The Tor Browser: mobile/android/chrome/content/aboutReader.js@fc2d59ddac77 (annotated)

mobile/android/chrome/content/aboutReader.js@fc2d59ddac77 (annotated)

mobile/android/chrome/content/aboutReader.js

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 let Ci = Components.interfaces, Cc = Components.classes, Cu = Components.utils;
 Cu.import("resource://gre/modules/Services.jsm")
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "UITelemetry",
                                   "resource://gre/modules/UITelemetry.jsm");
 XPCOMUtils.defineLazyGetter(window, "gChromeWin", function ()
   window.QueryInterface(Ci.nsIInterfaceRequestor)
     .getInterface(Ci.nsIWebNavigation)
     .QueryInterface(Ci.nsIDocShellTreeItem)
     .rootTreeItem
     .QueryInterface(Ci.nsIInterfaceRequestor)
     .getInterface(Ci.nsIDOMWindow)
     .QueryInterface(Ci.nsIDOMChromeWindow));
 function dump(s) {
   Services.console.logStringMessage("AboutReader: " + s);
 }
 let gStrings = Services.strings.createBundle("chrome://browser/locale/aboutReader.properties");
 let AboutReader = function(doc, win) {
   dump("Init()");
   this._docRef = Cu.getWeakReference(doc);
   this._winRef = Cu.getWeakReference(win);
   Services.obs.addObserver(this, "Reader:FaviconReturn", false);
   Services.obs.addObserver(this, "Reader:Add", false);
   Services.obs.addObserver(this, "Reader:Remove", false);
   Services.obs.addObserver(this, "Reader:ListStatusReturn", false);
   this._article = null;
   dump("Feching toolbar, header and content notes from about:reader");
   this._headerElementRef = Cu.getWeakReference(doc.getElementById("reader-header"));
   this._domainElementRef = Cu.getWeakReference(doc.getElementById("reader-domain"));
   this._titleElementRef = Cu.getWeakReference(doc.getElementById("reader-title"));
   this._creditsElementRef = Cu.getWeakReference(doc.getElementById("reader-credits"));
   this._contentElementRef = Cu.getWeakReference(doc.getElementById("reader-content"));
   this._toolbarElementRef = Cu.getWeakReference(doc.getElementById("reader-toolbar"));
   this._messageElementRef = Cu.getWeakReference(doc.getElementById("reader-message"));
   this._toolbarEnabled = false;
   this._scrollOffset = win.pageYOffset;
   let body = doc.body;
   body.addEventListener("touchstart", this, false);
   body.addEventListener("click", this, false);
   win.addEventListener("unload", this, false);
   win.addEventListener("scroll", this, false);
   win.addEventListener("popstate", this, false);
   win.addEventListener("resize", this, false);
   this._setupAllDropdowns();
   this._setupButton("toggle-button", this._onReaderToggle.bind(this));
   this._setupButton("share-button", this._onShare.bind(this));
   let colorSchemeOptions = [
     { name: gStrings.GetStringFromName("aboutReader.colorSchemeDark"),
       value: "dark"},
     { name: gStrings.GetStringFromName("aboutReader.colorSchemeLight"),
       value: "light"},
     { name: gStrings.GetStringFromName("aboutReader.colorSchemeAuto"),
       value: "auto"}
   ];
   let colorScheme = Services.prefs.getCharPref("reader.color_scheme");
   this._setupSegmentedButton("color-scheme-buttons", colorSchemeOptions, colorScheme, this._setColorSchemePref.bind(this));
   this._setColorSchemePref(colorScheme);
   let fontTypeSample = gStrings.GetStringFromName("aboutReader.fontTypeSample");
   let fontTypeOptions = [
     { name: fontTypeSample,
       description: gStrings.GetStringFromName("aboutReader.fontTypeSerif"),
       value: "serif",
       linkClass: "serif" },
     { name: fontTypeSample,
       description: gStrings.GetStringFromName("aboutReader.fontTypeSansSerif"),
       value: "sans-serif",
       linkClass: "sans-serif"
     },
   ];
   let fontType = Services.prefs.getCharPref("reader.font_type");
   this._setupSegmentedButton("font-type-buttons", fontTypeOptions, fontType, this._setFontType.bind(this));
   this._setFontType(fontType);
   let fontSizeSample = gStrings.GetStringFromName("aboutReader.fontSizeSample");
   let fontSizeOptions = [
     { name: fontSizeSample,
       value: 1,
       linkClass: "font-size1-sample" },
     { name: fontSizeSample,
       value: 2,
       linkClass: "font-size2-sample" },
     { name: fontSizeSample,
       value: 3,
       linkClass: "font-size3-sample" },
     { name: fontSizeSample,
       value: 4,
       linkClass: "font-size4-sample" },
     { name: fontSizeSample,
       value: 5,
       linkClass: "font-size5-sample" }
   ];
   let fontSize = Services.prefs.getIntPref("reader.font_size");
