MapComplete/Logic/State/ElementsState.ts

import FeatureSwitchState from "./FeatureSwitchState";
import {ElementStorage} from "../ElementStorage";
import {Changes} from "../Osm/Changes";
import LayoutConfig from "../../Models/ThemeConfig/LayoutConfig";
import {UIEventSource} from "../UIEventSource";
import Loc from "../../Models/Loc";
import {BBox} from "../BBox";
import {QueryParameters} from "../Web/QueryParameters";
import {LocalStorageSource} from "../Web/LocalStorageSource";
import {Utils} from "../../Utils";
import ChangeToElementsActor from "../Actors/ChangeToElementsActor";
import PendingChangesUploader from "../Actors/PendingChangesUploader";

/**
 * The part of the state keeping track of where the elements, loading them, configuring the feature pipeline etc
 */
export default class ElementsState extends FeatureSwitchState {

    /**
     The mapping from id -> UIEventSource<properties>
     */
    public allElements: ElementStorage = new ElementStorage();
 
    /**
     The latest element that was selected
     */
    public readonly selectedElement = new UIEventSource<any>(
        undefined,
        "Selected element"
    );


    /**
     * The map location: currently centered lat, lon and zoom
     */
    public readonly locationControl = new UIEventSource<Loc>(undefined, "locationControl");

    /**
     * The current visible extent of the screen
     */
    public readonly currentBounds = new UIEventSource<BBox>(undefined)


    constructor(layoutToUse: LayoutConfig) {
        super(layoutToUse);
        
        
            function localStorageSynced(key: string, deflt: number, docs: string ): UIEventSource<number>{
                const localStorage = LocalStorageSource.Get(key)
                const previousValue = localStorage.data
                const src = UIEventSource.asFloat(
                    QueryParameters.GetQueryParameter(
                        key,
                        "" + deflt,
                        docs
                    ).syncWith(localStorage)
                );
                
                if(src.data === deflt){
                    const prev = Number(previousValue)
                    if(!isNaN(prev)){
                        src.setData(prev)
                    }
                }
                
                return src;
            }

            // -- Location control initialization
            const zoom = localStorageSynced("z",(layoutToUse?.startZoom ?? 1),"The initial/current zoom level")
            const lat = localStorageSynced("lat",(layoutToUse?.startLat ?? 0),"The initial/current latitude")
            const lon = localStorageSynced("lon",(layoutToUse?.startLon ?? 0),"The initial/current longitude of the app")


            this.locationControl.setData({
                zoom: Utils.asFloat(zoom.data),
                lat: Utils.asFloat(lat.data),
                lon: Utils.asFloat(lon.data),
            })
            this.locationControl.addCallback((latlonz) => {
                // Sync the location controls
                zoom.setData(latlonz.zoom);
                lat.setData(latlonz.lat);
                lon.setData(latlonz.lon);
            });

      
    }
}