// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @fileoverview Definition of the PopupBase class.
 *
 */

goog.provide('goog.ui.PopupBase');
goog.provide('goog.ui.PopupBase.EventType');
goog.provide('goog.ui.PopupBase.Type');

goog.require('goog.Timer');
goog.require('goog.array');
goog.require('goog.dom');
goog.require('goog.dom.TagName');
goog.require('goog.events');
goog.require('goog.events.EventHandler');
goog.require('goog.events.EventTarget');
goog.require('goog.events.EventType');
goog.require('goog.events.KeyCodes');
goog.require('goog.fx.Transition');
goog.require('goog.style');
goog.require('goog.userAgent');



/**
 * The PopupBase class provides functionality for showing and hiding a generic
 * container element. It also provides the option for hiding the popup element
 * if the user clicks outside the popup or the popup loses focus.
 *
 * @constructor
 * @extends {goog.events.EventTarget}
 * @param {Element=} opt_element A DOM element for the popup.
 * @param {goog.ui.PopupBase.Type=} opt_type Type of popup.
 */
goog.ui.PopupBase = function(opt_element, opt_type) {
  goog.events.EventTarget.call(this);

  /**
   * An event handler to manage the events easily
   * @type {goog.events.EventHandler<!goog.ui.PopupBase>}
   * @private
   */
  this.handler_ = new goog.events.EventHandler(this);

  this.setElement(opt_element || null);
  if (opt_type) {
    this.setType(opt_type);
  }
};
goog.inherits(goog.ui.PopupBase, goog.events.EventTarget);
goog.tagUnsealableClass(goog.ui.PopupBase);


/**
 * Constants for type of Popup
 * @enum {string}
 */
goog.ui.PopupBase.Type = {
  TOGGLE_DISPLAY: 'toggle_display',
  MOVE_OFFSCREEN: 'move_offscreen'
};


/**
 * The popup dom element that this Popup wraps.
 * @type {Element}
 * @private
 */
goog.ui.PopupBase.prototype.element_ = null;


/**
 * Whether the Popup dismisses itself it the user clicks outside of it or the
 * popup loses focus
 * @type {boolean}
 * @private
 */
goog.ui.PopupBase.prototype.autoHide_ = true;


/**
 * Mouse events without auto hide partner elements will not dismiss the popup.
 * @type {Array<Element>}
 * @private
 */
goog.ui.PopupBase.prototype.autoHidePartners_ = null;


/**
 * Clicks outside the popup but inside this element will cause the popup to
 * hide if autoHide_ is true. If this is null, then the entire document is used.
 * For example, you can use a body-size div so that clicks on the browser
 * scrollbar do not dismiss the popup.
 * @type {Element}
 * @private
 */
goog.ui.PopupBase.prototype.autoHideRegion_ = null;


/**
 * Whether the popup is currently being shown.
 * @type {boolean}
 * @private
 */
goog.ui.PopupBase.prototype.isVisible_ = false;


/**
 * Whether the popup should hide itself asynchrously. This was added because
 * there are cases where hiding the element in mouse down handler in IE can
 * cause textinputs to get into a bad state if the element that had focus is
 * hidden.
 * @type {boolean}
 * @private
 */
goog.ui.PopupBase.prototype.shouldHideAsync_ = false;


/**
 * The time when the popup was last shown.
 * @type {number}
 * @private
 */
goog.ui.PopupBase.prototype.lastShowTime_ = -1;


/**
 * The time when the popup was last hidden.
 * @type {number}
 * @private
 */
goog.ui.PopupBase.prototype.lastHideTime_ = -1;


/**
 * Whether to hide when the escape key is pressed.
 * @type {boolean}
 * @private
 */
goog.ui.PopupBase.prototype.hideOnEscape_ = false;


/**
 * Whether to enable cross-iframe dismissal.
 * @type {boolean}
 * @private
 */
goog.ui.PopupBase.prototype.enableCrossIframeDismissal_ = true;


/**
 * The type of popup
 * @type {goog.ui.PopupBase.Type}
 * @private
 */
goog.ui.PopupBase.prototype.type_ = goog.ui.PopupBase.Type.TOGGLE_DISPLAY;