   this._setupSegmentedButton("font-size-buttons", fontSizeOptions, fontSize, this._setFontSize.bind(this));
   this._setFontSize(fontSize);
   dump("Decoding query arguments");
   let queryArgs = this._decodeQueryString(win.location.href);
   // Track status of reader toolbar add/remove toggle button
   this._isReadingListItem = -1;
   this._updateToggleButton();
   let url = queryArgs.url;
   let tabId = queryArgs.tabId;
   if (tabId) {
     dump("Loading from tab with ID: " + tabId + ", URL: " + url);
     this._loadFromTab(tabId, url);
   } else {
     dump("Fetching page with URL: " + url);
     this._loadFromURL(url);
   }
 }
 AboutReader.prototype = {
   _BLOCK_IMAGES_SELECTOR: ".content p > img:only-child, " +
                           ".content p > a:only-child > img:only-child, " +
                           ".content .wp-caption img, " +
                           ".content figure img",
   get _doc() {
     return this._docRef.get();
   },
   get _win() {
     return this._winRef.get();
   },
   get _headerElement() {
     return this._headerElementRef.get();
   },
   get _domainElement() {
     return this._domainElementRef.get();
   },
   get _titleElement() {
     return this._titleElementRef.get();
   },
   get _creditsElement() {
     return this._creditsElementRef.get();
   },
   get _contentElement() {
     return this._contentElementRef.get();
   },
   get _toolbarElement() {
     return this._toolbarElementRef.get();
   },
   get _messageElement() {
     return this._messageElementRef.get();
   },
   observe: function Reader_observe(aMessage, aTopic, aData) {
     switch(aTopic) {
       case "Reader:FaviconReturn": {
         let args = JSON.parse(aData);
         this._loadFavicon(args.url, args.faviconUrl);
         Services.obs.removeObserver(this, "Reader:FaviconReturn");
         break;
       }
       case "Reader:Add": {
         let args = JSON.parse(aData);
         if (args.url == this._article.url) {
           if (this._isReadingListItem != 1) {
             this._isReadingListItem = 1;
             this._updateToggleButton();
           }
         }
         break;
       }
       case "Reader:Remove": {
         if (aData == this._article.url) {
           if (this._isReadingListItem != 0) {
             this._isReadingListItem = 0;
             this._updateToggleButton();
           }
         }
         break;
       }
       case "Reader:ListStatusReturn": {
         let args = JSON.parse(aData);
         if (args.url == this._article.url) {
           if (this._isReadingListItem != args.inReadingList) {
             let isInitialStateChange = (this._isReadingListItem == -1);
             this._isReadingListItem = args.inReadingList;
             this._updateToggleButton();
             // Display the toolbar when all its initial component states are known
             if (isInitialStateChange) {
               this._setToolbarVisibility(true);
             }
           }
         }
         break;
       }
     }
   },
   handleEvent: function Reader_handleEvent(aEvent) {
     if (!aEvent.isTrusted)
       return;
     switch (aEvent.type) {
       case "touchstart":
         this._scrolled = false;
         break;
       case "click":
         if (!this._scrolled)
           this._toggleToolbarVisibility();
         break;
       case "scroll":
         if (!this._scrolled) {
           let isScrollingUp = this._scrollOffset > aEvent.pageY;
           this._setToolbarVisibility(isScrollingUp);
           this._scrollOffset = aEvent.pageY;
         }
         break;
       case "popstate":
         if (!aEvent.state)
           this._closeAllDropdowns();
         break;
       case "resize":
         this._updateImageMargins();
         break;
       case "devicelight":
         this._handleDeviceLight(aEvent.value);
         break;
       case "unload":
         Services.obs.removeObserver(this, "Reader:Add");
         Services.obs.removeObserver(this, "Reader:Remove");
         Services.obs.removeObserver(this, "Reader:ListStatusReturn");
         break;
     }
   },
   _updateToggleButton: function Reader_updateToggleButton() {
     let classes = this._doc.getElementById("toggle-button").classList;
     if (this._isReadingListItem == 1) {
       classes.add("on");
     } else {
       classes.remove("on");
     }
   },
   _requestReadingListStatus: function Reader_requestReadingListStatus() {
     gChromeWin.sendMessageToJava({
       type: "Reader:ListStatusRequest",
       url: this._article.url
     });
   },
   _onReaderToggle: function Reader_onToggle() {
