Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1130 insertions, 0 deletions

diff --git a/browser/components/search/SearchOneOffs.sys.mjs b/browser/components/search/SearchOneOffs.sys.mjs
new file mode 100644
index 0000000000..ddab74f94a
--- /dev/null
+++ b/browser/components/search/SearchOneOffs.sys.mjs
@@ -0,0 +1,1130 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
+  SearchUIUtils: "resource:///modules/SearchUIUtils.sys.mjs",
+});
+
+const EMPTY_ADD_ENGINES = [];
+
+/**
+ * Defines the search one-off button elements. These are displayed at the bottom
+ * of the address bar and search bar. The address bar buttons are a subclass in
+ * browser/components/urlbar/UrlbarSearchOneOffs.jsm. If you are adding a new
+ * subclass, see "Methods for subclasses to override" below.
+ */
+export class SearchOneOffs {
+  constructor(container) {
+    this.container = container;
+    this.window = container.ownerGlobal;
+    this.document = container.ownerDocument;
+
+    this.container.appendChild(
+      this.window.MozXULElement.parseXULToFragment(
+        `
+      <hbox class="search-panel-one-offs-header search-panel-header">
+        <label class="search-panel-one-offs-header-label" data-l10n-id="search-one-offs-with-title"/>
+      </hbox>
+      <box class="search-panel-one-offs-container">
+        <hbox class="search-panel-one-offs" role="group"/>
+        <button class="searchbar-engine-one-off-item search-setting-button" tabindex="-1" data-l10n-id="search-one-offs-change-settings-compact-button"/>
+      </box>
+      <box>
+        <menupopup class="search-one-offs-context-menu">
+          <menuitem class="search-one-offs-context-open-in-new-tab" data-l10n-id="search-one-offs-context-open-new-tab"/>
+          <menuitem class="search-one-offs-context-set-default" data-l10n-id="search-one-offs-context-set-as-default"/>
+          <menuitem class="search-one-offs-context-set-default-private" data-l10n-id="search-one-offs-context-set-as-default-private"/>
+        </menupopup>
+      </box>
+      `
+      )
+    );
+
+    this._popup = null;
+    this._textbox = null;
+
+    this._textboxWidth = 0;
+
+    /**
+     * Set this to a string that identifies your one-offs consumer.  It'll
+     * be appended to telemetry recorded with maybeRecordTelemetry().
+     */
+    this.telemetryOrigin = "";
+
+    this._query = "";
+
+    this._selectedButton = null;
+
+    this.buttons = this.querySelector(".search-panel-one-offs");
+
+    this.header = this.querySelector(".search-panel-one-offs-header");
+
+    this.settingsButton = this.querySelector(".search-setting-button");
+
+    this.contextMenuPopup = this.querySelector(".search-one-offs-context-menu");
+
+    this._engineInfo = null;
+
+    /**
+     * `_rebuild()` is async, because it queries the Search Service, which means
+     * there is a potential for a race when it's called multiple times in succession.
+     */
+    this._rebuilding = false;
+
+    this.addEventListener("mousedown", this);
+    this.addEventListener("click", this);
+    this.addEventListener("command", this);
+    this.addEventListener("contextmenu", this);
+
+    // Prevent popup events from the context menu from reaching the autocomplete
+    // binding (or other listeners).
+    let listener = aEvent => aEvent.stopPropagation();
+    this.contextMenuPopup.addEventListener("popupshowing", listener);
+    this.contextMenuPopup.addEventListener("popuphiding", listener);
+    this.contextMenuPopup.addEventListener("popupshown", aEvent => {
+      aEvent.stopPropagation();
+    });
+    this.contextMenuPopup.addEventListener("popuphidden", aEvent => {
+      aEvent.stopPropagation();
+    });
+
+    // Add weak referenced observers to invalidate our cached list of engines.
+    this.QueryInterface = ChromeUtils.generateQI([
+      "nsIObserver",
+      "nsISupportsWeakReference",
+    ]);
+    Services.prefs.addObserver("browser.search.hiddenOneOffs", this, true);
+    Services.obs.addObserver(this, "browser-search-engine-modified", true);
+    Services.obs.addObserver(this, "browser-search-service", true);
+
+    // Rebuild the buttons when the theme changes.  See bug 1357800 for
+    // details.  Summary: On Linux, switching between themes can cause a row
+    // of buttons to disappear.
+    Services.obs.addObserver(this, "lightweight-theme-changed", true);
+
+    // This defaults to false in the Search Bar, subclasses can change their
+    // default in the constructor.
