Fossil

  PS.e.previewModeLabel.innerText =
    PS.renderModeLabels[PS.renderModes[PS.renderModes.selectedIndex]];

  /**
     The 'pikchr-ready' event is fired (with no payload) when the
     wasm module has finished loading. */
  PS.addMsgHandler('pikchr-ready', function(event){
    PS.clearMsgHandlers('pikchr-ready');
    F.page.onPikchrshowLoaded(event.data);
  });

  /**
     Performs all app initialization which must wait until after the
     worker module is loaded. This function removes itself when it's
     called.
  */
  F.page.onPikchrshowLoaded = function(pikchrVersion){
    delete this.onPikchrshowLoaded;
    // Unhide all elements which start out hidden
    EAll('.initially-hidden').forEach((e)=>e.classList.remove('initially-hidden'));
    const taInput = E('#input');
    const btnClearIn = E('#btn-clear');
    btnClearIn.addEventListener('click',function(){
      taInput.value = '';

         link in the forum. */
      const src = window.sessionStorage.getItem('pikchr-xfer');
      if( src && (new URL(self.location.href).searchParams).has('fromSession') ){
        taInput.value =  src;
        window.sessionStorage.removeItem('pikchr-xfer');
      }
    }
    D.append(E('fieldset.options > div'),
             D.append(D.addClass(D.span(), 'labeled-input'),
                      'pikchr v. '+pikchrVersion));

    PS.e.btnRender.click();

    /** Debounce handler for auto-rendering while typing. */
    const debounceAutoRender = F.debounce(function f(){
      if(!PS._isDirty) return;
      const text = getCurrentText();