fixed selection handler befor/after transactions

src/Util/NamedEventHandler.js

@@ -1,26 +1,31 @@
 export default class NamedEventHandler {
   constructor () {
-    this._eventListener = {}
+    this._eventListener = new Map()
   }
   on (name, f) {
-    if (this._eventListener[name] == null) {
-      this._eventListener[name] = []
+    let fSet = this._eventListener.get(name)
+    if (fSet === undefined) {
+      fSet = new Set()
+      this._eventListener.set(name, fSet)
     }
-    this._eventListener[name].push(f)
+    fSet.add(f)
   }
   off (name, f) {
     if (name == null || f == null) {
       throw new Error('You must specify event name and function!')
     }
-    let listener = this._eventListener[name] || []
-    this._eventListener[name] = listener.filter(e => e !== f)
-  }
-  emit (name, value) {
-    let listener = this._eventListener[name] || []
-    if (name === 'error' && listener.length === 0) {
-      console.error(value)
+    const listener = this._eventListener.get(name)
+    if (listener !== undefined) {
+      listener.remove(f)
+    }
+  }
+  emit (name, ...args) {
+    const listener = this._eventListener.get(name)
+    if (listener !== undefined) {
+      listener.forEach(f => f.apply(null, args))
+    } else if (name === 'error') {
+      console.error(args[0])
     }
-    listener.forEach(l => l(value))
   }
   destroy () {
     this._eventListener = null