Add: Load fps plugin snippet

src/Snippets/defSnippets.es6

@@ -1,4 +1,5 @@
 import util from '../lib/util'
+import emitter from '../lib/emitter.es6'
 
 export default [
     {
@@ -39,6 +40,14 @@ export default [
             body.contentEditable = body.contentEditable !== 'true';
         },
         desc: 'Toggle body contentEditable'
+    },
+    {
+        name: 'Load Fps Plugin',
+        fn() 
+        {
+            loadPlugin('fps');
+        },
+        desc: 'Display page fps'
     }
 ];
 
@@ -99,3 +108,17 @@ function traverse(root, processor)
 
     return processor(root);
 }
+
+function loadPlugin(name) 
+{
+    let globalName = 'eruda' + util.upperFirst(name);
+    if (window[globalName]) return;
+
+    util.loadJs('//cdn.jsdelivr.net/npm/eruda-' + name, (isLoaded) =>
+    {
+        if (!isLoaded || !window[globalName]) return emitter.emit(emitter.LOG, 'error', 'Fail to load plugin ' + name);
+
+        emitter.emit(emitter.ADD, window[globalName]); 
+        emitter.emit(emitter.SHOW, name);
+    });
+}

src/index.es6

@@ -10,6 +10,7 @@ import Features from './Features/Features.es6'
 import Sources from './Sources/Sources.es6'
 import Settings from './Settings/Settings.es6'
 import util from './lib/util'
+import emitter from './lib/emitter.es6'
 import config from './lib/config.es6'
 import logger from './lib/logger.es6'
 import extraUtil from './lib/extraUtil.es6'
@@ -25,6 +26,7 @@ module.exports = {
         this._initEntryBtn();
         this._initSettings();
         this._initTools(tool);
+        this._registerListener();
     },
     _isInit: false,
     version: VERSION,
@@ -66,6 +68,11 @@ module.exports = {
 
         return this;
     },
+    _registerListener() 
+    {
+        emitter.on(emitter.ADD, (...args) => this.add(...args));
+        emitter.on(emitter.SHOW, (...args) => this.show(...args));
+    },
     _checkInit() 
     {
         if (!this._isInit) logger.error('Please call "eruda.init()" first');

src/lib/emitter.es6

@@ -0,0 +1,8 @@
+import util from './util'
+
+let emitter = new util.Emitter();
+emitter.ADD = 'ADD';
+emitter.LOG = 'LOG';
+emitter.SHOW = 'SHOW';
+
+module.exports = emitter;

src/lib/logger.es6

@@ -1,4 +1,5 @@
 import util from './util'
+import emitter from './emitter.es6'
 
 let logger;
 
@@ -10,3 +11,5 @@ logger.formatter = function (type, argList)
 
     return argList;
 };
+
+emitter.on(emitter.LOG, (type, ...args) => logger[type](...args));