diff --git a/src/asmCode.js b/src/asmCode.js
index 582466caab..c941b25297 100644
--- a/src/asmCode.js
+++ b/src/asmCode.js
@@ -23,8 +23,10 @@ module.exports = React.createClass({
   },
 
   componentDidMount: function () {
-    this.context.codeManager.registerIndexChangedListener(this, this.indexChanged)
-    this.context.codeManager.registerCodeChangedListener(this, this.codeChanged)
+    this.context.codeManager.register('indexChanged', this, this.indexChanged)
+    this.context.codeManager.register('codeChanged', this, this.codeChanged)
+    this.context.codeManager.register('loadingCode', this, function (address) {
+    })
   },
 
   indexChanged: function (index) {
diff --git a/src/codeManager.js b/src/codeManager.js
index 8afaa25a6e..5db4387d09 100644
--- a/src/codeManager.js
+++ b/src/codeManager.js
@@ -1,32 +1,30 @@
 'use strict'
 var traceManagerUtil = require('./traceManagerUtil')
 var codeResolver = require('./codeResolver')
+var util = require('./util')
+var eventManager = require('./eventManager')
+
+/*
+  resolve contract code referenced by vmtrace in order to be used by asm listview.
+  events:
+   - indexChanged: triggered when an item is selected
+   - codeChanged: triggered when an item (in a different context) is selected
+   - loadingCode: triggerred when loading new code
+   - resolvingStep: when CodeManager resolves code/selected instruction of a new step
+*/
+
 function CodeManager (_web3, _traceManager) {
+  util.extend(this, eventManager)
   this.web3 = _web3
   this.isLoading = false
   this.traceManager = _traceManager
   this.currentAddress = ''
-  this.indexChangedlisteners = []
-  this.codeChangedlisteners = []
   codeResolver.setWeb3(_web3)
 }
 
-CodeManager.prototype.registerIndexChangedListener = function (obj, func) {
-  this.indexChangedlisteners.push({
-    obj: obj,
-    func: func
-  })
-}
-
-CodeManager.prototype.registerCodeChangedListener = function (obj, func) {
-  this.codeChangedlisteners.push({
-    obj: obj,
-    func: func
-  })
-}
-
-CodeManager.prototype.resolveCodeFor = function (stepIndex, tx) {
+CodeManager.prototype.resolveStep = function (stepIndex, tx) {
   if (stepIndex < 0) return
+  this.trigger('resolvingStep')
   var self = this
   if (stepIndex === 0) {
     self.ensureCodeLoaded(tx.to, stepIndex, tx)
@@ -51,9 +49,10 @@ CodeManager.prototype.ensureCodeLoaded = function (address, currentStep, tx) {
           console.log(error)
         } else {
           var codes = codeResolver.cacheExecutingCode(address, hexCode)
+          self.trigger('loadingCode', [address])
           self.getInstructionIndex(address, currentStep, function (error, result) {
             if (!error) {
-              self.dispatchCodeChanged(codes.code, address, result)
+              self.trigger('codeChanged', [codes.code, address, result])
               self.currentAddress = address
             } else {
               console.log(error)
@@ -64,9 +63,10 @@ CodeManager.prototype.ensureCodeLoaded = function (address, currentStep, tx) {
     } else {
       codeResolver.resolveCode(address, currentStep, tx, function (address, code) {
         // resoling code from stack
+        self.trigger('loadingCode', [address])
         self.getInstructionIndex(address, currentStep, function (error, result) {
           if (!error) {
-            self.dispatchCodeChanged(code, address, result)
+            self.trigger('codeChanged', [code, address, result])
             self.currentAddress = address
           } else {
             console.log(error)
@@ -78,7 +78,7 @@ CodeManager.prototype.ensureCodeLoaded = function (address, currentStep, tx) {
     // only set selected item
     this.getInstructionIndex(this.currentAddress, currentStep, function (error, result) {
       if (!error) {
-        self.dispatchIndexChanged(result)
+        self.trigger('indexChanged', [result])
       }
     })
   }
@@ -96,18 +96,4 @@ CodeManager.prototype.getInstructionIndex = function (address, step, callback) {
   })
 }
 
-CodeManager.prototype.dispatchIndexChanged = function (itemIndex) {
-  for (var listener in this.indexChangedlisteners) {
-    var l = this.indexChangedlisteners[listener]
-    l.func.call(l.obj, itemIndex)
-  }
-}
-
-CodeManager.prototype.dispatchCodeChanged = function (code, address, itemIndex) {
-  for (var listener in this.codeChangedlisteners) {
-    var l = this.codeChangedlisteners[listener]
-    l.func.call(l.obj, code, address, itemIndex)
-  }
-}
-
 module.exports = CodeManager
diff --git a/src/debugger.js b/src/debugger.js
index e379de3fb7..9f6de8b0bd 100644
--- a/src/debugger.js
+++ b/src/debugger.js
@@ -44,7 +44,7 @@ module.exports = React.createClass({
     this.setState({
       currentStepIndex: stepIndex
     })
-    this.props.context.codeManager.resolveCodeFor(stepIndex, this.state.tx)
+    this.props.context.codeManager.resolveStep(stepIndex, this.state.tx)
   },
 
   startDebugging: function (blockNumber, txIndex, tx) {
@@ -62,7 +62,7 @@ module.exports = React.createClass({
         currentStepIndex: 0
       })
       self.refs.stepManager.newTraceAvailable()
-      self.props.context.codeManager.resolveCodeFor(0, tx)
+      self.props.context.codeManager.resolveStep(0, tx)
     })
   }
 })
diff --git a/src/eventManager.js b/src/eventManager.js
new file mode 100644
index 0000000000..82d9929c64
--- /dev/null
+++ b/src/eventManager.js
@@ -0,0 +1,22 @@
+'use strict'
+module.exports = {
+  registered: {},
+
+  register: function (eventName, obj, func) {
+    if (!this.registered[eventName]) {
+      this.registered[eventName] = []
+    }
+    this.registered[eventName].push({
+      obj: obj,
+      func: func
+    })
+  },
+
+  trigger: function (eventName, args) {
+    for (var listener in this.registered[eventName]) {
+      var l = this.registered[eventName][listener]
+      l.func.apply(l.obj, args)
+    }
+  }
+
+}
diff --git a/src/util.js b/src/util.js
new file mode 100644
index 0000000000..75c2570c4a
--- /dev/null
+++ b/src/util.js
@@ -0,0 +1,9 @@
+'use strict'
+module.exports = {
+  extend: function (destination, source) {
+    for (var property in source) {
+      destination[property] = source[property]
+    }
+    // return destination
+  }
+}