From 53f54248018db2a5bb6f5133ee08ad20f78dbbc6 Mon Sep 17 00:00:00 2001
From: Neil Fraser <fraser@google.com>
Date: Thu, 20 Aug 2015 15:46:44 -0700
Subject: [PATCH] Skc memory leaks (PR #159)

---
 blockly_compressed.js | 35 ++++++++++++++++++-----------------
 core/flyout.js        | 19 +++++++++++--------
 core/scrollbar.js     |  6 ------
 core/toolbox.js       |  1 +
 core/workspace_svg.js | 40 +++++++++++++++++++++++++++++++---------
 5 files changed, 61 insertions(+), 40 deletions(-)

diff --git a/blockly_compressed.js b/blockly_compressed.js
index 1fd656d47..ffb647805 100644
--- a/blockly_compressed.js
+++ b/blockly_compressed.js
@@ -933,13 +933,13 @@ Blockly.Input.prototype.appendField=function(a,b){if(!a&&!b)return this;goog.isS
 Blockly.Input.prototype.appendTitle=function(a,b){console.warn("Deprecated call to appendTitle, use appendField instead.");return this.appendField(a,b)};Blockly.Input.prototype.removeField=function(a){for(var b=0,c;c=this.fieldRow[b];b++)if(c.name===a){c.dispose();this.fieldRow.splice(b,1);this.sourceBlock_.rendered&&(this.sourceBlock_.render(),this.sourceBlock_.bumpNeighbours_());return}goog.asserts.fail('Field "%s" not found.',a)};Blockly.Input.prototype.isVisible=function(){return this.visible_};
 Blockly.Input.prototype.setVisible=function(a){var b=[];if(this.visible_==a)return b;for(var c=(this.visible_=a)?"block":"none",d=0,e;e=this.fieldRow[d];d++)e.setVisible(a);this.connection&&(a?b=this.connection.unhideAll():this.connection.hideAll(),d=this.connection.targetBlock())&&(d.getSvgRoot().style.display=c,a||(d.rendered=!1));return b};Blockly.Input.prototype.setCheck=function(a){if(!this.connection)throw"This input does not have a connection.";this.connection.setCheck(a);return this};
 Blockly.Input.prototype.setAlign=function(a){this.align=a;this.sourceBlock_.rendered&&this.sourceBlock_.render();return this};Blockly.Input.prototype.init=function(){if(this.sourceBlock_.workspace.rendered)for(var a=0;a<this.fieldRow.length;a++)this.fieldRow[a].init(this.sourceBlock_)};Blockly.Input.prototype.dispose=function(){for(var a=0,b;b=this.fieldRow[a];a++)b.dispose();this.connection&&this.connection.dispose();this.sourceBlock_=null};Blockly.ScrollbarPair=function(a){this.workspace_=a;this.oldHostMetrics_=null;this.hScroll=new Blockly.Scrollbar(a,!0,!0);this.vScroll=new Blockly.Scrollbar(a,!1,!0);this.corner_=Blockly.createSvgElement("rect",{height:Blockly.Scrollbar.scrollbarThickness,width:Blockly.Scrollbar.scrollbarThickness,"class":"blocklyScrollbarBackground"},null);Blockly.Scrollbar.insertAfter_(this.corner_,a.getBubbleCanvas())};
-Blockly.ScrollbarPair.prototype.dispose=function(){Blockly.unbindEvent_(this.onResizeWrapper_);this.onResizeWrapper_=null;goog.dom.removeNode(this.corner_);this.oldHostMetrics_=this.workspace_=this.corner_=null;this.hScroll.dispose();this.hScroll=null;this.vScroll.dispose();this.vScroll=null};
+Blockly.ScrollbarPair.prototype.dispose=function(){goog.dom.removeNode(this.corner_);this.oldHostMetrics_=this.workspace_=this.corner_=null;this.hScroll.dispose();this.hScroll=null;this.vScroll.dispose();this.vScroll=null};
 Blockly.ScrollbarPair.prototype.resize=function(){var a=this.workspace_.getMetrics();if(a){var b=!1,c=!1;this.oldHostMetrics_&&this.oldHostMetrics_.viewWidth==a.viewWidth&&this.oldHostMetrics_.viewHeight==a.viewHeight&&this.oldHostMetrics_.absoluteTop==a.absoluteTop&&this.oldHostMetrics_.absoluteLeft==a.absoluteLeft?(this.oldHostMetrics_&&this.oldHostMetrics_.contentWidth==a.contentWidth&&this.oldHostMetrics_.viewLeft==a.viewLeft&&this.oldHostMetrics_.contentLeft==a.contentLeft||(b=!0),this.oldHostMetrics_&&
 this.oldHostMetrics_.contentHeight==a.contentHeight&&this.oldHostMetrics_.viewTop==a.viewTop&&this.oldHostMetrics_.contentTop==a.contentTop||(c=!0)):c=b=!0;b&&this.hScroll.resize(a);c&&this.vScroll.resize(a);this.oldHostMetrics_&&this.oldHostMetrics_.viewWidth==a.viewWidth&&this.oldHostMetrics_.absoluteLeft==a.absoluteLeft||this.corner_.setAttribute("x",this.vScroll.xCoordinate);this.oldHostMetrics_&&this.oldHostMetrics_.viewHeight==a.viewHeight&&this.oldHostMetrics_.absoluteTop==a.absoluteTop||this.corner_.setAttribute("y",
 this.hScroll.yCoordinate);this.oldHostMetrics_=a}};Blockly.ScrollbarPair.prototype.set=function(a,b){this.hScroll.set(a);this.vScroll.set(b)};
 Blockly.Scrollbar=function(a,b,c){this.workspace_=a;this.pair_=c||!1;this.horizontal_=b;this.createDom_();b?(this.svgBackground_.setAttribute("height",Blockly.Scrollbar.scrollbarThickness),this.svgKnob_.setAttribute("height",Blockly.Scrollbar.scrollbarThickness-5),this.svgKnob_.setAttribute("y",2.5)):(this.svgBackground_.setAttribute("width",Blockly.Scrollbar.scrollbarThickness),this.svgKnob_.setAttribute("width",Blockly.Scrollbar.scrollbarThickness-5),this.svgKnob_.setAttribute("x",2.5));this.onMouseDownBarWrapper_=
 Blockly.bindEvent_(this.svgBackground_,"mousedown",this,this.onMouseDownBar_);this.onMouseDownKnobWrapper_=Blockly.bindEvent_(this.svgKnob_,"mousedown",this,this.onMouseDownKnob_)};Blockly.Scrollbar.scrollbarThickness=15;goog.events.BrowserFeature.TOUCH_ENABLED&&(Blockly.Scrollbar.scrollbarThickness=25);
-Blockly.Scrollbar.prototype.dispose=function(){this.onMouseUpKnob_();this.onResizeWrapper_&&(Blockly.unbindEvent_(this.onResizeWrapper_),this.onResizeWrapper_=null);Blockly.unbindEvent_(this.onMouseDownBarWrapper_);this.onMouseDownBarWrapper_=null;Blockly.unbindEvent_(this.onMouseDownKnobWrapper_);this.onMouseDownKnobWrapper_=null;goog.dom.removeNode(this.svgGroup_);this.workspace_=this.svgKnob_=this.svgBackground_=this.svgGroup_=null};