+    this.disableOneOffsHorizontalKeyNavigation = false;
+  }
+
+  addEventListener(...args) {
+    this.container.addEventListener(...args);
+  }
+
+  removeEventListener(...args) {
+    this.container.removeEventListener(...args);
+  }
+
+  dispatchEvent(...args) {
+    this.container.dispatchEvent(...args);
+  }
+
+  getAttribute(...args) {
+    return this.container.getAttribute(...args);
+  }
+
+  hasAttribute(...args) {
+    return this.container.hasAttribute(...args);
+  }
+
+  setAttribute(...args) {
+    this.container.setAttribute(...args);
+  }
+
+  querySelector(...args) {
+    return this.container.querySelector(...args);
+  }
+
+  handleEvent(event) {
+    let methodName = "_on_" + event.type;
+    if (methodName in this) {
+      this[methodName](event);
+    } else {
+      throw new Error("Unrecognized search-one-offs event: " + event.type);
+    }
+  }
+
+  /**
+   * @returns {boolean}
+   *   True if we will hide the one-offs when they are requested.
+   */
+  async willHide() {
+    if (this._engineInfo?.willHide !== undefined) {
+      return this._engineInfo.willHide;
+    }
+    let engineInfo = await this.getEngineInfo();
+    let oneOffCount = engineInfo.engines.length;
+    this._engineInfo.willHide =
+      !oneOffCount ||
+      (oneOffCount == 1 &&
+        engineInfo.engines[0].name == engineInfo.default.name);
+    return this._engineInfo.willHide;
+  }
+
+  /**
+   * Invalidates the engine cache. After invalidating the cache, the one-offs
+   * will be rebuilt the next time they are shown.
+   */
+  invalidateCache() {
+    if (!this._rebuilding) {
+      this._engineInfo = null;
+    }
+  }
+
+  /**
+   * Width in pixels of the one-off buttons.
+   * NOTE: Used in browser/components/search/content/searchbar.js only.
+   *
+   * @returns {number}
+   */
+  get buttonWidth() {
+    return 48;
+  }
+
+  /**
+   * The popup that contains the one-offs.
+   *
+   * @param {DOMElement} val
+   *        The new value to set.
+   */
+  set popup(val) {
+    if (this._popup) {
+      this._popup.removeEventListener("popupshowing", this);
+      this._popup.removeEventListener("popuphidden", this);
+    }
+    if (val) {
+      val.addEventListener("popupshowing", this);
+      val.addEventListener("popuphidden", this);
+    }
+    this._popup = val;
+
+    // If the popup is already open, rebuild the one-offs now.  The
+    // popup may be opening, so check that the state is not closed
+    // instead of checking popupOpen.
+    if (val && val.state != "closed") {
+      this._rebuild();
+    }
+  }
+
+  get popup() {
+    return this._popup;
+  }
+
+  /**
+   * The textbox associated with the one-offs.  Set this to a textbox to
+   * automatically keep the related one-offs UI up to date.  Otherwise you
+   * can leave it null/undefined, and in that case you should update the
+   * query property manually.
+   *
+   * @param {DOMElement} val
+   *        The new value to set.
+   */
+  set textbox(val) {
+    if (this._textbox) {
+      this._textbox.removeEventListener("input", this);
+    }
+    if (val) {
+      val.addEventListener("input", this);
+    }
+    this._textbox = val;
+  }
+
+  get style() {
+    return this.container.style;
+  }
+
+  get textbox() {
+    return this._textbox;
+  }
+
+  /**
+   * The query string currently shown in the one-offs.  If the textbox
+   * property is non-null, then this is automatically updated on
+   * input.
+   *
+   * @param {string} val
+   *        The new query string to set.
+   */
+  set query(val) {
+    this._query = val;
+    if (this.isViewOpen) {
+      let isOneOffSelected =
+        this.selectedButton &&
+        this.selectedButton.classList.contains(
+          "searchbar-engine-one-off-item"
+        ) &&
+        !(
+          this.selectedButton == this.settingsButton &&
+          this.hasAttribute("is_searchbar")
+        );
+      // Typing de-selects the settings or opensearch buttons at the bottom
+      // of the search panel, as typing shows the user intends to search.
+      if (this.selectedButton && !isOneOffSelected) {
+        this.selectedButton = null;
+      }
+    }
+  }
+
+  get query() {
+    return this._query;
+  }
+
+  /**
+   * The selected one-off, a xul:button, including the add-engine button
+   * and the search-settings button.
+   *
+   * @param {DOMElement|null} val
+   *        The selected one-off button. Null if no one-off is selected.
