reorganizing file structures;

src/lib/eventHandler.js

@@ -0,0 +1,42 @@
+const eventHandler = {
+    add: function (eventType, target, selector, callback) {
+        if (typeof selector === 'function' && !callback) {
+            callback = selector;
+            selector = target;
+        }
+        if (typeof target === 'object') {
+            if (target.attachEvent) {
+                target.attachEvent('on' + eventType, function (e) {
+                    callback.call(target, e);
+                });
+            }
+            else {
+                target.addEventListener(eventType, function (e) {
+                    callback.call(target, e);
+                });
+            }
+            return;
+        }
+        let el = document.querySelector(target);
+        if (!el) {
+           return;
+        }
+        el.addEventListener(eventType, function (e) {
+            let element = e.target;
+            if (element === this && selector === target) {
+                callback.call(element, e);
+                return;
+            }
+            for (; element && element != this; element = element.parentNode) {
+                if (element.matches(selector)) {
+                    callback.call(element, e);
+                    break;
+                }
+            }
+        });
+    },
+    off: function (element, eventType, callback) {
+        element.removeEventListener(eventType, callback);
+    }
+}
+export default eventHandler;