+Blockly.Scrollbar.prototype.dispose=function(){this.onMouseUpKnob_();Blockly.unbindEvent_(this.onMouseDownBarWrapper_);this.onMouseDownBarWrapper_=null;Blockly.unbindEvent_(this.onMouseDownKnobWrapper_);this.onMouseDownKnobWrapper_=null;goog.dom.removeNode(this.svgGroup_);this.workspace_=this.svgKnob_=this.svgBackground_=this.svgGroup_=null};
 Blockly.Scrollbar.prototype.resize=function(a){if(!a&&(a=this.workspace_.getMetrics(),!a))return;if(this.horizontal_){var b=a.viewWidth-1;this.pair_?b-=Blockly.Scrollbar.scrollbarThickness:this.setVisible(b<a.contentHeight);this.ratio_=b/a.contentWidth;if(-Infinity===this.ratio_||Infinity===this.ratio_||isNaN(this.ratio_))this.ratio_=0;var c=a.viewWidth*this.ratio_,d=(a.viewLeft-a.contentLeft)*this.ratio_;this.svgKnob_.setAttribute("width",Math.max(0,c));this.xCoordinate=a.absoluteLeft+.5;this.pair_&&
 this.workspace_.RTL&&(this.xCoordinate+=a.absoluteLeft+Blockly.Scrollbar.scrollbarThickness);this.yCoordinate=a.absoluteTop+a.viewHeight-Blockly.Scrollbar.scrollbarThickness-.5;this.svgGroup_.setAttribute("transform","translate("+this.xCoordinate+","+this.yCoordinate+")");this.svgBackground_.setAttribute("width",Math.max(0,b));this.svgKnob_.setAttribute("x",this.constrainKnob_(d))}else{b=a.viewHeight-1;this.pair_?b-=Blockly.Scrollbar.scrollbarThickness:this.setVisible(b<a.contentHeight);this.ratio_=
 b/a.contentHeight;if(-Infinity===this.ratio_||Infinity===this.ratio_||isNaN(this.ratio_))this.ratio_=0;c=a.viewHeight*this.ratio_;d=(a.viewTop-a.contentTop)*this.ratio_;this.svgKnob_.setAttribute("height",Math.max(0,c));this.xCoordinate=a.absoluteLeft+.5;this.workspace_.RTL||(this.xCoordinate+=a.viewWidth-Blockly.Scrollbar.scrollbarThickness-1);this.yCoordinate=a.absoluteTop+.5;this.svgGroup_.setAttribute("transform","translate("+this.xCoordinate+","+this.yCoordinate+")");this.svgBackground_.setAttribute("height",
@@ -982,16 +982,17 @@ if(d.nextConnection.targetConnection)throw"Next statement is already connected."
 d.setMovable("true"==a);(a=b.getAttribute("editable"))&&d.setEditable("true"==a);(b=b.getAttribute("collapsed"))&&d.setCollapsed("true"==b);return d};Blockly.Xml.deleteNext=function(a){for(var b=0,c;c=a.childNodes[b];b++)if("next"==c.nodeName.toLowerCase()){a.removeChild(c);break}};goog.global.Blockly||(goog.global.Blockly={});goog.global.Blockly.Xml||(goog.global.Blockly.Xml={});goog.global.Blockly.Xml.domToText=Blockly.Xml.domToText;goog.global.Blockly.Xml.domToWorkspace=Blockly.Xml.domToWorkspace;
 goog.global.Blockly.Xml.textToDom=Blockly.Xml.textToDom;goog.global.Blockly.Xml.workspaceToDom=Blockly.Xml.workspaceToDom;
 // Copyright 2014 Google Inc.  Apache License 2.0
-Blockly.WorkspaceSvg=function(a){Blockly.WorkspaceSvg.superClass_.constructor.call(this,a);this.getMetrics=a.getMetrics;this.setMetrics=a.setMetrics;Blockly.ConnectionDB.init(this);this.SOUNDS_=Object.create(null)};goog.inherits(Blockly.WorkspaceSvg,Blockly.Workspace);Blockly.WorkspaceSvg.prototype.rendered=!0;Blockly.WorkspaceSvg.prototype.isFlyout=!1;Blockly.WorkspaceSvg.prototype.isScrolling=!1;Blockly.WorkspaceSvg.prototype.scrollX=0;Blockly.WorkspaceSvg.prototype.scrollY=0;
-Blockly.WorkspaceSvg.prototype.dragDeltaX_=0;Blockly.WorkspaceSvg.prototype.dragDeltaY_=0;Blockly.WorkspaceSvg.prototype.scale=1;Blockly.WorkspaceSvg.prototype.trashcan=null;Blockly.WorkspaceSvg.prototype.scrollbar=null;
+Blockly.WorkspaceSvg=function(a){Blockly.WorkspaceSvg.superClass_.constructor.call(this,a);this.getMetrics=a.getMetrics;this.setMetrics=a.setMetrics;Blockly.ConnectionDB.init(this);this.SOUNDS_=Object.create(null);this.eventWrappers_=[]};goog.inherits(Blockly.WorkspaceSvg,Blockly.Workspace);Blockly.WorkspaceSvg.prototype.rendered=!0;Blockly.WorkspaceSvg.prototype.isFlyout=!1;Blockly.WorkspaceSvg.prototype.isScrolling=!1;Blockly.WorkspaceSvg.prototype.scrollX=0;
+Blockly.WorkspaceSvg.prototype.scrollY=0;Blockly.WorkspaceSvg.prototype.dragDeltaX_=0;Blockly.WorkspaceSvg.prototype.dragDeltaY_=0;Blockly.WorkspaceSvg.prototype.scale=1;Blockly.WorkspaceSvg.prototype.trashcan=null;Blockly.WorkspaceSvg.prototype.scrollbar=null;
 Blockly.WorkspaceSvg.prototype.createDom=function(a){this.svgGroup_=Blockly.createSvgElement("g",{"class":"blocklyWorkspace"},null);a&&(this.svgBackground_=Blockly.createSvgElement("rect",{height:"100%",width:"100%","class":a},this.svgGroup_),"blocklyMainBackground"==a&&(this.svgBackground_.style.fill="url(#"+this.options.gridPattern.id+")"));this.svgBlockCanvas_=Blockly.createSvgElement("g",{"class":"blocklyBlockCanvas"},this.svgGroup_,this);this.svgBubbleCanvas_=Blockly.createSvgElement("g",{"class":"blocklyBubbleCanvas"},
 this.svgGroup_,this);this.options.hasTrashcan&&this.addTrashcan_();this.options.zoomOptions&&this.options.zoomOptions.controls&&this.addZoomControls_();Blockly.bindEvent_(this.svgGroup_,"mousedown",this,this.onMouseDown_);var b=this;Blockly.bindEvent_(this.svgGroup_,"touchstart",null,function(a){Blockly.longStart_(a,b)});this.options.zoomOptions&&this.options.zoomOptions.wheel&&Blockly.bindEvent_(this.svgGroup_,"wheel",this,this.onMouseWheel_);this.options.hasCategories?this.toolbox_=new Blockly.Toolbox(this):
 this.options.languageTree&&this.addFlyout_();this.updateGridPattern_();return this.svgGroup_};