/**
 * Transition to play on showing the popup.
 * @type {goog.fx.Transition|undefined}
 * @private
 */
goog.ui.PopupBase.prototype.showTransition_;


/**
 * Transition to play on hiding the popup.
 * @type {goog.fx.Transition|undefined}
 * @private
 */
goog.ui.PopupBase.prototype.hideTransition_;


/**
 * Constants for event type fired by Popup
 *
 * @enum {string}
 */
goog.ui.PopupBase.EventType = {
  BEFORE_SHOW: 'beforeshow',
  SHOW: 'show',
  BEFORE_HIDE: 'beforehide',
  HIDE: 'hide'
};


/**
 * A time in ms used to debounce events that happen right after each other.
 *
 * A note about why this is necessary. There are two cases to consider.
 * First case, a popup will usually see a focus event right after it's launched
 * because it's typical for it to be launched in a mouse-down event which will
 * then move focus to the launching button. We don't want to think this is a
 * separate user action moving focus. Second case, a user clicks on the
 * launcher button to close the menu. In that case, we'll close the menu in the
 * focus event and then show it again because of the mouse down event, even
 * though the intention is to just close the menu. This workaround appears to
 * be the least intrusive fix.
 *
 * @type {number}
 */
goog.ui.PopupBase.DEBOUNCE_DELAY_MS = 150;


/**
 * @return {goog.ui.PopupBase.Type} The type of popup this is.
 */
goog.ui.PopupBase.prototype.getType = function() {
  return this.type_;
};


/**
 * Specifies the type of popup to use.
 *
 * @param {goog.ui.PopupBase.Type} type Type of popup.
 */
goog.ui.PopupBase.prototype.setType = function(type) {
  this.type_ = type;
};


/**
 * Returns whether the popup should hide itself asynchronously using a timeout
 * instead of synchronously.
 * @return {boolean} Whether to hide async.
 */
goog.ui.PopupBase.prototype.shouldHideAsync = function() {
  return this.shouldHideAsync_;
};


/**
 * Sets whether the popup should hide itself asynchronously using a timeout
 * instead of synchronously.
 * @param {boolean} b Whether to hide async.
 */
goog.ui.PopupBase.prototype.setShouldHideAsync = function(b) {
  this.shouldHideAsync_ = b;
};


/**
 * Returns the dom element that should be used for the popup.
 *
 * @return {Element} The popup element.
 */
goog.ui.PopupBase.prototype.getElement = function() {
  return this.element_;
};


/**
 * Specifies the dom element that should be used for the popup.
 *
 * @param {Element} elt A DOM element for the popup.
 */
goog.ui.PopupBase.prototype.setElement = function(elt) {
  this.ensureNotVisible_();
  this.element_ = elt;
};


/**
 * Returns whether the Popup dismisses itself when the user clicks outside of
 * it.
 * @return {boolean} Whether the Popup autohides on an external click.
 */
goog.ui.PopupBase.prototype.getAutoHide = function() {
  return this.autoHide_;
};


/**
 * Sets whether the Popup dismisses itself when the user clicks outside of it.
 * @param {boolean} autoHide Whether to autohide on an external click.
 */
goog.ui.PopupBase.prototype.setAutoHide = function(autoHide) {
  this.ensureNotVisible_();
  this.autoHide_ = autoHide;
};


/**
 * Mouse events that occur within an autoHide partner will not hide a popup
 * set to autoHide.
 * @param {!Element} partner The auto hide partner element.
 */
goog.ui.PopupBase.prototype.addAutoHidePartner = function(partner) {
  if (!this.autoHidePartners_) {
    this.autoHidePartners_ = [];
  }

  goog.array.insert(this.autoHidePartners_, partner);
};


/**
 * Removes a previously registered auto hide partner.
 * @param {!Element} partner The auto hide partner element.
 */
goog.ui.PopupBase.prototype.removeAutoHidePartner = function(partner) {
  if (this.autoHidePartners_) {
    goog.array.remove(this.autoHidePartners_, partner);
  }
};


/**
 * @return {boolean} Whether the Popup autohides on the escape key.
 */
goog.ui.PopupBase.prototype.getHideOnEscape = function() {
  return this.hideOnEscape_;
};


