1 files changed, 36 insertions, 0 deletions

diff --git a/web/src/js/utils.js b/web/src/js/utils.js
index 329de956..8ae7aa54 100644
--- a/web/src/js/utils.js
+++ b/web/src/js/utils.js
@@ -12,6 +12,7 @@ var AutoScrollMixin = {
     },
 };
 
+
 var StickyHeadMixin = {
     adjustHead: function () {
         // Abusing CSS transforms to set the element
@@ -21,6 +22,7 @@ var StickyHeadMixin = {
     }
 };
 
+
 var Key = {
     UP: 38,
     DOWN: 40,
@@ -38,6 +40,7 @@ var Key = {
     L: 76
 };
 
+
 var formatSize = function (bytes) {
     var size = bytes;
     var prefix = ["B", "KB", "MB", "GB", "TB"];
@@ -49,6 +52,7 @@ var formatSize = function (bytes) {
     return (Math.floor(size * 100) / 100.0).toFixed(2) + prefix[i];
 };
 
+
 var formatTimeDelta = function (milliseconds) {
     var time = milliseconds;
     var prefix = ["ms", "s", "min", "h"];
@@ -61,7 +65,39 @@ var formatTimeDelta = function (milliseconds) {
     return Math.round(time) + prefix[i];
 };
 
+
 var formatTimeStamp = function (seconds) {
     var ts = (new Date(seconds * 1000)).toISOString();
     return ts.replace("T", " ").replace("Z", "");
+};
+
+
+function EventEmitter() {
+    this.listeners = {};
+}
+EventEmitter.prototype.emit = function (event) {
+    if (!(event in this.listeners)) {
+        return;
+    }
+    var args = Array.prototype.slice.call(arguments, 1);
+    this.listeners[event].forEach(function (listener) {
+        listener.apply(this, args);
+    }.bind(this));
+};
+EventEmitter.prototype.addListener = function (events, f) {
+    events.split(" ").forEach(function (event) {
+        this.listeners[event] = this.listeners[event] || [];
+        this.listeners[event].push(f);
+    }.bind(this));
+};
+EventEmitter.prototype.removeListener = function (events, f) {
+    if (!(events in this.listeners)) {
+        return false;
+    }
+    events.split(" ").forEach(function (event) {
+        var index = this.listeners[event].indexOf(f);
+        if (index >= 0) {
+            this.listeners[event].splice(index, 1);
+        }
+    }.bind(this));
 };
\ No newline at end of file