-Blockly.WorkspaceSvg.prototype.dispose=function(){this.rendered=!1;Blockly.WorkspaceSvg.superClass_.dispose.call(this);this.svgGroup_&&(goog.dom.removeNode(this.svgGroup_),this.svgGroup_=null);this.svgBubbleCanvas_=this.svgBlockCanvas_=null;this.toolbox_&&(this.toolbox_.dispose(),this.toolbox_=null);this.flyout_&&(this.flyout_.dispose(),this.flyout_=null);this.trashcan&&(this.trashcan.dispose(),this.trashcan=null);this.zoomControls&&(this.zoomControls.dispose(),this.zoomControls=null);this.options.parentWorkspace||
-goog.dom.removeNode(this.options.svg)};Blockly.WorkspaceSvg.prototype.addTrashcan_=function(){this.trashcan=new Blockly.Trashcan(this);var a=this.trashcan.createDom();this.svgGroup_.insertBefore(a,this.svgBlockCanvas_);this.trashcan.init()};Blockly.WorkspaceSvg.prototype.addZoomControls_=function(){this.zoomControls=new Blockly.ZoomControls(this);var a=this.zoomControls.createDom();this.svgGroup_.appendChild(a);this.zoomControls.init()};
-Blockly.WorkspaceSvg.prototype.addFlyout_=function(){this.flyout_=new Blockly.Flyout({parentWorkspace:this,RTL:this.RTL});this.flyout_.autoClose=!1;var a=this.flyout_.createDom();this.svgGroup_.insertBefore(a,this.svgBlockCanvas_)};Blockly.WorkspaceSvg.prototype.resize=function(){this.toolbox_&&this.toolbox_.position();this.flyout_&&this.flyout_.position();this.trashcan&&this.trashcan.position();this.zoomControls&&this.zoomControls.position();this.scrollbar&&this.scrollbar.resize()};
-Blockly.WorkspaceSvg.prototype.getCanvas=function(){return this.svgBlockCanvas_};Blockly.WorkspaceSvg.prototype.getBubbleCanvas=function(){return this.svgBubbleCanvas_};Blockly.WorkspaceSvg.prototype.translate=function(a,b){var c="translate("+a+","+b+")scale("+this.scale+")";this.svgBlockCanvas_.setAttribute("transform",c);this.svgBubbleCanvas_.setAttribute("transform",c)};
-Blockly.WorkspaceSvg.prototype.addTopBlock=function(a){Blockly.WorkspaceSvg.superClass_.addTopBlock.call(this,a);Blockly.Realtime.isEnabled()&&!this.options.parentWorkspace&&Blockly.Realtime.addTopBlock(a)};Blockly.WorkspaceSvg.prototype.removeTopBlock=function(a){Blockly.WorkspaceSvg.superClass_.removeTopBlock.call(this,a);Blockly.Realtime.isEnabled()&&!this.options.parentWorkspace&&Blockly.Realtime.removeTopBlock(a)};Blockly.WorkspaceSvg.prototype.getWidth=function(){return this.getMetrics().viewWidth};
+Blockly.WorkspaceSvg.prototype.dispose=function(){this.rendered=!1;Blockly.unbindEvent_(this.eventWrappers_);Blockly.WorkspaceSvg.superClass_.dispose.call(this);this.svgGroup_&&(goog.dom.removeNode(this.svgGroup_),this.svgGroup_=null);this.svgBubbleCanvas_=this.svgBlockCanvas_=null;this.toolbox_&&(this.toolbox_.dispose(),this.toolbox_=null);this.flyout_&&(this.flyout_.dispose(),this.flyout_=null);this.trashcan&&(this.trashcan.dispose(),this.trashcan=null);this.scrollbar&&(this.scrollbar.dispose(),
+this.scrollbar=null);this.zoomControls_&&(this.zoomControls_.dispose(),this.zoomControls_=null);this.options.parentWorkspace||goog.dom.removeNode(this.options.svg)};Blockly.WorkspaceSvg.prototype.addTrashcan_=function(){this.trashcan=new Blockly.Trashcan(this);var a=this.trashcan.createDom();this.svgGroup_.insertBefore(a,this.svgBlockCanvas_);this.trashcan.init()};
+Blockly.WorkspaceSvg.prototype.addZoomControls_=function(){this.zoomControls_=new Blockly.ZoomControls(this);var a=this.zoomControls_.createDom();this.svgGroup_.appendChild(a);this.zoomControls_.init()};Blockly.WorkspaceSvg.prototype.addFlyout_=function(){this.flyout_=new Blockly.Flyout({parentWorkspace:this,RTL:this.RTL});this.flyout_.autoClose=!1;var a=this.flyout_.createDom();this.svgGroup_.insertBefore(a,this.svgBlockCanvas_)};
+Blockly.WorkspaceSvg.prototype.resize=function(){this.toolbox_&&this.toolbox_.position();this.flyout_&&this.flyout_.position();this.trashcan&&this.trashcan.position();this.zoomControls_&&this.zoomControls_.position();this.scrollbar&&this.scrollbar.resize()};Blockly.WorkspaceSvg.prototype.getCanvas=function(){return this.svgBlockCanvas_};Blockly.WorkspaceSvg.prototype.getBubbleCanvas=function(){return this.svgBubbleCanvas_};
+Blockly.WorkspaceSvg.prototype.translate=function(a,b){var c="translate("+a+","+b+")scale("+this.scale+")";this.svgBlockCanvas_.setAttribute("transform",c);this.svgBubbleCanvas_.setAttribute("transform",c)};Blockly.WorkspaceSvg.prototype.addTopBlock=function(a){Blockly.WorkspaceSvg.superClass_.addTopBlock.call(this,a);Blockly.Realtime.isEnabled()&&!this.options.parentWorkspace&&Blockly.Realtime.addTopBlock(a)};
+Blockly.WorkspaceSvg.prototype.removeTopBlock=function(a){Blockly.WorkspaceSvg.superClass_.removeTopBlock.call(this,a);Blockly.Realtime.isEnabled()&&!this.options.parentWorkspace&&Blockly.Realtime.removeTopBlock(a)};Blockly.WorkspaceSvg.prototype.getWidth=function(){return this.getMetrics().viewWidth};
 Blockly.WorkspaceSvg.prototype.setVisible=function(a){this.options.svg.style.display=a?"block":"none";this.toolbox_&&(this.toolbox_.HtmlDiv.style.display=a?"block":"none");a?(this.render(),this.toolbox_&&this.toolbox_.position()):Blockly.hideChaff(!0)};Blockly.WorkspaceSvg.prototype.render=function(){for(var a=this.getAllBlocks(),b=0,c;c=a[b];b++)c.getChildren().length||c.render()};
 Blockly.WorkspaceSvg.prototype.traceOn=function(a){this.traceOn_=a;this.traceWrapper_&&(Blockly.unbindEvent_(this.traceWrapper_),this.traceWrapper_=null);a&&(this.traceWrapper_=Blockly.bindEvent_(this.svgBlockCanvas_,"blocklySelectChange",this,function(){this.traceOn_=!1}))};
