Issue 2879 - Move element selection into the content process

lib/aardvark.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License

[saroyanm, 2016/11/23 17:44:37]

Irrelevant: Why is this file called Aadvark ?

[Wladimir Palant, 2016/11/24 14:02:00]

The origin of this code is the Aardvark extension for Firefox (now retired in
favor of the bookmarklet): http://www.karmatics.com/aardvark/. I convinced the
author to provide it under the MPL so that I could build EHH around it.

  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
 
 let {Prefs} = require("prefs");
 
-// Make sure to stop selection when we are uninstalled
-onShutdown.add(() => Aardvark.quit());
+let messageManager = Cc["@mozilla.org/parentprocessmessagemanager;1"]
+                       .getService(Ci.nsIMessageListenerManager)
+                       .QueryInterface(Ci.nsIMessageBroadcaster);
 
 // To be replaced when selection starts
 function E(id) {return null;}
 
-let messageCounter = 0;
+messageManager.addMessageListener("ElemHideHelper:SelectionStarted", selectionStarted);

[saroyanm, 2016/11/23 17:44:37]

Nit: Exceeding 80 chars

[Wladimir Palant, 2016/11/24 14:02:01]

Done.

+messageManager.addMessageListener("ElemHideHelper:SelectionSucceeded", selectionSucceeded);
+messageManager.addMessageListener("ElemHideHelper:SelectionStopped", selectionStopped);
+onShutdown.add(() =>
+{
+  messageManager.removeMessageListener("ElemHideHelper:SelectionStarted", selectionStarted);
+  messageManager.removeMessageListener("ElemHideHelper:SelectionSucceeded", selectionSucceeded);
+  messageManager.removeMessageListener("ElemHideHelper:SelectionStopped", selectionStopped);
 
-/*********************************
- * Minimal element creation code *
- *********************************/
+  selectionStopped();
+});
 
-function createElement(doc, tagName, attrs, children)
+function selectionStarted(message)
 {
-  let el = doc.createElement(tagName);
-  if (attrs)
-    for (let key in attrs)
-      el.setAttribute(key, attrs[key]);
-  if (children)
-    for (let child of children)
-      el.appendChild(child)
-  return el;
-};
+  Aardvark.selectionStarted();
+}
+
+function selectionSucceeded(message)
+{
+  Aardvark.selectionSucceeded(message.data);
+}
+
+function selectionStopped(message)
+{
+  Aardvark.selectionStopped();
+}
 
 /**********************************
  * General element selection code *
  **********************************/
 
 let Aardvark = exports.Aardvark =
 {
   window: null,
   browser: null,
-  anchorElem: null,
-  selectedElem: null,
-  isUserSelected: false,
-  lockedAnchor: null,
-  commentElem: null,
+  rememberedWrapper: null,

[saroyanm, 2016/11/23 17:44:37]

Curious: Why rememberedWrapper, but not just wrapper ?
Do we clear it's state because of memory leak ?

[Wladimir Palant, 2016/11/24 14:02:00]

Its a temporary state, a bit of a hack so that we don't need to figure out which
wrapper the message refers to. But I suspect that we'll need to do this properly
later on...

   mouseX: -1,
   mouseY: -1,
-  prevSelectionUpdate: -1,
   commandLabelTimer: null,
   viewSourceTimer: null,
-  boxElem: null,
-  paintNode: null,
-  prevPos: null,
 
   start: function(wrapper)
   {
-    if (!this.canSelect(wrapper.browser))
-      return;
+    this.rememberedWrapper = wrapper;
+    let browser = wrapper.browser;
+    if ("selectedBrowser" in browser)

[saroyanm, 2016/11/23 17:44:38]

What is "selectedBrowser" property ? 
Are we assigning it ?
Or is it just not documented here ->
https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser 

[Wladimir Palant, 2016/11/24 14:02:01]

You need to look at
https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/tabbrowser. In Firefox
and SeaMonkey we'll get a <xul:tabbrowser>, in Thunderbird a <xul:browser>.

+      browser = browser.selectedBrowser;
+    messageManager.broadcastAsyncMessage(
+      "ElemHideHelper:StartSelection",
+      browser.outerWindowID
+    );
+  },
 
-    if (this.browser)
-      this.quit();
+  selectionStarted: function()
+  {
+    let wrapper = this.rememberedWrapper;
+    this.rememberedWrapper = null;
 
     this.window = wrapper.window;
     this.browser = wrapper.browser;

[saroyanm, 2016/11/23 17:44:38]

We already assigning this.rememberedWrapper value to "this.browser" in "start"
method.

