viewSearch: E1('#chat-search'),
        searchContent: E1('#chat-search-content'),
        btnPreview: E1('#chat-button-preview'),
        views: document.querySelectorAll('.chat-view'),
        activeUserListWrapper: E1('#chat-user-list-wrapper'),
        activeUserList: E1('#chat-user-list'),
        eMsgPollError: undefined /* current connection error MessageMidget */,
        pollErrorMarker: undefined /* element to toggle 'connection-error' CSS class on */
      },
      me: F.user.name,
      mxMsg: F.config.chat.initSize ? -F.config.chat.initSize : -50,
      mnMsg: undefined/*lowest message ID we've seen so far (for history loading)*/,
      pageIsActive: 'visible'===document.visibilityState,
      changesSincePageHidden: 0,
      notificationBubbleColor: 'white',

        maxDelay: 60000 * 5 /* max interval when backing off for
                              connection errors */,
        minDelay: 5000 /* minimum delay time */,
        tidReconnect: undefined /*timer id for reconnection determination*/,
        errCount: 0 /* Current poller connection error count */,
        minErrForNotify: 4 /* Don't warn for connection errors until this
                              many have occurred */,
        skipErrDelay: 3500 /* time to wait/retry for the first minErrForNotify'th
                              connection errors. */,
        randomInterval: function(factor){
          return Math.floor(Math.random() * factor);
        },
        incrDelay: function(){
          if( this.maxDelay > this.currentDelay ){
            if(this.currentDelay < this.minDelay){
              this.currentDelay = this.minDelay + this.randomInterval(this.minDelay);

    if(D.attr(cs.e.inputX,'contenteditable','plaintext-only').isContentEditable){
      cs.$browserHasPlaintextOnly = true;
    }else{
      /* Only the Chrome family supports contenteditable=plaintext-only */
      cs.$browserHasPlaintextOnly = false;
      D.attr(cs.e.inputX,'contenteditable','true');
    }
    cs.e.pollErrorMarker = cs.e.viewMessages;
    cs.animate.$disabled = true;
    F.fetch.beforesend = ()=>cs.ajaxStart();
    F.fetch.aftersend = ()=>cs.ajaxEnd();
    cs.pageTitleOrig = cs.e.pageTitle.innerText;
    const qs = (e)=>document.querySelector(e);
    const argsToArray = function(args){
      return Array.prototype.slice.call(args,0);

           UI message about the outage. */
        let delay;
        D.addClass(Chat.e.pollErrorMarker, 'connection-error');
        if( ++Chat.timer.errCount < Chat.timer.minErrForNotify ){
          if(Chat.beVerbose){
            console.warn("Ignoring polling error #", Chat.timer.errCount);
          }
          delay = Chat.timer.resetDelay(Chat.timer.skipErrDelay);
        } else {
          delay = Chat.timer.incrDelay();
          //console.warn("afterPollFetch Chat.e.eMsgPollError",Chat.e.eMsgPollError);
          const msg = "Poller connection error. Retrying in "+delay+ " ms.";
          /* Replace the current/newest connection error widget. We could also
             just update its body with the new message, but then its timestamp
             never updates. OTOH, if we replace the message, we lose the