 Blockly.WorkspaceSvg.prototype.highlightBlock=function(a){this.traceOn_&&0!=Blockly.dragMode_&&this.traceOn(!1);if(this.traceOn_){var b=null;if(a&&(b=this.getBlockById(a),!b))return;this.traceOn(!1);b?b.select():Blockly.selected&&Blockly.selected.unselect();var c=this;setTimeout(function(){c.traceOn(!0)},1)}};Blockly.WorkspaceSvg.prototype.fireChangeEvent=function(){this.rendered&&this.svgBlockCanvas_&&Blockly.fireUiEvent(this.svgBlockCanvas_,"blocklyWorkspaceChange")};
@@ -1007,7 +1008,7 @@ Blockly.WorkspaceSvg.prototype.showContextMenu_=function(a){if(!this.options.rea
 Blockly.WorkspaceSvg.prototype.preloadAudio_=function(){for(var a in this.SOUNDS_){var b=this.SOUNDS_[a];b.volume=.01;b.play();b.pause();if(goog.userAgent.IPAD||goog.userAgent.IPHONE)break}};
 Blockly.WorkspaceSvg.prototype.playAudio=function(a,b){var c=this.SOUNDS_[a];c?(c=goog.userAgent.DOCUMENT_MODE&&9===goog.userAgent.DOCUMENT_MODE||goog.userAgent.IPAD||goog.userAgent.ANDROID?c:c.cloneNode(),c.volume=void 0===b?1:b,c.play()):this.options.parentWorkspace&&this.options.parentWorkspace.playAudio(a,b)};
 Blockly.WorkspaceSvg.prototype.updateToolbox=function(a){if(a=Blockly.parseToolboxTree_(a)){if(!this.options.languageTree)throw"Existing toolbox is null.  Can't create new toolbox.";if(this.options.hasCategories){if(!this.toolbox_)throw"Existing toolbox has no categories.  Can't change mode.";this.options.languageTree=a;this.toolbox_.populate_(a)}else{if(!this.flyout_)throw"Existing toolbox has categories.  Can't change mode.";this.options.languageTree=a;this.flyout_.show(a.childNodes)}}else if(this.options.languageTree)throw"Can't nullify an existing toolbox.";
-};Blockly.WorkspaceSvg.prototype.addChangeListener=function(a){return Blockly.bindEvent_(this.getCanvas(),"blocklyWorkspaceChange",null,a)};Blockly.WorkspaceSvg.prototype.removeChangeListener=function(a){Blockly.unbindEvent_(a)};Blockly.WorkspaceSvg.prototype.markFocused=function(){Blockly.mainWorkspace=this};
+};Blockly.WorkspaceSvg.prototype.addChangeListener=function(a){a=Blockly.bindEvent_(this.getCanvas(),"blocklyWorkspaceChange",null,a);Array.prototype.push.apply(this.eventWrappers_,a);return a};Blockly.WorkspaceSvg.prototype.removeChangeListener=function(a){Blockly.unbindEvent_(a);a=this.eventWrappers_.indexOf(a);-1!=a&&this.eventWrappers_.splice(a,1)};Blockly.WorkspaceSvg.prototype.markFocused=function(){Blockly.mainWorkspace=this};
 Blockly.WorkspaceSvg.prototype.zoom=function(a,b,c){var d=this.options.zoomOptions.scaleSpeed,e=this.getMetrics(),f=this.options.svg.createSVGPoint();f.x=a;f.y=b;f=f.matrixTransform(this.getCanvas().getCTM().inverse());a=f.x;b=f.y;f=this.getCanvas();c=1==c?d:1/d;d=this.scale*c;d>this.options.zoomOptions.maxScale?c=this.options.zoomOptions.maxScale/this.scale:d<this.options.zoomOptions.minScale&&(c=this.options.zoomOptions.minScale/this.scale);a=f.getCTM().translate(a*(1-c),b*(1-c)).scale(c);this.scale!=
 a.a&&(this.scale=a.a,this.scrollX=a.e-e.absoluteLeft,this.scrollY=a.f-e.absoluteTop,this.updateGridPattern_(),this.scrollbar.resize())};Blockly.WorkspaceSvg.prototype.zoomCenter=function(a){var b=this.getMetrics();this.zoom(b.viewWidth/2,b.viewHeight/2,a)};Blockly.WorkspaceSvg.prototype.zoomReset=function(){this.scale=1;this.updateGridPattern_();var a=this.getMetrics();this.scrollbar.set((a.contentWidth-a.viewWidth)/2,(a.contentHeight-a.viewHeight)/2)};
 Blockly.WorkspaceSvg.prototype.updateGridPattern_=function(){if(this.options.gridPattern){var a=this.options.gridOptions.spacing*this.scale||100;this.options.gridPattern.setAttribute("width",a);this.options.gridPattern.setAttribute("height",a);var a=Math.floor(this.options.gridOptions.spacing/2)+.5,b=a-this.options.gridOptions.length/2,c=a+this.options.gridOptions.length/2,d=this.options.gridPattern.firstChild,e=d&&d.nextSibling,a=a*this.scale,b=b*this.scale,c=c*this.scale;d&&(d.setAttribute("stroke-width",
@@ -1079,8 +1080,8 @@ Blockly.BlockSvg.prototype.setCollapsed=function(a){if(this.collapsed_!=a){for(v
 b[c];c++)a.render();this.workspace.fireChangeEvent()}};
 Blockly.BlockSvg.prototype.onMouseDown_=function(a){if(!this.isInFlyout){Blockly.svgResize(this.workspace);Blockly.terminateDrag_();this.select();Blockly.hideChaff();if(Blockly.isRightButton(a))this.showContextMenu_(a);else if(this.isMovable()){Blockly.removeAllRanges();Blockly.Css.setCursor(Blockly.Css.Cursor.CLOSED);this.dragStartXY_=this.getRelativeToSurfaceXY();this.workspace.startDrag(a,this.dragStartXY_.x,this.dragStartXY_.y);Blockly.dragMode_=1;Blockly.BlockSvg.onMouseUpWrapper_=Blockly.bindEvent_(document,
 "mouseup",this,this.onMouseUp_);Blockly.BlockSvg.onMouseMoveWrapper_=Blockly.bindEvent_(document,"mousemove",this,this.onMouseMove_);this.draggedBubbles_=[];for(var b=this.getDescendants(),c=0,d;d=b[c];c++){d=d.getIcons();for(var e=0;e<d.length;e++){var f=d[e].getIconLocation();f.bubble=d[e];this.draggedBubbles_.push(f)}}}else return;a.stopPropagation()}};
-Blockly.BlockSvg.prototype.onMouseUp_=function(a){var b=this;Blockly.doCommand(function(){Blockly.terminateDrag_();if(Blockly.selected&&Blockly.highlightedConnection_)Blockly.localConnection_.connect(Blockly.highlightedConnection_),b.rendered&&(Blockly.localConnection_.isSuperior()?Blockly.highlightedConnection_:Blockly.localConnection_).sourceBlock_.connectionUiEffect(),b.workspace.trashcan&&b.workspace.trashcan.close();else if(Blockly.selected.isDeletable()&&b.workspace.isDeleteArea(a)){var c=b.workspace.trashcan;
-c&&goog.Timer.callOnce(c.close,100,c);Blockly.selected.dispose(!1,!0);Blockly.fireUiEvent(window,"resize")}Blockly.highlightedConnection_&&(Blockly.highlightedConnection_.unhighlight(),Blockly.highlightedConnection_=null);Blockly.Css.setCursor(Blockly.Css.Cursor.OPEN)})};Blockly.BlockSvg.prototype.showHelp_=function(){var a=goog.isFunction(this.helpUrl)?this.helpUrl():this.helpUrl;a&&window.open(a)};
