct used to remove the capturer
type Capturer struct {
	handler CaptureFunc
}

// Observable describes an object that can be listened to by event listeners and capturers
type Observable interface {
	// AddListener adds a listener for the given event type
	AddListener(event EventType, handler HandleFunc) (listener *Listener)
	// ListenOnce adds a listener for the given event type that removes itself after it has been fired once
	ListenOnce(event EventType, handler HandleFunc) (listener *Listener)
	// AddCapturer adds an event capturer for all events
	AddCapturer(handler CaptureFunc) (capturer *Capturer)
	// RemoveListener removes the registered given listener for the given event
	RemoveListener(event EventType, listener *Listener)
	// RemoveCapturer removes the given capturer
	RemoveCapturer(capturer *Capturer)
}

// EventEmitter is the interface which allows implementers to emit events
type EventEmitter interface {
	// EmitEvent emits the given event to all listeners and capturers
	EmitEvent(event EventType, arguments ...interface{})
}