+   */
+  set selectedButton(val) {
+    let previousButton = this._selectedButton;
+    if (previousButton) {
+      previousButton.removeAttribute("selected");
+    }
+    if (val) {
+      val.setAttribute("selected", "true");
+    }
+    this._selectedButton = val;
+
+    if (this.textbox) {
+      if (val) {
+        this.textbox.setAttribute("aria-activedescendant", val.id);
+      } else {
+        let active = this.textbox.getAttribute("aria-activedescendant");
+        if (active && active.includes("-engine-one-off-item-")) {
+          this.textbox.removeAttribute("aria-activedescendant");
+        }
+      }
+    }
+
+    let event = new CustomEvent("SelectedOneOffButtonChanged", {
+      previousSelectedButton: previousButton,
+    });
+    this.dispatchEvent(event);
+  }
+
+  get selectedButton() {
+    return this._selectedButton;
+  }
+
+  /**
+   * The index of the selected one-off, including the add-engine button
+   * and the search-settings button.
+   *
+   * @param {number} val
+   *        The new index to set, -1 for nothing selected.
+   */
+  set selectedButtonIndex(val) {
+    let buttons = this.getSelectableButtons(true);
+    this.selectedButton = buttons[val];
+  }
+
+  get selectedButtonIndex() {
+    let buttons = this.getSelectableButtons(true);
+    for (let i = 0; i < buttons.length; i++) {
+      if (buttons[i] == this._selectedButton) {
+        return i;
+      }
+    }
+    return -1;
+  }
+
+  async getEngineInfo() {
+    if (this._engineInfo) {
+      return this._engineInfo;
+    }
+
+    this._engineInfo = {};
+    if (lazy.PrivateBrowsingUtils.isWindowPrivate(this.window)) {
+      this._engineInfo.default = await Services.search.getDefaultPrivate();
+    } else {
+      this._engineInfo.default = await Services.search.getDefault();
+    }
+
+    let currentEngineNameToIgnore;
+    if (!this.getAttribute("includecurrentengine")) {
+      currentEngineNameToIgnore = this._engineInfo.default.name;
+    }
+
+    let pref = Services.prefs.getStringPref("browser.search.hiddenOneOffs");
+    let hiddenList = pref ? pref.split(",") : [];
+
+    this._engineInfo.engines = (
+      await Services.search.getVisibleEngines()
+    ).filter(e => {
+      let name = e.name;
+      return (
+        (!currentEngineNameToIgnore || name != currentEngineNameToIgnore) &&
+        !hiddenList.includes(name)
+      );
+    });
+
+    return this._engineInfo;
+  }
+
+  observe(aEngine, aTopic, aData) {
+    // Make sure the engine list was updated.
+    this.invalidateCache();
+  }
+
+  _getAddEngines() {
+    return this.window.gBrowser.selectedBrowser.engines || EMPTY_ADD_ENGINES;
+  }
+
+  get _maxInlineAddEngines() {
+    return 3;
+  }
+
+  /**
+   * Infallible, non-re-entrant version of `__rebuild()`.
+   */
+  async _rebuild() {
+    if (this._rebuilding) {
+      return;
+    }
+
+    this._rebuilding = true;
+    try {
+      await this.__rebuild();
+    } catch (ex) {
+      console.error("Search-one-offs::_rebuild() error: " + ex);
+    } finally {
+      this._rebuilding = false;
+    }
+  }
+
+  /**
+   * Builds all the UI.
+   */
+  async __rebuild() {
+    // Return early if the list of engines has not changed.
+    if (!this.popup && this._engineInfo?.domWasUpdated) {
+      return;
+    }
+
+    const addEngines = this._getAddEngines();
+
+    // Return early if the engines and panel width have not changed.
+    if (this.popup && this._textbox) {
+      let textboxWidth = await this.window.promiseDocumentFlushed(() => {
+        return this._textbox.clientWidth;
+      });
+
+      if (
+        this._engineInfo?.domWasUpdated &&
+        this._textboxWidth == textboxWidth &&
+        this._addEngines == addEngines
+      ) {
+        return;
+      }
+      this._textboxWidth = textboxWidth;
+      this._addEngines = addEngines;
+    }
+
+    const isSearchBar = this.hasAttribute("is_searchbar");
+    if (isSearchBar) {
+      // Hide the container during updating to avoid flickering.
+      this.container.hidden = true;
+    }
+
+    // Finally, build the list of one-off buttons.
+    while (this.buttons.firstElementChild) {
+      this.buttons.firstElementChild.remove();
+    }
+
+    let headerText = this.header.querySelector(
+      ".search-panel-one-offs-header-label"
+    );
+    headerText.id = this.telemetryOrigin + "-one-offs-header-label";
+    this.buttons.setAttribute("aria-labelledby", headerText.id);
+
+    // For the search-bar, always show the one-off buttons where there is an
+    // option to add an engine.