+Blockly.BlockSvg.prototype.onMouseUp_=function(a){var b=this;Blockly.doCommand(function(){Blockly.terminateDrag_();if(Blockly.selected&&Blockly.highlightedConnection_)Blockly.localConnection_.connect(Blockly.highlightedConnection_),b.rendered&&(Blockly.localConnection_.isSuperior()?Blockly.highlightedConnection_:Blockly.localConnection_).sourceBlock_.connectionUiEffect(),b.workspace.trashcan&&b.workspace.trashcan.close();else if(!b.getParent()&&Blockly.selected.isDeletable()&&b.workspace.isDeleteArea(a)){var c=
+b.workspace.trashcan;c&&goog.Timer.callOnce(c.close,100,c);Blockly.selected.dispose(!1,!0);Blockly.fireUiEvent(window,"resize")}Blockly.highlightedConnection_&&(Blockly.highlightedConnection_.unhighlight(),Blockly.highlightedConnection_=null);Blockly.Css.setCursor(Blockly.Css.Cursor.OPEN)})};Blockly.BlockSvg.prototype.showHelp_=function(){var a=goog.isFunction(this.helpUrl)?this.helpUrl():this.helpUrl;a&&window.open(a)};
 Blockly.BlockSvg.prototype.showContextMenu_=function(a){if(!this.workspace.options.readOnly&&this.contextMenu){var b=this,c=[];if(this.isDeletable()&&this.isMovable()&&!b.isInFlyout){var d={text:Blockly.Msg.DUPLICATE_BLOCK,enabled:!0,callback:function(){b.duplicate_()}};this.getDescendants().length>this.workspace.remainingCapacity()&&(d.enabled=!1);c.push(d);this.isEditable()&&!this.collapsed_&&this.workspace.options.comments&&(d={enabled:!0},this.comment?(d.text=Blockly.Msg.REMOVE_COMMENT,d.callback=
 function(){b.setCommentText(null)}):(d.text=Blockly.Msg.ADD_COMMENT,d.callback=function(){b.setCommentText("")}),c.push(d));if(!this.collapsed_)for(d=1;d<this.inputList.length;d++)if(this.inputList[d-1].type!=Blockly.NEXT_STATEMENT&&this.inputList[d].type!=Blockly.NEXT_STATEMENT){var d={enabled:!0},e=this.getInputsInline();d.text=e?Blockly.Msg.EXTERNAL_INPUTS:Blockly.Msg.INLINE_INPUTS;d.callback=function(){b.setInputsInline(!e)};c.push(d);break}this.workspace.options.collapse&&(this.collapsed_?(d=
 {enabled:!0},d.text=Blockly.Msg.EXPAND_BLOCK,d.callback=function(){b.setCollapsed(!1)}):(d={enabled:!0},d.text=Blockly.Msg.COLLAPSE_BLOCK,d.callback=function(){b.setCollapsed(!0)}),c.push(d));this.workspace.options.disable&&(d={text:this.disabled?Blockly.Msg.ENABLE_BLOCK:Blockly.Msg.DISABLE_BLOCK,enabled:!this.getInheritedDisabled(),callback:function(){b.setDisabled(!b.disabled)}},c.push(d));var d=this.getDescendants().length,f=this.getNextBlock();f&&(d-=f.getDescendants().length);d={text:1==d?Blockly.Msg.DELETE_BLOCK:
@@ -1228,8 +1229,8 @@ Blockly.Realtime.addAuthUi_=function(a){a.style.background="url("+Blockly.pathTo
 Blockly.Realtime.updateCollabUi_=function(){if(Blockly.Realtime.collabElementId){var a=goog.dom.getElement(Blockly.Realtime.collabElementId);goog.dom.removeChildren(a);for(var b=Blockly.Realtime.document_.getCollaborators(),c=0;c<b.length;c++){var d=b[c],e=goog.dom.createDom("img",{src:d.photoUrl||Blockly.pathToMedia+Blockly.Realtime.ANONYMOUS_URL_,alt:d.displayName,title:d.displayName+(d.isMe?" ("+Blockly.Msg.ME+")":"")});e.style.backgroundColor=d.color;goog.dom.appendChild(a,e)}}};
 Blockly.Realtime.onCollaboratorJoined_=function(a){Blockly.Realtime.updateCollabUi_()};Blockly.Realtime.onCollaboratorLeft_=function(a){Blockly.Realtime.updateCollabUi_()};Blockly.Realtime.doCommand=function(a){a()};Blockly.Realtime.genUid=function(a){var b=Blockly.Realtime.sessionId_+"-"+a;return Blockly.Realtime.blocksMap_.has(b)?Blockly.Realtime.genUid("-"+a):b};Blockly.Flyout=function(a){var b=this;a.getMetrics=function(){return b.getMetrics_()};a.setMetrics=function(a){return b.setMetrics_(a)};this.workspace_=new Blockly.WorkspaceSvg(a);this.workspace_.isFlyout=!0;this.RTL=!!a.RTL;this.eventWrappers_=[];this.height_=this.width_=0;this.buttons_=[];this.listeners_=[]};Blockly.Flyout.prototype.autoClose=!0;Blockly.Flyout.prototype.CORNER_RADIUS=8;Blockly.Flyout.prototype.SCROLLBAR_PADDING=2;
 Blockly.Flyout.prototype.createDom=function(){this.svgGroup_=Blockly.createSvgElement("g",{"class":"blocklyFlyout"},null);this.svgBackground_=Blockly.createSvgElement("path",{"class":"blocklyFlyoutBackground"},this.svgGroup_);this.svgGroup_.appendChild(this.workspace_.createDom());return this.svgGroup_};
-Blockly.Flyout.prototype.init=function(a){this.targetWorkspace_=a;this.workspace_.targetWorkspace=a;this.scrollbar_=new Blockly.Scrollbar(this.workspace_,!1,!1);this.hide();this.eventWrappers_.concat(Blockly.bindEvent_(this.svgGroup_,"wheel",this,this.wheel_));this.eventWrappers_.concat(Blockly.bindEvent_(this.targetWorkspace_.getCanvas(),"blocklyWorkspaceChange",this,this.filterForCapacity_));this.eventWrappers_.concat(Blockly.bindEvent_(this.svgGroup_,"mousedown",this,this.onMouseDown_))};
-Blockly.Flyout.prototype.dispose=function(){this.hide();Blockly.unbindEvent_(this.eventWrappers_);this.eventWrappers_.length=0;this.scrollbar_&&(this.scrollbar_.dispose(),this.scrollbar_=null);this.workspace_=null;this.svgGroup_&&(goog.dom.removeNode(this.svgGroup_),this.svgGroup_=null);this.targetWorkspace_=this.svgBackground_=null};
+Blockly.Flyout.prototype.init=function(a){this.targetWorkspace_=a;this.workspace_.targetWorkspace=a;this.scrollbar_=new Blockly.Scrollbar(this.workspace_,!1,!1);this.hide();Array.prototype.push.apply(this.eventWrappers_,Blockly.bindEvent_(this.svgGroup_,"wheel",this,this.wheel_));Array.prototype.push.apply(this.eventWrappers_,Blockly.bindEvent_(this.targetWorkspace_.getCanvas(),"blocklyWorkspaceChange",this,this.filterForCapacity_));Array.prototype.push.apply(this.eventWrappers_,Blockly.bindEvent_(this.svgGroup_,
