Initial commit

com.pdma.notion-timer.sdPlugin/ui/libs/events.js

@@ -0,0 +1,38 @@
+/** ELGEvents
+ * Publish/Subscribe pattern to quickly signal events to
+ * the plugin, property inspector and data.
+ */
+
+const ELGEvents = {
+	eventEmitter: function (name, fn) {
+		const eventList = new Map();
+
+		const on = (name, fn) => {
+			if (!eventList.has(name)) eventList.set(name, ELGEvents.pubSub());
+
+			return eventList.get(name).sub(fn);
+		};
+
+		const has = name => eventList.has(name);
+
+		const emit = (name, data) => eventList.has(name) && eventList.get(name).pub(data);
+
+		return Object.freeze({on, has, emit, eventList});
+	},
+
+	pubSub: function pubSub() {
+		const subscribers = new Set();
+
+		const sub = fn => {
+			subscribers.add(fn);
+			return () => {
+				subscribers.delete(fn);
+			};
+		};
+
+		const pub = data => subscribers.forEach(fn => fn(data));
+		return Object.freeze({pub, sub});
+	}
+};
+
+const EventEmitter = ELGEvents.eventEmitter();