Method _delegate

src/dropkick.js:797–836

* @method delegate * @private

( event )

   * @private
   */
  _delegate( event ) {
    var selection, index, firstIndex, lastIndex,
    target = event.target;

    if ( _.hasClass( target, "dk-option-disabled" ) ) {
      return false;
    }

    if ( !this.multiple ) {
      this[ this.isOpen ? "close" : "open" ]();
      if ( _.hasClass( target, "dk-option" ) ) { this.select( target ); }
    } else {
      if ( _.hasClass( target, "dk-option" ) ) {
        selection = window.getSelection();
        if ( selection.type === "Range" ) selection.collapseToStart();

        if ( event.shiftKey ) {
          firstIndex = this.options.indexOf( this.selectedOptions[0] );
          lastIndex = this.options.indexOf( this.selectedOptions[ this.selectedOptions.length - 1 ] );
          index =  this.options.indexOf( target );

          if ( index > firstIndex && index < lastIndex ) index = firstIndex;
          if ( index > lastIndex && lastIndex > firstIndex ) lastIndex = firstIndex;

          this.reset( true );

          if ( lastIndex > index ) {
            while ( index < lastIndex + 1 ) { this.select( index++ ); }
          } else {
            while ( index > lastIndex - 1 ) { this.select( index-- ); }
          }
        } else if ( event.ctrlKey || event.metaKey ) {
          this.select( target );
        } else {
          this.reset( true );
          this.select( target );
        }
      }
    }
  }

  /**
   * @method highlight