+"mousedown",this,this.onMouseDown_))};Blockly.Flyout.prototype.dispose=function(){this.hide();Blockly.unbindEvent_(this.eventWrappers_);this.scrollbar_&&(this.scrollbar_.dispose(),this.scrollbar_=null);this.workspace_&&(this.workspace_.targetWorkspace=null,this.workspace_.dispose(),this.workspace_=null);this.svgGroup_&&(goog.dom.removeNode(this.svgGroup_),this.svgGroup_=null);this.targetWorkspace_=this.svgBackground_=null};
 Blockly.Flyout.prototype.getMetrics_=function(){if(!this.isVisible())return null;var a=this.height_-2*this.SCROLLBAR_PADDING,b=this.width_;try{var c=this.workspace_.getCanvas().getBBox()}catch(d){c={height:0,y:0}}return{viewHeight:a,viewWidth:b,contentHeight:c.height+c.y,viewTop:-this.workspace_.scrollY,contentTop:0,absoluteTop:this.SCROLLBAR_PADDING,absoluteLeft:0}};
 Blockly.Flyout.prototype.setMetrics_=function(a){var b=this.getMetrics_();b&&(goog.isNumber(a.y)&&(this.workspace_.scrollY=-b.contentHeight*a.y-b.contentTop),this.workspace_.translate(0,this.workspace_.scrollY+b.absoluteTop))};
 Blockly.Flyout.prototype.position=function(){if(this.isVisible()){var a=this.targetWorkspace_.getMetrics();if(a){var b=this.width_-this.CORNER_RADIUS;this.RTL&&(b*=-1);var c=["M "+(this.RTL?this.width_:0)+",0"];c.push("h",b);c.push("a",this.CORNER_RADIUS,this.CORNER_RADIUS,0,0,this.RTL?0:1,this.RTL?-this.CORNER_RADIUS:this.CORNER_RADIUS,this.CORNER_RADIUS);c.push("v",Math.max(0,a.viewHeight-2*this.CORNER_RADIUS));c.push("a",this.CORNER_RADIUS,this.CORNER_RADIUS,0,0,this.RTL?0:1,this.RTL?this.CORNER_RADIUS:
@@ -1253,7 +1254,7 @@ Blockly.Flyout.terminateDrag_=function(){Blockly.Flyout.onMouseUpWrapper_&&(Bloc
 Blockly.Flyout.onMouseUpWrapper_=null);Blockly.Flyout.startDownEvent_=null;Blockly.Flyout.startBlock_=null;Blockly.Flyout.startFlyout_=null};Blockly.Toolbox=function(a){this.workspace_=a};Blockly.Toolbox.prototype.width=0;Blockly.Toolbox.prototype.selectedOption_=null;Blockly.Toolbox.prototype.lastCategory_=null;Blockly.Toolbox.prototype.CONFIG_={indentWidth:19,cssRoot:"blocklyTreeRoot",cssHideRoot:"blocklyHidden",cssItem:"",cssTreeRow:"blocklyTreeRow",cssItemLabel:"blocklyTreeLabel",cssTreeIcon:"blocklyTreeIcon",cssExpandedFolderIcon:"blocklyTreeIconOpen",cssFileIcon:"blocklyTreeIconNone",cssSelectedRow:"blocklyTreeSelected"};
 Blockly.Toolbox.prototype.init=function(){var a=this.workspace_;this.HtmlDiv=goog.dom.createDom("div","blocklyToolboxDiv");this.HtmlDiv.setAttribute("dir",this.workspace_.RTL?"RTL":"LTR");document.body.appendChild(this.HtmlDiv);Blockly.bindEvent_(this.HtmlDiv,"mousedown",this,function(a){Blockly.isRightButton(a)||a.target==this.HtmlDiv?Blockly.hideChaff(!1):Blockly.hideChaff(!0)});this.flyout_=new Blockly.Flyout({parentWorkspace:a,RTL:a.RTL,svg:a.options.svg});goog.dom.insertSiblingAfter(this.flyout_.createDom(),
 a.svgGroup_);this.flyout_.init(a);this.CONFIG_.cleardotPath=a.options.pathToMedia+"1x1.gif";this.CONFIG_.cssCollapsedFolderIcon="blocklyTreeIconClosed"+(this.workspace_.RTL?"Rtl":"Ltr");var b=new Blockly.Toolbox.TreeControl(this,this.CONFIG_);this.tree_=b;b.setShowRootNode(!1);b.setShowLines(!1);b.setShowExpandIcons(!1);b.setSelectedItem(null);this.populate_(a.options.languageTree);b.render(this.HtmlDiv);this.position()};
-Blockly.Toolbox.prototype.dispose=function(){this.flyout_.dispose();this.tree_.dispose();goog.dom.removeNode(this.HtmlDiv)};Blockly.Toolbox.prototype.position=function(){var a=this.HtmlDiv;if(a){var b=this.workspace_.options.svg,c=goog.style.getPageOffset(b),b=Blockly.svgSize(b);a.style.left=this.workspace_.RTL?c.x+b.width-a.offsetWidth+"px":c.x+"px";a.style.height=b.height+"px";a.style.top=c.y+"px";this.width=a.offsetWidth;this.workspace_.RTL||--this.width;this.flyout_.position()}};
+Blockly.Toolbox.prototype.dispose=function(){this.flyout_.dispose();this.tree_.dispose();goog.dom.removeNode(this.HtmlDiv);this.workspace_=null};Blockly.Toolbox.prototype.position=function(){var a=this.HtmlDiv;if(a){var b=this.workspace_.options.svg,c=goog.style.getPageOffset(b),b=Blockly.svgSize(b);a.style.left=this.workspace_.RTL?c.x+b.width-a.offsetWidth+"px":c.x+"px";a.style.height=b.height+"px";a.style.top=c.y+"px";this.width=a.offsetWidth;this.workspace_.RTL||--this.width;this.flyout_.position()}};
 Blockly.Toolbox.prototype.populate_=function(a){function b(a,e){for(var f=0,g;g=a.childNodes[f];f++)if(g.tagName)switch(g.tagName.toUpperCase()){case "CATEGORY":var h=c.createNode(g.getAttribute("name"));h.blocks=[];e.add(h);var k=g.getAttribute("custom");k?h.blocks=k:b(g,h);"true"==g.getAttribute("expanded")&&(h.blocks.length&&c.setSelectedItem(h),h.setExpanded(!0));break;case "SEP":e.add(new Blockly.Toolbox.TreeSeparator);break;case "BLOCK":e.blocks.push(g)}}var c=this.tree_;c.removeChildren();
 c.blocks=[];b(a,this.tree_);if(c.blocks.length)throw"Toolbox cannot have both blocks and categories in the root level.";Blockly.fireUiEvent(window,"resize")};Blockly.Toolbox.prototype.clearSelection=function(){this.tree_.setSelectedItem(null)};Blockly.Toolbox.prototype.getRect=function(){var a=this.workspace_.RTL?Blockly.svgSize(this.workspace_.options.svg).width-this.width:-1E7;return new goog.math.Rect(a,-1E7,1E7+this.width,2E7)};