/**
 * Sets whether the Popup dismisses itself on the escape key.
 * @param {boolean} hideOnEscape Whether to autohide on the escape key.
 */
goog.ui.PopupBase.prototype.setHideOnEscape = function(hideOnEscape) {
  this.ensureNotVisible_();
  this.hideOnEscape_ = hideOnEscape;
};


/**
 * @return {boolean} Whether cross iframe dismissal is enabled.
 */
goog.ui.PopupBase.prototype.getEnableCrossIframeDismissal = function() {
  return this.enableCrossIframeDismissal_;
};


/**
 * Sets whether clicks in other iframes should dismiss this popup.  In some
 * cases it should be disabled, because it can cause spurious
 * @param {boolean} enable Whether to enable cross iframe dismissal.
 */
goog.ui.PopupBase.prototype.setEnableCrossIframeDismissal = function(enable) {
  this.enableCrossIframeDismissal_ = enable;
};


/**
 * Returns the region inside which the Popup dismisses itself when the user
 * clicks, or null if it's the entire document.
 * @return {Element} The DOM element for autohide, or null if it hasn't been
 *     set.
 */
goog.ui.PopupBase.prototype.getAutoHideRegion = function() {
  return this.autoHideRegion_;
};


/**
 * Sets the region inside which the Popup dismisses itself when the user
 * clicks.
 * @param {Element} element The DOM element for autohide.
 */
goog.ui.PopupBase.prototype.setAutoHideRegion = function(element) {
  this.autoHideRegion_ = element;
};


/**
 * Sets transition animation on showing and hiding the popup.
 * @param {goog.fx.Transition=} opt_showTransition Transition to play on
 *     showing the popup.
 * @param {goog.fx.Transition=} opt_hideTransition Transition to play on
 *     hiding the popup.
 */
goog.ui.PopupBase.prototype.setTransition = function(
    opt_showTransition, opt_hideTransition) {
  this.showTransition_ = opt_showTransition;
  this.hideTransition_ = opt_hideTransition;
};


/**
 * Returns the time when the popup was last shown.
 *
 * @return {number} time in ms since epoch when the popup was last shown, or
 * -1 if the popup was never shown.
 */
goog.ui.PopupBase.prototype.getLastShowTime = function() {
  return this.lastShowTime_;
};


/**
 * Returns the time when the popup was last hidden.
 *
 * @return {number} time in ms since epoch when the popup was last hidden, or
 * -1 if the popup was never hidden or is currently showing.
 */
goog.ui.PopupBase.prototype.getLastHideTime = function() {
  return this.lastHideTime_;
};


/**
 * Returns the event handler for the popup. All event listeners belonging to
 * this handler are removed when the tooltip is hidden. Therefore,
 * the recommended usage of this handler is to listen on events in
 * {@link #onShow}.
 * @return {goog.events.EventHandler<T>} Event handler for this popup.
 * @protected
 * @this {T}
 * @template T
 */
goog.ui.PopupBase.prototype.getHandler = function() {
  // As the template type is unbounded, narrow the "this" type
  var self = /** @type {!goog.ui.PopupBase} */ (this);

  return self.handler_;
};


/**
 * Helper to throw exception if the popup is showing.
 * @private
 */
goog.ui.PopupBase.prototype.ensureNotVisible_ = function() {
  if (this.isVisible_) {
    throw new Error('Can not change this state of the popup while showing.');
  }
};


/**
 * Returns whether the popup is currently visible.
 *
 * @return {boolean} whether the popup is currently visible.
 */
goog.ui.PopupBase.prototype.isVisible = function() {
  return this.isVisible_;
};


/**
 * Returns whether the popup is currently visible or was visible within about
 * 150 ms ago. This is used by clients to handle a very specific, but common,
 * popup scenario. The button that launches the popup should close the popup
 * on mouse down if the popup is alrady open. The problem is that the popup
 * closes itself during the capture phase of the mouse down and thus the button
 * thinks it's hidden and this should show it again. This method provides a
 * good heuristic for clients. Typically in their event handler they will have
 * code that is:
 *
 * if (menu.isOrWasRecentlyVisible()) {
 *   menu.setVisible(false);
 * } else {
 *   ... // code to position menu and initialize other state
 *   menu.setVisible(true);
 * }
 * @return {boolean} Whether the popup is currently visible or was visible
 *     within about 150 ms ago.
 */
goog.ui.PopupBase.prototype.isOrWasRecentlyVisible = function() {
  return this.isVisible_ ||
      (goog.now() - this.lastHideTime_ < goog.ui.PopupBase.DEBOUNCE_DELAY_MS);
};