[Wladimir Palant, 2016/11/24 14:02:01]

No, we are only assigning it to the local browser variable. start method doesn't
save any state, this is intentional - selection might not start, e.g. if you are
on a special page.

     E = id => wrapper.E(id);
 
-    this.browser.addEventListener("click", this.onMouseClick, true);
-    this.browser.addEventListener("DOMMouseScroll", this.onMouseScroll, true);
     this.browser.addEventListener("keypress", this.onKeyPress, true);
-    this.browser.addEventListener("mousemove", this.onMouseMove, true);
-    this.browser.addEventListener("select", this.quit, false);
-    this.browser.contentWindow.addEventListener("pagehide", this.onPageHide, true);
-
-    this.browser.contentWindow.focus();
-
-    let doc = this.browser.contentDocument;
-    let {elementMarkerClass} = require("main");
-    this.boxElem = createElement(doc, "div", {"class": elementMarkerClass}, [
-      createElement(doc, "div", {"class": "ehh-border"}),
-      createElement(doc, "div", {"class": "ehh-label"}, [
-        createElement(doc, "span", {"class": "ehh-labelTag"}),
-        createElement(doc, "span", {"class": "ehh-labelAddition"})
-      ])
-    ]);
+    this.browser.addEventListener("mousemove", this.onMouseMove, false);
+    this.browser.addEventListener("select", this.onTabSelect, false);
 
     this.initHelpBox();
 
     if (Prefs.showhelp)
       this.showMenu();
-
-    // Make sure to select some element immeditely (whichever is in the center of the browser window)
-    let [wndWidth, wndHeight] = this.getWindowSize(doc.defaultView);
-    this.isUserSelected = false;
-    this.onMouseMove({clientX: wndWidth / 2, clientY: wndHeight / 2, screenX: -1, screenY: -1, target: null});
   },
 
-  canSelect: function(browser)
+  selectionSucceeded: function(nodeInfo)
   {
-    if (!browser || !browser.contentWindow ||
-        !(browser.contentDocument instanceof Ci.nsIDOMHTMLDocument))
-    {
-      return false;
-    }
+    this.window.openDialog("chrome://elemhidehelper/content/composer.xul",

[saroyanm, 2016/11/23 17:44:37]

Shouldn't we also remove eventlisteners on selection succeeded or call
selectionstopped ? 

[Wladimir Palant, 2016/11/24 14:02:01]

No, the select command (in lib/child/commands.js) will call stopSelection()
after sending SelectionSucceeded message. So we will get a SelectionStopped
message as well.

+        "_blank", "chrome,centerscreen,resizable,dialog=no", nodeInfo);

[Wladimir Palant, 2016/11/17 13:54:47]

This function is pretty much what Aardvark.select() used to be. With this
function now being called from the child, it no longer needs to request the node
info so things got a lot simpler.

[saroyanm, 2016/11/23 17:44:38]

Acknowledged.

+  },
 
-    let location = browser.contentWindow.location;
-    if (location.href == "about:blank")
-      return false;
+  selectionStopped: function()
+  {
+    if (!this.browser)
+      return;
 
-    if (!Prefs.acceptlocalfiles &&
-        location.hostname == "" &&
-        location.protocol != "mailbox:" &&
-        location.protocol != "imap:" &&
-        location.protocol != "news:" &&
-        location.protocol != "snews:")
-    {
-      return false;
-    }
+    if (this.commandLabelTimer)
+      this.commandLabelTimer.cancel();
+    if (this.viewSourceTimer)
+      this.viewSourceTimer.cancel();
+    this.commandLabelTimer = null;
+    this.viewSourceTimer = null;
 
-    return true;
+    this.hideTooltips();
+
+    this.browser.removeEventListener("keypress", this.onKeyPress, true);
+    this.browser.removeEventListener("mousemove", this.onMouseMove, false);
+    this.browser.removeEventListener("select", this.onTabSelect, false);
+
+    this.window = null;
+    this.browser = null;
+    E = id => null;

[Wladimir Palant, 2016/11/17 13:54:47]

This function is what Aardvark.quit() used to be. With the actual command being
implemented in the child, this only does the necessary cleanup in the parent
now.

[saroyanm, 2016/11/23 17:44:37]

Acknowledged.