     if (!this._article)
       return;
     this._isReadingListItem = (this._isReadingListItem == 1) ? 0 : 1;
     this._updateToggleButton();
     // Create a relative timestamp for telemetry
     let uptime = Date.now() - Services.startup.getStartupInfo().linkerInitialized;
     if (this._isReadingListItem == 1) {
       gChromeWin.Reader.storeArticleInCache(this._article, function(success) {
         dump("Reader:Add (in reader) success=" + success);
         let result = gChromeWin.Reader.READER_ADD_FAILED;
         if (success) {
           result = gChromeWin.Reader.READER_ADD_SUCCESS;
           UITelemetry.addEvent("save.1", "button", uptime, "reader");
         }
         let json = JSON.stringify({ fromAboutReader: true, url: this._article.url });
         Services.obs.notifyObservers(null, "Reader:Add", json);
         gChromeWin.sendMessageToJava({
           type: "Reader:Added",
           result: result,
           title: this._article.title,
           url: this._article.url,
           length: this._article.length,
           excerpt: this._article.excerpt
         });
       }.bind(this));
     } else {
       // In addition to removing the article from the cache (handled in
       // browser.js), sending this message will cause the toggle button to be
       // updated (handled in this file).
       Services.obs.notifyObservers(null, "Reader:Remove", this._article.url);
       UITelemetry.addEvent("unsave.1", "button", uptime, "reader");
     }
   },
   _onShare: function Reader_onShare() {
     if (!this._article)
       return;
     gChromeWin.sendMessageToJava({
       type: "Reader:Share",
       url: this._article.url,
       title: this._article.title
     });
     // Create a relative timestamp for telemetry
     let uptime = Date.now() - Services.startup.getStartupInfo().linkerInitialized;
     UITelemetry.addEvent("share.1", "list", uptime);
   },
   _setFontSize: function Reader_setFontSize(newFontSize) {
     let bodyClasses = this._doc.body.classList;
     if (this._fontSize > 0)
       bodyClasses.remove("font-size" + this._fontSize);
     this._fontSize = newFontSize;
     bodyClasses.add("font-size" + this._fontSize);
     Services.prefs.setIntPref("reader.font_size", this._fontSize);
   },
   _handleDeviceLight: function Reader_handleDeviceLight(newLux) {
     // Desired size of the this._luxValues array.
     let luxValuesSize = 10;
     // Add new lux value at the front of the array.
     this._luxValues.unshift(newLux);
     // Add new lux value to this._totalLux for averaging later.
     this._totalLux += newLux;
     // Don't update when length of array is less than luxValuesSize except when it is 1.
     if (this._luxValues.length < luxValuesSize) {
       // Use the first lux value to set the color scheme until our array equals luxValuesSize.
       if (this._luxValues.length == 1) {
         this._updateColorScheme(newLux);
       }
       return;
     }
     // Holds the average of the lux values collected in this._luxValues.
     let averageLuxValue = this._totalLux/luxValuesSize;
     this._updateColorScheme(averageLuxValue);
     // Pop the oldest value off the array.
     let oldLux = this._luxValues.pop();
     // Subtract oldLux since it has been discarded from the array.
     this._totalLux -= oldLux;
   },
   _updateColorScheme: function Reader_updateColorScheme(luxValue) {
     // Upper bound value for "dark" color scheme beyond which it changes to "light".
     let upperBoundDark = 50;
     // Lower bound value for "light" color scheme beyond which it changes to "dark".
     let lowerBoundLight = 10;
     // Threshold for color scheme change.
     let colorChangeThreshold = 20;
     // Ignore changes that are within a certain threshold of previous lux values.
     if ((this._colorScheme === "dark" && luxValue < upperBoundDark) ||
         (this._colorScheme === "light" && luxValue > lowerBoundLight))
       return;
     if (luxValue < colorChangeThreshold)
       this._setColorScheme("dark");
     else
       this._setColorScheme("light");
   },
   _setColorScheme: function Reader_setColorScheme(newColorScheme) {
     if (this._colorScheme === newColorScheme)
       return;
     let bodyClasses = this._doc.body.classList;
     if (this._colorScheme)
       bodyClasses.remove(this._colorScheme);
     this._colorScheme = newColorScheme;
     bodyClasses.add(this._colorScheme);
   },
   // Pref values include "dark", "light", and "auto", which automatically switches
   // between light and dark color schemes based on the ambient light level.