/**
 * Sets whether the popup should be visible. After this method
 * returns, isVisible() will always return the new state, even if
 * there is a transition.
 *
 * @param {boolean} visible Desired visibility state.
 */
goog.ui.PopupBase.prototype.setVisible = function(visible) {
  // Make sure that any currently running transition is stopped.
  if (this.showTransition_) this.showTransition_.stop();
  if (this.hideTransition_) this.hideTransition_.stop();

  if (visible) {
    this.show_();
  } else {
    this.hide_();
  }
};


/**
 * Repositions the popup according to the current state.
 * Should be overriden by subclases.
 */
goog.ui.PopupBase.prototype.reposition = goog.nullFunction;


/**
 * Does the work to show the popup.
 * @private
 */
goog.ui.PopupBase.prototype.show_ = function() {
  // Ignore call if we are already showing.
  if (this.isVisible_) {
    return;
  }

  // Give derived classes and handlers a chance to customize popup.
  if (!this.onBeforeShow()) {
    return;
  }

  // Allow callers to set the element in the BEFORE_SHOW event.
  if (!this.element_) {
    throw new Error(
        'Caller must call setElement before trying to show the popup');
  }

  // Call reposition after onBeforeShow, as it may change the style and/or
  // content of the popup and thereby affecting the size which is used for the
  // viewport calculation.
  this.reposition();

  var doc = goog.dom.getOwnerDocument(this.element_);

  if (this.hideOnEscape_) {
    // Handle the escape keys.  Listen in the capture phase so that we can
    // stop the escape key from propagating to other elements.  For example,
    // if there is a popup within a dialog box, we want the popup to be
    // dismissed first, rather than the dialog.
    this.handler_.listen(
        doc, goog.events.EventType.KEYDOWN, this.onDocumentKeyDown_, true);
  }

  // Set up event handlers.
  if (this.autoHide_) {
    // Even if the popup is not in the focused document, we want to
    // close it on mousedowns in the document it's in.
    this.handler_.listen(
        doc, goog.events.EventType.MOUSEDOWN, this.onDocumentMouseDown_, true);

    if (goog.userAgent.IE) {
      // We want to know about deactivates/mousedowns on the document with focus
      // The top-level document won't get a deactivate event if the focus is
      // in an iframe and the deactivate fires within that iframe.
      // The active element in the top-level document will remain the iframe
      // itself.
      var activeElement;

      try {
        activeElement = doc.activeElement;
      } catch (e) {
        // There is an IE browser bug which can cause just the reading of
        // document.activeElement to throw an Unspecified Error.  This
        // may have to do with loading a popup within a hidden iframe.
      }
      while (activeElement &&
             activeElement.nodeName == goog.dom.TagName.IFRAME) {

        try {
          var tempDoc = goog.dom.getFrameContentDocument(activeElement);
        } catch (e) {
          // The frame is on a different domain that its parent document
          // This way, we grab the lowest-level document object we can get
          // a handle on given cross-domain security.
          break;
        }
        doc = tempDoc;
        activeElement = doc.activeElement;
      }

      // Handle mousedowns in the focused document in case the user clicks
      // on the activeElement (in which case the popup should hide).
      this.handler_.listen(
          doc, goog.events.EventType.MOUSEDOWN, this.onDocumentMouseDown_,
          true);

      // If the active element inside the focused document changes, then
      // we probably need to hide the popup.
      this.handler_.listen(
          doc, goog.events.EventType.DEACTIVATE, this.onDocumentBlur_);

    } else {
      this.handler_.listen(
          doc, goog.events.EventType.BLUR, this.onDocumentBlur_);
    }
  }

  // Make the popup visible.
  if (this.type_ == goog.ui.PopupBase.Type.TOGGLE_DISPLAY) {
    this.showPopupElement();
  } else if (this.type_ == goog.ui.PopupBase.Type.MOVE_OFFSCREEN) {
    this.reposition();
  }
  this.isVisible_ = true;

  this.lastShowTime_ = goog.now();
  this.lastHideTime_ = -1;