   },
 
   doCommand: function(command, event)
   {
-    if (this[command](this.selectedElem))
+    let showFeedback;
+    if (this.hasOwnProperty(command))
+      showFeedback = this[command]();

[Wladimir Palant, 2016/11/17 13:54:47]

The command handler no longer gets the selected element, this one is only
available in the child. The two commands remaining in the parent will need to
message the child in order to get the necessary information, this hasn't been
implemented yet.

[saroyanm, 2016/11/23 17:44:38]

Acknowledged.

+    else
+    {
+      showFeedback = (command != "select" && command != "quit");

[Wladimir Palant, 2016/11/17 13:54:47]

This changes behavior slightly - e.g. you will get visual feedback for the
"wider" command even if you are at the top level already. We could implement the
old behavior where you only get visual feedback if something actually changes
(the commands would have to message the parent in order to show the visual
feedback then) but I doubt that it is worth the added complexity.

[saroyanm, 2016/11/23 17:44:37]

Acknowledged.

+      messageManager.broadcastAsyncMessage("ElemHideHelper:Command", command);
+    }
+
+    if (showFeedback)
     {
       this.showCommandLabel(this.commands[command + "_key"], this.commands[command + "_altkey"], this.commands[command + "_label"]);
       if (event)
         event.stopPropagation();
     }
     if (event)
       event.preventDefault();
   },
 
   showCommandLabel: function(key, alternativeKey, label)
@@ skipping 60 matching lines @@
   {
     let tooltips = ["ehh-helpbox", "ehh-commandlabel", "ehh-viewsource"];
     for (let i = 0; i < tooltips.length; i++)
     {
       let tooltip = E(tooltips[i]);
       if (tooltip)
         tooltip.hidePopup();
     }
   },
 
-  onMouseClick: function(event)
-  {
-    if (event.button != 0 || event.shiftKey || event.altKey || event.ctrlKey || event.metaKey)
-      return;
-
-    this.doCommand("select", event);
-  },
-
-  onMouseScroll: function(event)
-  {
-    if (!event.shiftKey || event.altKey || event.ctrlKey || event.metaKey)
-      return;
-
-    if ("axis" in event && event.axis != event.VERTICAL_AXIS)
-      return;
-
-    this.doCommand(event.detail > 0 ? "wider" : "narrower", event);
-  },
-
   onKeyPress: function(event)
   {
     if (event.altKey || event.ctrlKey || event.metaKey)
       return;
 
     var command = null;
     if (event.keyCode == event.DOM_VK_ESCAPE)

[saroyanm, 2016/11/23 17:44:38]

Note: keyCode is a deprecated property.
You want me to file a separate issue for that ?

[Wladimir Palant, 2016/11/24 14:02:01]

Yes, definitely.

[saroyanm, 2016/11/25 16:18:13]

Done -> #4666

       command = "quit";
     else if (event.keyCode == event.DOM_VK_RETURN)
       command = "select";
     else if (event.charCode)
     {
       var key = String.fromCharCode(event.charCode).toLowerCase();
       var commands = this.commands;
       for (var i = 0; i < commands.length; i++)
         if (commands[commands[i] + "_key"] == key || commands[commands[i] + "_altkey"] == key)
           command = commands[i];
     }
 
     if (command)
       this.doCommand(command, event);
   },
 
-  onPageHide: function(event)
-  {
-    this.doCommand("quit", null);
-  },
-
   onMouseMove: function(event)
   {
     this.mouseX = event.screenX;
     this.mouseY = event.screenY;
-
-    this.hideSelection();
-    if (!this.browser)
-    {
-      // hideSelection() called quit()
-      return;
-    }
-
-    let x = event.clientX;
-    let y = event.clientY;
-
-    // We might have coordinates relative to a frame, recalculate relative to top window
-    let node = event.target;
-    while (node && node.ownerDocument && node.ownerDocument.defaultView && node.ownerDocument.defaultView.frameElement)
-    {
-      node = node.ownerDocument.defaultView.frameElement;
-      let rect = node.getBoundingClientRect();
-      x += rect.left;
-      y += rect.top;
-    }
-
-    let elem = this.browser.contentDocument.elementFromPoint(x, y);
-    while (elem && "contentDocument" in elem && this.canSelect(elem))
-    {
-      let rect = elem.getBoundingClientRect();
-      x -= rect.left;
-      y -= rect.top;
-      elem = elem.contentDocument.elementFromPoint(x, y);
-    }
-
-    if (elem)
-    {
-      if (!this.lockedAnchor)
-        this.setAnchorElement(elem);
-      else
-      {
-        this.lockedAnchor = elem;
-        this.selectElement(this.selectedElem);
-      }
-    }
   },
 