 Blockly.Toolbox.TreeControl=function(a,b){this.toolbox_=a;goog.ui.tree.TreeControl.call(this,goog.html.SafeHtml.EMPTY,b)};goog.inherits(Blockly.Toolbox.TreeControl,goog.ui.tree.TreeControl);Blockly.Toolbox.TreeControl.prototype.enterDocument=function(){Blockly.Toolbox.TreeControl.superClass_.enterDocument.call(this);if(goog.events.BrowserFeature.TOUCH_ENABLED){var a=this.getElement();Blockly.bindEvent_(a,goog.events.EventType.TOUCHSTART,this,this.handleTouchEvent_)}};
@@ -1320,8 +1321,8 @@ a.stopPropagation()}};
 Blockly.onKeyDown_=function(a){if(!Blockly.isTargetInput_(a))if(27==a.keyCode)Blockly.hideChaff();else if(8==a.keyCode||46==a.keyCode)try{Blockly.selected&&Blockly.selected.isDeletable()&&(Blockly.hideChaff(),Blockly.selected.dispose(!0,!0))}finally{a.preventDefault()}else if(a.altKey||a.ctrlKey||a.metaKey)Blockly.selected&&Blockly.selected.isDeletable()&&Blockly.selected.isMovable()&&(Blockly.hideChaff(),67==a.keyCode?Blockly.copy_(Blockly.selected):88==a.keyCode&&(Blockly.copy_(Blockly.selected),Blockly.selected.dispose(!0,
 !0))),86==a.keyCode&&Blockly.clipboardXml_&&Blockly.clipboardSource_.paste(Blockly.clipboardXml_)};Blockly.terminateDrag_=function(){Blockly.BlockSvg.terminateDrag_();Blockly.Flyout.terminateDrag_()};Blockly.longPid_=0;Blockly.longStart_=function(a,b){Blockly.longStop_();Blockly.longPid_=setTimeout(function(){a.button=2;b.onMouseDown_(a)},Blockly.LONGPRESS)};Blockly.longStop_=function(){Blockly.longPid_&&(clearTimeout(Blockly.longPid_),Blockly.longPid_=0)};
 Blockly.copy_=function(a){var b=Blockly.Xml.blockToDom_(a);Blockly.Xml.deleteNext(b);var c=a.getRelativeToSurfaceXY();b.setAttribute("x",a.RTL?-c.x:c.x);b.setAttribute("y",c.y);Blockly.clipboardXml_=b;Blockly.clipboardSource_=a.workspace};Blockly.onContextMenu_=function(a){Blockly.isTargetInput_(a)||a.preventDefault()};Blockly.hideChaff=function(a){Blockly.Tooltip.hide();Blockly.WidgetDiv.hide();a||(a=Blockly.getMainWorkspace(),a.toolbox_&&a.toolbox_.flyout_&&a.toolbox_.flyout_.autoClose&&a.toolbox_.clearSelection())};
-Blockly.getMainWorkspaceMetrics_=function(){var a=Blockly.svgSize(this.options.svg);this.toolbox_&&(a.width-=this.toolbox_.width);var b=a.width-Blockly.Scrollbar.scrollbarThickness,c=a.height-Blockly.Scrollbar.scrollbarThickness;try{var d=this.getCanvas().getBBox()}catch(e){return null}var f=d.width,g=d.height,h=d.x*this.scale,k=d.y*this.scale;if(this.scrollbar)var l=Math.min(h-b/2,h+f-b),b=Math.max(h+f+b/2,h+b),f=Math.min(k-c/2,k+g-c),c=Math.max(k+g+c/2,k+c);else l=d.x,b=l+d.width,f=d.y,c=f+d.height;
-d=0;!this.RTL&&this.toolbox_&&(d=this.toolbox_.width);return{viewHeight:a.height,viewWidth:a.width,contentHeight:c-f,contentWidth:b-l,viewTop:-this.scrollY,viewLeft:-this.scrollX,contentTop:f,contentLeft:l,absoluteTop:0,absoluteLeft:d}};
+Blockly.getMainWorkspaceMetrics_=function(){var a=Blockly.svgSize(this.options.svg);this.toolbox_&&(a.width-=this.toolbox_.width);var b=a.width-Blockly.Scrollbar.scrollbarThickness,c=a.height-Blockly.Scrollbar.scrollbarThickness;try{var d=this.getCanvas().getBBox()}catch(e){return null}var f=d.width*this.scale,g=d.height*this.scale,h=d.x*this.scale,k=d.y*this.scale;if(this.scrollbar)var l=Math.min(h-b/2,h+f-b),b=Math.max(h+f+b/2,h+b),f=Math.min(k-c/2,k+g-c),c=Math.max(k+g+c/2,k+c);else l=d.x,b=l+
+d.width,f=d.y,c=f+d.height;d=0;!this.RTL&&this.toolbox_&&(d=this.toolbox_.width);return{viewHeight:a.height,viewWidth:a.width,contentHeight:c-f,contentWidth:b-l,viewTop:-this.scrollY,viewLeft:-this.scrollX,contentTop:f,contentLeft:l,absoluteTop:0,absoluteLeft:d}};
 Blockly.setMainWorkspaceMetrics_=function(a){if(!this.scrollbar)throw"Attempt to set main workspace scroll without scrollbars.";var b=this.getMetrics();goog.isNumber(a.x)&&(this.scrollX=-b.contentWidth*a.x-b.contentLeft);goog.isNumber(a.y)&&(this.scrollY=-b.contentHeight*a.y-b.contentTop);a=this.scrollX+b.absoluteLeft;b=this.scrollY+b.absoluteTop;this.translate(a,b);this.options.gridPattern&&(this.options.gridPattern.setAttribute("x",a),this.options.gridPattern.setAttribute("y",b))};
 Blockly.doCommand=function(a){Blockly.Realtime.isEnabled?Blockly.Realtime.doCommand(a):a()};Blockly.addChangeListener=function(a){console.warn("Deprecated call to Blockly.addChangeListener, use workspace.addChangeListener instead.");return Blockly.getMainWorkspace().addChangeListener(a)};Blockly.getMainWorkspace=function(){return Blockly.mainWorkspace};goog.global.Blockly||(goog.global.Blockly={});goog.global.Blockly.getMainWorkspace=Blockly.getMainWorkspace;
 goog.global.Blockly.addChangeListener=Blockly.addChangeListener;
\ No newline at end of file
diff --git a/core/flyout.js b/core/flyout.js
index b764a2450..d93d518db 100644
--- a/core/flyout.js
+++ b/core/flyout.js
@@ -59,7 +59,7 @@ Blockly.Flyout = function(workspaceOptions) {
   this.RTL = !!workspaceOptions.RTL;
 
   /**
-   * Opaque data that can be passed to removeChangeListener.
+   * Opaque data that can be passed to Blockly.unbindEvent_.
    * @type {Array.<!Array>}
    * @private
    */
@@ -145,14 +145,14 @@ Blockly.Flyout.prototype.init = function(targetWorkspace) {
 
   this.hide();
 
-  this.eventWrappers_.concat(Blockly.bindEvent_(this.svgGroup_,
-      'wheel', this, this.wheel_));
-  this.eventWrappers_.concat(
+  Array.prototype.push.apply(this.eventWrappers_,
+      Blockly.bindEvent_(this.svgGroup_, 'wheel', this, this.wheel_));
+  Array.prototype.push.apply(this.eventWrappers_,
       Blockly.bindEvent_(this.targetWorkspace_.getCanvas(),
       'blocklyWorkspaceChange', this, this.filterForCapacity_));
   // Dragging the flyout up and down.