+    let addEngineNeeded = isSearchBar && addEngines.length;
+    let hideOneOffs = (await this.willHide()) && !addEngineNeeded;
+
+    // The _engineInfo cache is used by more consumers, thus it is not a good
+    // representation of whether this method already updated the one-off buttons
+    // DOM. For this reason we introduce a separate flag tracking the DOM
+    // updating, and use it to know when it's okay to not rebuild the one-offs.
+    // We set this early, since we might either rebuild the DOM or hide it.
+    this._engineInfo.domWasUpdated = true;
+
+    this.container.hidden = hideOneOffs;
+
+    if (hideOneOffs) {
+      return;
+    }
+
+    // Ensure we can refer to the settings buttons by ID:
+    let origin = this.telemetryOrigin;
+    this.settingsButton.id = origin + "-anon-search-settings";
+
+    let engines = (await this.getEngineInfo()).engines;
+    this._rebuildEngineList(engines, addEngines);
+
+    this.dispatchEvent(new Event("rebuild"));
+  }
+
+  /**
+   * Adds one-offs for the given engines to the DOM.
+   *
+   * @param {Array} engines
+   *        The engines to add.
+   * @param {Array} addEngines
+   *        The engines that can be added.
+   */
+  _rebuildEngineList(engines, addEngines) {
+    for (let i = 0; i < engines.length; ++i) {
+      let engine = engines[i];
+      let button = this.document.createXULElement("button");
+      button.engine = engine;
+      button.id = this._buttonIDForEngine(engine);
+      let iconURI =
+        engine.iconURI?.spec ||
+        "chrome://browser/skin/search-engine-placeholder.png";
+      button.setAttribute("image", iconURI);
+      button.setAttribute("class", "searchbar-engine-one-off-item");
+      button.setAttribute("tabindex", "-1");
+      this.setTooltipForEngineButton(button);
+      this.buttons.appendChild(button);
+    }
+
+    for (
+      let i = 0, len = Math.min(addEngines.length, this._maxInlineAddEngines);
+      i < len;
+      i++
+    ) {
+      const engine = addEngines[i];
+      const button = this.document.createXULElement("button");
+      button.id = this._buttonIDForEngine(engine);
+      button.classList.add("searchbar-engine-one-off-item");
+      button.classList.add("searchbar-engine-one-off-add-engine");
+      button.setAttribute("tabindex", "-1");
+      if (engine.icon) {
+        button.setAttribute("image", engine.icon);
+      }
+      button.setAttribute("data-l10n-id", "search-one-offs-add-engine");
+      button.setAttribute(
+        "data-l10n-args",
+        JSON.stringify({ engineName: engine.title })
+      );
+      button.setAttribute("engine-name", engine.title);
+      button.setAttribute("uri", engine.uri);
+      this.buttons.appendChild(button);
+    }
+  }
+
+  _buttonIDForEngine(engine) {
+    return (
+      this.telemetryOrigin +
+      "-engine-one-off-item-engine-" +
+      this._engineInfo.engines.indexOf(engine)
+    );
+  }
+
+  getSelectableButtons(aIncludeNonEngineButtons) {
+    const buttons = [
+      ...this.buttons.querySelectorAll(".searchbar-engine-one-off-item"),
+    ];
+
+    if (aIncludeNonEngineButtons) {
+      buttons.push(this.settingsButton);
+    }
+
+    return buttons;
+  }
+
+  /**
+   * Returns information on where a search results page should be loaded: in the
+   * current tab or a new tab.
+   *
+   * @param {event} aEvent
+   *        The event that triggered the page load.
+   * @param {boolean} [aForceNewTab]
+   *        True to force the load in a new tab.
+   * @returns {object} An object { where, params }.  `where` is a string:
+   *          "current" or "tab".  `params` is an object further describing how
+   *          the page should be loaded.
+   */
+  _whereToOpen(aEvent, aForceNewTab = false) {
+    let where = "current";
+    let params;
+    // Open ctrl/cmd clicks on one-off buttons in a new background tab.
+    if (aForceNewTab) {
+      where = "tab";
+      if (Services.prefs.getBoolPref("browser.tabs.loadInBackground")) {
+        params = {
+          inBackground: true,
+        };
+      }
+    } else {
+      let newTabPref = Services.prefs.getBoolPref("browser.search.openintab");
+      if (
+        (KeyboardEvent.isInstance(aEvent) && aEvent.altKey) ^ newTabPref &&
+        !this.window.gBrowser.selectedTab.isEmpty
+      ) {
+        where = "tab";
+      }
+      if (
+        MouseEvent.isInstance(aEvent) &&
+        (aEvent.button == 1 || aEvent.getModifierState("Accel"))
+      ) {
+        where = "tab";
+        params = {
+          inBackground: true,
+        };
+      }
+    }
+
+    return { where, params };
+  }
+
+  /**
+   * Increments or decrements the index of the currently selected one-off.
