ResourceFilter in Sidebar should be configurable with custom selection

[pmiklashevych]

Requested here:
https://www.bryntum.com/forum/viewtopic.php?p=79899#p79899
https://www.bryntum.com/forum/viewtopic.php?p=81630#p81630
https://www.bryntum.com/forum/viewtopic.php?f=51&t=19959

It should be possible to check some of resources by default instead of the whole dataset.

Workaround:
Calendar/examples/basic/app.js

import ResourceFilter from '../../lib/Scheduler/widget/ResourceFilter.js';

class MyResourceFilter extends ResourceFilter {
    static get $name() {
        return 'MyResourceFilter';
    }

    // Factoryable type name
    static get type() {
        return 'myresourcefilter';
    }

    // PRIVATE FUNCTION OVERRIDDEN
    initFilter() {
        const { eventStore } = this;

        if (eventStore.count && eventStore.resourceStore.count) {
            // SELECT THE RECORDS YOU NEED
            // this.selected.add(this.store.getRange());
            this.selected.add(this.store.first);
            this.detachListeners('project');
        }
    }
    
    // PRIVATE FUNCTION OVERRIDDEN
    onSelectionChange({ source : selected }) {
        const
            applyFirstFilter = !this.resourceFilter,
            disabled         = selected.count === this.eventStore.resourceStore.count;

        super.onSelectionChange(...arguments);

        // REQUIRED TO APPLY FIRST TIME BECAUSE FIRST FILTER IS APPLIED SILENTLY BY DEFAULT
        if (applyFirstFilter && this.resourceFilter) {
            // Filter disabled if all resources selected
            this.resourceFilter.disabled = disabled;
            // Have the client EventStore refresh its filtering but after a small delay so the List UI updates immediately.
            this.applyFilter();
        }
    }
}
// Register this widget type with its Factory
MyResourceFilter.initClass();

const calendar = new Calendar({
    sidebar : {
        items : {
            resourceFilter : {
                type : 'myresourcefilter'
            }
        }
    },

[pmiklashevych]

Also describe names of https://www.bryntum.com/docs/calendar/#Calendar/widget/Sidebar named items.

[ExtAnimal]

I think the solution is to fix the selected config in List.

If what is passed is an Array, then take it to be the requested initial selection.

So there will be a changeSelected

Right now updateSelected is incorrect in that it upgrades an incoming value to the final state, but that is the job of a changer:

            /**
             * A {@link Core.util.Collection Collection}, or Collection config object, or array of records
             * to use to use as this List's selected records.
             * @config {Core.util.Collection|Object|Object[]}
             */
            selected : {},

...

    changeSelected(selected) {
        if (selected) {
            if (Array.isArray(selected)) {
                selected = { values : selected };
            }
        }
        if (!selected.isCollection) {
            selected = new Collection(selected);
        }
        return selected;
    }

    updateSelected(selected) {
        selected.on({
            change  : 'onSelectionChange',
            thisObj : this
        });
    }

Then in ResourceFilter

    initFilter() {
        const
            me              = this,
            {
                eventStore,
                store,
                selected
            }                = me,
            initialSelection = me.initialConfig.selected;

        if (eventStore.count && eventStore.resourceStore.count) {
            if (initialSelection) {
                selected.splice(0, selected.count, initialSelection.map(s => store.storage.get(s.id, true) || s));
                me.onSelectionChange({ source : selected, removed : [], added : [] });
                me.applyFilter();
            }
            else {
                selected.add(store.getRange());
            }
            me.detachListeners('project');
        }
    }

Then in one of the examples, illustrate it by configuring the sidebar:

sidebar : {
    items : {
        resourceFilter : {
            // ids are matched. We don't need to have access to the record now
            selected : [{ id : 'bryntum' }]
        }
    }
},

[ExtAnimal]

Note that the initial election should be allowed to be [] to mean none.

This request asks for there to be non selected initially: https://www.bryntum.com/forum/viewtopic.php?f=54&t=16564&p=82434#p82434

Seems strange since that will result in no events being displayed, but, [] is technically valid for selection.