function PDFOutlineView_addToggleButton(div) {
      var toggler = document.createElement('div');
      toggler.className = 'outlineItemToggler';
      toggler.onclick = function(event) {
        event.stopPropagation();
        toggler.classList.toggle('outlineItemsHidden');

        if (event.shiftKey) {
          var shouldShowAll = !toggler.classList.contains('outlineItemsHidden');
          this._toggleOutlineItem(div, shouldShowAll);
        }
      }.bind(this);
      div.insertBefore(toggler, div.firstChild);
    }
/**
     * Prepend a button before an outline item which allows the user to toggle
     * the visibility of all outline items at that level.
     *
     * @private
     */
Prepend a button before an outline item which allows the user to toggle
the visibility of all outline items at that level.

@private
Prepend a button before an outline item which allows the user to toggle the visibility of all outline items at that level . @private
function PDFOutlineView_addToggleButton(div) {
      var toggler = document.createElement('div');
      toggler.className = 'outlineItemToggler';
      toggler.onclick = function(event) {
        event.stopPropagation();
        toggler.classList.toggle('outlineItemsHidden');
        if (event.shiftKey) {
          var shouldShowAll = !toggler.classList.contains('outlineItemsHidden');
          this._toggleOutlineItem(div, shouldShowAll);
        }
      }.bind(this);
      div.insertBefore(toggler, div.firstChild);
    }
function PDFOutlineView_addToggleButton ( div ) { var toggler = document . createElement ( 'div' ) ; toggler . className = 'outlineItemToggler' ; toggler . onclick = function ( event ) { event . stopPropagation ( ) ; toggler . classList . toggle ( 'outlineItemsHidden' ) ; if ( event . shiftKey ) { var shouldShowAll = ! toggler . classList . contains ( 'outlineItemsHidden' ) ; this . _toggleOutlineItem ( div , shouldShowAll ) ; } } . bind ( this ) ; div . insertBefore ( toggler , div . firstChild ) ; }
Prepend a button before an outline item which allows the user to toggle
 the visibility of all outline items at that level.
Prepend a button before an outline item which allows the user to toggle the visibility of all outline items at that level .