  // If there is transition to play, we play it and fire SHOW event after
  // the transition is over.
  if (this.showTransition_) {
    goog.events.listenOnce(
        /** @type {!goog.events.EventTarget} */ (this.showTransition_),
        goog.fx.Transition.EventType.END, this.onShow, false, this);
    this.showTransition_.play();
  } else {
    // Notify derived classes and handlers.
    this.onShow();
  }
};


/**
 * Hides the popup. This call is idempotent.
 *
 * @param {?Node=} opt_target Target of the event causing the hide.
 * @return {boolean} Whether the popup was hidden and not cancelled.
 * @private
 */
goog.ui.PopupBase.prototype.hide_ = function(opt_target) {
  // Give derived classes and handlers a chance to cancel hiding.
  if (!this.isVisible_ || !this.onBeforeHide(opt_target)) {
    return false;
  }

  // Remove any listeners we attached when showing the popup.
  if (this.handler_) {
    this.handler_.removeAll();
  }

  // Set visibility to hidden even if there is a transition.
  this.isVisible_ = false;
  this.lastHideTime_ = goog.now();

  // If there is transition to play, we play it and only hide the element
  // (and fire HIDE event) after the transition is over.
  if (this.hideTransition_) {
    goog.events.listenOnce(
        /** @type {!goog.events.EventTarget} */ (this.hideTransition_),
        goog.fx.Transition.EventType.END,
        goog.partial(this.continueHidingPopup_, opt_target), false, this);
    this.hideTransition_.play();
  } else {
    this.continueHidingPopup_(opt_target);
  }

  return true;
};


/**
 * Continues hiding the popup. This is a continuation from hide_. It is
 * a separate method so that we can add a transition before hiding.
 * @param {?Node=} opt_target Target of the event causing the hide.
 * @private
 */
goog.ui.PopupBase.prototype.continueHidingPopup_ = function(opt_target) {
  // Hide the popup.
  if (this.type_ == goog.ui.PopupBase.Type.TOGGLE_DISPLAY) {
    if (this.shouldHideAsync_) {
      goog.Timer.callOnce(this.hidePopupElement, 0, this);
    } else {
      this.hidePopupElement();
    }
  } else if (this.type_ == goog.ui.PopupBase.Type.MOVE_OFFSCREEN) {
    this.moveOffscreen_();
  }

  // Notify derived classes and handlers.
  this.onHide(opt_target);
};


/**
 * Shows the popup element.
 * @protected
 */
goog.ui.PopupBase.prototype.showPopupElement = function() {
  this.element_.style.visibility = 'visible';
  goog.style.setElementShown(this.element_, true);
};


/**
 * Hides the popup element.
 * @protected
 */
goog.ui.PopupBase.prototype.hidePopupElement = function() {
  this.element_.style.visibility = 'hidden';
  goog.style.setElementShown(this.element_, false);
};


/**
 * Hides the popup by moving it offscreen.
 *
 * @private
 */
goog.ui.PopupBase.prototype.moveOffscreen_ = function() {
  this.element_.style.top = '-10000px';
};


/**
 * Called before the popup is shown. Derived classes can override to hook this
 * event but should make sure to call the parent class method.
 *
 * @return {boolean} If anyone called preventDefault on the event object (or
 *     if any of the handlers returns false this will also return false.
 * @protected
 */
goog.ui.PopupBase.prototype.onBeforeShow = function() {
  return this.dispatchEvent(goog.ui.PopupBase.EventType.BEFORE_SHOW);
};


/**
 * Called after the popup is shown. Derived classes can override to hook this
 * event but should make sure to call the parent class method.
 * @protected
 */
goog.ui.PopupBase.prototype.onShow = function() {
  this.dispatchEvent(goog.ui.PopupBase.EventType.SHOW);
};


/**
 * Called before the popup is hidden. Derived classes can override to hook this
 * event but should make sure to call the parent class method.
 *
 * @param {?Node=} opt_target Target of the event causing the hide.
 * @return {boolean} If anyone called preventDefault on the event object (or
 *     if any of the handlers returns false this will also return false.
 * @protected
 */
goog.ui.PopupBase.prototype.onBeforeHide = function(opt_target) {
  return this.dispatchEvent(
      {type: goog.ui.PopupBase.EventType.BEFORE_HIDE, target: opt_target});
};