-  onAfterPaint: function()
+  onTabSelect: function(event)
   {
-    // Don't update position too often
-    if (this.selectedElem && Date.now() - this.prevSelectionUpdate > 20)
-    {
-      let pos = this.getElementPosition(this.selectedElem);
-      if (!this.prevPos || this.prevPos.left != pos.left || this.prevPos.right != pos.right
-                        || this.prevPos.top != pos.top || this.prevPos.bottom != pos.bottom)
-      {
-        this.selectElement(this.selectedElem);
-      }
-    }
-  },
-
-  setAnchorElement: function(anchor)
-  {
-    this.anchorElem = anchor;
-
-    let newSelection = anchor;
-    if (this.isUserSelected)
-    {
-      // User chose an element via wider/narrower commands, keep the selection if
-      // out new anchor is still a child of that element
-      let e = newSelection;
-      while (e && e != this.selectedElem)
-        e = this.getParentElement(e);
-
-      if (e)
-        newSelection = this.selectedElem;
-      else
-        this.isUserSelected = false;
-    }
-
-    this.selectElement(newSelection);
+    this.doCommand("quit", null);
   },
 
   appendDescription: function(node, value, className)
   {
     var descr = this.window.document.createElement("description");
     descr.setAttribute("value", value);
     if (className)
       descr.setAttribute("class", className);
     node.appendChild(descr);
   },
 
-  /**************************
-   * Element marker display *
-   **************************/
-
-  getElementLabel: function(elem)
-  {
-    let tagName = elem.tagName.toLowerCase();
-    let addition = "";
-    if (elem.id != "")
-      addition += ", id: " + elem.id;
-    if (elem.className != "")
-      addition += ", class: " + elem.className;
-    if (elem.style.cssText != "")
-      addition += ", style: " + elem.style.cssText;
-
-    return [tagName, addition];
-  },
-
-  selectElement: function(elem)
-  {
-    this.selectedElem = elem;
-    this.prevSelectionUpdate = Date.now();
-
-    let border = this.boxElem.getElementsByClassName("ehh-border")[0];
-    let label = this.boxElem.getElementsByClassName("ehh-label")[0];
-    let labelTag = this.boxElem.getElementsByClassName("ehh-labelTag")[0];
-    let labelAddition = this.boxElem.getElementsByClassName("ehh-labelAddition")[0];
-
-    if (this.boxElem.parentNode)
-      this.boxElem.parentNode.removeChild(this.boxElem);
-
-    let doc = this.browser.contentDocument;
-    let [wndWidth, wndHeight] = this.getWindowSize(doc.defaultView);
-
-    let pos = this.getElementPosition(elem);
-    this.boxElem.style.left = Math.min(pos.left - 1, wndWidth - 2) + "px";
-    this.boxElem.style.top = Math.min(pos.top - 1, wndHeight - 2) + "px";
-    border.style.width = Math.max(pos.right - pos.left - 2, 0) + "px";
-    border.style.height = Math.max(pos.bottom - pos.top - 2, 0) + "px";
-
-    [labelTag.textContent, labelAddition.textContent] = this.getElementLabel(elem);
-
-    // If there is not enough space to show the label move it up a little
