Readarr/src/UI/Cells/SelectAllCell.js

'use strict';
define(
    [
        'jquery',
        'underscore',
        'backgrid.selectall'
    ], function ($, _, BackgridSelectAll) {
        return BackgridSelectAll.extend({

            enterEditMode: function (e) {
                if (e.shiftKey && this.model.collection.lastToggled) {
                    this._selectRange();
                }

                var checked = $(e.target).prop('checked');

                this.model.collection.lastToggled = this.model;
                this.model.collection.checked = checked;
            },

            onChange: function (e) {
                var checked = $(e.target).prop('checked');
                this.$el.parent().toggleClass('selected', checked);
                this.model.trigger('backgrid:selected', this.model, checked);
            },

            _selectRange: function () {
                var collection = this.model.collection;
                var lastToggled = collection.lastToggled;
                var checked = collection.checked;

                var currentIndex = collection.indexOf(this.model);
                var lastIndex = collection.indexOf(lastToggled);

                var low = Math.min(currentIndex, lastIndex);
                var high = Math.max(currentIndex, lastIndex);
                var range = _.range(low + 1, high);

                _.each(range, function (index) {
                    var model = collection.at(index);

                    model.trigger('backgrid:select', model, checked);
                });

                this.model.collection.lastToggled = undefined;
                this.model.collection.checked = undefined;
            }
        });
    });