   _setColorSchemePref: function Reader_setColorSchemePref(colorSchemePref) {
     if (colorSchemePref === "auto") {
       this._win.addEventListener("devicelight", this, false);
       this._luxValues = [];
       this._totalLux = 0;
     } else {
       this._win.removeEventListener("devicelight", this, false);
       this._setColorScheme(colorSchemePref);
       delete this._luxValues;
       delete this._totalLux;
     }
     Services.prefs.setCharPref("reader.color_scheme", colorSchemePref);
   },
   _setFontType: function Reader_setFontType(newFontType) {
     if (this._fontType === newFontType)
       return;
     let bodyClasses = this._doc.body.classList;
     if (this._fontType)
       bodyClasses.remove(this._fontType);
     this._fontType = newFontType;
     bodyClasses.add(this._fontType);
     Services.prefs.setCharPref("reader.font_type", this._fontType);
   },
   _getToolbarVisibility: function Reader_getToolbarVisibility() {
     return !this._toolbarElement.classList.contains("toolbar-hidden");
   },
   _setToolbarVisibility: function Reader_setToolbarVisibility(visible) {
     let win = this._win;
     if (win.history.state)
       win.history.back();
     if (!this._toolbarEnabled)
       return;
     // Don't allow visible toolbar until banner state is known
     if (this._isReadingListItem == -1)
       return;
     if (this._getToolbarVisibility() === visible)
       return;
     this._toolbarElement.classList.toggle("toolbar-hidden");
     this._setSystemUIVisibility(visible);
     if (!visible && !this._hasUsedToolbar) {
       this._hasUsedToolbar = Services.prefs.getBoolPref("reader.has_used_toolbar");
       if (!this._hasUsedToolbar) {
         gChromeWin.NativeWindow.toast.show(gStrings.GetStringFromName("aboutReader.toolbarTip"), "short");
         Services.prefs.setBoolPref("reader.has_used_toolbar", true);
         this._hasUsedToolbar = true;
       }
     }
   },
   _toggleToolbarVisibility: function Reader_toggleToolbarVisibility(visible) {
     this._setToolbarVisibility(!this._getToolbarVisibility());
   },
   _setSystemUIVisibility: function Reader_setSystemUIVisibility(visible) {
     gChromeWin.sendMessageToJava({
       type: "SystemUI:Visibility",
       visible: visible
     });
   },
   _loadFromURL: function Reader_loadFromURL(url) {
     this._showProgressDelayed();
     gChromeWin.Reader.parseDocumentFromURL(url, function(article) {
       if (article)
         this._showContent(article);
       else
         this._showError(gStrings.GetStringFromName("aboutReader.loadError"));
     }.bind(this));
   },
   _loadFromTab: function Reader_loadFromTab(tabId, url) {
     this._showProgressDelayed();
     gChromeWin.Reader.getArticleForTab(tabId, url, function(article) {
       if (article)
         this._showContent(article);
       else
         this._showError(gStrings.GetStringFromName("aboutReader.loadError"));
     }.bind(this));
   },
   _requestFavicon: function Reader_requestFavicon() {
     gChromeWin.sendMessageToJava({
       type: "Reader:FaviconRequest",
       url: this._article.url
     });
   },
   _loadFavicon: function Reader_loadFavicon(url, faviconUrl) {
     if (this._article.url !== url)
       return;
     let doc = this._doc;
     let link = doc.createElement('link');
     link.rel = 'shortcut icon';
     link.href = faviconUrl;
     doc.getElementsByTagName('head')[0].appendChild(link);
   },
   _updateImageMargins: function Reader_updateImageMargins() {
     let windowWidth = this._win.innerWidth;
     let contentWidth = this._contentElement.offsetWidth;
     let maxWidthStyle = windowWidth + "px !important";
     let setImageMargins = function(img) {
       if (!img._originalWidth)
         img._originalWidth = img.offsetWidth;
       let imgWidth = img._originalWidth;
       // If the image is taking more than half of the screen, just make
       // it fill edge-to-edge.
