新增事件发送接收器

source/src/Utils/Emitter.ts

@@ -0,0 +1,29 @@
+class Emitter<T> {
+    private _messageTable: Map<T, Function[]>;
+
+    constructor(){
+        this._messageTable = new Map<T, Function[]>();
+    }
+
+    public addObserver(eventType: T, handler: Function){
+        let list: Function[] = this._messageTable.get(eventType);
+        if (!list){
+            list = [];
+            this._messageTable.set(eventType, list);
+        }
+
+        if (list.contains(handler))
+            console.warn("您试图添加相同的观察者两次");
+        list.push(handler);
+    }
+
+    public removeObserver(eventType: T, handler: Function){
+        this._messageTable.get(eventType).remove(handler);
+    }
+
+    public emit(eventType: T, data: any){
+        let list: Function[] = this._messageTable.get(eventType);
+        for (let i = list.length - 1; i >= 0; i --)
+            list[i](data);
+    }
+}