/**
 * Called after the popup is hidden. Derived classes can override to hook this
 * event but should make sure to call the parent class method.
 * @param {?Node=} opt_target Target of the event causing the hide.
 * @protected
 */
goog.ui.PopupBase.prototype.onHide = function(opt_target) {
  this.dispatchEvent(
      {type: goog.ui.PopupBase.EventType.HIDE, target: opt_target});
};


/**
 * Mouse down handler for the document on capture phase. Used to hide the
 * popup for auto-hide mode.
 *
 * @param {goog.events.BrowserEvent} e The event object.
 * @private
 */
goog.ui.PopupBase.prototype.onDocumentMouseDown_ = function(e) {
  var target = e.target;

  if (!goog.dom.contains(this.element_, target) &&
      !this.isOrWithinAutoHidePartner_(target) &&
      this.isWithinAutoHideRegion_(target) && !this.shouldDebounce_()) {
    // Mouse click was outside popup and partners, so hide.
    this.hide_(target);
  }
};


/**
 * Handles key-downs on the document to handle the escape key.
 *
 * @param {goog.events.BrowserEvent} e The event object.
 * @private
 */
goog.ui.PopupBase.prototype.onDocumentKeyDown_ = function(e) {
  if (e.keyCode == goog.events.KeyCodes.ESC) {
    if (this.hide_(e.target)) {
      // Eat the escape key, but only if this popup was actually closed.
      e.preventDefault();
      e.stopPropagation();
    }
  }
};


/**
 * Deactivate handler(IE) and blur handler (other browsers) for document.
 * Used to hide the popup for auto-hide mode.
 *
 * @param {goog.events.BrowserEvent} e The event object.
 * @private
 */
goog.ui.PopupBase.prototype.onDocumentBlur_ = function(e) {
  if (!this.enableCrossIframeDismissal_) {
    return;
  }

  var doc = goog.dom.getOwnerDocument(this.element_);

  // Ignore blur events if the active element is still inside the popup or if
  // there is no longer an active element.  For example, a widget like a
  // goog.ui.Button might programatically blur itself before losing tabIndex.
  if (typeof document.activeElement != 'undefined') {
    var activeElement = doc.activeElement;
    if (!activeElement || goog.dom.contains(this.element_, activeElement) ||
        activeElement.tagName == goog.dom.TagName.BODY) {
      return;
    }

    // Ignore blur events not for the document itself in non-IE browsers.
  } else if (e.target != doc) {
    return;
  }

  // Debounce the initial focus move.
  if (this.shouldDebounce_()) {
    return;
  }

  this.hide_();
};


/**
 * @param {Node} element The element to inspect.
 * @return {boolean} Returns true if the given element is one of the auto hide
 *     partners or is a child of an auto hide partner.
 * @private
 */
goog.ui.PopupBase.prototype.isOrWithinAutoHidePartner_ = function(element) {
  return goog.array.some(this.autoHidePartners_ || [], function(partner) {
    return element === partner || goog.dom.contains(partner, element);
  });
};


/**
 * @param {Node} element The element to inspect.
 * @return {boolean} Returns true if the element is contained within
 *     the autohide region. If unset, the autohide region is the entire
 *     entire document.
 * @private
 */
goog.ui.PopupBase.prototype.isWithinAutoHideRegion_ = function(element) {
  return this.autoHideRegion_ ?
      goog.dom.contains(this.autoHideRegion_, element) :
      true;
};


/**
 * @return {boolean} Whether the time since last show is less than the debounce
 *     delay.
 * @private
 */
goog.ui.PopupBase.prototype.shouldDebounce_ = function() {
  return goog.now() - this.lastShowTime_ < goog.ui.PopupBase.DEBOUNCE_DELAY_MS;
};


/** @override */
goog.ui.PopupBase.prototype.disposeInternal = function() {
  goog.ui.PopupBase.base(this, 'disposeInternal');
  this.handler_.dispose();
  goog.dispose(this.showTransition_);
  goog.dispose(this.hideTransition_);
  delete this.element_;
  delete this.handler_;
  delete this.autoHidePartners_;
};