+   *
+   * @param {boolean} aForward
+   *        If true, the index is incremented, and if false, the index is
+   *        decremented.
+   * @param {boolean} aIncludeNonEngineButtons
+   *        If true, buttons that do not have engines are included.
+   *        These buttons include the OpenSearch and settings buttons.  For
+   *        example, if the currently selected button is an engine button,
+   *        the next button is the settings button, and you pass true for
+   *        aForward, then passing true for this value would cause the
+   *        settings to be selected.  Passing false for this value would
+   *        cause the selection to clear or wrap around, depending on what
+   *        value you passed for the aWrapAround parameter.
+   * @param {boolean} aWrapAround
+   *        If true, the selection wraps around between the first and last
+   *        buttons.
+   */
+  advanceSelection(aForward, aIncludeNonEngineButtons, aWrapAround) {
+    let buttons = this.getSelectableButtons(aIncludeNonEngineButtons);
+    let index;
+    if (this.selectedButton) {
+      let inc = aForward ? 1 : -1;
+      let oldIndex = buttons.indexOf(this.selectedButton);
+      index = (oldIndex + inc + buttons.length) % buttons.length;
+      if (
+        !aWrapAround &&
+        ((aForward && index <= oldIndex) || (!aForward && oldIndex <= index))
+      ) {
+        // The index has wrapped around, but wrapping around isn't
+        // allowed.
+        index = -1;
+      }
+    } else {
+      index = aForward ? 0 : buttons.length - 1;
+    }
+    this.selectedButton = index < 0 ? null : buttons[index];
+  }
+
+  /**
+   * This handles key presses specific to the one-off buttons like Tab and
+   * Alt+Up/Down, and Up/Down keys within the buttons.  Since one-off buttons
+   * are always used in conjunction with a list of some sort (in this.popup),
+   * it also handles Up/Down keys that cross the boundaries between list
+   * items and the one-off buttons.
+   *
+   * If this method handles the key press, then it will call
+   * event.preventDefault() and return true.
+   *
+   * @param {Event} event
+   *        The key event.
+   * @param {number} numListItems
+   *        The number of items in the list.  The reason that this is a
+   *        parameter at all is that the list may contain items at the end
+   *        that should be ignored, depending on the consumer.  That's true
+   *        for the urlbar for example.
+   * @param {boolean} allowEmptySelection
+   *        Pass true if it's OK that neither the list nor the one-off
+   *        buttons contains a selection.  Pass false if either the list or
+   *        the one-off buttons (or both) should always contain a selection.
+   * @param {string} [textboxUserValue]
+   *        When the last list item is selected and the user presses Down,
+   *        the first one-off becomes selected and the textbox value is
+   *        restored to the value that the user typed.  Pass that value here.
+   *        However, if you pass true for allowEmptySelection, you don't need
+   *        to pass anything for this parameter.  (Pass undefined or null.)
+   * @returns {boolean} True if the one-offs handled the key press.
+   */
+  handleKeyDown(event, numListItems, allowEmptySelection, textboxUserValue) {
+    if (!this.hasView) {
+      return false;
+    }
+    let handled = this._handleKeyDown(
+      event,
+      numListItems,
+      allowEmptySelection,
+      textboxUserValue
+    );
+    if (handled) {
+      event.preventDefault();
+      event.stopPropagation();
+    }
+    return handled;
+  }
+
+  _handleKeyDown(event, numListItems, allowEmptySelection, textboxUserValue) {
+    if (this.container.hidden) {
+      return false;
+    }
+    if (
+      event.keyCode == KeyEvent.DOM_VK_RIGHT &&
+      this.selectedButton &&
+      this.selectedButton.classList.contains("addengine-menu-button")
+    ) {
+      // If the add-engine overflow menu item is selected and the user
+      // presses the right arrow key, open the submenu.  Unfortunately
+      // handling the left arrow key -- to close the popup -- isn't
+      // straightforward.  Once the popup is open, it consumes all key
+      // events.  Setting ignorekeys=handled on it doesn't help, since the
+      // popup handles all arrow keys.  Setting ignorekeys=true on it does
+      // mean that the popup no longer consumes the left arrow key, but
+      // then it no longer handles up/down keys to select items in the
+      // popup.