       if (imgWidth < contentWidth && imgWidth > windowWidth * 0.55)
         imgWidth = windowWidth;
       let sideMargin = Math.max((contentWidth - windowWidth) / 2,
                                 (contentWidth - imgWidth) / 2);
       let imageStyle = sideMargin + "px !important";
       let widthStyle = imgWidth + "px !important";
       let cssText = "max-width: " + maxWidthStyle + ";" +
                     "width: " + widthStyle + ";" +
                     "margin-left: " + imageStyle + ";" +
                     "margin-right: " + imageStyle + ";";
       img.style.cssText = cssText;
     }
     let imgs = this._doc.querySelectorAll(this._BLOCK_IMAGES_SELECTOR);
     for (let i = imgs.length; --i >= 0;) {
       let img = imgs[i];
       if (img.width > 0) {
         setImageMargins(img);
       } else {
         img.onload = function() {
           setImageMargins(img);
         }
       }
     }
   },
   _maybeSetTextDirection: function Read_maybeSetTextDirection(article){
     if(!article.dir)
       return;
     //Set "dir" attribute on content
     this._contentElement.setAttribute("dir", article.dir);
     this._headerElement.setAttribute("dir", article.dir);
   },
   _showError: function Reader_showError(error) {
     this._headerElement.style.display = "none";
     this._contentElement.style.display = "none";
     this._messageElement.innerHTML = error;
     this._messageElement.style.display = "block";
     this._doc.title = error;
   },
   // This function is the JS version of Java's StringUtils.stripCommonSubdomains.
   _stripHost: function Reader_stripHost(host) {
     if (!host)
       return host;
     let start = 0;
     if (host.startsWith("www."))
       start = 4;
     else if (host.startsWith("m."))
       start = 2;
     else if (host.startsWith("mobile."))
       start = 7;
     return host.substring(start);
   },
   _showContent: function Reader_showContent(article) {
     this._messageElement.style.display = "none";
     this._article = article;
     this._domainElement.href = article.url;
     let articleUri = Services.io.newURI(article.url, null, null);
     this._domainElement.innerHTML = this._stripHost(articleUri.host);
     this._creditsElement.innerHTML = article.byline;
     this._titleElement.textContent = article.title;
     this._doc.title = article.title;
     this._headerElement.style.display = "block";
     let parserUtils = Cc["@mozilla.org/parserutils;1"].getService(Ci.nsIParserUtils);
     let contentFragment = parserUtils.parseFragment(article.content, Ci.nsIParserUtils.SanitizerDropForms,
                                                     false, articleUri, this._contentElement);
     this._contentElement.innerHTML = "";
     this._contentElement.appendChild(contentFragment);
     this._updateImageMargins();
     this._maybeSetTextDirection(article);
     this._contentElement.style.display = "block";
     this._requestReadingListStatus();
     this._toolbarEnabled = true;
     this._setToolbarVisibility(true);
     this._requestFavicon();
   },
   _hideContent: function Reader_hideContent() {
     this._headerElement.style.display = "none";
     this._contentElement.style.display = "none";
   },
   _showProgressDelayed: function Reader_showProgressDelayed() {
     this._win.setTimeout(function() {
       // Article has already been loaded, no need to show
       // progress anymore.
