saving

Author: raju-opti

lib/project_config/project_config_manager.ts

@@ -0,0 +1,5 @@
+export interface ProjectConfigManager {
+  onReady(): Promise<void>;
+  getConfig(): ProjectConfig | null;
+  onUpdate(listener: (config: ProjectConfig) => void): () => void;
+}

lib/utils/event_emitter/event_emitter.ts

@@ -0,0 +1,44 @@
+type Consumer<T> = (arg: T) => void;
+
+type Disposer = () => void;
+
+interface Listeners<T> {
+  [index: string]: {
+    // index is event name
+    [index: string]: Listener; // index is listener id
+  };
+}
+
+export class EventEmitter<T> {
+  private listeners: Listeners = {};
+
+  private listenerId = 1;
+
+  on<E extends keyof T>(eventName: E, listener: Consumer<T[E]>): Disposer {
+    if (!this.listeners[eventName]) {
+      this.listeners[eventName] = {};
+    }
+    const currentListenerId = String(this.listenerId);
+    this.listenerId++;
+    this.listeners[eventName][currentListenerId] = listener;
+    return (): void => {
+      if (this.listeners[eventName]) {
+        delete this.listeners[eventName][currentListenerId];
+      }
+    };
+  }
+
+  emit(eventName: string, arg?: DatafileUpdate): void {
+    const listeners = this.listeners[eventName];
+    if (listeners) {
+      Object.keys(listeners).forEach(listenerId => {
+        const listener = listeners[listenerId];
+        listener(arg);
+      });
+    }
+  }
+
+  removeAllListeners(): void {
+    this.listeners = {};
+  }
+}