+      this.selectedButton.open = true;
+      return true;
+    }
+
+    // Handle the Tab key, but only if non-Shift modifiers aren't also
+    // pressed to avoid clobbering other shortcuts (like the Alt+Tab
+    // browser tab switcher).  The reason this uses getModifierState() and
+    // checks for "AltGraph" is that when you press Shift-Alt-Tab,
+    // event.altKey is actually false for some reason, at least on macOS.
+    // getModifierState("Alt") is also false, but "AltGraph" is true.
+    if (
+      event.keyCode == KeyEvent.DOM_VK_TAB &&
+      !event.getModifierState("Alt") &&
+      !event.getModifierState("AltGraph") &&
+      !event.getModifierState("Control") &&
+      !event.getModifierState("Meta")
+    ) {
+      if (
+        this.getAttribute("disabletab") == "true" ||
+        (event.shiftKey && this.selectedButtonIndex <= 0) ||
+        (!event.shiftKey &&
+          this.selectedButtonIndex ==
+            this.getSelectableButtons(true).length - 1)
+      ) {
+        this.selectedButton = null;
+        return false;
+      }
+      this.selectedViewIndex = -1;
+      this.advanceSelection(!event.shiftKey, true, false);
+      return !!this.selectedButton;
+    }
+
+    if (event.keyCode == KeyboardEvent.DOM_VK_UP) {
+      if (event.altKey) {
+        // Keep the currently selected result in the list (if any) as a
+        // secondary "alt" selection and move the selection up within the
+        // buttons.
+        this.advanceSelection(false, false, false);
+        return true;
+      }
+      if (numListItems == 0) {
+        this.advanceSelection(false, true, false);
+        return true;
+      }
+      if (this.selectedViewIndex > 0) {
+        // Moving up within the list.  The autocomplete controller should
+        // handle this case.  A button may be selected, so null it.
+        this.selectedButton = null;
+        return false;
+      }
+      if (this.selectedViewIndex == 0) {
+        // Moving up from the top of the list.
+        if (allowEmptySelection) {
+          // Let the autocomplete controller remove selection in the list
+          // and revert the typed text in the textbox.
+          return false;
+        }
+        // Wrap selection around to the last button.
+        if (this.textbox && typeof textboxUserValue == "string") {
+          this.textbox.value = textboxUserValue;
+        }
+        this.selectedViewIndex = -1;
+        this.advanceSelection(false, true, true);
+        return true;
+      }
+      if (!this.selectedButton) {
+        // Moving up from no selection in the list or the buttons, back
+        // down to the last button.
+        this.advanceSelection(false, true, true);
+        return true;
+      }
+      if (this.selectedButtonIndex == 0) {
+        // Moving up from the buttons to the bottom of the list.
+        this.selectedButton = null;
+        return false;
+      }
+      // Moving up/left within the buttons.
+      this.advanceSelection(false, true, false);
+      return true;
+    }
+
+    if (event.keyCode == KeyboardEvent.DOM_VK_DOWN) {
+      if (event.altKey) {
+        // Keep the currently selected result in the list (if any) as a
+        // secondary "alt" selection and move the selection down within
+        // the buttons.
+        this.advanceSelection(true, false, false);
+        return true;
+      }
+      if (numListItems == 0) {
+        this.advanceSelection(true, true, false);
+        return true;
+      }
+      if (
+        this.selectedViewIndex >= 0 &&
+        this.selectedViewIndex < numListItems - 1
+      ) {
+        // Moving down within the list.  The autocomplete controller
+        // should handle this case.  A button may be selected, so null it.
+        this.selectedButton = null;
+        return false;
+      }
+      if (this.selectedViewIndex == numListItems - 1) {
+        // Moving down from the last item in the list to the buttons.
+        if (!allowEmptySelection) {
+          this.selectedViewIndex = -1;
+          if (this.textbox && typeof textboxUserValue == "string") {
+            this.textbox.value = textboxUserValue;
+          }
+        }
+        this.selectedButtonIndex = 0;
+        if (allowEmptySelection) {
+          // Let the autocomplete controller remove selection in the list
+          // and revert the typed text in the textbox.
+          return false;
+        }
+        return true;
+      }
+      if (this.selectedButton) {
+        let buttons = this.getSelectableButtons(true);
+        if (this.selectedButtonIndex == buttons.length - 1) {
+          // Moving down from the buttons back up to the top of the list.
+          this.selectedButton = null;
+          if (allowEmptySelection) {
+            // Prevent the selection from wrapping around to the top of
+            // the list by returning true, since the list currently has no
+            // selection.  Nothing should be selected after handling this
+            // Down key.
+            return true;
+          }
+          return false;
+        }
+        // Moving down/right within the buttons.