-  this.eventWrappers_.concat(Blockly.bindEvent_(this.svgGroup_,
-      'mousedown', this, this.onMouseDown_));
+  Array.prototype.push.apply(this.eventWrappers_,
+      Blockly.bindEvent_(this.svgGroup_, 'mousedown', this, this.onMouseDown_));
 };
 
 /**
@@ -162,12 +162,15 @@ Blockly.Flyout.prototype.init = function(targetWorkspace) {
 Blockly.Flyout.prototype.dispose = function() {
   this.hide();
   Blockly.unbindEvent_(this.eventWrappers_);
-  this.eventWrappers_.length = 0;
   if (this.scrollbar_) {
     this.scrollbar_.dispose();
     this.scrollbar_ = null;
   }
-  this.workspace_ = null;
+  if (this.workspace_) {
+    this.workspace_.targetWorkspace = null;
+    this.workspace_.dispose();
+    this.workspace_ = null;
+  }
   if (this.svgGroup_) {
     goog.dom.removeNode(this.svgGroup_);
     this.svgGroup_ = null;
diff --git a/core/scrollbar.js b/core/scrollbar.js
index 80adc623e..0712df792 100644
--- a/core/scrollbar.js
+++ b/core/scrollbar.js
@@ -53,8 +53,6 @@ Blockly.ScrollbarPair = function(workspace) {
  * Unlink from all DOM elements to prevent memory leaks.
  */
 Blockly.ScrollbarPair.prototype.dispose = function() {
-  Blockly.unbindEvent_(this.onResizeWrapper_);
-  this.onResizeWrapper_ = null;
   goog.dom.removeNode(this.corner_);
   this.corner_ = null;
   this.workspace_ = null;
@@ -190,10 +188,6 @@ if (goog.events.BrowserFeature.TOUCH_ENABLED) {
  */
 Blockly.Scrollbar.prototype.dispose = function() {
   this.onMouseUpKnob_();
-  if (this.onResizeWrapper_) {
-    Blockly.unbindEvent_(this.onResizeWrapper_);
-    this.onResizeWrapper_ = null;
-  }
   Blockly.unbindEvent_(this.onMouseDownBarWrapper_);
   this.onMouseDownBarWrapper_ = null;
   Blockly.unbindEvent_(this.onMouseDownKnobWrapper_);
diff --git a/core/toolbox.js b/core/toolbox.js
index cdc8f0a82..e975ba2ac 100644
--- a/core/toolbox.js
+++ b/core/toolbox.js
@@ -147,6 +147,7 @@ Blockly.Toolbox.prototype.dispose = function() {
   this.flyout_.dispose();
   this.tree_.dispose();
   goog.dom.removeNode(this.HtmlDiv);
+  this.workspace_ = null;
 };
 
 /**
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index 2030eec2d..9bea8211e 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -52,12 +52,20 @@ Blockly.WorkspaceSvg = function(options) {
   this.setMetrics = options.setMetrics;
 
   Blockly.ConnectionDB.init(this);
+
   /**
    * Database of pre-loaded sounds.
    * @private
    * @const
    */
   this.SOUNDS_ = Object.create(null);
+
+  /**
+   * Opaque data that can be passed to Blockly.unbindEvent_.
+   * @type {Array.<!Array>}
+   * @private
+   */
+  this.eventWrappers_ = [];
 };
 goog.inherits(Blockly.WorkspaceSvg, Blockly.Workspace);
 
@@ -187,6 +195,7 @@ Blockly.WorkspaceSvg.prototype.createDom = function(opt_backgroundClass) {
 Blockly.WorkspaceSvg.prototype.dispose = function() {
   // Stop rerendering.
   this.rendered = false;
+  Blockly.unbindEvent_(this.eventWrappers_);
   Blockly.WorkspaceSvg.superClass_.dispose.call(this);
   if (this.svgGroup_) {
     goog.dom.removeNode(this.svgGroup_);
@@ -206,9 +215,13 @@ Blockly.WorkspaceSvg.prototype.dispose = function() {
     this.trashcan.dispose();
     this.trashcan = null;
   }
-  if (this.zoomControls) {
-    this.zoomControls.dispose();
-    this.zoomControls = null;
+  if (this.scrollbar) {
+    this.scrollbar.dispose();
+    this.scrollbar = null;
+  }
+  if (this.zoomControls_) {
+    this.zoomControls_.dispose();
+    this.zoomControls_ = null;
   }
   if (!this.options.parentWorkspace) {
     // Top-most workspace.  Dispose of the SVG too.
@@ -221,6 +234,7 @@ Blockly.WorkspaceSvg.prototype.dispose = function() {
  * @private
  */
 Blockly.WorkspaceSvg.prototype.addTrashcan_ = function() {
+  /** @type {Blockly.Trashcan} */
   this.trashcan = new Blockly.Trashcan(this);
   var svgTrashcan = this.trashcan.createDom();
   this.svgGroup_.insertBefore(svgTrashcan, this.svgBlockCanvas_);
@@ -232,10 +246,11 @@ Blockly.WorkspaceSvg.prototype.addTrashcan_ = function() {
  * @private
  */
 Blockly.WorkspaceSvg.prototype.addZoomControls_ = function() {
-  this.zoomControls = new Blockly.ZoomControls(this);
-  var svgZoomControls = this.zoomControls.createDom();
+  /** @type {Blockly.ZoomControls} */
+  this.zoomControls_ = new Blockly.ZoomControls(this);
+  var svgZoomControls = this.zoomControls_.createDom();
   this.svgGroup_.appendChild(svgZoomControls);
-  this.zoomControls.init();
+  this.zoomControls_.init();
 };
 
 /**
@@ -247,6 +262,7 @@ Blockly.WorkspaceSvg.prototype.addFlyout_ = function() {
     parentWorkspace: this,
     RTL: this.RTL
   };
+  /** @type {Blockly.Flyout} */
   this.flyout_ = new Blockly.Flyout(workspaceOptions);
   this.flyout_.autoClose = false;
   var svgFlyout = this.flyout_.createDom();
@@ -266,8 +282,8 @@ Blockly.WorkspaceSvg.prototype.resize = function() {
   if (this.trashcan) {
     this.trashcan.position();
   }
-  if (this.zoomControls) {
-    this.zoomControls.position();
+  if (this.zoomControls_) {
+    this.zoomControls_.position();
   }
   if (this.scrollbar) {
     this.scrollbar.resize();
@@ -811,8 +827,10 @@ Blockly.WorkspaceSvg.prototype.updateToolbox = function(tree) {
  *     removeChangeListener.
  */
 Blockly.WorkspaceSvg.prototype.addChangeListener = function(func) {
-  return Blockly.bindEvent_(this.getCanvas(),
+  var wrapper = Blockly.bindEvent_(this.getCanvas(),
                             'blocklyWorkspaceChange', null, func);
+  Array.prototype.push.apply(this.eventWrappers_, wrapper);
+  return wrapper;
 };
 
 /**
@@ -821,6 +839,10 @@ Blockly.WorkspaceSvg.prototype.addChangeListener = function(func) {
  */
 Blockly.WorkspaceSvg.prototype.removeChangeListener = function(bindData) {
   Blockly.unbindEvent_(bindData);
+  var i = this.eventWrappers_.indexOf(bindData);
+  if (i != -1) {
+    this.eventWrappers_.splice(i, 1);
+  }
 };
 
 /**