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

  overflow: auto;
  padding: 0 0.25em;
}
body.chat #chat-messages-wrapper.loading > * {
  /* An attempt at reducing flicker when loading lots of messages. */
  visibility: hidden;
}
body.chat #chat-messages-wrapper.connection-error {





  border-bottom: thin dotted red;
}

body.chat div.content {
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column-reverse;