+        this.advanceSelection(true, true, false);
+        return true;
+      }
+      return false;
+    }
+
+    if (event.keyCode == KeyboardEvent.DOM_VK_LEFT) {
+      if (
+        this.selectedButton &&
+        this.selectedButton.engine &&
+        !this.disableOneOffsHorizontalKeyNavigation
+      ) {
+        // Moving left within the buttons.
+        this.advanceSelection(false, true, true);
+        return true;
+      }
+      return false;
+    }
+
+    if (event.keyCode == KeyboardEvent.DOM_VK_RIGHT) {
+      if (
+        this.selectedButton &&
+        this.selectedButton.engine &&
+        !this.disableOneOffsHorizontalKeyNavigation
+      ) {
+        // Moving right within the buttons.
+        this.advanceSelection(true, true, true);
+        return true;
+      }
+      return false;
+    }
+
+    return false;
+  }
+
+  /**
+   * Determines if the target of the event is a one-off button or
+   * context menu on a one-off button.
+   *
+   * @param {Event} event
+   *        An event, like a click on a one-off button.
+   * @returns {boolean} True if telemetry was recorded and false if not.
+   */
+  eventTargetIsAOneOff(event) {
+    if (!event) {
+      return false;
+    }
+
+    let target = event.originalTarget;
+
+    if (KeyboardEvent.isInstance(event) && this.selectedButton) {
+      return true;
+    }
+    if (
+      MouseEvent.isInstance(event) &&
+      target.classList.contains("searchbar-engine-one-off-item")
+    ) {
+      return true;
+    }
+    if (
+      this.window.XULCommandEvent.isInstance(event) &&
+      target.classList.contains("search-one-offs-context-open-in-new-tab")
+    ) {
+      return true;
+    }
+
+    return false;
+  }
+
+  // Methods for subclasses to override
+
+  /**
+   * @returns {boolean} True if the one-offs are connected to a view.
+   */
+  get hasView() {
+    return !!this.popup;
+  }
+
+  /**
+   * @returns {boolean} True if the view is open.
+   */
+  get isViewOpen() {
+    return this.popup && this.popup.popupOpen;
+  }
+
+  /**
+   * @returns {number} The selected index in the view or -1 if no selection.
+   */
+  get selectedViewIndex() {
+    return this.popup.selectedIndex;
+  }
+
+  /**
+   * Sets the selected index in the view.
+   *
+   * @param {number} val
+   *        The selected index or -1 if no selection.
+   */
+  set selectedViewIndex(val) {
+    this.popup.selectedIndex = val;
+  }
+
+  /**
+   * Closes the view.
+   */
+  closeView() {
+    this.popup.hidePopup();
+  }
+
+  /**
+   * Called when a one-off is clicked or the "Search in New Tab" context menu
+   * item is picked.  This is not called for the settings button.
+   *
+   * @param {event} event
+   *        The event that triggered the pick.
+   * @param {nsISearchEngine|SearchEngine} engine
+   *        The engine that was picked.
+   * @param {boolean} forceNewTab
+   *        True if the search results page should be loaded in a new tab.
+   */
+  handleSearchCommand(event, engine, forceNewTab = false) {
+    let { where, params } = this._whereToOpen(event, forceNewTab);
+    this.popup.handleOneOffSearch(event, engine, where, params);
+  }
+
+  /**
+   * Sets the tooltip for a one-off button with an engine.  This should set
+   * either the `tooltiptext` attribute or the relevant l10n ID.
+   *
+   * @param {element} button
+   *        The one-off button.
+   */
+  setTooltipForEngineButton(button) {
+    button.setAttribute("tooltiptext", button.engine.name);
+  }
+
+  // Event handlers below.
+
+  _on_mousedown(event) {
+    // This is necessary to prevent the input from losing focus and closing the
+    // popup. Unfortunately it also has the side effect of preventing the
+    // buttons from receiving the `:active` pseudo-class.
+    event.preventDefault();
+  }
+
+  _on_click(event) {
+    if (event.button == 2) {
+      return; // ignore right clicks.
+    }
+
+    let button = event.originalTarget;
+    let engine = button.engine;
+
+    if (!engine) {
+      return;
+    }
+
+    // Select the clicked button so that consumers can easily tell which
+    // button was acted on.
+    this.selectedButton = button;
+    this.handleSearchCommand(event, engine);
+  }
+
+  _on_command(event) {
+    let target = event.target;
+
+    if (target == this.settingsButton) {
+      this.window.openPreferences("paneSearch");
+
+      // If the preference tab was already selected, the panel doesn't
+      // close itself automatically.
