diff --git a/blockly_uncompressed.js b/blockly_uncompressed.js
index 81ecab986..7acc19faf 100644
--- a/blockly_uncompressed.js
+++ b/blockly_uncompressed.js
@@ -39,13 +39,14 @@ window.BLOCKLY_BOOT = function() {
   }
 goog.addDependency("../../../" + dir + "/core/block.js", ['Blockly.Block'], ['Blockly.Blocks', 'Blockly.Comment', 'Blockly.Connection', 'Blockly.Input', 'Blockly.Mutator', 'Blockly.Warning', 'Blockly.Workspace', 'Blockly.Xml', 'goog.array', 'goog.asserts', 'goog.math.Coordinate', 'goog.string']);
 goog.addDependency("../../../" + dir + "/core/block_svg.js", ['Blockly.BlockSvg'], ['Blockly.Block', 'Blockly.ContextMenu', 'goog.Timer', 'goog.asserts', 'goog.dom', 'goog.math.Coordinate', 'goog.userAgent']);
-goog.addDependency("../../../" + dir + "/core/blockly.js", ['Blockly'], ['Blockly.BlockSvg', 'Blockly.FieldAngle', 'Blockly.FieldCheckbox', 'Blockly.FieldColour', 'Blockly.FieldDropdown', 'Blockly.FieldImage', 'Blockly.FieldTextInput', 'Blockly.FieldVariable', 'Blockly.Generator', 'Blockly.Msg', 'Blockly.Procedures', 'Blockly.Toolbox', 'Blockly.WidgetDiv', 'Blockly.WorkspaceSvg', 'Blockly.inject', 'Blockly.utils', 'goog.color', 'goog.userAgent']);
+goog.addDependency("../../../" + dir + "/core/blockly.js", ['Blockly'], ['Blockly.BlockSvg', 'Blockly.Events', 'Blockly.FieldAngle', 'Blockly.FieldCheckbox', 'Blockly.FieldColour', 'Blockly.FieldDropdown', 'Blockly.FieldImage', 'Blockly.FieldTextInput', 'Blockly.FieldVariable', 'Blockly.Generator', 'Blockly.Msg', 'Blockly.Procedures', 'Blockly.Toolbox', 'Blockly.WidgetDiv', 'Blockly.WorkspaceSvg', 'Blockly.inject', 'Blockly.utils', 'goog.color', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/blocks.js", ['Blockly.Blocks'], []);
 goog.addDependency("../../../" + dir + "/core/bubble.js", ['Blockly.Bubble'], ['Blockly.Workspace', 'goog.dom', 'goog.math', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/comment.js", ['Blockly.Comment'], ['Blockly.Bubble', 'Blockly.Icon', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/connection.js", ['Blockly.Connection', 'Blockly.ConnectionDB'], ['goog.dom']);
 goog.addDependency("../../../" + dir + "/core/contextmenu.js", ['Blockly.ContextMenu'], ['goog.dom', 'goog.events', 'goog.style', 'goog.ui.Menu', 'goog.ui.MenuItem']);
 goog.addDependency("../../../" + dir + "/core/css.js", ['Blockly.Css'], []);
+goog.addDependency("../../../" + dir + "/core/events.js", ['Blockly.Events'], []);
 goog.addDependency("../../../" + dir + "/core/field.js", ['Blockly.Field'], ['goog.asserts', 'goog.dom', 'goog.math.Size', 'goog.style', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/field_angle.js", ['Blockly.FieldAngle'], ['Blockly.FieldTextInput', 'goog.math', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/field_checkbox.js", ['Blockly.FieldCheckbox'], ['Blockly.Field']);
@@ -74,7 +75,7 @@ goog.addDependency("../../../" + dir + "/core/variables.js", ['Blockly.Variables
 goog.addDependency("../../../" + dir + "/core/warning.js", ['Blockly.Warning'], ['Blockly.Bubble', 'Blockly.Icon']);
 goog.addDependency("../../../" + dir + "/core/widgetdiv.js", ['Blockly.WidgetDiv'], ['Blockly.Css', 'goog.dom', 'goog.style']);
 goog.addDependency("../../../" + dir + "/core/workspace.js", ['Blockly.Workspace'], ['goog.math']);
-goog.addDependency("../../../" + dir + "/core/workspace_svg.js", ['Blockly.WorkspaceSvg'], ['Blockly.ScrollbarPair', 'Blockly.Trashcan', 'Blockly.ZoomControls', 'Blockly.Workspace', 'Blockly.Xml', 'goog.dom', 'goog.math.Coordinate', 'goog.userAgent']);
+goog.addDependency("../../../" + dir + "/core/workspace_svg.js", ['Blockly.WorkspaceSvg'], ['Blockly.ScrollbarPair', 'Blockly.Trashcan', 'Blockly.ZoomControls', 'Blockly.Workspace', 'Blockly.Xml', 'goog.dom', 'goog.events', 'goog.math.Coordinate', 'goog.userAgent']);
 goog.addDependency("../../../" + dir + "/core/xml.js", ['Blockly.Xml'], ['goog.dom']);
 goog.addDependency("../../../" + dir + "/core/zoom_controls.js", ['Blockly.ZoomControls'], ['goog.dom']);
 goog.addDependency("../../alltests.js", [], []);
@@ -1586,6 +1587,7 @@ goog.require('Blockly.Connection');
 goog.require('Blockly.ConnectionDB');
 goog.require('Blockly.ContextMenu');
 goog.require('Blockly.Css');
+goog.require('Blockly.Events');
 goog.require('Blockly.Field');
 goog.require('Blockly.FieldAngle');
 goog.require('Blockly.FieldCheckbox');
diff --git a/core/blockly.js b/core/blockly.js
index 07403d972..ca9aafeaf 100644
--- a/core/blockly.js
+++ b/core/blockly.js
@@ -28,6 +28,7 @@
 goog.provide('Blockly');
 