       if (this._article)
         return;
       this._headerElement.style.display = "none";
       this._contentElement.style.display = "none";
       this._messageElement.innerHTML = gStrings.GetStringFromName("aboutReader.loading");
       this._messageElement.style.display = "block";
     }.bind(this), 300);
   },
   _decodeQueryString: function Reader_decodeQueryString(url) {
     let result = {};
     let query = url.split("?")[1];
     if (query) {
       let pairs = query.split("&");
       for (let i = 0; i < pairs.length; i++) {
         let [name, value] = pairs[i].split("=");
         result[name] = decodeURIComponent(value);
       }
     }
     return result;
   },
   _setupSegmentedButton: function Reader_setupSegmentedButton(id, options, initialValue, callback) {
     let doc = this._doc;
     let segmentedButton = doc.getElementById(id);
     for (let i = 0; i < options.length; i++) {
       let option = options[i];
       let item = doc.createElement("li");
       let link = doc.createElement("a");
       link.textContent = option.name;
       item.appendChild(link);
       if (option.linkClass !== undefined)
         link.classList.add(option.linkClass);
       if (option.description !== undefined) {
         let description = doc.createElement("div");
         description.textContent = option.description;
         item.appendChild(description);
       }
       link.style.MozUserSelect = 'none';
       segmentedButton.appendChild(item);
       link.addEventListener("click", function(aEvent) {
         if (!aEvent.isTrusted)
           return;
         aEvent.stopPropagation();
         // Create a relative timestamp for telemetry
         let uptime = Date.now() - Services.startup.getStartupInfo().linkerInitialized;
         // Just pass the ID of the button as an extra and hope the ID doesn't change
         // unless the context changes
         UITelemetry.addEvent("action.1", "button", uptime, id);
         let items = segmentedButton.children;
         for (let j = items.length - 1; j >= 0; j--) {
           items[j].classList.remove("selected");
         }
         item.classList.add("selected");
         callback(option.value);
       }.bind(this), true);
       if (option.value === initialValue)
         item.classList.add("selected");
     }
   },
   _setupButton: function Reader_setupButton(id, callback) {
     let button = this._doc.getElementById(id);
     button.addEventListener("click", function(aEvent) {
       if (!aEvent.isTrusted)
         return;
       aEvent.stopPropagation();
       callback();
     }, true);
   },
   _setupAllDropdowns: function Reader_setupAllDropdowns() {
     let doc = this._doc;
     let win = this._win;
     let dropdowns = doc.getElementsByClassName("dropdown");
     for (let i = dropdowns.length - 1; i >= 0; i--) {
       let dropdown = dropdowns[i];
       let dropdownToggle = dropdown.getElementsByClassName("dropdown-toggle")[0];
       let dropdownPopup = dropdown.getElementsByClassName("dropdown-popup")[0];
       if (!dropdownToggle || !dropdownPopup)
         continue;
       let dropdownArrow = doc.createElement("div");
       dropdownArrow.className = "dropdown-arrow";
       dropdownPopup.appendChild(dropdownArrow);
       let updatePopupPosition = function() {
         let popupWidth = dropdownPopup.offsetWidth + 30;
         let arrowWidth = dropdownArrow.offsetWidth;
         let toggleWidth = dropdownToggle.offsetWidth;
         let toggleLeft = dropdownToggle.offsetLeft;
         let popupShift = (toggleWidth - popupWidth) / 2;
         let popupLeft = Math.max(0, Math.min(win.innerWidth - popupWidth, toggleLeft + popupShift));
         dropdownPopup.style.left = popupLeft + "px";
         let arrowShift = (toggleWidth - arrowWidth) / 2;
         let arrowLeft = toggleLeft - popupLeft + arrowShift;
         dropdownArrow.style.left = arrowLeft + "px";
       };
       win.addEventListener("resize", function(aEvent) {
         if (!aEvent.isTrusted)
           return;
         // Wait for reflow before calculating the new position of the popup.
         setTimeout(updatePopupPosition, 0);
       }, true);
       dropdownToggle.addEventListener("click", function(aEvent) {
         if (!aEvent.isTrusted)
           return;
         aEvent.stopPropagation();
         if (!this._getToolbarVisibility())
           return;
         let dropdownClasses = dropdown.classList;
         if (dropdownClasses.contains("open")) {
           win.history.back();
         } else {
           updatePopupPosition();
           if (!this._closeAllDropdowns())
             this._pushDropdownState();
           dropdownClasses.add("open");
         }
       }.bind(this), true);
     }
   },
   _pushDropdownState: function Reader_pushDropdownState() {
     // FIXME: We're getting a NS_ERROR_UNEXPECTED error when we try
     // to do win.history.pushState() here (see bug 682296). This is
     // a workaround that allows us to push history state on the target
     // content document.
     let doc = this._doc;
     let body = doc.body;
     if (this._pushStateScript)
       body.removeChild(this._pushStateScript);
     this._pushStateScript = doc.createElement('script');
     this._pushStateScript.type = "text/javascript";
     this._pushStateScript.innerHTML = 'history.pushState({ dropdown: 1 }, document.title);';
     body.appendChild(this._pushStateScript);
   },
   _closeAllDropdowns : function Reader_closeAllDropdowns() {
     let dropdowns = this._doc.querySelectorAll(".dropdown.open");
     for (let i = dropdowns.length - 1; i >= 0; i--) {
       dropdowns[i].classList.remove("open");
     }
     return (dropdowns.length > 0)
   }
 };