fipamo/brain/tools/events/EventEmitter.js

53 lines
1.2 KiB
JavaScript

class EventEmitter {
//--------------------------
// constructor
//--------------------------
constructor() {
this.listeners = new Map();
}
//--------------------------
// methods
//--------------------------
addListener(label, callback) {
this.listeners.has(label) || this.listeners.set(label, []);
this.listeners.get(label).push(callback);
}
removeListener(label, callback) {
var isFunction = function(obj) {
return typeof obj == 'function' || false;
};
var listeners = this.listeners.get(label),
index;
if (listeners && listeners.length) {
index = listeners.reduce((i, listener, index) => {
return isFunction(listener) && listener === callback ? (i = index) : i;
}, -1);
if (index > -1) {
listeners.splice(index, 1);
this.listeners.set(label, listeners);
return true;
}
}
return false;
}
emitEvent(label, ...args) {
var listeners = this.listeners.get(label);
if (listeners && listeners.length) {
listeners.forEach(listener => {
listener(...args);
});
return true;
}
return false;
}
//--------------------------
// event handlers
//--------------------------
}
export default EventEmitter;