-    if (pos.bottom < wndHeight - 25)
-      label.className = "ehh-label";
-    else
-      label.className = "ehh-label onTop";
-
-    doc.documentElement.appendChild(this.boxElem);
-
-    this.paintNode = doc.defaultView;
-    if (this.paintNode)
-    {
-      this.prevPos = pos;
-      this.paintNode.addEventListener("MozAfterPaint", this.onAfterPaint, false);
-    }
-  },
-
-  hideSelection: function()
-  {
-    try
-    {
-      if (this.boxElem.parentNode)
-        this.boxElem.parentNode.removeChild(this.boxElem);
-    }
-    catch (e)
-    {
-      // Are we using CPOW whose process is gone? Quit!
-      // Clear some variables to prevent recursion (quit will call us again).
-      this.boxElem = {};
-      this.paintNode = null;
-      this.quit();
-      return;
-    }
-
-    if (this.paintNode)
-      this.paintNode.removeEventListener("MozAfterPaint", this.onAfterPaint, false);
-
-    this.paintNode = null;
-    this.prevPos = null;
-  },
-
-  getWindowSize: function(wnd)
-  {
-    return [wnd.innerWidth, wnd.document.documentElement.clientHeight];
-  },
-
-  getElementPosition: function(element)
-  {
-    // Restrict rectangle coordinates by the boundaries of a window's client area
-    function intersectRect(rect, wnd)
-    {
-      let [wndWidth, wndHeight] = this.getWindowSize(wnd);
-      rect.left = Math.max(rect.left, 0);
-      rect.top = Math.max(rect.top, 0);
-      rect.right = Math.min(rect.right, wndWidth);
-      rect.bottom = Math.min(rect.bottom, wndHeight);
-    }
-
-    let rect = element.getBoundingClientRect();
-    let wnd = element.ownerDocument.defaultView;
-
-    rect = {left: rect.left, top: rect.top,
-            right: rect.right, bottom: rect.bottom};
-    while (true)
-    {
-      intersectRect.call(this, rect, wnd);
-
-      if (!wnd.frameElement)
-        break;
-
-      // Recalculate coordinates to be relative to frame's parent window
-      let frameElement = wnd.frameElement;
-      wnd = frameElement.ownerDocument.defaultView;
-
-      let frameRect = frameElement.getBoundingClientRect();
-      let frameStyle = wnd.getComputedStyle(frameElement, null);
-      let relLeft = frameRect.left + parseFloat(frameStyle.borderLeftWidth) + parseFloat(frameStyle.paddingLeft);
-      let relTop = frameRect.top + parseFloat(frameStyle.borderTopWidth) + parseFloat(frameStyle.paddingTop);
-
-      rect.left += relLeft;
-      rect.right += relLeft;
-      rect.top += relTop;
-      rect.bottom += relTop;
-    }
-
-    return rect;
-  },
-
-  getParentElement: function(elem)
-  {
-    let result = elem.parentNode;
-    if (result && result.nodeType == Ci.nsIDOMElement.DOCUMENT_NODE && result.defaultView && result.defaultView.frameElement)
-      result = result.defaultView.frameElement;
-
-    if (result && result.nodeType != Ci.nsIDOMElement.ELEMENT_NODE)
-      return null;
-
-    return result;
-  },
-
   /***************************
    * Commands implementation *
    ***************************/
 