+      this.closeView();
+      return;
+    }
+
+    if (target.classList.contains("searchbar-engine-one-off-add-engine")) {
+      // On success, hide the panel and tell event listeners to reshow it to
+      // show the new engine.
+      lazy.SearchUIUtils.addOpenSearchEngine(
+        target.getAttribute("uri"),
+        target.getAttribute("image"),
+        this.window.gBrowser.selectedBrowser.browsingContext
+      )
+        .then(result => {
+          if (result) {
+            this._rebuild();
+          }
+        })
+        .catch(console.error);
+      return;
+    }
+
+    if (target.classList.contains("search-one-offs-context-open-in-new-tab")) {
+      // Select the context-clicked button so that consumers can easily
+      // tell which button was acted on.
+      this.selectedButton = target.closest("menupopup")._triggerButton;
+      this.handleSearchCommand(event, this.selectedButton.engine, true);
+    }
+
+    const isPrivateButton = target.classList.contains(
+      "search-one-offs-context-set-default-private"
+    );
+    if (
+      target.classList.contains("search-one-offs-context-set-default") ||
+      isPrivateButton
+    ) {
+      const engineType = isPrivateButton
+        ? "defaultPrivateEngine"
+        : "defaultEngine";
+      let currentEngine = Services.search[engineType];
+
+      const isPrivateWin = lazy.PrivateBrowsingUtils.isWindowPrivate(
+        this.window
+      );
+      let button = target.closest("menupopup")._triggerButton;
+      // We're about to replace this, so it must be stored now.
+      let newDefaultEngine = button.engine;
+      if (
+        !this.getAttribute("includecurrentengine") &&
+        isPrivateButton == isPrivateWin
+      ) {
+        // Make the target button of the context menu reflect the current
+        // search engine first. Doing this as opposed to rebuilding all the
+        // one-off buttons avoids flicker.
+        let uri = "chrome://browser/skin/search-engine-placeholder.png";
+        if (currentEngine.iconURI) {
+          uri = currentEngine.iconURI.spec;
+        }
+        button.setAttribute("image", uri);
+        button.setAttribute("tooltiptext", currentEngine.name);
+        button.engine = currentEngine;
+      }
+
+      if (isPrivateButton) {
+        Services.search.setDefaultPrivate(
+          newDefaultEngine,
+          Ci.nsISearchService.CHANGE_REASON_USER_SEARCHBAR_CONTEXT
+        );
+      } else {
+        Services.search.setDefault(
+          newDefaultEngine,
+          Ci.nsISearchService.CHANGE_REASON_USER_SEARCHBAR_CONTEXT
+        );
+      }
+    }
+  }
+
+  _on_contextmenu(event) {
+    let target = event.originalTarget;
+    // Prevent the context menu from appearing except on the one off buttons.
+    if (
+      !target.classList.contains("searchbar-engine-one-off-item") ||
+      target.classList.contains("search-setting-button")
+    ) {
+      event.preventDefault();
+      return;
+    }
+    this.contextMenuPopup
+      .querySelector(".search-one-offs-context-set-default")
+      .setAttribute(
+        "disabled",
+        target.engine == Services.search.defaultEngine.wrappedJSObject
+      );
+
+    const privateDefaultItem = this.contextMenuPopup.querySelector(
+      ".search-one-offs-context-set-default-private"
+    );
+
+    if (
+      Services.prefs.getBoolPref(
+        "browser.search.separatePrivateDefault.ui.enabled",
+        false
+      ) &&
+      Services.prefs.getBoolPref("browser.search.separatePrivateDefault", false)
+    ) {
+      privateDefaultItem.hidden = false;
+      privateDefaultItem.setAttribute(
+        "disabled",
+        target.engine == Services.search.defaultPrivateEngine.wrappedJSObject
+      );
+    } else {
+      privateDefaultItem.hidden = true;
+    }
+
+    // When a context menu is opened on a one-off button, this is set to the
+    // button to be used for the command.
+    this.contextMenuPopup._triggerButton = target;
+    this.contextMenuPopup.openPopupAtScreen(event.screenX, event.screenY, true);
+    event.preventDefault();
+  }
+
+  _on_input(event) {
+    // Allow the consumer's input to override its value property with
+    // a oneOffSearchQuery property.  That way if the value is not
+    // actually what the user typed (e.g., it's autofilled, or it's a
+    // mozaction URI), the consumer has some way of providing it.
+    this.query = event.target.oneOffSearchQuery || event.target.value;
+  }
+
+  _on_popupshowing() {
+    this._rebuild();
+  }
+
+  _on_popuphidden() {
+    this.selectedButton = null;
+  }
+}