 goog.require('Blockly.BlockSvg');
+goog.require('Blockly.Events');
 goog.require('Blockly.FieldAngle');
 goog.require('Blockly.FieldCheckbox');
 goog.require('Blockly.FieldColour');
diff --git a/core/events.js b/core/events.js
new file mode 100644
index 000000000..21e9813ff
--- /dev/null
+++ b/core/events.js
@@ -0,0 +1,53 @@
+/**
+ * @license
+ * Visual Blocks Editor
+ *
+ * Copyright 2016 Google Inc.
+ * https://developers.google.com/blockly/
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Events fired as a result of actions in Blockly's editor.
+ * @author fraser@google.com (Neil Fraser)
+ */
+'use strict';
+
+goog.provide('Blockly.Events');
+
+/**
+ * Allow change events to be created and fired.
+ * @type {boolean}
+ */
+Blockly.Events.enabled = true;
+
+/**
+ * Create a custom event and fire it.
+ * @param {Object} detail Custom data for event.
+ */
+Blockly.Events.fire = function(detail) {
+  var workspace = Blockly.Workspace.getById(detail.workspace);
+  if (workspace.rendered) {
+    // Create a custom event in a browser-compatible way.
+    if (typeof CustomEvent == 'function') {
+      // W3
+      var evt = new CustomEvent('blocklyWorkspaceChange', {'detail': detail});
+    } else {
+      // MSIE
+      var evt = document.createEvent('CustomEvent');
+      evt.initCustomEvent(eventName, false, false, detail);
+    }
+    workspace.getCanvas().dispatchEvent(evt);
+  }
+};
diff --git a/core/field_textinput.js b/core/field_textinput.js
index a5cac7ebb..4cac181b2 100644
--- a/core/field_textinput.js
+++ b/core/field_textinput.js
@@ -109,6 +109,7 @@ Blockly.FieldTextInput.prototype.setSpellcheck = function(check) {
  * @private
  */
 Blockly.FieldTextInput.prototype.showEditor_ = function(opt_quietInput) {
+  var workspace = this.sourceBlock_.workspace;
   var quietInput = opt_quietInput || false;
   if (!quietInput && (goog.userAgent.MOBILE || goog.userAgent.ANDROID ||
                       goog.userAgent.IPAD)) {
@@ -131,8 +132,7 @@ Blockly.FieldTextInput.prototype.showEditor_ = function(opt_quietInput) {
   // Create the input.
   var htmlInput = goog.dom.createDom('input', 'blocklyHtmlInput');
   htmlInput.setAttribute('spellcheck', this.spellcheck_);
-  var fontSize = (Blockly.FieldTextInput.FONTSIZE *
-                  this.sourceBlock_.workspace.scale) + 'pt';
+  var fontSize = (Blockly.FieldTextInput.FONTSIZE * workspace.scale) + 'pt';
   div.style.fontSize = fontSize;
   htmlInput.style.fontSize = fontSize;
   /** @type {!HTMLInputElement} */
@@ -157,9 +157,8 @@ Blockly.FieldTextInput.prototype.showEditor_ = function(opt_quietInput) {
   // Bind to keyPress -- repeatedly resize when holding down a key.
   htmlInput.onKeyPressWrapper_ =
       Blockly.bindEvent_(htmlInput, 'keypress', this, this.onHtmlInputChange_);
-  var workspaceSvg = this.sourceBlock_.workspace.getCanvas();
   htmlInput.onWorkspaceChangeWrapper_ =
-      Blockly.bindEvent_(workspaceSvg, 'blocklyWorkspaceChange', this,
+      Blockly.bindEvent_(workspace.getCanvas(), 'blocklyWorkspaceChange', this,
       this.resizeEditor_);
 };
 
diff --git a/core/utils.js b/core/utils.js
index c8fc97c0f..ce3cea70b 100644
--- a/core/utils.js
+++ b/core/utils.js
@@ -177,19 +177,16 @@ Blockly.fireUiEventNow = function(node, eventName) {
       list.splice(i, 1);
     }
   }
-  // Fire the event in a browser-compatible way.
-  if (document.createEvent) {
+  // Create a UI event in a browser-compatible way.
+  if (typeof UIEvent == 'function') {
     // W3
-    var evt = document.createEvent('UIEvents');
-    evt.initEvent(eventName, true, true);  // event type, bubbling, cancelable
-    node.dispatchEvent(evt);
-  } else if (document.createEventObject) {
-    // MSIE
-    var evt = document.createEventObject();
-    node.fireEvent('on' + eventName, evt);
+    var evt = new UIEvent(eventName, {});
   } else {
-    throw 'FireEvent: No event creation mechanism.';
+    // MSIE
+    var evt = document.createEvent('UIEvent');
+    evt.initUIEvent(eventName, false, false, window, 0);
   }
+  node.dispatchEvent(evt);
 };
 
 /**
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index 185255a54..3d702e45f 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -472,7 +472,8 @@ Blockly.WorkspaceSvg.prototype.highlightBlock = function(id) {
  */
 Blockly.WorkspaceSvg.prototype.fireChangeEvent = function() {
   if (this.rendered && this.svgBlockCanvas_) {
-    Blockly.fireUiEvent(this.svgBlockCanvas_, 'blocklyWorkspaceChange');
+    var details = {workspace: this.id};
+    Blockly.Events.fire(details);
   }
 };