add throttle decorator

src/utils/decorators.ts

@@ -0,0 +1,29 @@
+
+
+export function throttle(func: Function, ms: number) {
+    let isThrottled = false;
+    let savedArgs: any;
+    let savedThis: any;
+
+    function wrapper(this: any) {
+        if (isThrottled) {
+            savedArgs = arguments;
+            savedThis = this;
+            return;
+        }
+
+        func.apply(this , arguments);
+
+        isThrottled = true;
+
+        setTimeout(function () {
+            isThrottled = false;
+            if (savedArgs) {
+                wrapper.apply(savedThis, savedArgs);
+                savedArgs = savedThis = null;
+            }
+        }, ms);
+    }
+
+    return wrapper;
+}