   commands: [
     "select",
     "wider",
     "narrower",
     "lock",
     "quit",
     "blinkElement",
     "viewSource",
     "viewSourceWindow",
     "showMenu"
   ],
 
-  wider: function(elem)
-  {
-    if (!elem)
-      return false;
-
-    let newElem = this.getParentElement(elem);
-    if (!newElem)
-      return false;
-
-    this.isUserSelected = true;
-    this.selectElement(newElem);
-    return true;
-  },
-
-  narrower: function(elem)
-  {
-    if (elem)
-    {
-      // Search selected element in the parent chain, starting with the anchor element.
-      // We need to select the element just before the selected one.
-      let e = this.anchorElem;
-      let newElem = null;
-      while (e && e != elem)
-      {
-        newElem = e;
-        e = this.getParentElement(e);
-      }
-
-      if (!e || !newElem)
-        return false;
-
-      this.isUserSelected = true;
-      this.selectElement(newElem);
-      return true;
-    }
-    return false;
-  },
-
-  lock: function(elem)
-  {
-    if (!elem)
-      return false;
-
-    if (this.lockedAnchor)
-    {
-      this.setAnchorElement(this.lockedAnchor);
-      this.lockedAnchor = null;
-    }
-    else
-      this.lockedAnchor = this.anchorElem;
-
-    return true;
-  },
-
-  quit: function()
-  {
-    if (!this.browser)
-      return false;
-
-    if ("blinkTimer" in this)
-      this.stopBlinking();
-
-    if (this.commandLabelTimer)
-      this.commandLabelTimer.cancel();
-    if (this.viewSourceTimer)
-      this.viewSourceTimer.cancel();
-    this.commandLabelTimer = null;
-    this.viewSourceTimer = null;
-
-    this.hideSelection();
-    this.hideTooltips();
-
-    this.browser.removeEventListener("click", this.onMouseClick, true);
-    this.browser.removeEventListener("DOMMouseScroll", this.onMouseScroll, true);
-    this.browser.removeEventListener("keypress", this.onKeyPress, true);
-    this.browser.removeEventListener("mousemove", this.onMouseMove, true);
-    this.browser.removeEventListener("select", this.quit, false);
-    this.browser.contentWindow.removeEventListener("pagehide", this.onPageHide, true);
-
-    this.anchorElem = null;
-    this.selectedElem = null;
-    this.window = null;
-    this.browser = null;
-    this.commentElem = null;
-    this.lockedAnchor = null;
-    this.boxElem = null;
-    E = id => null;
-    return false;
-  },
-
-  select: function(elem)
-  {
-    if (!elem || !this.window)
-      return false;
-
-    let messageManager = Cc["@mozilla.org/parentprocessmessagemanager;1"]
-                           .getService(Ci.nsIMessageBroadcaster);
-    let messageId = ++messageCounter;
-    let callback = (message) =>
-    {
-      let response = message.data;
-      if (response.messageId != messageId)
-        return;
-
-      messageManager.removeMessageListener(
-        "ElemHideHelper:GetNodeInfo:Response",
-        callback
-      );
-
-      if (!response.nodeData)
-        return;
-
-      this.window.openDialog("chrome://elemhidehelper/content/composer.xul",
-          "_blank", "chrome,centerscreen,resizable,dialog=no", response);
-      this.quit();
-    };
-
-    messageManager.addMessageListener(
-      "ElemHideHelper:GetNodeInfo:Response",
-      callback
-    );
-    messageManager.broadcastAsyncMessage(
-      "ElemHideHelper:GetNodeInfo",
-      messageId,
-      {
-        element: elem
-      }
-    );
-    return false;
-  },
-
-  blinkElement: function(elem)
-  {
-    if (!elem)
-      return false;
-
-    if ("blinkTimer" in this)
-      this.stopBlinking();
-
-    let counter = 0;
-    this.blinkElem = elem;
-    this.blinkOrigValue = elem.style.visibility;
-    this.blinkTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
-    this.blinkTimer.initWithCallback(function()
-    {
-      counter++;
-      elem.style.visibility = (counter % 2 == 0 ? "visible" : "hidden");
-      if (counter == 6)
-        Aardvark.stopBlinking();
-    }, 250, Ci.nsITimer.TYPE_REPEATING_SLACK);
-
-    return true;
-  },
-
-  stopBlinking: function()
-  {
-    this.blinkTimer.cancel();
-    this.blinkElem.style.visibility = this.blinkOrigValue;
-
-    delete this.blinkElem;
-    delete this.blinkOrigValue;
-    delete this.blinkTimer;
-  },
-
   viewSource: function(elem)
   {
     if (!elem)
       return false;
 
     var sourceBox = E("ehh-viewsource");
-    if (sourceBox.state == "open" && this.commentElem == elem)
+    if (sourceBox.state == "open")

[Wladimir Palant, 2016/11/17 13:54:47]

This is a behavior change, originally we would only hide the source code tooltip
if the selection was unchanged, otherwise we would show the source of the new
selection. The complexity here doesn't seem to be worth it so now this command
will always hide an already visible tooltip.

     {
       sourceBox.hidePopup();
       return true;
     }
     sourceBox.hidePopup();
 
     while (sourceBox.firstElementChild)
       sourceBox.removeChild(sourceBox.firstElementChild);
     this.getOuterHtmlFormatted(elem, sourceBox);
-    this.commentElem = elem;
 
     let anchor = this.window.document.documentElement;
     let x = this.mouseX;
     let y = this.mouseY;
     this.viewSourceTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
     this.viewSourceTimer.initWithCallback(function()
     {
       sourceBox.showPopup(anchor, x, y, "tooltip", "topleft", "topleft");
       Aardvark.viewSourceTimer = null;
     }, 500, Ci.nsITimer.TYPE_ONE_SHOT);
@@ skipping 124 matching lines @@
     }
 
     // Show help box
     helpBox.showPopup(this.browser, -1, -1, "tooltip", "topleft", "topleft");
     return true;
   }
 }
 
 // Makes sure event handlers like Aardvark.onKeyPress always have the correct
 // this pointer set.
-for (let method of ["onMouseClick", "onMouseScroll", "onKeyPress", "onPageHide", "onMouseMove", "onAfterPaint", "quit"])
+for (let method of ["onKeyPress", "onMouseMove", "onTabSelect"])
   Aardvark[method] = Aardvark[method].bind(Aardvark);